John Alexander Simpson
Encyclopedia
John Alexander Simpson worked as an experimental nuclear
, and cosmic ray
physicist who was deeply committed to educating the public and political leaders about science and its implications. The year he died, his instruments in space had been sending data back for nearly 40 years. Simpson spent his career as an instructor and researcher for the University of Chicago
Physics department. His research continued up until a few weeks prior to his death on August 31 of 2000.
He is known for inventions such as the gas flow a-particle proportional counter for measuring plutonium
yields in the presence of high intensity fission
products, and the neutron monitor
. And also for having several of the instruments he created lunched into space.
John A. Simpson died at age 83. His death was caused from a case of Pneumonia in which he contracted in the hospital following a successful heart surgery, and he is survived by his wife Elizabeth, and by his two children Mary Ann and Simpson from his first marriage.
, Simpson was an accomplished clarinetist and saxophonist in his early years, receiving recognition in high school with an award for his virtuosity
. He received an AB degree
from Reed College
in 1940, where he became interested in the history of science and technology spanning from the Greeks and Romans to the Middle Ages, to the most recent discoveries in astronomy
and physics
. He obtained an MS
from New York University
in 1943, and a Ph.D a year later. It was at New York University in 1943 when Simpson first got his invitation to become employed at Chicago University. Volney Wilson, an administrator at the Metallurgical Laboratory
of the university had asked him to come help invent instruments for measuring high levels of radioactivity. It took much convincing, but Simpson finally agreed to help.
in 1943 where he acted as a group leader on the Manhattan Project
. The Manhattan Project was the codename for a United States
project with the United Kingdom
and Canada
conducted during World War II
to develop the first atomic bombs. It was common for government to recruit physicists during World War II for such tasks. Simpson had taken up the offer after recognizing the social and human implications of nuclear energy
and wanted to partake in its development. Because of this, Simpson became a founding member and first chairman of the Atomic Scientists of Chicago, founded two years after the start of his career in August 1945, a day after the United States dropped the atomic bomb on Hiroshima. He was also a co-founder that same year of the Bulletin of the Atomic Scientists
. This bulletin's aim was to spell out the implications of the atomic bomb, as well as to provide rational courses of action in response to the implications. In the October 29, 1945 issue of Life
, Simpson, along with Eugene Rabinowitch
spoke about their involvement with nuclear energy, and said that scientists for the first time had recognized a moral responsibility to carry the warning of the danger of any further use of nuclear weapons. He felt that scientists and engineers could no longer remain aloof from the consequences of their work.
This same year Simpson began his tenure
as a faculty member at the University of Chicago as a physics instructor, and remained there throughout his career partaking in research as well until shortly before his death in August 2000. In 1945 also he was able to work as an unofficial adviser to Connecticut Senator Brien McMahon
after taking a leave of absence from the university. As part of the university faculty, Simpson was able to invent and patent a gas flow a-particle proportional counter for measuring plutonium yields in the presence of high intensity fission products. He had come up with the idea to pipe the plutonium-bearing gas through the counter itself.
Simpson has 15 patents under his name which include the multiwire proportional counter
, a device that assists in improving reading speed and accuracy, and the Neutron monitor
.
In 1946 Simpson developed a special interest in cosmic rays, which very little was known about at the time as the field which was still in the process of being established, including their origin. Beginning with investigations pertaining to the cosmic ray neutrons in the lower atmosphere
, Simpson was there from the beginning developmental phases of the field, and contributed significantly throughout the years to its development with his scientific investigations
. Simpson's contributions were unique in that he somehow accomplished his work in a way which boosted the accomplishments and careers of others around him such as graduate students, research associates and other faculty. In 1955 he gave Eugene N. Parker a job as a research associate in the Enrico Fermi Institute
of the University of Chicago, and his progress was largely a consequence of Simpson's continued support. His research on cosmic ray neutrons in the lower atmosphere was developed upon its founding by Serge Korff before World War II. Simpson in his research contributed the discovery that the latitude effect seen with neutrons is around 20 times greater than with ionization chamber
s in 1949. In 1951 he found that the time variations are much greater as well. He had recognized the potential of the neutrons and the lower energy cosmic ray particles for exploring the causes of the time variations. That year he also invented the neutron monitor to fulfill the need for a stable ground-based neutron detector. In doing so, he established neutron monitor stations at various locations including Peru, huancayo
, Mexico, Mexico City
, New Mexico
, Sacramento Peak, Colorado, Climax
, and Chicago Illinois.
