Time travel

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Time travel

Time travel Discussion Forum

Is time travel possible?

Is time travel possible?

crazyman2
2/1/09

Is time travel possible?

fractal
11/11/09

I only want to discuss backward timetravel, since it's already been proven forward time travel is more or less possible.

I hardly pass as a mathematician or scientist, but I believe backward time travel can be proved to be impossible. Look at the physical aspect of what time travel is doing:

Solid matter (created by energy) moving backward through time to a time it already existed. Our bodies use energy from food which got its energy from the sun. If we went back in time, that energy will be in a different place than our body. Either in the food that still has yet to be eaten, or even possibly still in the sun. Since there is a law that states matter cannot be duplicated, it's clearly impossible.

tBoone
11/17/09

What law states that "matter cannot be duplicated?" There is no such law. There is one that says that matter/energy cannot be created or destroyed.

scholar12
11/11/09

I have no scientific proof to say not, although many scientists have tried and failed America never thought it would be possible to fly, then the Wright brothers came along and invented the plane in 1905 that could fly half an hour or more at a time. "The law is reason free from passion-" Aristotle... this applies to science too for the scientific law.

dazzerd03
11/2/09

Time travel will never happen for the simple fact that if in the future time travel became possible then we would know because someone would have travelled back through time. As this has never happened time travel will never be possible.

scholar12
11/11/09

That is quite an intriguing theory... It is ethical, but I am not sure I agree, for what if they say not?

godfather
10/31/09

Time travel is nothing but creation of a world where a identical copy of u exists or an advanced one that will maybe exist...

such event need energy that can only be created by GOD and no one else...of course not any human...

dnt think of time travel...enjoy ur present...maybe u wont have any future...

painkiller24
10/31/09

It's all just a matter of opinion. Remember in history class when you were studying the 1700's or whatever? People would have been burned at the stake for even mentioning human cloning. But look at where we are today. It's definetly possible. Even back then, time travel was just some whack job's idea in writing a book to make a few bucks. But look at where we are today. It's really surprising. I say that it's a matter of opinion because it depends on what your definition of the word "possible" is. There's evidence that only forward time travel may be possible and backwards is not allowed, yet at the same time, there is no law in the universe that says we cannot time travel in any sense.

There's a book I often see at the book store that I will most likely purchase on my next visit. It's called "Is God a Mathematician?" Of course it doesn't touch on the existence of god at all but argues of whether mathematics is truly the way the universe works or just a man-made concept to help compensate for our understanding of how everything works.

I look at time with the same question. Is time truly the fourth dimension? Or is it just a man-made concept to help us measure the distance between events over our unique perception? Perhaps this is why there's no law that says we cannot time travel...time might not exist. You cannot penalize a basketball team for a foul ball that would be accounted for in a baseball game! :)

painkiller24
10/5/09

Yes, I am from 2312. As of that date, Christ has not yet returned (no will he ever, you'll find out about 2058 or so), there has been 4 more revolutions since the one you are experiencing now (the information revolution) and the world has gotten away from dependency of oil and the car that runs on water has been reveiled and is open for sale to the public. Captialism has shown to not be the ideal government and has fallen into a dictatorship (though it definetly had the longest run). Yes, 300 years into the future, things are not a whole lot different. You can even tell that my lingo and grammar are still as they are in 2009.

megrox
11/23/09

You are talking crap!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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Owenbomar
11/14/09

Wow do you think the world is full of dumbies nobody is going to blieve that

painkiller24
11/14/09

Hmmm. Apparently, by using Owenbomar as an example with his arrogance, not all of us can appreciate a friendly joke. :)

scholar12
11/11/09

REALLY? ARE YOU SERIOUS? You actually think you can fool people like that? Now I am not a dream crusher, or a "party pooper," so I believe that is possible. If so who is president? Is America in a drout? What wars are going on? What are popular songs?

painkiller24
11/14/09

Calm down or you'll shoot in your pants haha If you just read the post that I left above the joke post, you'll see my real view on time travel. :)

whiten
10/9/09

Very pleased to know if in the year 2312 it is still called "Time travel".
Can you be so nice and tell me where do you like it more? "here" or "there"?! :-)

painkiller24
10/9/09

I like it better "then" actually. We still call it Time Travel because of it's notorious background of fringe science and to call it something else would be just plain no fun!

scholar12
11/11/09

How has technology advanced other than time travel. How are computers more modern?

whiten
10/10/09

Sure u must like it better "then" as in "Now" u are not even borne yet,or are you? :-)

In the past there has been vehicles that run on water and not on oil fuel.
In the year 2312 those vehicles that run on water do they manage to heat the water by the same ways (wood or coal burning) or is there some other way?!
It will be very nice of you if u can brink some more fun on this subject. :-) :-)

cheers.

painkiller24
10/15/09

As you mentioned, the vehicles that run on water are indeed very real during this time (2009). Unfortunetly due to the economy and conflicts between nations, I'm sure you're aware of the touchiness of it, oil is the name of the game and the H20 car will not be fully available to the public until just before 2100. All of those worries about oil shortages are just propaganda. You need not give concern to them. :)

whiten
10/17/09

Thank you for your reply.

Even that there was not any worries on me, what so ever, about the oil shortages, now you have managed to make me worry about the water supply shortages in the future.

Even that,at the present,the water has not entered yet the equation as a fuel substitute for the oil,it is in some way costly and, to a point of management;in shortage(even while in substance is considered free for all).

How do work the economics of it all in the future?!
Forgive my ignorance but am really puzzled.
Appreciated a lot if you can shed a bit more light in the matter.

cheers :-)

painkiller24
10/17/09

I fear that I am exhausting the extent of information that I am allowed to expose. It is through a water shortage at some point in the 2100's that forces the nations of the world to re-evaluate what it means to BE HUMAN. Hehe, emphasis on those words because it is a world wide revolution that changes economies, cultural values and all around morals. Not a single human being is able to survive without water so what kind of asinine being would deny its own race the means to survive? Truly embaressing if any other civilization would be observing (hint hint!)

whiten
10/18/09

Thank you for the reply.

I see your point,I think.
In the end it seams to come down to a revolution instead of a willing to freely embrace the so much needed harmonious and reasonable reformation of Our Social and Civic order. A shame for us all if we still can't see despite all that was given to us. Still not able to give back any thing of value.
It seams we are lead more by our own fears than by our virtues.Can't see how a revolution can change that.
But in the end that is only me.

Hope you work your way to control your own fears and grow to lead your self through the principals and the virtues.(hint hint!(if that means any thing)):-) :-)

As, in one way or another, there will be water,the problem it lies with the pollution of it rather than with it's shortage, I think.
What do you think?
Will we be able to keep it unpolluted and clean enough in the future?!

cheers. :-)

painkiller24
10/18/09

What I don't think a whole lot of people appreciate is that our water is not so polluted as it is made to seem. It's cleaner than it has ever been in human history. If you look at a timeline of the human race's life span, it climbs the graph higher and higher as time goes on. As time went on, cleaner water systems developed. As of today (2009) the average lifespan of an American male is 77 (+-2) years. As far as some less fortunate countries in Africa, the average life span may be no higher than the mid 40's or 50's. This of course hurts the world average but it still remains higher than ever in humanity's existence. The reason why people are so fearful of water contamination is because of the huge population on the planet. Nearly seven billion people on one habitable rock in the solar system is quite a cramped place. Should a contamination strike a source of fresh water, or any water seeing that filters are available that can freshen almost any water, the result would be horrific. Hundreds of thousands, millions, maybe even billions of people could go without fresh water. A chunk of the population would fall into anarchy. Some may even refer to it as the end of days, but that's a whole different story.

whiten
10/19/09

Hi again there.

Very clever reasoning, but must say that it is to selective and focused in a very narrow point of the time line of the human civilization.
Through most of that time line the world was considered a very cramped or very crowded a place by the humanity, apart from the instances of horrific destruction,like plagues, natural disasters,horrible wars..etc.

And always it seams there is a connection between the pollution of the water and the disasters.It seams like humanity gets intoxicated with it's own,so much claimed,purified source of fresh water.
These water systems and especially the filters,you mention, seams to degrade and get corrupt unchecked, and most probably become the source of the contamination itself.

As for the USA,sorry to say this,but through all it's national history,as far as I know,it has been considered as a very crowded place by the American people, despite of it been one of the less crowded nations on this world of ours.

And Africa once upon the time was home to the very top of the human civilization and for same reason it did totally perish as a such. There is some historical(so to say) claims, that apart from other causes, the water pollution played some part in it too.
And prior to this happening there seams to have been claims that the water was cleaner than ever before in human history.

Will be pleased if you, with your better knowledge of the future you come from, can shed some more light in this matter.

Don't know if that makes some sense for you,as you been from the future and therefore from a better place.

By the way,if it is not much of asking, what nationality do you have in the future,if that still make same sense for you?!

Thank you for your reply.:-)

painkiller24
10/19/09

I would first like to clearify that the year I traveled from may not be "better" in the eyes of everybody. I prefer it then, than now. Beauty is in the eye of the beholder.

This almost is taking on the characteristics of a political debate. It can rage on and on and both sides may neither be wrong or right. Just a big waste of time ha! I tend to stay away from politics because of that matter. As far as this conversation goes, I'd see it from a more sociological point of view. In my late teen years, I took a bit of an interest in sociology. I was so curious as to why people do the things that they do. How they react under certain situations. But much like politics, there just ends up being no right or wrong answer. Only a theory. When it comes to water contaminations and over population, which are obviously huge issues that need to be addressed, they tend to be recognized but go unaccounted for. I like this to sociology and why I lost interest in it. There just isn't any real answer as to why people do the things that they do. Maybe over population and water contamination will be addressed when we're on the brink of extinction. I'll even put 20 dollars on that. :)

I am a resident of the United States. Yes, it has survived that long. The world's nations aren't a whole lot different in my year than they are today.

whiten
10/21/09

Thank you for your reply.
Been very pleased with all of your replies, as they shed a bit more light on my understanding of the world I live in and share with the rest of us all, despite the time factor.
Happy to see a connection of interest,no matter how that perceived through the eye of the beholder.

Do like your point of view, even while I really fail to see where actually the politics did manage to snick in on this discussion we have.

Always liked the theoretical point of view in general, specially when it has a touch of fun.

Always been interested in understanding of the water and it's related properties as it seams to be the main conduit to life and energy configuration in this world of ours, either in the natural or the social aspect(At least that is how it seams to me).

My self I do consider the reaction as a connection to the counter-reaction, whatever be the subject. It seams to be a basic unavoidable rule of the existence.
Am not pretending this to be right or true, only that this is how I see it, at least for now.

Wish you the very best, which ever the time be in any moment of your life.

Welcomed to share your thoughts any time you see fit.

Whatever or whenever you think that can shed a bit more light on that way of my trying to understand the world, will be appreciated.

