John Richard Gott III (b.
LouisvilleLouisville is Kentucky's largest city and county seat of Jefferson County. Since 2003, the city's borders have been coterminous with those of the county because of a city-county merger. The city's estimated population as of 2008 was 713,877 , with a population of 1,244,696 in the Louisville...
,
KentuckyThe Commonwealth of Kentucky is a state located in the East Central United States of America. Kentucky is a Southern state situated in the Upland South, although the state is infrequently placed, geographically and culturally, in the Midwest. Kentucky is one of four U.S. states constituted as a...
, 1947) is a professor of
astrophysical sciencesAstrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects such as galaxies, stars, planets, exoplanets, and the interstellar medium, as well as their...
at
Princeton UniversityPrinceton University a private university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League and is considered one of the Colonial Colleges....
. He is especially well known for developing and advocating two cosmological theories with the flavor of
science fictionScience fiction is a genre of fiction. It differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically-established or scientifically-postulated laws of nature...
:
Time travelTime travel is the concept of moving between different moments in time in a manner analogous to moving between different points in space, either sending objects backwards in time to a moment before the present, or sending objects forward from the present to the future without the need to...
, and the
Doomsday argumentThe Doomsday argument is a probabilistic argument that claims to predict the future lifetime of the human species given only an estimate of the total number of humans born so far...
.
Paul DaviesPaul Charles William Davies AM is an English physicist, writer and broadcaster, currently a professor at Arizona State University as well as the Director of BEYOND: Center for Fundamental Concepts in Science...
's bestseller
How to build a time machine credits Gott with the proposal of using cosmic strings to create a
time machineTime travel is the concept of moving between different moments in time in a manner analogous to moving between different points in space, either sending objects backwards in time to a moment before the present, or sending objects forward from the present to the future without the need to...
. Gott's machine depends upon the antigravitational tension of the (hypothetical) strings to
deform spaceGeneral relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics. It unifies special relativity and Newton's law of universal gravitation, and describes gravity as a...
without attracting nearby objects.
John Richard Gott III (b.
LouisvilleLouisville is Kentucky's largest city and county seat of Jefferson County. Since 2003, the city's borders have been coterminous with those of the county because of a city-county merger. The city's estimated population as of 2008 was 713,877 , with a population of 1,244,696 in the Louisville...
,
KentuckyThe Commonwealth of Kentucky is a state located in the East Central United States of America. Kentucky is a Southern state situated in the Upland South, although the state is infrequently placed, geographically and culturally, in the Midwest. Kentucky is one of four U.S. states constituted as a...
, 1947) is a professor of
astrophysical sciencesAstrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects such as galaxies, stars, planets, exoplanets, and the interstellar medium, as well as their...
at
Princeton UniversityPrinceton University a private university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League and is considered one of the Colonial Colleges....
. He is especially well known for developing and advocating two cosmological theories with the flavor of
science fictionScience fiction is a genre of fiction. It differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically-established or scientifically-postulated laws of nature...
:
Time travelTime travel is the concept of moving between different moments in time in a manner analogous to moving between different points in space, either sending objects backwards in time to a moment before the present, or sending objects forward from the present to the future without the need to...
, and the
Doomsday argumentThe Doomsday argument is a probabilistic argument that claims to predict the future lifetime of the human species given only an estimate of the total number of humans born so far...
.
Exotic matter time travel theories
Paul DaviesPaul Charles William Davies AM is an English physicist, writer and broadcaster, currently a professor at Arizona State University as well as the Director of BEYOND: Center for Fundamental Concepts in Science...
's bestseller
How to build a time machine credits Gott with the proposal of using cosmic strings to create a
time machineTime travel is the concept of moving between different moments in time in a manner analogous to moving between different points in space, either sending objects backwards in time to a moment before the present, or sending objects forward from the present to the future without the need to...
. Gott's machine depends upon the antigravitational tension of the (hypothetical) strings to
deform spaceGeneral relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics. It unifies special relativity and Newton's law of universal gravitation, and describes gravity as a...
without attracting nearby objects. The traveler would follow a precise path around rapidly separating strings, and find that she had moved backwards in time.
Gott also proposed a "time mirror": a time travel device based on the principle of time delays. The device would be situated near a black hole some hundred or more light years from Earth. The device would act as a light collector and would power the light rays deformed and curved by the gravitational depression of the black hole. The collector would then reveal the past as detailed by the photons that had originated from Earth.