In 1954 and 1955, Simpson explored the global and time variations of cosmic rays around the world at these neutron monitor stations. In 1956, the giant cosmic ray flare provided for Simpson the first direct glimpse of the state of things in interplanetary space. At this point the scientific community surrounding cosmic rays and solar activity had grown largely, and for the International Geophysical Year (1957–58) Simpson was one of 12 other scientists responsible for organizing and coordinating the international program, helping to make it a huge success.
At the end of 1957 after the launch of Sputnik by the Soviet Union
, Simpson, realizing the necessity for the U.S. to send instruments into space, outlined the scientific situation and his plans for such activity to University chancellor Lawrence Kimpton
. Kimpton granted Simpson $5000 to get the project off the ground, and partnered with Peter Meyer to develop small lightweight particle detector
s suited for the space environment. Simpson's first particle detector was launched in 1958 on spacecraft Pioneer 2
.
In 1962 Simpson and Professor Peter Meyer established the Laboratory for Astrophysics and Space Research (LASR) which was built within the Enrico Fermi Institute at the University of Chicago. NASA contributed towards the laboratory and funded a building for LASR which was completed in 1964. In the laboratory instrument development and space research were consolidated under one roof, along with theoretical research connected with the results of the ongoing research and space experiments.
In 1965 Simpson, along with his students and co-workers, built the first cosmic ray (energy particle) detectors to visit Mars
. In 1973 it was the first to visit Jupiter
, in 1974 Mercury
, and in 1979 Saturn
. Jupiter's mission detected the relativistic (3-30 MeV) electron population for the first time which the planet was emitting. This first recognized the electrons contained within the Jovian magnetosphere and then the escaping electrons at distances of at least 1 AU
. Simpson's detection in 1974 is what first established that the magnetic fields being observed at Mercury were not being carried from the Sun by the impacting solar wind
, but in fact belonged to the planet itself. Simpson had been helping to develop the mission from concept since 1959. Also, in 1980, his detection of a tiny gap in the distribution of energetic particles trapped in the magnetic field of Saturn indicated to them the presence of a previously undetected small moon
there orbiting at that position in space and absorbing particles which would otherwise be found there were there no disruption. Subsequently, scientists became able to identify Saturn's moon optically. In 1976 and 1982 Simpson also detected bursts of energetic particles associated with the passage of shock waves in the solar wind, and provided evidence that the transition serves as an efficient accelerator of particles, and provided a basis for further studies.
In 1970 Simpson discovered that the impulsive sun flares
produce energetic particles among which Helium-3
, a light non-radioactive isotope
of helium
with two protons and one neutron, is at least ten times more abundant than Helium-4
, a non-radioactive and light isotope of helium. On Earth
, Helium-4
is what makes up about 99.986% of the helium here. In 1973 his instruments on Pioneer 10
and 11
indicated a cosmic ray intensity increase of about 1 percent per AU. In 1975 he found that during the low point of activity three years prior, the abundance of cosmic ray helium was strangely enhanced at these very low energies, as opposed to it dropping off with declining energies like the protons do, toward zero energy
.
In the 1975s and 1977s Simpson discovered the fact that Beryllium-10
nuclei
are scarce in cosmic rays, and that that scarcity indicates that they have been around for about 2 x 107 years. This led him to conclude that cosmic rays pass freely between the gaseous disk
and the extended magnetic halo portion of the galaxy
, where the ambient gas density is more like 10−2 atoms/cm3 or less.
In the 1980s Simpson Simpson and A. J. Tuzzolino developed the dust flux monitor instrument which involved a thin sheet of plastic which was polymerized in the presence of a strong electric field
perpendicular to the plane of the plastic, and then electrically polarized carrying a positive electric charge
on one of its surfaces and a negative charge on the other. The way it operated was such that a dust particle
or heavy nucleus penetrating through the sheet first vaporizes in a small area releasing the charges, then the electrical signal indicates the location and size of the hole in the plastic which is then calibrated to give information on its speed and size. These calibrations took place from 1985 until 1989. Simpson's device was used on spacecraft Vega 1
and Vega 2
to Halley's comet in 1986, and earned him the Gagarin Medal for Space Exploration that year for his contribution towards the success of the Vega mission, as his instruments had been the only ones from the United States to encounter the comet.
noted that he was one of the most prolific inventors of scientific instruments for space exploration
. In 1958 his first created instrument was launched into space, and the last two were launched in 1999. One on board the Stardust
, met up with Comet Wild-2
, a frozen snowball one and a half miles in diameter in 2004.