Thank you very much again, painkiller24. :-)

realeyes
9/26/09

I nearly forgot. Two years (?) ago I went into my local grocery shop at the time the Euromillions Lottery hit it's maximum value, £180m (or thereabouts, everyone remember this?) The earliest they could have advertised the massive Jackpot before it was reset, was 7 days before the next Draw, yes? The promotional materials were in place mid week; I bought a ticket on Wed/Thur for the Friday Mega Draw. On Saturday I went back to the shop, picked up a Results printout, saw that I hadnt won a bean, and left. Monday I was back at the shop and chatted to the shopkeeper; I asked him if he knew how many people had shared the Mega Prize Fund payout, was it one lucky winner or lots of people sharing the £180m. He said "They havent done the Draw yet, it's next week".

B'Boom. TIME TRAVEL!

realeyes
9/26/09

Yes. Ive done it. Didnt know I was doing it at the time of course, but then worked out that Time Travel was the ONLY rational+logical explanation for all the anomalous events in my life over the past 2yrs. The first time I noticed it was a simple situation which, had something else not happened to make me question my 'temporal stability', a neighbour reporting an equally surprising event in HIS life which I knew backed up understanding of having "shifted" to another date and back again.. I'd not have realised anything was happening for perhaps several years. During a storm in 2006, a tile fell off the roof+landed on the grass. I removed it and put it against the back wall in case it killed the grass. The following day I looked out the back door to see how the weather was, and to my surprise saw the tile back in exactly the same place as it had been the day before. Hm... I assumed (as you would) that my neighbour had replaced it eg. maybe she'd used it to mark the fall point thus aiding any roof repairer to locate the area needing attention. Being scientific, I asked her saying I hadnt meant to cause any trouble by moving the tile.
Neither she nor anyone upstairs had seen let alone replaced the tile onto the grass. No visitor would have been able to replace it on EXACTLY the same spot.

I think Time Travel is/can also be Dimension Hopping.
The way you spot this is - a person you spoke to last week, perhaps asked a specific question of, tells you something \*completely different\* the next time.
eg. After my Gran died, I asked my mother if there had been much to clear out of her flat. She said "Nothing. Gran didnt keep lots of clutter, her house was always immaculate". 3wks later I decided to check my theory of "moving around" and I asked her again about Gran's flat.. Had there been much to clear out? "LOADS she said. Gran never threw anything away, it took us all week and we're all exhausted".

So, if you were suspecting that Time Travel was real.
It is. What we do with the opportunity though..that's another question. I already have the impression that someone/something has fu\*ked up my life by affecting events in other Time Frames/Dimensions. One minute I had a number of friends, then, suddenly, I walked into a Social Night in Edinburgh and half the people int he room walked out. It was as if I had a Harry Potter cloak on; they thought I was someone else altogether!? Friends have spoken to me as if Im fabulously wealthy. Ive seen that my own sister is virtually IDENTICAL to Rhonda Wylie, the super rich woman recently connected to the McCann case. Do I have a double out there?!?!

I pay my Gas Bill and find myself fighting for A YEAR with NPower who refuse to admit they have the money.
A year later, they say they've "found it". Another year passes and I find that the same money isnt on the printout of "all money paid to them by me". Someone even rang me from a competitor company saying "I was afraid to call and speak to you". WHIT?! WHY would a member of staff in a call centre at a fuel supply company who havent even taken over my accounts yet, and who dont know me AT ALL - be afraid to phone me??

Time+Dimension Travel is a reality. God help us all.

doingnothing
9/19/09

In general relativity, space and time are regarded to be similar. As we can travel in space, there is no reason for time travel to be not possible. Consider a star in the sky; the light from it will continue to reach us even after the star as burned out.(As light doesn't travel instantaneously but takes time, so the information wouldn't reach us for many years) We are living in the 'past' every second.

Also we can enter a spaceship and travel near the speed of light and when we come back, more time would have passed on earth than the time on spaceship. So we can 'travel' to the future.

Going to the past by extension could very well be possible, but the possibility of actually changing the past events is questionable. Also, time travel is possible theoretically by some results of general relativity.

oncearoyal
9/18/09

Time travel is absolutely impossible!
The Past is FIXED. It's gone so there is no destination to travel to. Even God can't change the past.God can only wish to do what is logically possible. He would not do any thing that was illogical, nor would he wish to, as this would deminish his perfection

The Future is yet to be!- So again there can be no destination to travel to.

The speed of light has nothing to do with it.

We live in a continuum of 'nows'.

The past is no longer and the future again is yet to be. Ergo time travel is impossible - QED.

realeyes
9/26/09

Complete rubbish.

yaaaaaaaay
9/16/09

No quite simply

timsauder
8/17/09

Time is a measurement of sequence. The time past has already happened and can not be revisited. The time future has not yet happened and it would alter the sequence of choices that make up the future. I fact that possible alien life forms move through another dimension does not destroy sequence. Even if you talk about eternity you are talking sequence. The measurement of that sequence can change but the fact of it will not. The spiritual world has no time space as we know it but it does have sequence. Time travel will never destroy sequence of events.

zerogee
8/3/09

Impossible is a word that is used when the explantion is beyond the comprehension of those that claim to know what they are saying. Until a true understanding of time is gained and is there anyone
out there that can make that claim? Then like many of the things that were thought to be impossible that have later been shown to be completely possble I would most definitely have to say yes. The direction will not matter. Time is not related to space as is currently thought and is only a by product of speed. It is the result of what happens to a mass that is accelerated and is a completely local phenomenon which is why it can only compared to anything else from a fixed position. The action that causes time to pass can be recreated with out motion it can be accelerated and reversed. The only problem you will have is that nothing was where it is now and what is here now will not be there when the time comes.

Owenbomar
7/28/09

Thru time dilaton you could pass thru time at a faster pace relitive to others but you could not go backwards.

realeyes
9/26/09

It's completely wrong that you can't travel backwards. Like Willy Wonka's Great Glass Elevator, you can travel up, down, sideways... :-)
These forums are refreshing in that all debate is good, but, when people simply post "it's impossible" whilst offering NO evidence, that's irritating. When I began to realise that something strange was happening to me, I got very "pissy scientific" about it. I have this friend who was phoning me up from 30miles away and telling me all manner of specific things about my flat; stuff she couldnt know because she'd never been in the flat & other people could not have told her because she named things I'd only just bought, or which were stored away inside boxes and I'd never shown them to anyone. I was SO impressed by her bizarre ability that when she next rang me, and I had half a Snickers Bar from the fridge on a side plate; I picked it up, turned it over in my hand + asked; What do I have in my hand? Her reply (verbatim) was:
It's cold. I can feel edges. Nuts. Toffee. Something like mint?? (no) Well, light anyway. I can see a 50p piece shape Sal. So, what is all that anyway?

Chilled Snickers Bar. Nuts. Toffee. An 8-sided plate.

Timewise; A year ago I looked out my front window and saw "life" happening at triple speed. I blinked. I saw LOTS of people passing back & forth in each direction I was confused. Didnt believe it at first. I saw a car drive at some speed the wrong way along our one-way road. 2wks later I was outside in the street and saw a car coming right at me from the wrong direction. I have never before seen ANY vehicle drive the wrong way down this road since I moved here 3yrs ago. Not once. What really happened here is, I saw the event from TWO DIFFERENT PERSPECTIVES. That is what Time Travel, and "Being seen to be someone else" etc is all about.
I also had a friend sit 5ft from me, look me in the eye and ask "How do you know it's not me". I got an email from Microsoft saying "If you're not already subscribed to receive this mailing, click here".
How's that for circular logic. haha

ayeshaasif
7/2/09

Time travel is absolutely possible. if you can travel with speed of light and your heart is so much strong to support your body and brain then it is absolutely possible. see videos on cosmic strings and black holes in you tube.

lisapruitt10
5/8/09

As a part of our DNA, chromosomes, cells, going back in time, there is a scene that is a part of it, that can be seen. It is there as a part of your cells. If you think back to any time in your life, or at any time, if you let yourself see, you will see what was happening at that time, even feel it.
This is great for doing the Universe. For instance . . .
In the very beginning, take the idea of Space with nothing in it at all. Space does exist but it's nothing and doesn't move. (logic-there is nothing to move) and space goes on forever in all directions. If you "look" you will "see" white. why? because with nothing to differentiate areas, everywhere seems to be everywhere. there seems to be more everywhere, which is white (with white you "feel" nothing. And alot happened after that.
I wonder, if you have lots of info. who do you get it to. the stuff I know is beyond everyone. Just wondering. I love doing the Universe. I can see it. Try it - the white - try and see it.

KALMANGI1974
5/6/09

Yes it is possible. I have a "TIME MACHINE" project idea. Please e-mail me to rameshkalmangi@yahoo.com, then I will send you my idea.

Thank you,

RAMESH

valisammabhi
8/1/09

Can you send me the project idea to my account on absolute astrnomy my email ID is valisamma abhi

jayzee943
5/25/09

Oh!!!really???

how can you travel to the past or future???
here is my email add: jayzee_943@yahoo.com

pls send me your idea.thanks

derogatron
4/23/09

THE SPEED OF THOUGHT IS ONLY ACCESSIBLE TO TIME PSYCHOLOGY REVERSE.I've said it before but that was the past,so i'll say it again....the speed of thought is only accessible to time psychology reverse.I've said it again but that was the future,so i'll say it before.....and this went on for some time.

tBoone
4/15/09

Going back in time is impossible. It's an exercise in meaninglessness! Why? Who says time is something that you "can travel" anyways? Time is simple: time = change; nothing more and nothing less. You can have more change (like time "speeds" up), less change (like time "slows" down), or no change (like time stays "still"), but you can't have negative change. I hope that clears things up.

Also, even if the "super string" theory of "alternate universes" is correct (which I HIGHLY doubt) you would still NOT be traveling to the past through time; instead, you would be traveling to alternate universes. C is the universal speed limit...it is the speed of time! Once you reach c you will have used up all of your available time in the universe!

Cheers!

realeyes
9/26/09

"...even if the "super string" theory of "alternate universes" is correct (which I HIGHLY doubt) you would still NOT be traveling to the past through time;"

What surprised me was to recently watch Dr Who programs and see a lot of things which related perfectly to the notion of - when you die, you go to another dimension. What happens to me is, when I talk to people, I frequently find other people talking within the same conversation, or speaking within the gaps. So where eg. a person were to simply walk across a room, instead of doing so in silence, someone in what appears to be an adjacent universe seems to be able to use them to talk to me. Bizarre, but correct. I see the changes very quickly sometimes. Here's another phenomena that suggests that we also access information from other dimensions through dreams;
One morning in July/Aug 2001, my partner and I woke up and turned to each other to describe having had Disaster Movie dreams. What followed was unbelievable
- A few weeks later we were looking back on having described in graphic detail the events of the WTC attack. Curiously we also both woke up with mirror image phrases in our minds; "Planes crashing+planes tipping over", and "Trains crashing+trains tipping over". (Madrid of course). In my dream I saw events from every angle; From within the plane as though through the eyesa of a hijacker who sat in the frotn left seat of the cockpit, I saw the green spire-topped building which that plane flew past on the right of before smashing into the South Tower; I saw as if I were a cloud(!) people "herded to the back of a plane by a man wielding a surgically sharp knife"; I knew a plane had "bounced in the desert they nearly made it". We saw the city from overhead, from the ground, and from a distance. I had NO idea where NY was, not really and I certainly didnt know it had "fingerlike projections around the water-filled edges", and I had no idea of the existence of the WTC let alone that one of the "identical, designer quality" buildings which my partner saw as "half built" had a conductivity spike on top. We saw all these things as clear as daylight several weeks before the events took place in the real world. Would anyone expect us to try to TELL someone of the details in advance of the fact? Hm. Do you think I'd have been wearing an orange suit, or a closely fitted padded cell within 24hrs.

