Armed with Albert Einstein’s powerful new equations and no data, physicists in the 1920s invented all sorts of universes. For many scientists throughout recent history, the suspicion is that something, somewhere doesn’t add up. Asteroids are rich with the metals used in clean energy technologies. As demand soars, advocates argue that mining them in space might be better than mining them on Earth. A five-year “adversarial collaboration” of scientists led to a stagy showdown in front of an audience. Sarah Scoles is the author of Making Contact and They Are Already Here. Scolnic calls this moment “the era of tension cosmology.” Others just call it a crisis.
The first public use of the modern term for Lemaître’s idea actually came from a critic — English astronomer Fred Hoyle. On March 28, 1949, Hoyle coined the phrase during a defense of his preferred theory of an eternal universe that created matter to cancel out the dilution of expansion. Hoyle said the notion that “all matter of the universe was created in one big bang at a particular time in the remote past,” was irrational. In later interviews, Hoyle denied intentionally inventing a slanderous name, but the moniker stuck, much to the frustration of some.
Einstein’s bold move attracted attention, and soon other physicists were proposing their own cosmic models, all of them playing with the right-hand side of the equation. Another method uses the “cosmic distance ladder.” Astronomers figure out how far away objects are, and how fast they’re moving even farther away, starting from here and building outward. They calculate the distances to nearby stars, and from them to more distant stars in other galaxies, and from them to supernovae in still-farther-off galaxies. They measure their movement away from us, providing another estimate of the Hubble constant. Stephen Hawkingpredicted thatblack holes slowly evaporateby releasing their particles into the universe.
This fact is now known as Hubble’s law, though the numerical factor Hubble found relating recessional velocity and distance was off by a factor of ten, due to not knowing about the types of Cepheid variables. Gravity, the force that revealed all that dark matter, has proved to be nearly as baffling. A pivotal moment came in 1915 when Albert Einstein published his general theory of relativity, which transcended Isaac Newton’s mechanics and revealed that gravity is actually the deformation of the fabric of space and time. Even after it was shown to be correct by observations of a 1919 solar eclipse, many dismissed the theory as an interesting quirk—after all, Newton’s laws were still good enough for calculating most things. “The discoveries, while very important, did not, however, affect anything on this earth,” astronomer W.J.S. Lockyer told the New York Times after the eclipse. For almost half a century after it was proposed, general relativity was sidelined from the mainstream of physics.
In 2022, the James Webb Space Telescope brought us new views of the cosmos
These will help cosmologists settle the question of when and how structure formed in the universe. The Lyman-alpha forest, which allows cosmologists to measure the distribution of neutral atomic hydrogen gas in the early universe, by measuring the absorption of light from distant quasars by the gas. And distant galaxies that lie behind a massive galaxy cluster called Abell 2744 are also more numerous and distant than expected, astrophysicist Guido Roberts-Borsani of UCLA said at the meeting. BALTIMORE — The James Webb Space Telescope is living up to its promise as a wayback machine. The spectacularly sensitive observatory is finding and confirming galaxies more distant, and therefore existing earlier in the universe’s history, than any seen before. Much of a cosmologist’s work involves recording data and research results for future analysis.
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Webb is showing us the earliest moment in our universe’s history, fossilized in light. Its image, part of which is seen here, shows nearly 94,000 galaxies. For centuries, we could record only what was visible to the human eye, first with illustrations, then with photographs. Cave drawings, monuments and folklore that have survived for thousands of years show us that early humans had a sophisticated understanding of the cosmos. The light from this galaxy traveled through space for 40 million years before reaching Webb’s mirrors, which means we’re seeing it as it looked 40 million years ago. Other layers of dust are illuminated in the infrared, giving scientists a more three-dimensional portrait of events like the deaths of stars, known as supernovas.
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Three required conditions for baryogenesis were derived by Andrei Sakharov in 1967, and requires a violation of the particle physics symmetry, called CP-symmetry, between matter and antimatter. However, particle accelerators measure too small a violation of CP-symmetry to account for the baryon asymmetry. Cosmologists and particle physicists look for additional violations of the CP-symmetry in the early universe that might account for the baryon asymmetry.
A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood. Study of supernovae billions of lightyears away as seen in the picture below has shown that the expansion of our Universe is accelerating, contrary to the past belief. As Universe expands, we expected that everything thins out, and the expansion slows down. If it is accelerating, however, there must be a form of energy that does not thin out even as Universe expands. This form of energy then must have negative pressure, so that it gains energy as the expansion of Universe tries to pull it apart.
Important parts of many cosmologists’ responsibilities include speaking with others regarding their findings, writing grant applications for research funding and writing academic articles to publish their research results. As a result, both verbal and written communication skills can aid a cosmologist in their work. There is a “primordial universe” Wuji , and Hongjun Laozu, water or qi. It transformed into Taiji then multiplied into everything known as the Wuxing. The Pangu legend tells a formless chaos coalesced into a cosmic egg. Pangu emerged and separated Yin from Yang with a swing of his giant axe, creating the Earth and the Sky .
I will not hold my breath for the discovery of aliens, but I think the search for extraterrestrial intelligence is a worthwhile gamble. Success in the search would carry the momentous message that concepts of logic and physics are not limited to the hardware in human skulls.
