Far out cosmology: related parts of universe from quanta (Introduction)

by David Turell @, Tuesday, October 29, 2019, 17:36 (1633 days ago) @ David Turell

A new approach to understanding the early universe:

https://www.quantamagazine.org/the-origin-of-time-bootstrapped-from-fundamental-symmetr...

“'We look at patterns in space today, and we infer a cosmological history in order to explain them.”

"One curious pattern cosmologists have known about for decades is that space is filled with correlated pairs of objects: pairs of hot spots seen in telescopes’ maps of the early universe; pairs of galaxies or of galaxy clusters or superclusters in the universe today; pairs found at all distances apart. You can see these “two-point correlations” by moving a ruler all over a map of the sky. When there’s an object at one end, cosmologists find that this ups the chance that an object also lies at the other end.

"The simplest explanation for the correlations traces them to pairs of quantum particles that fluctuated into existence as space exponentially expanded at the start of the Big Bang. Pairs of particles that arose early on subsequently moved the farthest apart, yielding pairs of objects far away from each other in the sky today. Particle pairs that arose later separated less and now form closer-together pairs of objects. Like fossils, the pairwise correlations seen throughout the sky encode the passage of time — in this case, the very beginning of time.

"Cosmologists believe that rare quantum fluctuations involving three, four or even more particles should also have occurred during the birth of the universe. These presumably would have yielded more complicated configurations of objects in the sky today: triangular arrangements of galaxies, along with quadrilaterals, pentagons and other shapes. Telescopes haven’t yet spotted these statistically subtle “higher-point” correlations, but finding them would help physicists better understand the first moments after the Big Bang.

"Yet theorists have found it challenging even to calculate what the signals would look like — until recently. In the past four years, a small group of researchers has approached the question in a new way. They have found that the form of the correlations follows directly from symmetries and other deep mathematical principles.

"The physicists employed a strategy known as the bootstrap, a term derived from the phrase “pick yourself up by your own bootstraps” (instead of pushing off of the ground). The approach infers the laws of nature by considering only the mathematical logic and self-consistency of the laws themselves, instead of building on empirical evidence. Using the bootstrap philosophy, the researchers derived and solved a concise mathematical equation that dictates the possible patterns of correlations in the sky that result from different primordial ingredients.

***

"There’s no “time” variable anywhere in the new bootstrapped equation. Yet it predicts cosmological triangles, rectangles and other shapes of all sizes that tell a sensible story of quantum particles arising and evolving at the beginning of time.

***

"In 1980, the cosmologist Alan Guth, pondering a number of cosmological features, posited that the Big Bang began with a sudden burst of exponential expansion, known as “cosmic inflation.” Two years later, many of the world’s leading cosmologists gathered in Cambridge, England, to iron out the details of the new theory. Over the course of the three-week Nuffield workshop, a group that included Guth, Stephen Hawking, and Martin Rees, the future Astronomer Royal, pieced together the effects of a brief inflationary period at the start of time. By the end of the workshop, several attendees had separately calculated that quantum jitter during cosmic inflation could indeed have happened at the right rate and evolved in the right way to yield the universe’s observed density variations.

***

"Recall that an inflating universe would have had almost, but not exactly, the geometry of de Sitter space. In perfect de Sitter space, nothing changes in time; the whole outwardly stretching geometry exists at once. The inflaton field weakly broke this temporal symmetry by slowly dropping in energy over time, initiating change. Baumann sees this as necessary for creating cosmology. “In cosmology by definition we want something that’s evolving in time,” he said. “In de Sitter space, there’s no evolution. It’s interesting that we live very close to that point.” He compared the primordial universe to a system like water or a magnet very near the critical point where it undergoes a phase transition. “We live in a very special place,” he said." (my bold)

Comment: I skipped much of the current research which is very still uncertain. Note that quantum mechanics are at the basis of this early universe research. It supports my statements that this universe is based on quantum particles. Our unusual status is noted in the bolded statement. All indications of design .


Complete thread:

 RSS Feed of thread

powered by my little forum