Parallel Universes appear to be separated by a time differential. Movement between them is Time Travel.
It's the ONION RING PRINCIPLE.

lisapruitt
5/16/09

Everything has what was in it before - thats how we evolved. So actually, we do have all of evolutionary time in us. We don't have to actually travel back in time. Its always there with us and it keeps coming up in different ways.
Why do they keep thinking about dinosaurs? Maybe its part of our evolution - it could be possible,
then you say some other really complicated things, which I can't figure out. Are dinosaurs in alternate universes. JK.

lisapruitt
5/16/09

Well we are here in the present time, but we may have holding from the past that hold us there, so it affects the way we feel about the present. Like, people hold in abusive things from a childhood and are always feeling like they have to protect themselves, and until they connect to the scene and release it (which can take time) they keep going back to is.
The rest of what you said is really complicated - I might have to work in out in some future time.

lisapruitt
5/16/09

That sounded really complicated. You would have to think about it alot, before replying. I just wanted to tell you that.

axus
4/16/09

The speed of thought is said to be equal to the speed of light.
Since we have to comprehend the speed of light, and the speed of thought takes no comprehension but is comprehension, I propose the speed of thought to be faster.
We use the speed of thought to measure the speed of light, meaning the speed of thought is faster.

Time travel is possible traveling at the speed of thought, we do it all the time.

tBoone
4/23/09

Well, maybe in philosophy the ?speed of thought? is said to be equal to the speed of light, but in science it?s simply not the case. Regardless, thought is an abstract concept that is not physical and speed is a physical thing; although one can remember the past by thinking about it, it is quite different from the concepts of time travel being discussed here. BTW, the electrical signals that constitute ?thought? in your brain travel at speeds lower than c. Neither mass nor information can exceed c.

axus
4/23/09

You stated "time equals change..." Wouldn't you say that "change" is abstract and not physical? So if time is change then time travel is only possible if we change the way we think. The physical cannot separate from the psyche. Both have to travel together. Ok, let?s say you are correct, and the speed of thought is slower than c. Time travel is theoretically possible at ?near? light speed, since nothing but light travels at the speed of light. So our physical body could then travel metaphysically and achieve ?near? light speed. Thus, we would travel in time, travel in ?change?. I?ve ?changed my mind? have you?
Why do you want to be Einstein? (a reference to the icon)

tBoone
5/4/09

(A) No. I wouldn't say change is abstract and not physical. Quite the contrary: change is very physical and not abstract (at least that's the type of change that I'm refering to.)
(B) So if time = change...then time isn't something that you travel. Does it make sense to say that you can travel change? My point is that time is NOT something that you travel. The "time travel" thing is a common misconception. Within this framework, if change occurs then time is progressing (you age, you live your life, etc.) You can slow down, speed up, or stop time (relativity) according to Einstein by traveling closer to c, (time dilation, etc.) You can even stop time by traveling at c (like a photon does) because once you reach c you use up all the time in the universe (relative to the photon of course.) But you cannot have unchange or negative change; consequently no returning to the past. To sum it up, just think of change as the forward progression of time.

(C) As far as thought being faster, it's actually much slower. Our involuntary reflexes are much faster than thought; as is muscle memory, etc. Yet all are slower than c. Look them up, very interesting stuff.

(D) "The physical cannot separate from the psyche" I do not know what you mean by this.

(E) Our physical bodies physically travel through spacetime; they are not of the metaphysical realm. However, I suppose that our metaphysical bodies can travel metaphysically anywhere. Also, I beleive that Relativity doesn't apply in the metaphysical realm, so I suppose one can travel as fast as one wants. However, I was only refering to the physical realm.

(F) Einstein icon: the guy was a friggin genious. I only hope that I can know 1/2 the things he forgot!

axus
5/9/09

Wow, nice post! Are you writing a book?
"The physical cannot separate from the psyche"?
To "physically" travel in "space" you have to change your mind, the way you think. If your mind thinks you are still at home but you are physically at work you would have issues. Traveling in time is similar. Did you ever get home from school, take a nap and when you woke up you didn't know "when" you were? Your mind AND body were lost in time. You traveled in time the instant you looked at the clock, your mind told you when it was and your body went right along with it. To travel in time ?physically? we have to change the way we think.
I've changed my mind.
Have you changed yours?

tBoone
5//09

Thanks, but...you can change your mind all you want it still isn't going to happen. "If your mind thinks you are still at home but you are physically at work you would have issues..." I'll say, mental issues.

"Did you ever get home from school, take a nap and when you woke up you didn't know 'when' you were? Your mind AND body were lost in time." Actually, it's called disorientation. It's your perception of time that's disoriented and not time itself as it progressed normally whether you were aware of it or not.

"You traveled in time the instant you looked at the clock, your mind told you when it was and your body went right along with it." No. You became oriented once you read the clock and so you now became aware of the current time. Your body didn't care whether your mind new what time it was; it aged just the same.

"To travel in time 'physically' we have to change the way we think. I've changed my mind. Have you changed yours?" Not really, as time isn't something that's traveled (again.) You can change your mind all you want about something that isn't true; it'll still not be true. Someone famous once said that the moon is still there whether we are looking at it or not. :o)

lisapruitt
5/16/09

I thought I answered that but am learning how to do this.
The reason you may think you are in a place, is that you can go into holding mode in any situation (its a physical thing) and these holdings hold in a whole place, the scene even, and until you release whatever it was that made you go into the holding - it may keep coming back, and you'll kind of think you're in that place where the holding began.
I only come to the library once a week or so. Yes I am writing a book - about the Universe.
Thanks for your reply - and you keep it simple enough.

It all started simply - Once there was only empty space.

tBoone
5//09

You do realize that there is no such thing as empty space, right?

realeyes
9/26/09

"You do realize that there is no such thing as empty space, right?"

I love the simplicity of this comment :-)
Whether perceived or not, all that comes out of a place has to be inside it in the first place, yes?

tBoone
11/2/09

Of course that something that's inside a place and comes out has to have been inside in order for it to come out. Why state the obvious though? What are you rambling about?

derogatron
4/23/09

If however vulnerable a species evolved then once before it 'crack' to which contest.Only the unfortunate survive in normality,the science is there but only if the dinosaurs that smoke it are themselves in this sentence.To which i summise correct how more mad are you.

Deadfire
5/21/09

I think Im going to have to get reeaalllyy high to understand this...

KALMANGI1974
3/26/09

Yes it is possible. I have an "TIME MACHINE" project idea. If anybody please e-mail to rameshkalmangi@yahoo.com, then I will send you my idea.

Thank you,

K. RAMESH

Alexander
4/10/09

I really want to see them, this subject is the talk amongst my friends many times. and guess what were only fourteen years old so please send me them
my email is
alexbolek45@yahoo.com

derogatron
3/13/09

Only to the time traveller.Whether or not you discuss desire or objectively fool,time only goes forward nowhere.It depends on what you do with YOUR time toward its longevity and force,and therefore you travel in time travel.

fizanali
2/7/09

It is possible according to one of Einstein theory of special relativity where he says that time and distance approach zero while reaching the speed of light.
But it is impossible according to another theory of Einstein: e=MC^2 where all mass is destroyed at speed of light.
From here we can conclude that few things are possible:
- We can definitely slow time down
- We can even go into the past if we could exist in the form of energy rather than mass ! (may be our souls)

mthoms
2/3/07

We're all time travelers, of course. We're all traveling forward in time at the same rate - but is it possible to travel faster or slower than this rate?

Einstein says yes. In his theory called 'Special Relativity', he suggests if you were traveling in a spaceship at near the speed of light, time would slow down.. You wouldn't notice the change, but when you returned to your point of origin, much more time would have passed for the people you left behind.

Bjort
3/5/09

Hello everyone, I am looking for an explanation of something imparticular. Or what it may be called so I can do more research on it.

Example:
You look at the clock, rub your eye for a couple seconds and look at the clock again and 10 minutes past.
Where were you, what happened during that 10 minutes?
What is this fast forward in time?

If anyone can help me with this I would appreciate it.
Thanks!

whiten
10/9/09

Very clever.What you describe it is called, I think, "spaced out".Your first question starts with a "where" not with a "when". It looks more like a space switch than a time switch. :-)

cheers

tbone
2/4/09

Some theories, most notably special and general relativity, suggest that suitable geometries of spacetime, or specific types of motion in space, might allow time travel into the past and future if these geometries or motions are possible.[9] In technical papers physicists generally avoid the commonplace language of "moving" or "traveling" through time ('movement' normally refers only to a change in spatial position as the time coordinate is varied), and instead discuss the possibility of closed timelike curves, which are worldlines that form closed loops in spacetime, allowing objects to return to their own past. There are known to be solutions to the equations of general relativity that describe spacetimes which contain closed timelike curves, but the physical plausibility of these solutions is uncertain.

Physicists take for granted that if one were to move away from the Earth at relativistic velocities and return, more time would have passed on Earth than for the traveler, so in this sense it is accepted that relativity allows "travel into the future" (although according to relativity there is no single objective answer to how much time has 'really' passed between the departure and the return). On the other hand, many in the scientific community believe that backwards time travel is highly unlikely. Any theory which would allow time travel would require that issues of causality be resolved. For example, what if one were to go back in time and kill one's own grandfather? (see grandfather paradox)

aseforlife
2/4/09

Theoretically it is possible by use of worm holes in space , which are allowed by Einsteins theory of special relativity

space and time are irrelevant in a worm hole to the person/thing going through but time would still pass for those outside the wormhole

it has been suggested that wormholes also may provide passage between time past or future

so one could go in a wormhole and possibly come back in 1400 BC

of course none have been found till now but once upon a time black holes were ridiculed as science fantasy hype

aseforlife
2/4/09

There's nothing in Special Relativity that predicts it is possible - but nothing that forbids it, either.

swartzy
2/4/09

There is not a lot of science on this subject but we can use a little common sense:

I think it is reasonalbe to assume that since we have not been visited by time travelers from the future - time travel will never be possible.

axus
2/25/09

If a time traveler from the future could only successfully accomplish time travel to the past by purging his knowledge of the future, could we have been visited by time travelers, they just didn't know it?

fizanali
2/7/09

I would say that may be we have been visited by time travelers like UFOs ! but we won't believe them that's because we already know we didn't believe them !

wellis
2/4/09

True, but we also have to consider that everything that hasn't been proved to be impossible is possible.

scbrow
2/8/09

That logic could be used to justify any crazy argument.