Since Gott believes that time travel is not cosmologically excluded, he has presented the possibility that the universe was created out of itself (at a later time). This controversial suggestion was published with Li-Xin Lin, and it was described by Gott as "it would be like having one branch of a tree circle around and grow up to be the trunk. In that way, the universe could be its own mother."
In his own book,
Time Travel in Einstein's Universe: The Physical Possibilities of Travel Through Time, Gott argues that travel to the past is quite possible, although probably only after the construction of a working device (
during its existence), and certainly not onto the time traveler's own past timeline (he argues that either the
many worldsThe many-worlds interpretation is an interpretation of quantum mechanics.It is also known as MWI, the relative state formulation, theory of the universal wavefunction, parallel universes, many-universes interpretation or just many worlds.Many-worlds asserts the objective reality of the...
QMQuantum mechanics is a set of principles describing the physical reality at the atomic level of matter and the subatomic . These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation...
interpretation must be invoked to overcome the
Grandfather paradoxThe grandfather paradox is a proposed paradox of time travel first described by the science fiction writer René Barjavel in his 1943 book Le Voyageur Imprudent . Nevertheless, similar paradoxes had already been described, for instance by Robert A. Heinlein in "By His Bootstraps"...
, or that all time travel remain self-consistent, i.e., one can visit the past, but not change it). Although he is keen to emphasize that time travel itself is a commonplace physical phenomenon, by this he means time travel into the future at varying rates through
special relativitySpecial relativity is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies"...
, he is not completely committal on the subject of time travel to the past. The book does say that nothing known excludes such travel, but he doesn't completely rule out the possibility that future research may prove it impossible.
Copernicus method and Doomsday theory
Gott first thought of his "Copernicus method" of lifetime estimation in 1969 when stopping at the
Berlin Wall|-||-||-||-||}The Berlin Wall was a physical barrier erected by the German Democratic Republic completely encircling West Berlin, separating it from East Germany, including East Berlin. The longer inner German border demarcated the border between East and West Germany...
and wondering how long it would stand. Instead of extrapolating a set of developments in world geo-politics (
futurologyFutures studies, foresight, or futurology is the philosophy, science, art and practice of postulating possible, probable, and preferable futures and the worldviews and myths that underlie them. Futures studies seeks to understand what is likely to continue, what is likely to change, and what is...
), Gott used his relative ignorance to his advantage by saying that the
Copernican principleIn physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states the Earth is not in a central, specially favoured position. More recently, the principle is generalised to the relativistic concept that humans are not privileged observers of the universe...
is applicable in cases where nothing is known; unless there was something special about his visit (which he didn't think there was) this gave a 75% chance that he was seeing the wall
after the first quarter of its life. Based on its age in 1969 (8 years), Gott left the wall with 75% confidence that it wouldn't be there in 1993 ((8/.25) + 1961).
In fact, the wall was brought down in 1989, and 1993 was the year in which Gott applied his "Copernicus method" to the lifetime of the human race. His paper in
NatureNature is a prominent British scientific journal, first published on 4 November 1869. Most scientific journals are now highly specialized, and Nature is among the few journals that still publish original research articles across a wide range of scientific...
was the first to apply the
Copernican principleIn physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states the Earth is not in a central, specially favoured position. More recently, the principle is generalised to the relativistic concept that humans are not privileged observers of the universe...
to the survival of humanity; His original prediction gave 95% confidence that the human race would last for between 5100 and 7.8 million years. (
Brandon CarterBrandon Carter is an Australian theoretical physicist, best known for his work on the properties of black holes and for being the first to name and employ the anthropic principle in its contemporary form...
's alternative form of the
Doomsday argumentThe Doomsday argument is a probabilistic argument that claims to predict the future lifetime of the human species given only an estimate of the total number of humans born so far...
was delivered earlier that year, but Gott's derivation was independent.)
He made a major effort subsequently to defend his form of the
Doomsday argumentThe Doomsday argument is a probabilistic argument that claims to predict the future lifetime of the human species given only an estimate of the total number of humans born so far...
from a variety of philosophical attacks, and this debate (like the feasibility of closed time loops) is still ongoing. To popularize the
Copernicus method, Gott gave
The New YorkerThe New Yorker is an American magazine of reportage, commentary, criticism, essays, fiction, satire, cartoons, and poetry published by Condé Nast Publications...
magazine a 95% confidence interval for the closing time of forty-four
BroadwayBroadway Theatre, commonly called simply Broadway, is the theatre associated with the 40 large professional theaters with 500 seats or more located in the Theatre District, New York in Manhattan, New York City...
and Off Broadway productions based only on their opening dates. He was more or less 95% correct.