In 1959 Simpson was elected to the National Academy of Sciences
, in 1968 he held the first Ryerson Chair and was made Distinguished Service Professor at his university, in 1974 was the first to be appointed to the Copton Chair, and in 1986 he became Emeritus
. Simpson is the recipient of the 1986 Gagarin Medal for Space Exploration for his contribution towards the success of the Vega mission, which sent satellites to Halley's comet earlier that year. In 1991 he was awarded the Bruno Rossi Prize
by the American Astronomical Society
for his contributions towards high-energy astrophysics
, and in 1993 was awarded the Arctowski Medal
of the National Academy of Sciences. In 1999 he was awarded the Leo Szilard Lectureship Award for his role in educating scientists, members of the United States Congress
and the public on the importance of civilian control
of nuclear policy
and his critical efforts in planning and execution of the International Geophysical Year
. In 2000 he was also additionally awarded the William Bowie Medal
which is the highest award given by the American Geophysical Union
, for his extensive explorations of the cosmic rays and other energetic particles that our planet is continually bombarded by. He is known as having been an outstanding professor, having throughout the course of his academic career supervised the research of 34 doctoral students, many who are now leaders in the space sciences. Simpson has also provided lectures to the public using funds in 1974 which came from his Compton Chair in an attempt to reach a larger audience with his research. In 1982 he also established and became the first chairman of the Universities Space Science Working Group located in Washington, D.C.
in order to represent the space science laboratories in their dealings with congress and NASA
Nuclear physics
Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those...
, and cosmic ray
Cosmic ray
Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...
physicist who was deeply committed to educating the public and political leaders about science and its implications. The year he died, his instruments in space had been sending data back for nearly 40 years. Simpson spent his career as an instructor and researcher for the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
Physics department. His research continued up until a few weeks prior to his death on August 31 of 2000.
He is known for inventions such as the gas flow a-particle proportional counter for measuring plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
yields in the presence of high intensity fission
Fission
Fission is a splitting of something into two parts.Fission may refer to:*In physics, nuclear fission is a process where a large atomic nucleus is split into two smaller particles....
products, and the neutron monitor
Neutron monitor
A neutron monitor is a ground-based detector designed to measure the number of high-energy charged particles striking the Earth's atmosphere from outer space. For historical reasons the incoming particles are called "cosmic rays", but in fact they are particles, predominantly protons and Helium...
. And also for having several of the instruments he created lunched into space.
John A. Simpson died at age 83. His death was caused from a case of Pneumonia in which he contracted in the hospital following a successful heart surgery, and he is survived by his wife Elizabeth, and by his two children Mary Ann and Simpson from his first marriage.
Early life
Born in Portland, OregonPortland, Oregon
Portland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...
, Simpson was an accomplished clarinetist and saxophonist in his early years, receiving recognition in high school with an award for his virtuosity
Virtuosity
Virtuosity is a 1995 techno-thriller film directed by Brett Leonard. The movie tells the story of a virtual villain's successful attempt to escape into the "real world". SID 6.7, the villain program portrayed by Russell Crowe, is eventually transplanted into an android body and escapes...
. He received an AB degree
Bachelor of Arts
A Bachelor of Arts , from the Latin artium baccalaureus, is a bachelor's degree awarded for an undergraduate course or program in either the liberal arts, the sciences, or both...
from Reed College
Reed College
Reed College is a private, independent, liberal arts college located in southeast Portland, Oregon. Founded in 1908, Reed is a residential college with a campus located in Portland's Eastmoreland neighborhood, featuring architecture based on the Tudor-Gothic style, and a forested canyon wilderness...
in 1940, where he became interested in the history of science and technology spanning from the Greeks and Romans to the Middle Ages, to the most recent discoveries in astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
and physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
. He obtained an MS
Master of Science
A Master of Science is a postgraduate academic master's degree awarded by universities in many countries. The degree is typically studied for in the sciences including the social sciences.-Brazil, Argentina and Uruguay:...
from New York University
New York University
New York University is a private, nonsectarian research university based in New York City. NYU's main campus is situated in the Greenwich Village section of Manhattan...
in 1943, and a Ph.D a year later. It was at New York University in 1943 when Simpson first got his invitation to become employed at Chicago University. Volney Wilson, an administrator at the Metallurgical Laboratory
Metallurgical Laboratory
The Metallurgical Laboratory or "Met Lab" at the University of Chicago was part of the World War II–era Manhattan Project, created by the United States to develop an atomic bomb...
of the university had asked him to come help invent instruments for measuring high levels of radioactivity. It took much convincing, but Simpson finally agreed to help.
