Thomas Gold^[3] (May 22, 1920 – June 22, 2004^[4]) was an Austrian-born American astrophysicist, a professor of astronomy at Cornell University, a member of the U.S. National Academy of Sciences, and a Fellow of the Royal Society (London).^[4] Gold was one of three young Cambridge scientists who in 1948 proposed the now mostly abandoned "steady state" hypothesis of the universe. Gold's work crossed boundaries of academic and scientific disciplines, into biophysics, astronomy, aerospace engineering, and geophysics.

Gold was born on May 22, 1920, in Vienna, Austria, to Max Gold, a wealthy Jewish industrialist (pre-war) who ran one of Austria's largest mining and metal fabrication companies, and German former actress Josefine Martin. Following the economic downfall of the European mining industry in the late 1920s, Max Gold moved his family to Berlin, where he had taken a job as director of a metal trading company.^[5] Following the start of Nazi leader Adolf Hitler's anti-Jewish campaigns in 1933, Gold and his family left Germany because of his father's heritage. The family travelled through Europe for the next few years. Gold attended boarding school at the Lyceum Alpinum Zuoz in Zuoz, Switzerland, where he quickly proved to be a clever, competitive and physically and mentally aggressive individual.^[6] Gold finished his schooling at Zuoz in 1938, and fled with his family to England after the German invasion of Austria in early 1938. Gold entered Trinity College, Cambridge in 1939 and began studying mechanical sciences.^[7] In May 1940, just as Hitler was commencing his advance in Belgium and France, Gold was sent into internment as an enemy alien by the British government. It was on the first night of internment, at an army barracks in Bury St Edmunds, that he met his future collaborator and close friend, Hermann Bondi.^[8][9]

Gold spent most of his nearly 15 months of internment in a camp in Canada, after which he returned to England and reentered Cambridge University, where he abandoned his study of mechanical sciences for physics.^[8] After graduating with a pass (Ordinary) degree in June 1942, Gold worked briefly as an agricultural labourer and lumberjack in northern England before joining Bondi and Fred Hoyle on naval research into radar ground clutter near Dunsfold, Surrey. The three men would spend their off-duty hours in "intense and wide-ranging scientific discussion" on topics such as cosmology, mathematics and astrophysics.^[10] Within months, Gold was placed in charge of constructing new radar systems. Gold determined how landing craft could use radar to navigate to the appropriate landing spot on D-Day and also discovered that the German navy had fitted snorkels to its U-boats, making them operable underwater while still taking in air from above the surface.^[5]

Immediately after the war, Hoyle and Bondi returned to Cambridge, while Gold stayed with naval research until 1947. He then began working at Cambridge's Cavendish Laboratory to help construct the world's largest magnetron, a device invented by two British scientists in 1940 that generated intense microwaves for radar. Soon after, Gold joined R. J. Pumphrey, a zoologist at the Cambridge Zoology Laboratory who had served as the deputy head of radar naval research during the war, to study the effect of resonance on the human ear. He found that the degree of resonance observed in the cochlea was not in accordance with the level of damping that would be expected from the viscosity of the watery liquid that fills the inner ear. In 1948, Gold hypothesized that the ear operates by "regeneration", in that electromechanical action occurs when electrical energy is used to counteract the effects of damping.^[11] Although Gold won a prize fellowship from Trinity College for his thesis on the regeneration and obtained a junior lectureship at the Cavendish Laboratory, his theory was widely ignored by ear specialists and physiologists, such as future (1961) Nobel Prize winner Georg von Békésy, who did not believe the cochlea operated under a feedback system.^[12] In the 1970s, researchers discovered that Gold's hypothesis had been correct – the ear contained microscopic hair cells that operated on a feedback mechanism to generate resonance.^[9][11]

In 1951, at a meeting of the Royal Astronomical Society, Gold proposed that the source of recent radio signals detected from space was outside the Milky Way galaxy, much to the derision of radio astronomer Martin Ryle and several mathematical cosmologists. However, a year later, a distant source was identified and Gold announced at an International Astronomical Union meeting in Rome that his theory had been proven. Ryle would later take Gold's argument as proof of extragalactic evolution, claiming that it invalidated the steady-state theory.^[22]

