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Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 3:16 am
by Mercury
Tracing Gold's Cosmic Origin Story

Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

by Ken Croswell

Link: Proceedings of the National Academy of Sciences

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 10:24 am
by Ann
Mercury wrote: Thu Jan 21, 2021 3:16 am Tracing Gold's Cosmic Origin Story

Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

by Ken Croswell

Link: Proceedings of the National Academy of Sciences
Thank you for this interesting link, Mercury! :D

Ann

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 3:17 pm
by neufer
https://en.wikipedia.org/wiki/Thomas_Gold wrote:
<<Thomas Gold (also known as Tommy Gold), (May 22, 1920 – June 22, 2004) was an Austrian-born 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).

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. 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. 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. 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.

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. 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. 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.

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. 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 Nobel Prize winner Georg von Békésy, who did not believe the cochlea operated under a feedback system. 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.

Gold suggested a "garbage theory" for the origin of life which was an accidental panspermia; the theory says that life on Earth might have spread from a pile of waste products accidentally dumped on Earth long ago by extraterrestrials.

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.

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. 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.

Gold 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. 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. 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. 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 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". 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.

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 1.33 seconds. 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. Anthony Tucker of The Guardian remarked that Gold's discovery paved the way for Stephen Hawking's groundbreaking research into black holes.

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". This led to the dust being jokingly referred to as "Gold dust". 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. 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.
  • 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". 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.
In a 1992 paper "The Deep Hot Biosphere" in the Proceedings of the National Academy of Sciences, Gold first suggested that microbial life is widespread in the porosity of the crust of the Earth, down to depths of several kilometers, where rising temperatures finally set a limit. The subsurface life obtains its energy not from photosynthesis but from chemical sources in fluids migrating upwards through the crust. The mass of the deep biosphere may be comparable to that of the surface biosphere. Subsurface life may be widespread on other bodies in the solar system and throughout the universe, even on worlds unaccompanied by other stars. In his foreword to Gold's 1999 book The Deep Hot Biosphere, theoretical physicist Freeman Dyson stated, "Gold's theories are always original, always important, usually controversial – and usually right."

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.">>

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 3:51 pm
by bystander
neufer wrote: Thu Jan 21, 2021 3:17 pm
https://en.wikipedia.org/wiki/Thomas_Gold wrote:
<<Thomas Gold (also known as Tommy Gold), (May 22, 1920 – June 22, 2004) was an Austrian-born 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).
What is the relevance of this?

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 7:25 pm
by BDanielMayfield
Ann wrote: Thu Jan 21, 2021 10:24 am
Mercury wrote: Thu Jan 21, 2021 3:16 am Tracing Gold's Cosmic Origin Story

Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

by Ken Croswell

Link: Proceedings of the National Academy of Sciences
Thank you for this interesting link, Mercury! :D

Ann
I second Ann's thanks. Here's the paper and its abstract:
The Origin of Elements from Carbon to Uranium

Chiaki Kobayashi1, Amanda I. Karakas2,3, and Maria Lugaro2,4,5
Published 2020 September 15 • © 2020. The American Astronomical Society. All rights reserved.
The Astrophysical Journal, Volume 900, Number 2
Citation Chiaki Kobayashi et al 2020 ApJ 900 179

Abstract

To reach a deeper understanding of the origin of elements in the periodic table, we construct Galactic chemical evolution (GCE) models for all stable elements from C (A = 12) to U (A = 238) from first principles, i.e., using theoretical nucleosynthesis yields and event rates of all chemical enrichment sources. This enables us to predict the origin of elements as a function of time and environment. In the solar neighborhood, we find that stars with initial masses of M > 30M ⊙ can become failed supernovae if there is a significant contribution from hypernovae (HNe) at M ~ 20–50M ⊙. The contribution to GCE from super-asymptotic giant branch (AGB) stars (with M ~ 8–10M ⊙ at solar metallicity) is negligible, unless hybrid white dwarfs from low-mass super-AGB stars explode as so-called Type Iax supernovae, or high-mass super-AGB stars explode as electron-capture supernovae (ECSNe). Among neutron-capture elements, the observed abundances of the second (Ba) and third (Pb) peak elements are well reproduced with our updated yields of the slow neutron-capture process (s-process) from AGB stars. The first peak elements (Sr, Y, Zr) are sufficiently produced by ECSNe together with AGB stars. Neutron star mergers can produce rapid neutron-capture process (r-process) elements up to Th and U, but the timescales are too long to explain observations at low metallicities. The observed evolutionary trends, such as for Eu, can well be explained if ~3% of 25–50M ⊙ HNe are magneto-rotational supernovae producing r-process elements. Along with the solar neighborhood, we also predict the evolutionary trends in the halo, bulge, and thick disk for future comparison with Galactic archeology surveys.
All of their findings are of interest, but especially the part I highlighted in red. It is most logical that there must be another source for very old heavy elements in addition to NS pair collisions, since there wouldn't have been enough time for such systems to have fully evolved in the early universe.