Research
Simpson began his professional career as a physicistPhysicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
in 1943 where he acted as a group leader on the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
. The Manhattan Project was the codename for a United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
project with the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
conducted during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
to develop the first atomic bombs. It was common for government to recruit physicists during World War II for such tasks. Simpson had taken up the offer after recognizing the social and human implications of nuclear energy
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
and wanted to partake in its development. Because of this, Simpson became a founding member and first chairman of the Atomic Scientists of Chicago, founded two years after the start of his career in August 1945, a day after the United States dropped the atomic bomb on Hiroshima. He was also a co-founder that same year of the Bulletin of the Atomic Scientists
Bulletin of the Atomic Scientists
The Bulletin of the Atomic Scientists is a nontechnical online magazine that covers global security and public policy issues, especially related to the dangers posed by nuclear and other weapons of mass destruction...
. This bulletin's aim was to spell out the implications of the atomic bomb, as well as to provide rational courses of action in response to the implications. In the October 29, 1945 issue of Life
Life (magazine)
Life generally refers to three American magazines:*A humor and general interest magazine published from 1883 to 1936. Time founder Henry Luce bought the magazine in 1936 solely so that he could acquire the rights to its name....
, Simpson, along with Eugene Rabinowitch
Eugene Rabinowitch
Eugene Rabinowitch was a Russian-born American biophysicist who is best known for his work in relation to nuclear weapons, especially as a co-author of the Franck Report and a co-founder in 1945 of the Bulletin of the Atomic Scientists, a global security and public policy magazine, which he edited...
spoke about their involvement with nuclear energy, and said that scientists for the first time had recognized a moral responsibility to carry the warning of the danger of any further use of nuclear weapons. He felt that scientists and engineers could no longer remain aloof from the consequences of their work.
This same year Simpson began his tenure
Tenure
Tenure commonly refers to life tenure in a job and specifically to a senior academic's contractual right not to have his or her position terminated without just cause.-19th century:...
as a faculty member at the University of Chicago as a physics instructor, and remained there throughout his career partaking in research as well until shortly before his death in August 2000. In 1945 also he was able to work as an unofficial adviser to Connecticut Senator Brien McMahon
Brien McMahon
Brien McMahon, born James O'Brien McMahon was an American lawyer and politician who served in the United States Senate from 1945 to 1952...
after taking a leave of absence from the university. As part of the university faculty, Simpson was able to invent and patent a gas flow a-particle proportional counter for measuring plutonium yields in the presence of high intensity fission products. He had come up with the idea to pipe the plutonium-bearing gas through the counter itself.
Simpson has 15 patents under his name which include the multiwire proportional counter
Wire chamber
A multi-wire chamber is a detector for particles of ionizing radiation which is an advancement of the concept of the Geiger counter and the proportional counter....
, a device that assists in improving reading speed and accuracy, and the Neutron monitor
Neutron monitor
A neutron monitor is a ground-based detector designed to measure the number of high-energy charged particles striking the Earth's atmosphere from outer space. For historical reasons the incoming particles are called "cosmic rays", but in fact they are particles, predominantly protons and Helium...
.