Gold left Cambridge in 1952 to become the chief assistant to Astronomer Royal Harold Spencer Jones at the Royal Greenwich Observatory in Herstmonceux, Sussex, England. While there, Gold attracted some controversy by suggesting that the interaction between charged particles from the Sun with the Earth's magnetic field in creating magnetic storms in the upper atmosphere was an example of a collisionless shock wave.^[23] The theory was widely disputed, until American scientists in 1957 discovered that Gold's theory held up to mathematical scrutiny by conducting a simulation using a shock tube.^[9]

Gold resigned from the Royal Observatory following Spencer-Jones's retirement and moved to the United States in 1956, where he served as Professor of Astronomy (1957–1958) and Robert Wheeler Wilson Professor of Applied Astronomy (1958–1959) at Harvard University.^[19] In early 1959, he accepted an appointment at Cornell University, which had offered him the opportunity to set up an interdisciplinary unit for radiophysics and space research, and take charge of the Department of Astronomy.^[24] At the time, there was only one other faculty member in the department. Gold would serve as director of the Center for Radiophysics and Space Research until 1981, establishing Cornell as a leading hub of scientific research. During his tenure, Gold hired famed astronomers Carl Sagan and Frank Drake, helped establish the world's largest radio telescope at the Arecibo Observatory in Puerto Rico and the Cornell-Sydney University Astronomy Center with Harry Messel. In addition, Gold served as Assistant Vice President for Research from 1969–1971 and the John L. Wetherill Professor of Astronomy from 1971 until his retirement in 1986.^[25][26][27]

In 1959, Gold expanded on his previous prediction of a collisionless shock wave, arguing that solar flares would eject material into magnetic clouds to produce a shock front that would result in geomagnetic storms. He also coined the term "magnetosphere" in his paper "Motions in the Magnetosphere of the Earth" to describe "the region above the ionosphere in which the magnetic field of the Earth has a dominant control over the motions of gas and fast charged particles ... [which was] known to extend out to a distance of the order of 10 Earth radii".^[28] In 1960, Gold collaborated again with Fred Hoyle to show that magnetic energy fueled solar flares and that flares were triggered when opposite magnetic loops interact and release their stored energy.^[29][30]

In 1968, a Cambridge radio astronomy postgraduate student Jocelyn Bell Burnell and her doctoral adviser Antony Hewish discovered a pulsing radio source with a period of 1.337 seconds.^[31] The source – which was termed "pulsar" – emitted beams of electromagnetic radiation at a very short and consistent interval. Gold proposed that these objects were rapidly rotating neutron stars. Gold argued that due to their strong magnetic fields and high rotational speed, pulsars would emit radiation similar to a rotating beacon. Gold's conclusion was initially not well received by the scientific community; in fact, he was refused permission to present his theory at the first international conference on pulsars. However, Gold's theory became widely accepted following the discovery of a pulsar in the Crab Nebula using the Arecibo radio telescope, opening the door for future advancements in solid-state physics and astronomy.^[32] Anthony Tucker of The Guardian remarked that Gold's discovery paved the way for Stephen Hawking's groundbreaking research into black holes.^[10]

From the 1950s, Gold served as a consultant to NASA and held positions on several national space committees, including the President's Science Advisory Committee, as the United States tried to develop its space program. At the time, scientists were engaged in a heated debate over the physical properties of the Moon's surface. In 1955, he predicted that the Moon was covered by a layer of fine rock powder stemming from "the ceaseless bombardment of its surface by Solar System debris".^[24] This led to the dust being jokingly referred to as "Gold dust"^[33] or "Gold's dust".^[34] Gold initially suggested that astronauts would sink into the dust, but upon later analysis of impact craters and electrostatic fields, he determined that the astronauts' boots would sink only three centimeters into the Moon's surface. In any case, NASA sent unmanned Surveyors to analyze the conditions on the surface of the Moon. Gold was ridiculed by fellow scientists, not only for his hypothesis, but for the approach he took in communicating NASA's concerns to the American public; in particular, some experts were infuriated with his usage of the term "Moon dust" in reference to lunar regolith.^[35] When the Apollo 11 crew landed on the Moon in 1969 and brought back the first samples of lunar rocks, researchers found that lunar soil was in fact powdery. Gold said the findings were consistent with his hypothesis, noting that "in one area as they walked along, they sank in between five and eight inches". However, Gold received little credit for his correct prediction, and was even criticized for his original prediction of a deep layer of lunar dust.^[24] Gold had also contributed to the Apollo program by designing the Apollo Lunar Surface Closeup Camera (ALSCC) (a kind of stereo camera) used on the Apollo 11, 12, and 14 missions.^[24][36]