Kivey90
3/29/09

No , its not possible .
not so scientific explanation : Because if it were possible , someone would have came back from the future by now holding evidence and so .. (or we would have heard that sometime in the past .. a strange guy appeared from no where and claimed to be a time traveller ) .

tBoone
4/15/09

1st of all, that is totally ridiculous. Just because something IS possible doesn't mean it will ever happen. Those are 2 different things. Let's say that time travel is possible...ok...but now let's say that no one EVER figures it out...also a possibility. So now we have a situation where time travel is possible but NEVER gets executed. You see, raw logic is useless. You can prove anything to be true using logic...anything. You can say that "anything is possible" which should eventually lead to the fact that impossibility is one of those possibilities and thus there are things that are impossible.

Deadfire
5//09

I agree with tBoone 100% on everything. Time is a concept used to comprehend change. Everything happens in an order of events. Its quite possible to relatively speed up or slow down these chain of events, but once something has occured, there is no way to "undo" it. And I dont mean like the "Undo" command on your computer. Thats not wiping the first event (Such as typing an error) from existence such that it had never happened, but merely erasing it what you have done. The error has still occured, and will forever have occured.

Deadfire
5//09

Sort of on the subject, have you guys seen Donnie Darko. Weird movie, but intriguing at the same time. Watch the movie first, then check out some websites on it discussing it's background on time travel and parallel universes. The movie itself has very interesting concepts which come to light near the end, but the information read about it on various websites really make you think about possibilities.

sls02
9/5/09

Movies are only the result of weird imagination which may or may not have credible concepts.Time travel seems impossible for atleast the the next few aeons.
Explanations in movies are for make-believe people and to prevent it from being a flop.

tBoone
5/21/09

Thanks Deadfire.

I have seen Donnie Darko; I liked it but I liked Southland Tales better. I will take a look at some websites as you suggested to see what they say about it. I'm not too fond of the alternate universes or parallel universes theories but they do make for great movie plots!

IMO, parallel/alternate universe theory of time travel is quite ridiculous because in reality you are not going back in time; the fact that you went back in time already means that you are in another universe to begin with. That's the problem w/that theory; there's just too many darn combinations of possible alternate universes.

To elaborate on alternate universe theory: let's pick point A (1990), point B (2000), point C (2009), let's say these points lie in U1 (Universe 1.) As you live your life in U1, you go past point A, then B, and then C. At all these points, there was always only 1 of you in U1. Now at point C you decide to hop into your nifty time machine and go back in time to point B. You set all of your knobs and power up the flux capacitor and presto whammo you traveled back in time to B. But wait, there's 2 of you at B BUT in U1 there was only 1...therefore you are NOT in U1.

Kind of like the old "psychic" that see's the future. He has this "vision" of his friend crossing the street and getting hit and killed by a car. So the next day he see's his friend about to cross the street and he pulls him back & saves him! Wow! Only one thing, he didn't see the future because had he seen the future he would have seen himself save his friend!

Deadfire
5/21/09

I agree with all of that too. I said something similar in the thread about the possibility of someone going back in time 4 years. And I agree that that seer didnt see the "future" necessarily as much as he did the outcome of the current consequent series of events leading up to that point unaffected by outside forces. An outside force being him pulling his friend back away from the position he'd have been in had he not been acted on by that force, thus resulting in a different outcome. Much like physics and predicting the trajectory of an object, Id imagine, or an event tree.

5ws1h
8/11/09

Hello, I'm not supposed to do this, but I figured raz the shaz, know what I mean. So I'm here at Disney Planet in the Time Machine Room. I decided to use this external PC-A and try out a keyboard. It's so dupe, I've only seen these things in holopics.
Just to let you know...We don't have "time travel" where I come from. What we do have is probably as close as we will ever get. You might think of it as a superstring recorder, of course that whole superstring theory was disproven years ago, as just and myth.
So newya – what we have here, you might think of it as a mixamash of HDR's and VR displays. Whatever we record, we playback in this room.
I guess that would mean if you’re reading this, well than – you’re just part of a recording!

tBoone
8/17/09

We have them too, they're called a video cameras!
And wait, hold on, I am going to erase you!

doingnothing
9/19/09

tBoone
11/2/09

Hello doingnothing.

I must say that "observing" light from the past and traveling to the past, are two completely different things. Seeing an event that occurred long ago and actually being present long ago are not the same.
I believe that we are living in the present not the past and "traveling" (one could say) to the future at 1 sec/sec. This is true regardless at what speed one travels; however, the closer we approach c, the more time slows down relative to others. But it is indistinguishable to the traveler.

As you mentioned, changing past events is questionable. Not only is it questionable but it is impossible as this would violate causality. Can you have a reaction precede an action? Of course not, that would be non-sense.

doingnothing
11/3/09

You enter machine A. A does something. You wait inside it for 1 minute. You exit A and find your twin brother is now 1 year older than you. This is time travel right?

key:
A- spacecraft
something-traveling near the speed of light(taking a u turn and coming back at speed near c)

Since time travel to the future is possible, I appeal to symmetry and say time travel to the past is possible.
(you can use a wormhole)

But I don't believe we will ever build such machines.

doingnothing
9/19/09

"To elaborate on alternate universe theory: let's pick point A (1990), point B (2000), point C (2009), let's say these points lie in U1 (Universe 1.) As you live your life in U1, you go past point A, then B, and then C. At all these points, there was always only 1 of you in U1. Now at point C you decide to hop into your nifty time machine and go back in time to point B. You set all of your knobs and power up the flux capacitor and presto whammo you traveled back in time to B. But wait, there's 2 of you at B BUT in U1 there was only 1...therefore you are NOT in U1. "

err.. thats wrong. Who said there was only 1 you at B? There was always 2 of you at B if you decide(or decided?) to go back.

tBoone
11/2/09

Actually, it's quite right.

To answer your question "Who said there was only 1 at B" I did. It is a GIVEN part of the thought experiment; if you change the GIVEN, then you change the experiment. It becomes a completely different experiment. One simply cannot violate causality. That's one of the reasons why "backwards" time travel is not possible. The other is the fact that time isn't really something you travel: it is change. As long as change is occurring so it time. You can more change (like approaching c), less change (like time slows down), or no change (time stops like reaching c); but you can't have negative change as that is nonsense and meaningless.

tBoone
11/2/09

doingnothing
11/3/09

Well then, by taking a given you are reducing the problem to its subset. You merely proved you will never time travel back to B. You didn't prove that time travel is impossible.

Who said you are going to violate causality?
http://en.wikipedia.org/wiki/Novikov_self-consistency_principle.

Negative change? It is used in maths all the time.
What would you denote a change that was undone:
change + (-change).

Your definition of time is not the scientific one.
The time is 0s at the big bang and you can measure others relative to it.
The world was completely different 1 sec ago(call that state A), now it is state B. What is meaningless about shifting everything(including electrons,...) back to state A and replacing some amount of air molecules there with yours?
You can call it state shift if you want. If that is possible, I will be excited. But if I invent it, I will call it time travel.

tBoone
11/3/09

According to the MWI, I did prove that it is not possible to time travel to B, because once you arrive at B you are no longer in U1 and so you have instead universe traveled and NOT time traveled. It may "appear" as if it were time travel but it most certainly is not. This logic is irrefutable. Furthermore, due to quantum uncertainty, once you arrive at B there is NO guarantee that the universe you are in (whether it's U1 or U2) will evolve in exactly the same way as it did up to point C (whence you departed to the past from!) Matter of fact, it is actually HIGHLY unlikely that it will! Which means you might never leave to the past to begin with! This is why I have no love for MWI.

As far as violating causality, the only way that I see you won't violate it is with the MWI which I have shown isn't really time travel at all. Then there's Novikov: there is SO MUCH more assumption, speculation, & conjecture in that proposition than there is in mine. Basically it says that "the universe just won't let a paradox happen." (my paraphrase.) Never mind free will, quantum uncertainty, and other paradoxes that it may lead to. Using Occam's razor, we can see that it's more likely that time travel to the past is not possible vs Novikov's Consistency Principle.

Negative change (as you describe) is still change. A fraction (a ratio or change) is still a fraction regardless of the sign of the numerator or denominator. Of course I can walk forwards and then backwards but it doesn't mean I can time travel to the past. In both instances time is still going forward because change is occurring and entropy is still increasing. You have change occurring in one direction and then another. Think of it like distance: there is no such thing as negative distance.

My definition of time is most certainly a scientific one. I defy you to prove it wrong scientifically. The fact that you can measure time (Big Bang onward) only proves me right: we measure time by measuring change in cesium atoms (for example.) As far as your example is concerned (state A to state B): it's nice but it only shows forward progression of time. I mean, we can theoretically go back to state A on "paper" (i.e. thought experiment) but not in physical reality. It would violate a score of thermodynamic laws (especially entropy.) You would have to return EVERY quark, atom, photon, & "energy" in the entire Universe to that state without using any energy...What do you think is more likely that or simply that time travel to the past is not possible. Precisely.

doingnothing
11/6/09

You didn't see my point. You didn't prove that time travel is impossible.
After searching everywhere to see whether a copy of you exists, and you find it does not.
So, Given:There is only one of you at B.
So, YOU can't time travel 'back to B', because you know YOU haven't time traveled to B. You haven't proven anything else. For someone who has actually time traveled to B, the given is not possible.(see circular reasoning)

I am not talking about alternate universe travel.

There are no assumptions in Novikov's principle. It goes merely: If time travel is possible, the probability of causing a paradox is zero.(the possibility of causing a paradox is always zero;it is not going to change merely because you traveled to the past)
It doesn't affect free will. You can do whatever you want, but you still won't be able to change the past.
You are the one making the assumption that you can actually change what has already happened(which leads to paradoxes).

You can't apply Occam's razor, as time travel is theoretically possible due to bending of space-time.

Same way a negative number is still a number. Can you give me -5 number of apples? The sign is merely a notation. -5 can be taken a removing +5. Similarly, undoing a change delta(x) is denoted -delta(x).
Time can be compared to distance only if you think it can go only forward(which is what you are trying to prove). Otherwise, you should compare it with displacement. Displacement can be negative.
I didn't say you have to shift everything back to state A(in that case changing the past will actually become possible).
I merely provided you a way to visualize time travel without using negative change(which you think is not possible).Err... I just noticed that describing time travel as negative change is not right(changing past becomes possible)

So my argument becomes very short:
1)There is nothing logically wrong with time travel
(Novikov Principle(what assumptions does it make?))
2)It is theoretically possible
http://en.wikipedia.org/wiki/Time_travel#Time_travel_to_the_past_in_physics
3)You don't cause negative change. You loop back into the past. You are never traveling back in time. You travel to a wormhole(while time progresses normally around you), go through it and come back in time instantaneously.(Yes, I made a mistake before)
4) Due to 2), Occam's Razor(which can't prove anything anyway) is not applicable.
5)Traveling to the future is very simple(atleast theoretically) by traveling very near the speed of light and combing back to the place from where you left at the speed of light. If you travel at 0.99995c and come back taking 1 year for the forward and back journey combined, 100 years would have passed at the starting point.So effectively you have traveled 99yrs into the future.

tBoone
11/6/09

"For someone who has actually time traveled to B, the given is not possible." Yes. That's because your premise is false; my given (your conclusion) is only true if your premise is true. In other words, for someone who does the impossible then my given is not possible.