In 1946 Simpson developed a special interest in cosmic rays, which very little was known about at the time as the field which was still in the process of being established, including their origin. Beginning with investigations pertaining to the cosmic ray neutrons in the lower atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
, Simpson was there from the beginning developmental phases of the field, and contributed significantly throughout the years to its development with his scientific investigations
Scientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
. Simpson's contributions were unique in that he somehow accomplished his work in a way which boosted the accomplishments and careers of others around him such as graduate students, research associates and other faculty. In 1955 he gave Eugene N. Parker a job as a research associate in the Enrico Fermi Institute
Enrico Fermi Institute
The Institute for Nuclear Studies was founded September, 1945 as part of the University of Chicago with Samuel King Allison as director. On November 20, 1955 it was renamed The Enrico Fermi Institute for Nuclear Studies...
of the University of Chicago, and his progress was largely a consequence of Simpson's continued support. His research on cosmic ray neutrons in the lower atmosphere was developed upon its founding by Serge Korff before World War II. Simpson in his research contributed the discovery that the latitude effect seen with neutrons is around 20 times greater than with ionization chamber
Ionization chamber
The ionization chamber is the simplest of all gas-filled radiation detectors, and is used for the detection or measurement of ionizing radiation...
s in 1949. In 1951 he found that the time variations are much greater as well. He had recognized the potential of the neutrons and the lower energy cosmic ray particles for exploring the causes of the time variations. That year he also invented the neutron monitor to fulfill the need for a stable ground-based neutron detector. In doing so, he established neutron monitor stations at various locations including Peru, huancayo
Huancayo
Huancayo with a rock') is the capital of the Junín Region, in the central highlands of Peru. It is located in Junín Province, of which it is also capital. Situated near the Mantaro Valley at an altitude of 3,271 meters, it has a population of 377,000 and is the fifth most populous city of the...
, Mexico, Mexico City
Mexico City
Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Sacramento Peak, Colorado, Climax
Climax, Colorado
Climax was an unincorporated mining village and a former U.S. Post Office located in Lake County, Colorado. Climax was known for its large molybdenum ore deposit. The former Climax Post Office had the ZIP Code 80429. Climax is located along the Continental Divide at an elevation of about 11,360 feet...
, and Chicago Illinois.
In 1954 and 1955, Simpson explored the global and time variations of cosmic rays around the world at these neutron monitor stations. In 1956, the giant cosmic ray flare provided for Simpson the first direct glimpse of the state of things in interplanetary space. At this point the scientific community surrounding cosmic rays and solar activity had grown largely, and for the International Geophysical Year (1957–58) Simpson was one of 12 other scientists responsible for organizing and coordinating the international program, helping to make it a huge success.
At the end of 1957 after the launch of Sputnik by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
, Simpson, realizing the necessity for the U.S. to send instruments into space, outlined the scientific situation and his plans for such activity to University chancellor Lawrence Kimpton
Lawrence A. Kimpton
Lawrence Alpheus Kimpton was an American philosopher and educator, and a president of the University of Chicago. He earned a B.A. at Stanford and a Ph.D...
. Kimpton granted Simpson $5000 to get the project off the ground, and partnered with Peter Meyer to develop small lightweight particle detector
Particle detector
In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify high-energy particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a...
s suited for the space environment. Simpson's first particle detector was launched in 1958 on spacecraft Pioneer 2
Pioneer 2
Pioneer 2 was the last of the three project Able space probes designed to probe lunar and cislunar space. Shortly after launch at 07:30:00 UTC on November 8, 1958, the third stage of the launch vehicle separated but failed to ignite, and Pioneer 2 did not achieve its intended lunar orbit...
.
In 1962 Simpson and Professor Peter Meyer established the Laboratory for Astrophysics and Space Research (LASR) which was built within the Enrico Fermi Institute at the University of Chicago. NASA contributed towards the laboratory and funded a building for LASR which was completed in 1964. In the laboratory instrument development and space research were consolidated under one roof, along with theoretical research connected with the results of the ongoing research and space experiments.
In 1965 Simpson, along with his students and co-workers, built the first cosmic ray (energy particle) detectors to visit Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
. In 1973 it was the first to visit Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
, in 1974 Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
, and in 1979 Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
. Jupiter's mission detected the relativistic (3-30 MeV) electron population for the first time which the planet was emitting. This first recognized the electrons contained within the Jovian magnetosphere and then the escaping electrons at distances of at least 1 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
. Simpson's detection in 1974 is what first established that the magnetic fields being observed at Mercury were not being carried from the Sun by the impacting solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
, but in fact belonged to the planet itself. Simpson had been helping to develop the mission from concept since 1959. Also, in 1980, his detection of a tiny gap in the distribution of energetic particles trapped in the magnetic field of Saturn indicated to them the presence of a previously undetected small moon
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
there orbiting at that position in space and absorbing particles which would otherwise be found there were there no disruption. Subsequently, scientists became able to identify Saturn's moon optically. In 1976 and 1982 Simpson also detected bursts of energetic particles associated with the passage of shock waves in the solar wind, and provided evidence that the transition serves as an efficient accelerator of particles, and provided a basis for further studies.
