Another article update: Cosmic inflation theory is a well verified scientific theory. [
https://www.forbes.com/sites/starts...-well-has-cosmic-inflation-been-verified/amp/ ]
1st point.)
- "But superseding the Big Bang isn't easy at all. To do so, a new theory would have to do all three of the following:
- Reproduce all of the successes of the Big Bang, including the creation of an expanding, hot, dense, almost-perfectly uniform Universe.
- Provide a mechanism for explaining those three puzzles — the temperature uniformity, the lack of high-energy relics, and the flatness problem — that the Big Bang has no solution for.
- Finally, and perhaps most importantly it must make new, testable predictions that are different from the standard Big Bang that it's attempting to supersede.
The idea of inflation, and the hope that it could do so, began in late 1979, when Alan Guth wrote the idea down in his notebook.
What inflation specifically hypothesized is that the Big Bang wasn't the beginning, but rather was set up by a prior stage of the Universe. In this early state — dubbed an inflationary state by Guth — the dominant form of energy wasn't in matter or radiation, but was inherent to the fabric of space itself, and possessed a very large energy density.
This would cause the Universe to expand both rapidly and relentlessly, driving any pre-existing matter apart.
The Universe would be stretched so large it would be indistinguishable from flat. All the parts that an observer (like us) would be able to access would now have the same uniform properties everywhere, since they originated from a previously-connected state in the past. And since there would be a maximum temperature the Universe achieved when inflation ended, and the energy inherent to space transitioned into matter, antimatter, and radiation, we could avoid the production of leftover, high-energy relics.
All at once, all three of those puzzles that the Big Bang couldn't explain were solved. This was truly a watershed moment for cosmology, and immediately led to a deluge of scientists working to correct Guth's original model in order to reproduce all of the Big Bang's successes. Guth's idea was published in 1981, and by 1982, two independent teams — Andrei Linde and the duo of Paul Steinhardt and Andy Albrecht — had done it.
The key was to picture inflation as a slowly-rolling ball atop a hill.
At last, not only did we have a solution to all of the problems that the Big Bang couldn't resolve, but we could reproduce all of its successes. "
2nd point. )
- " In brief, the six most generic predictions were:
- There should be an upper-limit to the maximum temperature the Universe achieves post-inflation; it cannot approach the Planck scale of ~1019 GeV.
- Super-horizon fluctuations, or fluctuations on scales larger than light could have traversed since the Big Bang, should exist.
- The quantum fluctuations during inflation should produce the seeds of density fluctuations, and they should be 100% adiabatic and 0% isocurvature. (Where adiabatic and isocurvature are the two allowed classes.)
- These fluctuations should be almost perfectly scale-invariant, but should have slightly greater magnitudes on larger scales than smaller ones.
- The Universe should be nearly, but not quite, perfectly flat, with quantum effects producing curvature only at the 0.01% level or below.
- And the Universe should be filled with primordial gravitational waves, which should imprint on the cosmic microwave background as B-modes.
- It's now 2019, and the first four predictions have been observationally confirmed. The fifth has been tested down to the ~0.4% level and is consistent with inflation.
- Only the sixth point has not been tested at all, with a famous
POTENTIAL (its something up for debate in the scientific community.) false-positive detection appearing earlier this decade owing to the BICEP2 collaboration.
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The maximum temperature has been verified, by looking at the cosmic microwave background, to be no greater than about 1016 GeV.
- Super-horizon fluctuations have been seen from the polarization data provided by both WMAP and Planck, and are in perfect agreement with what inflation predicts.
- The latest data from structure formation indicates that these early, seed fluctuations are at least 98.7% adiabatic and no more than 1.3% isocurvature, consistent with inflation's predictions.
- But the best test — and what I'd call the most significant confirmation of inflation — has come from measuring the spectrum of the initial fluctuations.
As of today, s is approximately 0.965 or so, with an uncertainty of around 0.008. This means there's about a 4-to-5 sigma certainty that s is truly less than 1, a remarkable confirmation of inflatio
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3rd point.)
"
Inflation has literally met every threshold that science demands, with clever new tests becoming possible with improved observations and instrumentation. Whenever the data has been capable of being collected, inflation's predictions have been verified. Although it's perhaps more palatable and fashionable to be a contrarian, inflation is the leading theory for the best reason of all: it works. If we ever make a critical observation that disagrees with inflation, perhaps that will be the harbinger of an even more revolutionary theory of how it all began."
Summary:
Cosmic inflation theory has 5 out of 6 points verified with the 6th one being a controversial debate, but that 1 point that is in debate is not as important as the others, but with Ligo running its only a matter of time before they find actual primordial gravitional waves.