You say it is circular logic but, then again, time travel to the past IS circular logic.

"There are no assumptions in Novikov's principle." It assumes that the universe will somehow not let a paradox occur.

"It goes merely: If time travel is possible, the probability of causing a paradox is zero." If there is free will then the probability is NOT zero. Because the probability is NOT zero, time travel to the past is not possible.

"It doesn't affect free will." It completely undermines it. Let me explain: you say that there were always 2 of you at point B; but, in order for that to be true it means that the events from B to C (which have not occurred yet from point B) are set in stone. In other words, you are predestined to come back to B. And you think that this allows for free will? Don’t think so.

"You are the one making the assumption that you can actually change what has already happened (which leads to paradoxes)." True, and that’s why time travel to the past is impossible because the probability of a paradox IS zero. What you don’t realize is that at some possible point far enough into the future, everything is the past. How can you have free will?

"You can't apply Occam's razor, as time travel is theoretically possible due to bending of space-time." Of course I can. Furthermore, time travel HAS been shown to be possible…time travel to the future that is; to the past, never.

"Same way a negative number is still a number." Who has ever said it wasn't a number? Not me.

"Can you give me -5 number of apples?" Of course not. That only proves my point. "The sign is merely a notation. -5 can be taken a removing +5." That’s right. It is a direction and the number a magnitude.

"Similarly, undoing a change delta(x) is denoted -delta(x). Time can be compared to distance only if you think it can go only forward(which is what you are trying to prove)." I’m not trying to prove it: it’s the status quo. There is no empirical evidence anywhere that shows that it can flow any other way.

"Otherwise, you should compare it with displacement. Displacement can be negative." I could but that would be a mistake as it does not behave that way and thus it would be a poor comparison.

"1) There is nothing logically wrong with time travel (Novikov Principle(what assumptions does it make?))" There's plenty wrong; see above.

"2) It is theoretically possible http://en.wikipedia.org/wiki/Time_travel#Time_travel_to_the_past_in_physics" Most of the theories border on fiction. The more accepted ones are the MWI; regardless, they are built on what ifs, on top of more what ifs, and more, and more, etc. Incidentally, I have shown how the MWI theories on time travel are not actually time travel.

"3) You don't cause negative change. You loop back into the past. You are never traveling back in time. You travel to a wormhole (while time progresses normally around you), go through it and come back in time instantaneously.(Yes, I made a mistake before.)" Amazing! You travel to the past, but you don’t, but you do. Make up your mind! Anyways, wormholes do not exist and are purely theoretical; they are possible solutions to EFE.

"4) Occam's Razor(which can't prove anything anyway) is not applicable." It isn't proving anything but it is applicable in the sense that I am using it here.

"5)Traveling to the future is very simple(at least theoretically)…" Theoretically? Are you kidding? It's what's happening around us right now! We are traveling into the future at 1 sec/sec.

"…by traveling very near the speed of light and combing back to the place from where you left at the speed of light." You don’t have to return for the time dilation to occur. This has already been shown experimentally.

"If you travel at 0.99995c and come back taking 1 year for the forward and back journey combined, 100 years would have passed at the starting point. So effectively you have traveled 99yrs into the future." That's great but I never said that time travel to the future wasn't possible; but to the past it is.

doingnothing
11/7/09

I used the negative number argument to show that negative change is as valid as negative numbers.(as you mentioned the negative sign only shows the 'direction')
But, I am not describing time travel as negative change anymore.

tBoone
11/9/09

"Negative change" is just change in another direction. Again, that's not time travel and I am still correct. I am glad you agree that time travel is not "negative change."

doingnothing
11/9/09

You claimed time is change and that there can be no negative change. You were wrong on that count.
The only reason I agreed that time travel is not negative change, as the term would imply UNDOING everything. That is simply impossible(entropy,...)
I have described time travel to the past properly in my other reply.

tBoone
11/10/09

"You claimed time is change and that there can be no negative change. You were wrong on that count." No. I was right.

"The only reason I agreed that time travel is not negative change, as the term would imply UNDOING everything. That is simply impossible(entropy,...)" Exactly. And that's why time travel to the past is impossible. See how easy that was?

doingnothing
11/9/09

Read the post below

doingnothing
11/7/09

Your argument is circular logic. You haven't proven anything.
("my given (your conclusion) is only true if your premise is true. In other words, for someone who does the impossible then my given is not possible. ")
Again circular, you are trying to prove time travel is impossible.

Your argument condensed:
Given:Time travel is not possible
("for someone who does the 'impossible(time travel)' then my given is not possible. ")
Conclusion:Time travel is not possible.
So scrap that argument and try another angle.

The universe will never let a paradox happen.(Do you disagree?). If you think it will, then your whole argument against time travel collapse.
So, no assumption, it is tautology. Time travel by itself is not paradoxical. But, you won't be able to kill your own grandfather before you are born even if you went to past. The logic simply goes that you failed at your attempt(s), and that is why you were born. The 'universe' does nothing. It happened in the past i.e. it is predetermined.

Free will? Is this a philosophical discussion?
You have no more or less free will even if time travel to the past is possible.

Just because the choice is already made, it doesn't mean you didn't make it.(The Oracle from Matrix)

Swami Vivekananda:"Therefore we see at once that there cannot be any such thing as free-will; the very words are a contradiction, because will is what we know, and everything that we know is within our universe, and everything within our universe is moulded by conditions of time, space and causality. ... To acquire freedom we have to get beyond the limitations of this universe; it cannot be found here."
http://en.wikipedia.org/wiki/Free_will. You will find the concept of free will is disputed.

I am not arguing for MWI.
Theories predict time travel is possible. If you think that is 'almost' fiction, that is your POV.
About negative change, there is nothing wrong with it, but I have abandoned that angle as the theories are describe them differently.
"Amazing! You travel to the past, but you don’t, but you do. Make up your mind! "
My mind is made up. What I meant was:
While you are on the machine, time is not moving in the backward direction(i.e. no negative change). You loop back into the past through a path created by a traversable wormhole.
"...You don’t have to return for the time dilation to occur..."
I never said that. But wouldn't you like to see what happens to your country after 99yrs.

Occam Razor:"entities must not be multiplied beyond necessity"
You are using it erroneously.
Wikipedia:Occam's razor is not an embargo against the positing of any kind of entity, or a recommendation of the simplest theory come what may[32] (Note that simplest theory is something like "only I exist" or "nothing exists").The other things in question are the evidential support for the theory[33] Therefore, according to the principle, a simpler but less correct theory should not be preferred over a more complex but more correct one.
If you are using Occam Razor using Hawking's argument:
"A time machine will be built someday, but hasn't been built yet, so the tourists from the future can't reach this far back in time." So, we don't have evidence yet.
But I believe in something simpler, humans will never time travel even though it is possible.There is no emprical evidence for time travel, as the concept is beyond our time(no pun intended)

Wormholes are hypothetical as in predicted by theory. Which is what I was saying. Time travel is theoretically possible, but we have no evidence.

There is no evidence for time travel AND there is no evidence against time travel. But since it is theoretically possible, you can't toss the concept aside.
Since, this is not actually a debate, I will end my discussion here.
You have stated your POV and I have stated mine.

tBoone
11/9/09

I don't think that you understand what I am saying. The concept of time travel (other than MWI) is circular logic itself; why would you expect it to be anything else? Your example grossly misrepresents my argument: it is simple & is shown in previous posts. When you are at point B there is only 1 of you but in order to time travel to the past there must be 2. Pretty simple; I don't see what the problem is. You claim that there are 2 of you at point B but then that means that from B to C that the future is FIXED & immutable. You must then be arguing that all things are predestined & there is no free will. But apart from the (as you say) philosophical question, you are implying some kind of new PHYSICAL phenomenon: a type of reverse causation. This is completely illogical.

"The universe will never let a paradox happen (Do you disagree?). Of course, I agree!" That's why time travel to the past cannot occur: it is a paradox! But you say that what I'm calling time travel to the past isn't really correct. Instead, it's possible to time travel to the past it's just that when you get there you cannot do anything that hasn't already happened even though it hasn't happened yet. So your will doesn't matter, quantum uncertainty, etc; everything get's played out according to some master plan. The future is fixed & immutable. Sorry, I don't buy it.

"Time travel by itself is not paradoxical." Sure, so long as you don't explain it. Once you explain it, you see that it leads to contradictions. Then you say: "But, you won't be able to kill your own grandfather before you are born even if you went to past. The logic simply goes that you failed at your attempt(s), & that is why you were born." I mean, really. Are we supposed to believe that in this scenario one would, much like Wiley Coyote, comically go about trying to kill grandpa but "somehow" fail all the time. What if we tried to kill ourselves? Same thing I suppose, right? So, we are to disregard an almost infinite number of probable & POSSIBLE scenarios that do NOT violate any known laws of the Universe (other than this new "time paradox" law) & then the Universe somehow prevents them from happening (a more complex & questionably correct theory)...or that (Occam's Razor) time travel to the past isn't possible (a simpler and correct theory)...I think I'll choose the latter instead of Wiley Coyote, thank you.

"The 'universe' does nothing. It happened in the past i.e. it is predetermined." When you are at point B, point C is NOT the past. "Free will? Is this a philosophical discussion?" Of sorts; it is a theoretical physics discussion. "You have no more or less free will even if time travel to the past is possible. Just because the choice is already made, it doesn't mean you didn't make it.(The Oracle from Matrix)" The Matrix is a movie; it's not real. Not to say I didn't like it; I did. But it is fictional, nonetheless. Did you notice the paradoxes in your previous sentences? You speak of the future as if it were the past. That's a paradox & circular reasoning.

"Swami Vivekananda:'Therefore we see at once that there cannot be any such thing as free-will; the very words are a contradiction, because will is what we know, & everything that we know is within our universe, & everything within our universe is moulded by conditions of time, space & causality...To acquire freedom we have to get beyond the limitations of this universe; it cannot be found here.' http://en.wikipedia.org/wiki/Free_will. You will find the concept of free will is disputed." This is a metaphysical argument & does nothing for all the other scientific arguments that I posited. But, for arguments sake: that's neither the definition of the Universe nor free will that I am using or that I believe is even correct. If you begin with a concept of free will that is a contradiction, then what do you expect? It is silly to operate from that perspective. Anyways, the Universe is "all that is," to suggest that there are limitations to the Universe is ludicrous: what else is there other than all that is?