In 1970 Simpson discovered that the impulsive sun flares
Solar flare
A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy . The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day...
produce energetic particles among which Helium-3
Helium-3
Helium-3 is a light, non-radioactive isotope of helium with two protons and one neutron. It is rare on Earth, and is sought for use in nuclear fusion research...
, a light non-radioactive isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
of helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
with two protons and one neutron, is at least ten times more abundant than Helium-4
Helium-4
Helium-4 is a non-radioactive isotope of helium. It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is the same as an alpha particle, consisting of two protons and two neutrons. Alpha decay of heavy...
, a non-radioactive and light isotope of helium. On Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, Helium-4
Helium-4
Helium-4 is a non-radioactive isotope of helium. It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is the same as an alpha particle, consisting of two protons and two neutrons. Alpha decay of heavy...
is what makes up about 99.986% of the helium here. In 1973 his instruments on Pioneer 10
Pioneer 10
Pioneer 10 is a 258-kilogram robotic space probe that completed the first interplanetary mission to Jupiter, and became the first spacecraft to achieve escape velocity from the Solar System. The project was managed by the NASA Ames Research Center and the contract for the construction of the...
and 11
Pioneer 11
Pioneer 11 is a 259-kilogram robotic space probe launched by NASA on April 6, 1973 to study the asteroid belt, the environment around Jupiter and Saturn, solar wind, cosmic rays, and eventually the far reaches of the solar system and heliosphere...
indicated a cosmic ray intensity increase of about 1 percent per AU. In 1975 he found that during the low point of activity three years prior, the abundance of cosmic ray helium was strangely enhanced at these very low energies, as opposed to it dropping off with declining energies like the protons do, toward zero energy
Zero-energy Universe
The zero-energy universe hypothesis states that the total amount of energy in the universe is exactly zero. When the energy of the universe is considered from a pseudo-tensor point of view, zero values are obtained in the resulting calculations...
.
In the 1975s and 1977s Simpson discovered the fact that Beryllium-10
Beryllium-10
Beryllium-10 is a radioactive isotope of beryllium. It is formed mainly by cosmic ray spallation. Be-10 has a half-life of 1.36 × 106 years, and decays by beta decay to stable Boron-10 with a maximum energy of 556.2 keV....
nuclei
Atomic nucleus
The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. The...
are scarce in cosmic rays, and that that scarcity indicates that they have been around for about 2 x 107 years. This led him to conclude that cosmic rays pass freely between the gaseous disk
Disc (galaxy)
A disc is a component of disc galaxies, such as spiral galaxies, or lenticular galaxies.The galactic disc is the plane in which the spirals, bars and discs of disc galaxies exist. Galaxy discs tend to have more gas and dust, and younger stars than galactic bulges, or galactic haloes.The galactic...
and the extended magnetic halo portion of the galaxy
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
, where the ambient gas density is more like 10−2 atoms/cm3 or less.
In the 1980s Simpson Simpson and A. J. Tuzzolino developed the dust flux monitor instrument which involved a thin sheet of plastic which was polymerized in the presence of a strong electric field
Electric field
In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
perpendicular to the plane of the plastic, and then electrically polarized carrying a positive electric charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
on one of its surfaces and a negative charge on the other. The way it operated was such that a dust particle
Cosmic dust
Cosmic dust is a type of dust composed of particles in space which are a few molecules to 0.1 µm in size. Cosmic dust can be further distinguished by its astronomical location; for example: intergalactic dust, interstellar dust, interplanetary dust and circumplanetary dust .In our own Solar...
or heavy nucleus penetrating through the sheet first vaporizes in a small area releasing the charges, then the electrical signal indicates the location and size of the hole in the plastic which is then calibrated to give information on its speed and size. These calibrations took place from 1985 until 1989. Simpson's device was used on spacecraft Vega 1
Vega 1
Vega 1 is a Soviet space probe part of the Vega program. The spacecraft was a development of the earlier Venera craft...
and Vega 2
Vega 2
Vega 2 is a Soviet space probe part of the Vega program. The spacecraft was a development of the earlier Venera craft. They were designed by Babakin Space Center and constructed as 5VK by Lavochkin at Khimki...
to Halley's comet in 1986, and earned him the Gagarin Medal for Space Exploration that year for his contribution towards the success of the Vega mission, as his instruments had been the only ones from the United States to encounter the comet.