In the 1970s and 1980s, Gold was a vocal critic of NASA's Space Shuttle program, deriding claims that the agency could fly 50 missions a year or that it could have low budget costs. NASA officials warned Gold that if he testified his concerns before Congress, his research proposals would lose their support from NASA. Gold ignored the warning and testified before a Congressional committee headed by Senator Walter Mondale. In a letter to NASA administrator James C. Fletcher, George Low wrote that "Gold should realize that being funded by the Government and NASA is a privilege, and that it would make little sense for us to fund him as long as his views are what they are now".^[37] Gold recalled the aftermath of his testimony in a 1983 interview with astronomy historian David H. DeVorkin:

I had a very hard time with NASA, year after year. I got some more money, but eventually it fizzled out, after three years or so after this event. My applications, which previously each year had always gone through very smoothly, were turned down. I would then have to go to Washington, discuss it with them. and I then would get a certain fraction of it resurrected. For several years running this happened, and then eventually it fizzled permanently, and I've not tried to get any money out of NASA since.
...
I was certainly regarded as persona non grata with NASA after that. I had a very hard time. Shortly after that Noel Hinners became the Space Science administrator, and he used to joke about it and say, "Oh. Tommy's got to come to his annual pilgrimage to Washington," and regarded it as very funny, but then he'd always give me some money. But always clearly as a persona non grata.^[38]

Gold first became interested in the origins of petroleum in the 1950s, postulating a theory on the abiogenic formation of fossil fuels. Gold engaged in thorough discussion on the matter with Fred Hoyle, who even included a chapter on "Gold's Pore Theory" in his 1955 book Frontiers in Astronomy.^[26] In the late 1970s, just as the United States faced another major energy crisis, Gold resurrected his work on petroleum. In 1977, a research submarine near the Galapagos Islands discovered a number of thriving ecosystems down on the ocean floor, living alongside hydrothermal vents. Later expeditions found that these vents were host to a number of organisms, including giant tube worms and albino crabs, that survived off heat-loving chemosynthetic microbes. The discovery of life in this adverse environment led Gold to reconsider the established interpretation of biogenic petroleum formation. Gold believed that "biology is just a branch of thermodynamics" and that the history of life is just "a gradual systematic development toward more efficient ways of degrading energy".^[39]

He began his investigation by studying how earthquakes facilitated the migration of methane gas from the deep Earth to the surface.^[40] He speculated that a large enough earthquake would fracture the ground, thus opening up an "escape route" for gas. Gold believed that this would explain the number of unusual phenomena associated with earthquakes, such as fires, flares, earthquake lights and gas emissions. With his colleague Steven Soter, Gold constructed a map of the world depicting major oil-producing regions and areas with historical seismic activity. Several oil-rich regions, such as Alaska, Texas, the Caribbean, Mexico, Venezuela, the Persian Gulf, the Urals, Siberia, and Southeast Asia, were found to be lying on major earthquake belts. Gold and Soter suggested that these belts may explain the upward migration of gases through the ground, and subsequently, the production of oil and gas fields.^[40][41]

Gold theorized that since petroleum and its component hydrocarbons were present across the entire universe, there was no reason to believe "that on Earth they must be biological in origin".^[39] Gold proposed that fuels were trapped inside the core of the Earth in randomized molecular form nearly 4.5 billion years ago. Over time, the extreme heat of the core "sweated" the rocks that contained these molecules, pushing them up through the porous layers of the Earth. As they move up toward the surface, the hydrocarbons fueled the development of large microbial colonies, which served as the basis for life on Earth. The migrating fossil fuels collect biological remnants before becoming trapped in deep underground reservoirs.^[39] Soon after Gold started publishing his theories, researchers discovered a number of ecosystems functioning under "conditions of heat and pressure once thought impossible to sustain life". In addition, Gold discovered that the location of major oil-producing regions in the Middle East and southeast Asia was defined by large scale patterns in surface geology and topography, such as deep fault lines. He also pointed to the abundance of helium in oil and gas reserves as evidence for "a deep source of the hydrocarbons".^[40] Moreover, a few oil reserves thought to have been exhausted were suddenly generating vast amounts of crude oil.^[42] From this, Gold proposed that the Earth may possess a virtually endless supply – suggesting as much as "at least 500 million years' worth of gas" – of fossil fuels.^[43][44]