"I am not arguing for MWI." I know that. You said several times already & I never said that you have stated otherwise. I am merely pointing out to you that the MOST plausible form of time travel to the past is through the MWI. This is currently the MOST accepted view.

"Theories predict time travel is possible. If you think that is 'almost' fiction, that is your POV." Yes; mine & most of the scientific community. There are so many physics text books about time travel to the past.

"About negative change, there is nothing wrong with it, but I have abandoned that angle as the theories are describe them differently." Again, negative change is simply change in another direction. This must be abandoned because the way that you have described it has nothing to do with time travel.

"While you are on the machine, time is not moving in the backward direction (i.e. no negative change). You loop back into the past..." What does "loop back to the past mean" other than magic or negative change? "...through a path created by a traversable wormhole." Wormholes do not exist, never mind traversable ones. They are PURELY theoretical. You are grasping at straws. Did you see all of the highly unlikely conditions attached to time travel to the past via a Wormhole? It is speculation, on top of speculation, on top of more...practically ad infinitum.

"You are using Occam's razor erroneously." I am not. There is NO EXPERIMENTAL evidence of time travel to the past. My theory is a simple & more correct so it is preferred. Heck, I'll even concede that it is not more correct: I'll say equally. It still holds.

"Hawking's argument: 'A time machine will be built someday, but hasn't been built yet, so the tourists from the future can't reach this far back in time.'" Hawking's argument is not experimental (empirical) evidence; it is a thought experiment: speculation. But I love the logic of this one too: in other words, you'll be able to travel from anytime in the future back only up until the first time machine was made. & that's because of Hawking's law of cause I said so? Nope. It is speculation.

"So, we don't have evidence yet. But I believe in something simpler, humans will never time travel even though it is possible. There is no empirical evidence for time travel, as the concept is beyond our time (no pun intended)" Good, but I agree for different reasons :0)

"Wormholes are hypothetical as in predicted by theory. Which is what I was saying. Time travel is theoretically possible, but we have no evidence. There is no evidence for time travel & there is no evidence against time travel." As I said before, one thing is prediction by theory & another is a concept derived from theory upon theory upon theory. You don't see the distinction? Also, the evidence against time travel is scientific theory (relativity: the speed of light is invariant) backed by observations & empirical results. Anyways, it makes no sense to try and prove a negative.

"But since it is theoretically possible, you can't toss the concept aside." Yes but the most commonly accepted theory is the MWI form of time travel to the past.

"Since, this is not actually a debate, I will end my discussion here. You have stated your POV & I have stated mine." Very well.

doingnothing
11/10/09

A concept cannot be circular. Only arguments can be circular. Your argument is definitely circular.

"Your example"
That wasn't an example
Your Given:There is only one of you at B
Me:But that would only mean you didn't travel back to B
You:("for someone who does the impossible(time travel) then my given is not possible. ")
So Your Given is EQUIVALENT to Time travel is impossible.

You are overestimating your capability to change anything.
Suppose if you went back before titanic even left the shore, and warned them about the disaster, you would have been thought as a fool and no one would've listened. With guards around, you wouldn't be able to resort to any other means either.
(Cassandra Complex)
Your grandfather isn't going to be alone. Even a professional will have trouble to assasinate anyone. In a time where he doesn't belong, he will have further trouble blending in.
In a one person system, you will be able to change anything. But with millions of people, you won't be able to affect it.
Time travel is no different than space travel. You put an apple in a some secret place, when you go back to that place the apple is going to be there. Similarly, something happened in

You fail to understand Novikov Principle

The only solutions to the laws of physics that can occur locally in the real Universe are those which are globally self-consistent.
Novikov Principle follows directly from the above statement. If time travel is possible, the solutions of 'your actions' cannot be inconsistent.

(about oracle)Just because the statement came in a movie it doesn't make it invalid. The statement wasn't specific to the movie. In fact I wrote the statement first, and then wondered where I got it from.

"Just because a choice is already made, it doesn't mean you didn't make it"
If you are going to ask a girl who loves you to marry you, you know she is going to say yes. But, you didn't make her choice-she did. So, going to the past you know who your father is going to marry. But, neither you nor anyone else other than your father(and mother) made that choice. You merely observed a chain of causaly related events which would nevertheless happen even if you did go the past.
The past was a result of you(if you go the past) and everyone else there. Obviously, the result cannot be such that you won't go to the past.

Also, you fail to realise that if time travel was ever shown to be logically flawed(by scientists or anyone else), no one would be discussing this in the first place(especially not scientists).

tBoone
11/10/09

"A concept cannot be circular. Only arguments can be circular." You're kidding, right? You're going to play semantics? You're grasping at straws. Try again.

"Your argument is definitely circular..." What followed after that was completely unintelligible. Anyways, I already explained to you that given my definition of time, time travel to the past is a paradox in and of itself. End of story. If time travel to the past is a contradiction to begin with, then none of what you have mentioned will change that. I have already agreed that if you were to use another definition of time, then your contentions hold. I can't see what's so hard to understand about that?

"You are overestimating your capability to change anything." Not at all: this is extremely simple, why are you complicating it? You keep insisting that somehow change in reverse is undoing what has been done. This is incorrect. Just because you walk forward and then walk backwards doesn't mean that you have time traveled to the past: they are BOTH change, just in different directions. Perhaps if I state it differently: Change in ANY direction is the forward progression of time. Did that help? I still don't understand why you're hung up on direction, but anyways.

"Suppose if you went back before titanic even left the shore...Even a professional will have trouble to assassinate anyone." Are you joking? How many more excuses can you come up with? I mean, really.

"In a one person system, you will be able to change anything. But with millions of people, you won't be able to affect it." You think that it's just "one person" that's a big deal? Have you ever heard of Chaos Theory? Just 1 atom, 1 quark, 1 Plank energy state of a difference in the ENTIRE Universe can have an ENORMOUS effect in the system as time progresses. Never mind an entire person! This coupled with quantum uncertainty is a formula for the practical guarantee that things will NEVER happen in exactly the same way. This is yet another reason why the MWI is the preferred time travel mechanism; again, not that I agree with it.

"Time travel is no different than space travel." Sure, if you are traveling forwards in time, otherwise it is a bit different. It is called space-time after all.

"You fail to understand Novikov Principle." Do you think that something will become true if you keep repeating it? I understand it perfectly; it's you who doesn't comprehend that NP depends on the definition of time & consequently time travel.

"If time travel is possible, the solutions of 'your actions' cannot be inconsistent." Yes. But you did notice the first word in that sentence, right? IF. Now, suppose a definition of time/travel is such that it is a paradox to travel to the past, then NP is useless.

"Also, you fail to realize that if time travel was ever shown to be logically flawed (by scientists or anyone else), no one would be discussing this in the first place (especially not scientists)." It has been shown to be flawed many times. Look at your own sources, man. As I said before, there are many definitions of time, time travel, etc. Depending upon the one that you choose, this will change whether or not time travel is possible and how it might be implemented.

doingnothing
11/9/09

On freewill:
You should also note that scientists favoured determinism and were peeved by the results of quantum theory.(most notably Einstein)
Still, most macroscopic observations are deterministic.

tBoone
11/9/09

True. As am I...but it is there nonetheless and cannot be ignored. It is even more empirical evidence to show that the future is not fixed; hence to time travel to the past. ;o)

doingnothing
11/10/09

Quantum uncertainty is almost entirely limited to microscopic behaviour.

The only entity on the other side is the unfortunate Schordinger's cat.

Since such an apparatus has never been created, nor does any natural phenomena is analogous to the experiment, quantum uncertainty doesn't come into picture describing any human or animal behaviour.
The world is deterministic.
Even the other side of the argument doesn't claim that the world is not deterministic, but rather that not everything is deterministic.

tBoone
11/10/09

"Quantum uncertainty is almost entirely limited to microscopic behavior." Key words: almost entirely. There have been many experiments that show quantum uncertainty at the macroscopic level! This is exciting stuff.

See>> http://www.sciencedaily.com/releases/2009/11/091104140812.htm

Also, there are those that believe that quantum mechanics is applies to the macroscopic level as well, and interpret it as such.

Anyways, this is all fun stuff but the micro/macro has absolutely NOTHING to do with this discussion. I am going to guess at what you are trying to get at: you may be thinking that a person (macroscopic) going back in time will not experience any quantum uncertainty effects. However, a person is made up of atoms, atoms of leptons & nucleons, and those quarks, etc. There might be 7x10^27 atoms in a human body: now let's throw in chaos theory and mix it with a little quantum uncertainty and you are pretty much GUARANTEED NOT to have the same outcomes.

doingnothing
11/10/09

Even for the cat, if you already know(from signals sent from the future) that it is going to die, it will die.
(Information from the future is beyond determinism, you have actually determined what is going to happen)

Think quantum entanglement.
Once you determine the state of one object, the state of the other(which may be killometres away) is automatically determined.
(Information traveling at speed above c which is essentially information from future)
Unfortunately, quantum entanglement cannot be used for transmitting real information.

tBoone
11/10/09

Information cannot exceed c. Entanglement can and is used to transmit information: it just cannot be used to transmit information faster than c.

Example: You and I are 2 light years apart & we share a pair of entangled photons. You check your photon and now know it's state as well as mine BUT I don't know the state or that you even measured it. You still need a classical channel (sub-luminal or luminal) to alert me of your findings.

This is still very useful because it can be used to have totally secure communications between us. If anyone where to eavesdrop 2 things would happen: (1) they would be unable to decipher the signal and (2) the signal would be changed and thus we would be alerted to this.

doingnothing
11/12/09

But YOU know the state of the photon which is light years of the photon.

If you can change the state of your photon, the state of the other photon must change. So, you are transmitting something to him faster than c.

You are out of your depth. I end my discussion here.

tBoone
11/12/09

You are not transmitting any information faster than c. You know, Wikipedia isn't the most reliable source out there. You should always look for alternatives but, if you are going to use it at least read the WHOLE article and not just the parts that you feel will back your points. If you did, you would know that QE does NOT allow for FTL communication.

doingnothing
11/10/09

Also, MWI is NOT the favoured explanation for time travel.

tBoone
11/10/09

Yes it is. It is in physics and it is in Hollywood as well.

painkiller24
11/8/09

I am just now adding in my two cents to this argument so I apologize if I say something that may have already been said. There is a concept called Time Dilation in which time travels slower in a moving frame of reference (say a spaceship) than a stationary frame of reference (say Earth, Earth is moving but the frame is so large to our perception that it is negligible to factor in its movement.) Having said that, the closer to the speed of light you get, the slower time goes. You will asymptotically (not sure if that's a word ha) get ever closer to the speed of light, but never reach it. However, if you were to go beyond that asymptote onto another curve of speed, the faster you go, time reverses itself. HOWEVER, mathematically in order to be on this second curve you must take the square root of a negative number which is imaginary. A negative number multiplied by another negative number, even itself, creates a positive number. So this just simply does not exist. For example, the square root of 25 is obviously 5. Or, the square root of negative 25 is 5i.

tBoone
11/9/09

Yes. Time Dilation is in the forward direction. In other words, time can go slowly, quickly, or stop, but NOT backwards. Once you reach c, time will stop as you will have consumed all possible time available in the Universe!