Accomplishments
John Alexander Simpson is known for inventions such as the gas flow a-particle proportional counter for measuring plutonium yields in the presence of high intensity fission products, and a neutron monitor. His obituary in The GuardianThe Guardian
The Guardian, formerly known as The Manchester Guardian , is a British national daily newspaper in the Berliner format...
noted that he was one of the most prolific inventors of scientific instruments for space exploration
Space exploration
Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....
. In 1958 his first created instrument was launched into space, and the last two were launched in 1999. One on board the Stardust
Stardust (spacecraft)
Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...
, met up with Comet Wild-2
81P/Wild
Comet 81P/Wild, also known as Wild 2 , is a comet named after Swiss astronomer Paul Wild, who discovered it in 1978 using a 40-cm Schmidt telescope at Zimmerwald....
, a frozen snowball one and a half miles in diameter in 2004.
In 1959 Simpson was elected to the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
, in 1968 he held the first Ryerson Chair and was made Distinguished Service Professor at his university, in 1974 was the first to be appointed to the Copton Chair, and in 1986 he became Emeritus
Emeritus
Emeritus is a post-positive adjective that is used to designate a retired professor, bishop, or other professional or as a title. The female equivalent emerita is also sometimes used.-History:...
. Simpson is the recipient of the 1986 Gagarin Medal for Space Exploration for his contribution towards the success of the Vega mission, which sent satellites to Halley's comet earlier that year. In 1991 he was awarded the Bruno Rossi Prize
Bruno Rossi Prize
The Bruno Rossi Prize is awarded annually by the High Energy Astrophysics division of the American Astronomical Society "for a significant contribution to High Energy Astrophysics, with particular emphasis on recent, original work". Named after astrophysicist Bruno Rossi, the prize is awarded with...
by the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
for his contributions towards high-energy astrophysics
High-energy astronomy
High energy astronomy is the study of astronomical objects that release EM radiation of highly energetic wavelengths. It includes X-ray astronomy, gamma-ray astronomy, and extreme UV astronomy, as well as studies of neutrinos and cosmic rays...
, and in 1993 was awarded the Arctowski Medal
Arctowski Medal
The Arctowski Medal is awarded by the U.S. National Academy of Sciences "for studies in solar physics and solar-terrestrial relationships." Named in honor of Henryk Arctowski, it was first awarded in 1969.- List of Arctowski Medal winners :...
of the National Academy of Sciences. In 1999 he was awarded the Leo Szilard Lectureship Award for his role in educating scientists, members of the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
and the public on the importance of civilian control
Civilian control of the military
Civilian control of the military is a doctrine in military and political science that places ultimate responsibility for a country's strategic decision-making in the hands of the civilian political leadership, rather than professional military officers. One author, paraphrasing Samuel P...
of nuclear policy
Nuclear energy policy
Nuclear energy policy is a national and international policy concerning some or all aspects of nuclear energy, such as mining for nuclear fuel, extraction and processing of nuclear fuel from the ore, generating electricity by nuclear power, enriching and storing spent nuclear fuel and nuclear fuel...
and his critical efforts in planning and execution of the International Geophysical Year
International Geophysical Year
The International Geophysical Year was an international scientific project that lasted from July 1, 1957, to December 31, 1958. It marked the end of a long period during the Cold War when scientific interchange between East and West was seriously interrupted...
. In 2000 he was also additionally awarded the William Bowie Medal
William Bowie Medal
The William Bowie Medal is awarded annually by the American Geophysical Union for 'outstanding contributions to fundamental geophysics and for unselfish cooperation in research"...
which is the highest award given by the American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...
, for his extensive explorations of the cosmic rays and other energetic particles that our planet is continually bombarded by. He is known as having been an outstanding professor, having throughout the course of his academic career supervised the research of 34 doctoral students, many who are now leaders in the space sciences. Simpson has also provided lectures to the public using funds in 1974 which came from his Compton Chair in an attempt to reach a larger audience with his research. In 1982 he also established and became the first chairman of the Universities Space Science Working Group located in Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
in order to represent the space science laboratories in their dealings with congress and NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...