Gold was accused of plagiarizing the abiogenic theory from Soviet geologists who first published it in the 1950s, but the accusations were refuted.^[45][46] After first publishing his views on abiogenic petroleum in 1979, Gold began finding the papers on the subject by Soviet geologists and had them translated. He was both disappointed (that his ideas were not original) and delighted (because such independent formulation of these ideas added weight to the hypothesis). He always credited the Soviet work once he knew about it.^[4] His 1987 book Power from the Earth devoted five pages to describing important Russian contributions to the field, including those by Mendeleev, Sokoloff, Vernadsky, Kudryavtsev, Beskrovny, Porfir'ev, Kravtsov, Kropotkin, Valyaev, Voronoy, and Chekaliuk.^[45]

Throughout his academic career, Gold received a number of honors and distinctions. He was a Fellow of the Royal Astronomical Society (1948), the Royal Society (1964),^[4] the American Geophysical Union (1962), the American Academy of Arts and Sciences (1974), and the American Astronautical Society, a member of the American Philosophical Society (1972), the United States National Academy of Sciences (1974) and the International Academy of Astronautics, and an Honorary Fellow of Trinity College, Cambridge (1986).^[65] In addition, he served as President of the New York Astronomical Society from 1981 to 1986.^[25] Gold won the John Frederick Lewis Prize from the American Philosophical Society in 1972 for his paper "The Nature of the Lunar Surface: Recent Evidence"^[66] and the Humboldt Prize from the Alexander von Humboldt Foundation in 1979.^[65] In 1985, Gold won the prestigious Gold Medal of the Royal Astronomical Society, an award whose recipients include Fred Hoyle, Hermann Bondi, Martin Ryle, Edwin Hubble, James Van Allen, Fritz Zwicky, Hannes Alfvén and Albert Einstein.^[67] Gold did not earn a doctorate, but received an honorary Doctor of Science degree from Cambridge University in 1969.^[68]

Astrophysicists Geoffrey and Margaret Burbidge remarked that Gold "was one of the outstanding physicists of his time" and that his "versatility was unmatched".^[69] In his foreword to Gold's book The Deep Hot Biosphere, theoretical physicist Freeman Dyson stated, "Gold's theories are always original, always important, usually controversial – and usually right."^[61]

In the journal Nature, Hermann Bondi wrote "Tommy Gold will long be remembered as a singular scientist who stepped into any field where he thought an option was being overlooked. He was also unusual in working mainly theoretically, but using little mathematics, relying instead on his profound intuitive understanding of physics."^[24] Stanley F. Dermott wrote "Tommy was a handsome, charming and generous man and a loyal colleague who formed many long-lasting friendships. A witty and articulate speaker, he was regarded by some as a scientific maverick who delighted in controversy. In reality, he was an iconoclast whose strength was in penetrating analysis of the assumptions on which some of our most important theories are based."^[70] Anthony Tucker of The Guardian said, "Throughout his life he would dive into new territory to open up problems unseen by others – in biophysics, astrophysics, space engineering, or geophysics. Controversy followed him everywhere. Possessing profound scientific intuition and open-minded rigour, he usually ended up challenging the cherished assumptions of others and, to the discomfiture of the scientific establishment, often found them wanting. His stature and influence were international."^[10] Harvard biologist Stephen Jay Gould labeled Gold as "one of America's most iconoclastic scientists".^[39] Gold has been derided by geologists, such as Harmon Craig and John Hunt,^[39] who are strongly opposed to Gold's abiogenic petroleum theory. Others had even started campaigns to prevent Gold from publishing his findings.^[39]

Gold married his first wife, Merle Eleanor Tuberg, an American astrophysicist who had worked with Subrahmanyan Chandrasekhar, in Cambridge in 1947. He had three daughters with her – Linda, Lucy, and Tanya. After divorcing her, Gold married Carvel Lee Beyer in 1972.^[5][9][10] With her, he had a daughter Lauren.