One cannot go beyond the c as that is impossible. However, even if one were to, one would only APPEAR to go back in time and not actually do so.

As you know, i is an imaginary number; it is a concept of the imagination.

doingnothing
11/10/09

'Consumed all possible time'? You know that sounds weird.

It is mathematically possible to go beyond speed c.
An object of zero mass(photons) or imaginary mass can travel faster than c. So, you can transmit information(via photons) to the past.

One of the basic postulates of general relativity is that there is no preferred frame.
So, the fact that you appear to go back in time from a particular frame implies that you did, infact, go back in time.

tBoone
11/10/09

"You know that sounds weird." I know. Did you know that c can be thought of as the speed of time? You see, a photon travels at c and from its perspective, it has consumed all of the time available to it in the universe. To a photon (or anything traveling @ c) there is no more time left.

"It is mathematically possible to go beyond speed c. An object of zero mass(photons) or imaginary mass can travel faster than c." Yup. But as my good friend once said, "Insofar as mathematics is exact, it does not apply to reality; and insofar as mathematics applies to reality, it is not exact."

"So, you can transmit information (via photons) to the past." Absolutely not. Even according to SR, you would need a super-luminal channel and we know that's not possible.

"So, the fact that you appear to go back in time from a particular frame implies that you did, in fact, go back in time." No it doesn't; that's ludicrous! By that rationale, every time we look at the sky or through a telescope we are really traveling through time. Rubbish.

When we look through a telescope at an object 100 light years away we are seeing what that object looked like 100 years ago: it "appears" as if we have gone back in time but we really have not.

doingnothing
11/11/09

See http://arxiv.org/abs/gr-qc/0107091 for a PHYSICS paper on faster than c signals.

The time slows as we approach c, stops at c, and goes backwards at c.
There is no reason,other than mathematical one of the requirement for zero mass, for faster than c speed to be impossible.
Using your approach to 'argument':What does the universe do to prevent you from exceeding speed c?
Before 'your friend's' theory, would you have said that traveling faster than the speed of light is impossible?
But even his theory only says that objects of non-zero and real mass cannot travel faster than the speed of light.

"Did you know that c can be thought of as the speed of time?"

Exactly, so you 'merely' need to transmit signals faster than c to send it to the past

"that's ludicrous!"

No. It is the main postulate of general relativity. No frame is preferred.
You: "You appear to go back in time from a frame". Since, no frame is given preference you did travel back in time.

Your telescope argument is wrong. You don't apply relativity like that. Study the basics atleast.
From the reference frame of the earth, the star IS as old as it appears.
No reference frame is preferred for measuring the stars' age(including its own).

tBoone
11/12/09

FTL Signals: you really need to verify your sources and understand what you are reading. FTL signaling is not possible and has never been done. Let me explain. The speed of light in a vacuum is c and is 300,000 kps; this is also the maximum speed anything can travel (matter, energy, information.) However, light tends to travel more slowly when propagating through different mediums which means that it is less than c. Whenever you hear about FTL signaling, it is signaling that occurs inside such mediums where they are able to send signals at a slightly faster rate than light IN THAT MEDIUM but they NEVER exceed c. This of course will not violate causality or cause any time travel to the past to occur.

"The time slows as we approach c, stops at c, and goes backwards at c. There is no reason,other than mathematical one of the requirement for zero mass, for faster than c speed to be impossible." There are MANY reasons why c is the maximum speed in our Universe, not just a mathematical requirement. As you know, anything with mass (even in the smallest amount) will require an infinite amount of energy to get to c, never mind surpassing it. There is not an infinite amount of energy available in the Universe.

"Using your approach to 'argument':What does the universe do to prevent you from exceeding speed c?" It requires you to use an infinite amount of energy to do so. Next question.

"Before 'your friend's' theory, would you have said that traveling faster than the speed of light is impossible?" Probably not. The common sense thing is to ask oneself "why would there be an ultimate speed?"

"But even his theory only says that objects of non-zero and real mass cannot travel faster than the speed of light. "Did you know that c can be thought of as the speed of time?" Exactly, so you 'merely' need to transmit signals faster than c to send it to the past..." Actually, the theory also suggests that information also cannot exceed c, as I have shown you above. No one has sent a signal back through time.

"It is the main postulate of general relativity. No frame is preferred." So? What does that have to do with what we are talking about?

"Since, no frame is given preference you did travel back in time." No. That's got nothing to do with what we are talking about.

"Your telescope argument is wrong. You don't apply relativity like that. Study the basics at least." Lol! I should charge you for these lessons!

"From the reference frame of the earth, the star IS as old as it appears." Yes. But we weren't talking about the frame of reference of the earth, were we? We were talking about from the frame of reference of the star.

"No reference frame is preferred for measuring the stars' age(including its own)." Other than you, no one's picking a preferred reference frame. Do you even know what you are talking about? There are 2 frames of reference the earth's & star's; what SR tells us is that these 2 may not agree upon the simultaneity of an event.

doingnothing
11/9/09

Tachyons(hypothetical and not predicted by theory) are unstable particles that can travel faster than speed of light.
And you don't necessarily get imaginary masses or energy.
http://en.wikipedia.org/wiki/Tachyons#Basic_properties
Also getting an imaginary mass for a particle does not imply it doesn't exist, just questions its physical meaning.

However,
By that theory, faster than light information transmission and causality violation with tachyons are impossible on both grounds: they are non-existent in the first place (by tachyon condensation)[4] and even if they existed they wouldn't be able to transmit information (by Feinberg's analysis).(Wikipedia)

painkiller24
11/9/09

I agree with your statement that getting an imaginary mass does not mean that it doesn't exist. It appears to be that mathematically, there is no literal way to travel through time. As in there is no basic or fundemental law like the laws of physics that say this will happen. However, there's also no law in the universe that says it is not possible. Perhaps we need not to break the rules of the speed of light and mass and energy, nor do we need to bend them, but we need to find a way around them. This is often an argument that introduces worm holes and something traveling through one that "appears" to be exceeding the speed of light. I'm sure we're familiar with worm holes to an extent. The shortest distance between two points is a line. Suppose this were on a piece of paper. However, if you folded that paper and made a bridge to link the two points, this would be a much much shorter distance. Exactly what a worm hole is. The space between the points is condensed and whatever travels through appears to greatly exceed speeds thought possible when in reality, it could be moving no faster than we mathematically may prove possible.

tBoone
11/9/09

Wormholes are completely hypothetical; but, in your example, you are simply covering a large distance in what seems to be faster than c. In actuality you are not exceeding c because you are really just traveling a shorter distance. All this will achieve is the illusion of time travel. To use your example, you leave earth & go to the hypothetical Wormhole 5 minutes away. It's Nov 2009 and you enter the worm hole which leads you to a place 100 light years away from earth. Now you look back at earth with your nifty telescope & what do you see? The earth as it was 100 years ago! Are you in the past? No. just observing the light that left earth 100 years ago.

doingnothing
11/10/09

No. You are in the past. That is why you are able to observe the light from 100 years ago. A person looking at you from the earth would see you even though you were not born yet. And you can travel back to the earth.(Be sure to choose a nearby wormhole)

tBoone
11/10/09

"No. You are in the past." No. You are not.

"That is why you are able to observe the light from 100 years ago." No. We observe light from 100 years ago all the time whenever we look at objects in the sky that are 100 light years away. Are you implying that looking up at the sky is time travel? Didn't think so.

"A person looking at you from the earth would see you even though you were not born yet." Uh, no. No one from earth would see you for another 100 years as it would take the light (i.e. the light of you being there) 100 years to get to earth.

doingnothing
11/11/09

Read below post and see its date. I didn't read your previous post properly. I corrected my statement promptly.

doingnothing
11/10/09

Hmmm...Didn't read your post properly. Wormholes can also be used to travel to the past. But the wormhole should have already been existence in the past.
What you described is not time travel.

painkiller24
11/9/09

Yes, worm holes are just shortening the distance and making something seem to be faster than the speed of light. Thats exactly what I said before...

tBoone
11/3/09

"The Novikov self-consistency principle proposes that contradictory causal loops cannot form, but that consistent ones can."

Does nothing for this scenario:

"On your 13th birthday, a familiar looking man of middle age gives you a beautifully crafted pocket watch; what appears to be a priceless antique in pristine condition. He tells you that he is a friend of your father's and he'd want you to have it. So you accept the watch, thank the man and he goes on his way.

You never see him again, but you keep the watch in a cigar box and it goes untouched until 35 years later when you finally complete work on your time machine. With the watch, you go back in time to meet your former teenage self and give yourself the watch."

So...where did the watch come from originally? Thin air?

doingnothing
11/6/09

Simple. Such a thing won't happen.

doingnothing
11/6/09

For your scenario to be possible, it should be possible to conjure watch out of thin air.
Since, you can't do that, the scenario you described is not possible.
You haven't proved time travel by itself is a paradox

tBoone
11/9/09

It is simple...it's simply circular logic. The Grandfather Paradox (GFP) is a perfect example. Your reply to the GFP: the universe just won't let you kill your grandfather. Based on what the much forgotten "can't kill grandpa" Law of Thermodynamics? Or maybe it's based on circular logic of: "I am able to come to the past because I won't be able to kill grandpa in the future."

I think that clearly proves it.

doingnothing
11/10/09

I will state the argument properly:

0)Assume time travel is possible
1)You know your grandfather was not killed before your father were born.
2)You go to the past, and try to kill him.
3)But he wasn't killed before your father was born.
4)EITHER 0) is false OR you won't be able to kill him.

So, the grandfather paradox doesn't prove that time travel is impossible.

It follows,
5) IF time travel is possible:
5.1)You won't be able to kill your grandfather.

The numbering will help you find any logical flaws. (There isn't any)

tBoone
11/10/09

0)Assume time travel is possible.
1)You know your grandfather was not killed before your father were born.
2)You go to the past, and try to kill him.
3)But he wasn't killed before your father was born. 4)EITHER 0 is false OR you won't be able to kill him.\*

Let's set aside a flaw in the logic above, which I'll explain later; the key is in #4. One is a possibility (i.e. time travel is impossible) the other is an absurdity. Again, what law of physics prevents you from killing grandpa? The Universe somehow "knows" that you went to the past and "knows" that you can't change anything & will stop you if you try? Don't you see how ludicrous that is?

Now, the flaw in logic: (2)you go to the past & decide to kill grandpa. You are currently in the past: the future has NOT happened yet; you have never experienced going to the past before. Then there is reverse causality (3)But he isn't going to be killed before your father will be born." This is an error in logic: an effect cannot precede its cause.