The above paper is locked behind a paywall. :cry: It is one I would very much love to read and study in detail.

Bruce

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 11:21 pm
by neufer
https://en.wikipedia.org/wiki/America_(Cattelan) wrote:


<<America is a sculpture created in 2016 by the Italian artist Maurizio Cattelan. An example of satirical participatory art, it is a fully functioning toilet made of 18-karat solid gold. The Guggenheim museum linked the meaning of the sculpture to the career of Donald Trump, writing in September 2016 that "the aesthetics of this 'throne' recall nothing so much as the gilded excess of Trump's real-estate ventures and private residences".

Cattelan created the toilet in 2016 for the Solomon R. Guggenheim Museum in New York City. It was made in a foundry in Florence, cast in several parts that were welded together. Made to look like the museum's other Kohler toilets, it was installed in one of the museum's bathrooms for visitors to use. A special cleaning routine was put in place. The museum stated that the work was paid for with private funds.

According to the museum, over 100,000 people waited in line to use America, which was guarded by a security guard posted outside the bathroom. According to Cattelan, the work was made of 103 kilograms of gold, which in September 2019 was valued at more than four million dollars as bullion. As an artwork, it has been estimated as high as six million.

In September 2017, when the museum declined a White House request to loan its 1888 Van Gogh painting Landscape with Snow for President Donald Trump's private rooms, curator Nancy Spector offered to loan America instead. Any reply by the White House was not reported.

In September 2019, America was installed at Blenheim Palace in the United Kingdom, where it was available for use as part of an exhibition of Cattelan's works. It was placed in a water closet formerly used by Winston Churchill.

On 14 September, the sculpture was stolen. A representative of Blenheim had earlier commented that because America was plumbed in, and potential thieves would be aware of its use, security was not much of an issue. Because it had been connected to the building's water pipes, the theft caused structural damage and flooding to the World Heritage Site. Two men were arrested and released in connection with the incident.>>

Re: Tracing Gold's Cosmic Origin Story

Posted: Thu Jan 21, 2021 11:37 pm
by neufer
bystander wrote: Thu Jan 21, 2021 3:51 pm
neufer wrote: Thu Jan 21, 2021 3:17 pm
https://en.wikipedia.org/wiki/Thomas_Gold wrote:
<<Thomas Gold (also known as Tommy Gold), (May 22, 1920 – June 22, 2004) was an Austrian-born 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).
What is the relevance of this?
    • All that is Gold does not glitter,
      Not all those who wander are lost;
      The old that is strong does not wither,
      Deep roots are not reached by the frost.
      From the ashes a fire shall be woken,
      A light from the shadows shall spring;
      Renewed shall be blade that was broken,
      The crownless again shall be king.
    — J.R.R. Tolkien, The Riddle of Strider,
    The Lord of the Rings: The Fellowship of the Ring

Re: Tracing Gold's Cosmic Origin Story

Posted: Wed Jan 27, 2021 5:11 pm
by Mercury
This story is now on the radio: The John Batchelor Show: The Origin of All the Gold in the Universe

Re: Tracing Gold's Cosmic Origin Story

Posted: Tue Apr 13, 2021 4:25 am
by Forrest White
One merger of neutron stars can create gold in the volume of 20 masses of our Moon, which means that even if there may be thousands of times more supernovae and planetary nebulae than mergers of neutron stars, the latter is the main source of elements with the highest atomic weight in the periodic table, namely, gold, platinum, tungsten, as well as radioactive elements such as thorium and uranium.

Re: Tracing Gold's Cosmic Origin Story

Posted: Fri May 14, 2021 10:40 pm
by Mercury
A Study of Earth's Crust Hints That Supernovae Aren't Gold Mines

by Emily Conover

Link: Science News