Thomas Gold died at the age of 84 from complications due to heart disease, at Cayuga Medical Center in Ithaca, New York. He was buried in the Pleasant Grove Cemetery in Ithaca.^[25] He was survived by his wife, four daughters, and six grandchildren.^[34]

• Pumphrey, R. J.; Gold, T. (1947), "Transient reception and the degree of resonance of the human ear", Nature, 160 (4056): 124–125, Bibcode:1947Natur.160..124P, doi:10.1038/160124b0, ISSN 0028-0836, PMID 20344383, S2CID 4095013.
• Pumphrey, R. J.; Gold, T. (1948), "Hearing. I. The Cochlea as a Frequency Analyzer", Proceedings of the Royal Society B, 135 (881): 462–491, Bibcode:1948RSPSB.135..462G, doi:10.1098/rspb.1948.0024, ISSN 0080-4649, JSTOR 82558.
• Gold, T. (1948), "Hearing. II. The Physical Basis of the Action of the Cochlea", Proceedings of the Royal Society B, 135 (881): 492–498, Bibcode:1948RSPSB.135..492G, doi:10.1098/rspb.1948.0025, ISSN 0080-4649, JSTOR 82559.
• Bondi, H.; Gold, T. (1948), "The Steady-State Theory of the Expanding Universe", Monthly Notices of the Royal Astronomical Society, 108 (3): 252–270, Bibcode:1948MNRAS.108..252B, doi:10.1093/mnras/108.3.252, ISSN 1365-2966.
• Gold, T. (1955), "Instability of the Earth's Axis of Rotation", Nature, 175 (4456): 526–529, Bibcode:1955Natur.175..526G, doi:10.1038/175526a0, ISSN 0028-0836, S2CID 5235427.
• Gold, T. (1959), "Motions in the Magnetosphere of the Earth", Journal of Geophysical Research, 64 (9): 1219–1224, Bibcode:1959JGR....64.1219G, CiteSeerX 10.1.1.431.8096, doi:10.1029/JZ064i009p01219, ISSN 0148-0227.
• Gold, T.; Hoyle, F. (1960), "On the origin of solar flares", Monthly Notices of the Royal Astronomical Society, 120 (2): 89–105, Bibcode:1960MNRAS.120...89G, doi:10.1093/mnras/120.2.89, ISSN 1365-2966.
• Gold, T. (1962), "The Arrow of Time", American Journal of Physics, 30 (6): 403–410, Bibcode:1962AmJPh..30..403G, doi:10.1119/1.1942052, ISSN 0002-9505.
• Gold, T. (1969), "Rotating neutron stars and the nature of pulsars", Nature, 221 (5175): 25–27, Bibcode:1969Natur.221...25G, doi:10.1038/221025a0, ISSN 0028-0836, S2CID 4181490.
• Gold, T. (1971), "The Nature of the Lunar Surface: Recent Evidence", Proc. Am. Philos. Soc., 115 (2): 74–82, ISSN 0003-049X, JSTOR 985848.
• Gold, T. (1979), "Terrestrial sources of carbon and earthquake outgassing", Journal of Petroleum Geology, 1 (3): 3–19, Bibcode:1979JPetG...1....3G, doi:10.1111/j.1747-5457.1979.tb00616.x, ISSN 0141-6421.
• Gold, T.; Soter, S. (1980), "The deep earth gas hypothesis", Scientific American, 242 (6): 155–161, Bibcode:1980SciAm.242f.154G, doi:10.1038/scientificamerican0680-154, ISSN 0036-8733.
• Gold, T.; Soter, S. (1982), "Abiogenic methane and the origin of petroleum", Energy Exploration & Exploitation, 1 (2): 89–104, doi:10.1177/014459878200100202, ISSN 0144-5987, S2CID 135282142.
• Gold, T. (1987), Power From the Earth: Deep Earth Gas - Energy for the Future, London: Dent & Sons, ISBN 978-0-460-04462-2.
• Gold, T. (1992), "The deep, hot biosphere", Proceedings of the National Academy of Sciences, 89 (13): 6045–6049, Bibcode:1992PNAS...89.6045G, doi:10.1073/pnas.89.13.6045, ISSN 1091-6490, PMC 49434, PMID 1631089.
• Gold, Thomas (1999), The Deep Hot Biosphere, New York: Copernicus (Springer Verlag), ISBN 0-387-98546-8.
• Gold, T. (2012), Taking the Back Off the Watch: A Personal Memoir, New York: Springer, ISBN 9783642275876.

• Abiogenic petroleum origin
• Gold universe
• Astronomy
• Astrophysics
• Petroleum
• Theoretical astrophysics