Gott's education work
He received the President’s Award for Distinguished Teaching in acknowledgment of his work on the
National Westinghouse and Intel Science Talent Search high school student science competition. He is an active promoter of the public awareness of science at the popular level, and Princeton students have voted him the school's outstanding professor several times.
Gott is a Presbyterian who distinguishes physical from meta-physical questions by their
teleologyTeleology is the philosophical study of design and purpose. A teleological school of thought is one that holds all things to be designed for or directed toward a final result, that there is an inherent purpose or final cause for all that exists.As a school of thought it can be contrasted with...
; he believes (
http://www.science-spirit.org/article_detail.php?article_id=270) that his writings are entirely scientific (not trespassing into the
theologyThe term "theology" literally means the study of God, deriving from the Greek word theos, meaning 'God', and the suffix -ology from the Greek word logos meaning "discourse", "theory", or "reasoning"...
) because the motivation for the way things are (or might be) is never examined.
See also
- Kip Thorne
Kip Stephen Thorne is an American theoretical physicist, known for his prolific contributions in gravitation physics and astrophysics and for having trained a generation of scientists...
's writings on wormhole time travel marked the introduction of the subject's serious discussion in physicsPhysics is a natural science; it is the study of matter and its motion through spacetime and all that derives from these, such as energy and force...
.
- Science Fiction
Science fiction is a genre of fiction. It differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically-established or scientifically-postulated laws of nature...
has "often sparked interesting science investigations" in Gott's view (for instance Kip Thorne's original time travel work was provoked by Carl SaganCarl Edward Sagan was an American astronomer, astrochemist, author, and highly successful popularizer of astronomy, astrophysics and other natural sciences...
). His favourite work is H.G. Wells' The Time MachineThe Time Machine is a novella by H. G. Wells, first published in 1895 and later directly adapted into at least two feature films of the same name, as well as two television versions, and a large number of comic book adaptations. It indirectly inspired many more works of fiction in all media...
.
- Regular pseudopolyhedrons - Infinite periodic polyhedra in 3-space
External links
- "J. Richard Gott on Life, the Universe, and Everything" an interview with science & spirit magazine which briefly covers Gott's personal views on the major controversies he has stirred up. He combines his two more controversial positions by saying that he would like to travel 200,000 years into the future to see whether his Doomsday argument
The Doomsday argument is a probabilistic argument that claims to predict the future lifetime of the human species given only an estimate of the total number of humans born so far...
prediction would pay off.
- Time Travel in Einstein's Universe on Google Print
- Q & A with Dejan Vinkovic
Dejan Vinković is Croatian-born astrophysicist, born in Šenkovec, Croatia. Currently working at the University of Split in Split, Croatia, his main focus of research is the early planetary formation. He is very active in the field of science policy, namely the research and education challenges in...
illustrated with a few pictures and a GIF animation of a self-creating universe, in which Gott advocates the importance of the average person having an education in science and especially physicsPhysics is a natural science; it is the study of matter and its motion through spacetime and all that derives from these, such as energy and force...
.
- Abstract to Gott's "A grim reckoning" New Scientist article - online content of the full article requires a paid registration.
- A link to the entire New scientist article.
- Gott & Li's 1998 self-creating universe model compared with other cosmological models of time Rüdiger Vaas argues that Gott's self-creating universe is not rendered meaningless by Kant
KANT is a computer algebra system for mathematicians interested in algebraic number theory, performing sophisticated computations in algebraic number fields, in global function fields, and in local fields. KASH is the associated command line interface...
's first antinomyAntinomy literally means the mutual incompatibility, real or apparent, of two laws. It is a term used in logic and epistemology....
of pure reason.
- http://nickgogerty.typepad.com/designing_better_futures/files/observation.xls Excel spreadsheet for prection using Gott's approach
- http://www.newyorker.com/archive/1999/07/12/1999_07_12_035_TNY_LIBRY_000018591?printable=true New Yorker Magazine interview. 12-July-1999