In order for this logical proof to function you must dismiss logic at some point or another. Anyways, logic alone can tell us nothing new about the real world. The same goes for mathematics, as Albert Einstein observed: "Insofar as mathematics is exact, it does not apply to reality; and insofar as mathematics applies to reality, it is not exact."

doingnothing
11/11/09

The grandfather paradox is used as thought experiment against time travel. I merely pointed out the grandfather paradox is impossible even if time travel is possible.

I didn't say that the paradox proved time travel is possible.(that would be stupid)

The other is not an absurdity.
You are overestimating your ability to change anything
Also see Cassandra complex.
See my previous replies commenting why the statement is not absurd.

Your whole arguments clings on your ability to affect the past. Accounting the fact there are millions of other persons, millions of external factors which would affect your action of trying to affect an action, it isn't absurd to claim you will fail.
Further, the fact that you know you will fail will discourage you to go the past in the first place.

Suppose you go the past, let the change you caused be x

Past + x = Present

The present you observed was the result of your actions + the actions of everyone else in the past.

The equation as you see is very simple. The equation also makes it absurd to go to the past to change anything.

Infact this is the basis for Hawking's argument against time travel.(the argument was only against humans time traveling)

Mathematics is used to MODEL reality. The challenge for physicists is to make the model as accurate as necessary. The equations of physics is not maths. It models reality, and as such is applicable. Since, wormholes are possible by the relativity theory-which has been proven right time and again-it is reality.
Ofcourse,the fact that wormholes can exist doesn't mean it exists.

About causality
The chain of events
Your grandfather->(you try to kill him)->gives birth to your father->your father irritates you->you want to kill him->you go back to the past to try to kill him

So, you claim the effect happens(you trying to kill him) before the cause(your father irritates you)
But rather, you are not part of that time. For you everything has already happened. You have already experienced it. The chain of events and effects leading to your father being an irritating person will still occur and the younger-you will go back to the past. Also, this isn't a cycle. You will go into the future older than you should have been.

You can argue semantics till the world ends.

Also, note that causality is not a necessary condition.
It has merely been observed that all events follow causality and in the face of new science, it would need to be abandoned.

Logic can prove something to be impossible, if it is self-contradicting.
"logic alone can tell us nothing new about the real world."
Thank you for finally accepting that time travel is not logically impossible. Goodbye.

tBoone
11/11/09

"The grandfather paradox is used as thought experiment against time travel. I merely pointed out the grandfather paradox is impossible even if time travel is possible." Again, the Novikov Principle is a tautology. Paradoxes can never happen as they are contradictions and are not physically real. Consequently, whether time travel to the past (or anything for that matter) is possible or not will have zero effect on the fact that paradoxes do not exist physically. The NP does nothing for the Grand Father paradox.

"I didn't say that the paradox proved time travel is possible.(that would be stupid)" And also makes no sense.

"The other is not an absurdity." have you ever watched the Roadrunner cartoon? Wile E. Coyote tries to kill the Roadrunner in so many different ways but always fails as he is destined to do. This is how someone trying to kill their grandpa in the past, would fail. And you don't think that that's absurd?

"You are overestimating your ability to change anything...Also see Cassandra complex." What does this have to do with anything? I think I might know what the problem is. You might think that I'm referring to some personal form of change like a person's actions or something like that. While this is also change it is by no means the only change that I am referring to.

My definition is: "change" is the forward progression of time. I am talking about its most simplest form: motion, temperature, etc. Here are some more examples: an atom moving or shaking; an electron "orbit"; molecules moving about; water falling down the side of a mountain; me typing this. This is all change. So you see, you can have more or less or none but you can't have anti-change or negative change. Do you understand now?

"Your whole arguments clings on your ability to affect the past..." No. My argument clings on my ability to affect the present. Once you time travel to the past, the past becomes the present to you. So time travel to the past is like making past = present...wait a second...isn't that whatcha call a paradox? Oh yeah!

As far as trying to kill grandpa is concerned, I guess walking up to him and putting a couple of bullets in his head wouldn't work, right? I guess it'll be like Wile E. Coyote and the Roadrunner. Yup. That's an accurate depiction of reality and it isn't absurd at all. Or maybe not.

"Suppose you go the past, let the change you caused be x..." I guess you mean that a made change x in order to go to the past. OK, I'll bite.

"...Past + x = Present..." Not sure if I'd agree on the equation. How about Present - x = Past? Anyways, even if I agree with your equation you still executed change which is of course the forward progression of time and all you did was go forward in time again. Think of time as an operand (+ - / x exponentiation, any action); no matter which operand you choose it's still the forward progression of time.

"The present you observed was the result of your actions + the actions of everyone else in the past." It should read the present you observe not observed as that would make it past tense and thus not the present but the past. Anyways, there are an almost unlimited number things other than people that affect the way time progresses.

"The equation as you see is very simple. The equation also makes it absurd to go to the past to change anything. Infact this is the basis for Hawking's argument against time travel.(the argument was only against humans time traveling)" Actually, I think it makes it absurd to go to the past.

"Mathematics is used to MODEL reality. The challenge for physicists is to make the model as accurate as necessary. The equations of physics is not maths." You couldn't be more hopelessly wrong: physics IS math. I Think what you might be trying to express is that all physics is math but not all math is physics. That I would agree with.

"It models reality, and as such is applicable. Since, wormholes are possible by the relativity theory-which has been proven right time and again-it is reality." You couldn't be more hopelessly wrong, again. SR might be a very good approximation of some aspects of reality, but it is not perfect. Furthermore, Wormholes are solutions to the math of SR but that doesn't mean that it has an equivalent in real life. Not all solutions to math reveal a real life equivalent.

"Of course,the fact that wormholes can exist doesn't mean it exists. About causality The chain of events Your grandfather->(you try to kill him)->gives birth to your father->your father irritates you->you want to kill him->you go back to the past to try to kill him So, you claim the effect happens(you trying to kill him) before the cause(your father irritates you) But rather, you are not part of that time." Agreed. You aren't part of that time because you are in the present and time travel to the past is impossible. If it were possible, then you would be part of that time by being simply there.

"For you everything has already happened. You have already experienced it." Lol! If you go to the past in your time machine (having never done so before) how can you say anything already happened if you've never time traveled to the past before? That's ridiculous and circular reasoning.

"The chain of events and effects leading to your father being an irritating person will still occur and the younger-you will go back to the past. Also, this isn't a cycle." Oh no. Not a cycle at all...Actually, I don't think it can get more circular than that!

"You will go into the future older than you should have been. You can argue semantics till the world ends. Also, note that causality is not a necessary condition. It has merely been observed that all events follow causality and in the face of new science, it would need to be abandoned." Cause & effect is the root of logic as well as science: abandon that and what do you have left? Nonsense.

"Logic can prove something to be impossible, if it is self-contradicting. "logic alone can tell us nothing new about the real world." I said that logic can't prove a negative unless the Universe of discourse is extremely small. The Universe is practically infinite so proving a negative there is not possible.

"Thank you for finally accepting that time travel is not logically impossible." It is if you use my definition of time.

doingnothing
11/10/09

I will further clarify that Novikov principle is not a proof for time travel. But, rather aims to merely prove that time travel(if possible) will not lead to logical paradox and that time travel is not a paradox.

This is my last reply. Honest.

doingnothing
11/10/09

You didn't understand my position at all.
I did not claim that there is some traversable wormhole somewhere and we can travel to the past.
I understand that they are wormholes are purely hypothetical and a traversable one needs to satisfy additional number of conditions.

I state that time travel is not impossible but only unlikely.

tBoone
11/10/09

I understand you perfectly your position; heck, I even believed in it at one point or another in my life. However, even using that definition of time, time travel to the past via Wormhole in VERY VERY HIGHLY unlikely.

As I am sure that you are aware of, most of this depends on the definition of time. Using some of the acceptable definitions out there, there may be a possibility for time travel to the past; however, there are perfectly acceptable definitions of time (like the one that I am using here) that would make such a thing impossible.

The reason is that when using said definition, time travel to the past is itself a paradox; it is a paradox by definition. Consequently, the Novikov principle would fail because it would be assuming a false premise. As you may have guessed, I prefer my definition of time: it is quite elegant in its simplicity and neatly solves all these issues of time time travel.

doingnothing
11/11/09

Your belief that you have 'disproved' time travel when no scientist has, is audacious to say the least.

tBoone
11/12/09

Many scientists have shown that it is so. Many don't even entertain the idea at all.

doingnothing
11/11/09

Novikov principle is not on the premise of time travel.
It holds if time travel is possible, the Novikov priciple is followed.

In other words:
Time travel is not paradoxical. It would follow Novikov principle.

Novikov principle DOESN'T ASSUME ANYTHING.

doingnothing
11/11/09

The nuances of the definition cannot prove or disprove anything. If your definition is time, we will take our definition as timee and say time travel is not possible but timee travel is possible.

doingnothing
11/11/09

I know that sounded childish, but it is still true.

Definition is for grammar freaks.

tBoone
11/11/09

Right. Physics doesn't use definitions. Why didn't I realize that? Physics is just a bunch of good sci fi movie plots put together. Or maybe not. Definitions matter, especially in physics. I hope you realize that.

doingnothing
11/12/09

I meant YOUR DEFINITION of time doesn't prove anything.

tBoone
11/12/09

Sure it does. It proves that time travel to the past is impossible! In other words, it makes time travel to the past = a contradiction. Quite simple, really.

I like my definition because of its simplicity, profound implications, and rigorous empirical support. Of course, you are more than welcome to refuse this definition, but it is a very good one! If you use a different definition, then it may have different consequences like time travel to the past being possible, etc.

jackiecox333
11/23/09

Time is a word ment to describe the moment, there is no past, no future. Einstieinian /lorentz math equasion states that if you travel faster than light 300,000 miles per second, then you could leave the earth and return, before you left, or before the suns energy would arrive on earth if you had never left, which if the assumptions were correct, then the equasion would be accurate, however the problem arises when you add an independent observor with a stop watch, for instance a vessel traveling at 1,200,000 miles per second left the earth and went for 60 seconds into outer space, then immediately returned, arriving back on earth 60 seconds before the suns energy would arive on earth had the vessel not left, thus space-time continium theory and relativity are satisified, however the man with the stop watch states 120 seconds passed, and that in fact time and the speed of light are not equatable as stated, probably why Lorentz tossed the idea. Einstein picked it up, added a bit more gibberish and has fooled the academic ventures for more than 100 years, stifiling and confusing actual students trying to understand reality. Einstein, discovered nothing, is a plaguarist, and exposes the convoluted order of things

tBoone
11/24/09

In physics time is much more than a word meant to "describe the moment." The Einstein/Lorentz equations "state" no such thing. If we allow for "unlimited speed" (which relativity does not) then a solution can show "backwards time travel." The only problem is c is a constant & is the ultimate speed & this has been demonstrated to be so time and time again through experimentation. Secondly, if c is not the "ultimate speed limit" as some conspiracy theorists would have you believe, then neither time dilation or time travel to the past would occur! It is BECAUSE c is the ultimate speed limit that the other 2 are so.

Or you can believe the nonsensical gibberish above based on pseudo science and conspiracies.