New Inflation Data: Trouble for Cosmology?

In the 7 years since BICEP2 first claimed detection of primordial B-mode polarization, cosmologists have continued to whittle away at the allowed parameter space within which inflationary gravitational waves could have been produced. These observations have added powerfully constraining data

Recently, a team of colleagues completed an analysis of all the data from the South Pole experiments BICEP2, Keck Array, and BICEP3 through 2018, and correlated the results with results from the CMB space missions Planck and WMAP. Data from the latter two satellites are primarily used to remove the foreground contamination from interstellar dust, which was the culprit behind BICEP2’s original claim in 2014

The BICEP team’s new results improve the previous best constraints on B-modes by a factor of two, and powerfully constrain or eliminate many of the kinds of models of inflation previously believed to most accurately describe the earliest moments of the cosmos.

Almost all simple models of inflation — those first proposed by Alan Guth and others — are now thoroughly ruled out. Does that spell the end for inflation? Where are cosmologists turning next?

DOI: 10.1103/PhysRevLett.127.151301

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[DrBrianKeating]

Do you believe inflation will be confirmed in this decade?

[thomasgilson]

I saw this title and thought Brian had become an economist! Whew, what a relief (package).

[dewiz]

In 100 years people will be looking at this “stuff” the way WE currently look at Ptolemayan Orbital Mechanics. To me, inflation is just a huge fudge factor. A good starting point in the investigations would be determining why the values of various copies of the Standard Kilogram are drifting. . .

[gregmonks]

Inflation has been resoundingly debunked. The 1st problem with the BB theory is that none of its predictions turned out to be true. The big 4 that the model got dead wrong are helium, hydrogen, lithium, and deuterium. The red shift has been debunked on several fronts, but its main problem was that it was never backed up by direct observation. Inference is worthless if you haven't done your due diligence and backed it up with direct observation.

[wulphstein]

What common sense says that inflationary epoch means multiverse?

[TimBee]

Inflation ignited the big bang? How would that happen?

[lspringerjones]

Not a cosmologist. Where's Sabine when I need her? :-)

[PearlmanYeC]

Comparing SCM-LCDM vs the competing SPIRAL cosmological model that the findings appear to favor.
Assume CMB attest to a hyper cosmic expansion 'inflation' epoch relatively early in the history of the universe.
Assume a start from the same small area/volume, but NOT the same density.
If SPIRAL the universe is 5% as dense NO dark energy and matter predicted/required, so 99% + just normal matter.
If SPIRAL the estimated radius of the entire universe (which we find approximates the visible universe) is 2B LY.
vs SCM 46.5B LY radius the visible universe alone, and the entire universe at least 200 times that.
We see the near black-body CMB based on the current, not past, size/volume of the entire universe.
the start area density parsimony advantage if SPIRAL vs SCM-LCDM is volume of a sphere 46.5B LY / 2BLY (20) x (200) :1

[ttmallard]

Regard Sternglass-Einstein work late 50's finding a named meson by theory in the lab.

Their dynamic property equations were built on electron_positron pairs, two counter-rotating pairs create the meson.

A single pair has no external charge, a portion of dark_matter ? Regardless, when they decay the energy_of_annihilation is released, a portion of inflation ?

What process can create such exact opposites in nature other than a fluid ?

In first condensates after a BigBang, then, a neutrino hitting a viscous charge fluid entity can do this and be modelled.

Have fun in 2022 🍺

[samuelbrooks]

I understand the importance of inflation but I wish we would slow down for a second (pun intended).

Many physicists have presented their arguments about what happened during the first second of the universe.

TBH I struggle with the question itself. Unless I am mistaken I believe that one second after existence began a second would not have actually existed. My concern is mathematical rather than philosophical.

One second after the universe began there were no clocks, earths, suns, or cesium atoms (as far as we know). How could any event or observation from the first second be reconciled against an actual second? Near as I can tell we couldn’t use our constant (c), as research suggests the universe was opaque at this time.

My sense is that our existing mathematical frameworks are insufficient to properly quantize the Big Bang or black holes etc. At some point we need to progress forward from our geocentric notions of time.

[louisgiokas]

When you talk about the evolution of the decorators, and iPhones, you really either show your ignorance of engineering, or are trying to say something I don't understand.
As for experimental design, or product design, there is never a perfect time, from a scientific or engineering perspective, to introduce a new product or experiment. You must make do with what you have and then move forward. Otherwise, you would wait forever. Even a flawed, or incomplete, experiment will give information that will be useful going forward.

[dirtbird]

Curious, what would be the threshold or prerequisite that would initiate inflation ?

[damoneaves]

Great video. Thank you. Weird and awkward and fascinating!

[chriszachtian]

Your video production really improves!

[robertbutsch]

The thing that interests me, especially in the context of Popper’s famous dictum that you quote, is whether we’re on the cusp of a paradigm shift when it comes to the scientific method. Eternal Inflation, String Theory, the Multiverse, etc. all are theories that, at this point, look like they may in principle not be falsifiable. Are we getting to the point where we may have to consider things to be “scientific” or “accepted scientific fact” which we can never actually collect any solid objective evidence for? If so, my prediction is that Inflation will never be confirmed, but unless some way can be found to falsify it it still will be accepted as orthodox Cosmology.

[gregmonks]

Theoretical physics is philosophy, not science.

[Seekthetruth]

Will we ever find out where our universe comes from?

[KaliFissure]

A steady state is just so much cleaner. No theatrical plot is needed. The universe exists. All parts are at different points in evolution. Evolution is neutron decay into hydrogen into all the usual stuff until event horizon. Some paths are short some are long.
Consider each path one of the possible solutions to Riemann paradox.

[picksalot]

I have a few questions regarding Gravitational Waves moving through Space.

It seem like all waves moving through a material cause the material to distort such that there is a difference in density of the material at different locations along the wave (compression and rarefaction). Space seems to act like a material, as it is "curved/warped" by gravity, etc. Does this mean that as a Gravitational Wave moves through Space the density of Space is different along different locations of the Gravitational Wave? If that is so, does light travel at different speeds through those areas of different densities of Space?

Are there any materials that don't change in density "at all" as a wave moves through them?
Thanks in advance.

[madderhat]

Will you ever do a video on life at an Antarctica base. From the "human in the great empty polar expanse" feeling rather than the work you were there for.