Contrabang! #28 Cosmic Tension

Astronomically Rare ‘Double Lens’ Yields Best Single System Measurement Of Cosmic Expansion (link)

The background is that, while mainstream scientists mostly agree that the universe is expanding, they get different numbers when they use different approaches. One approach yields an expansion number of 67; the other 74.

Here, Ethan reports on a new method for determining the expansion rate, which has to do with measurement of distant gravitationally lensed system. (I confess I don't understand the mechanics of this approach, but it doesn't matter.)

The resultant expansion rate matches the other distance ladder values: 74.2 km/s/Mpc, with a 3.9% uncertainty.

It would appear that the system under review agrees with one of the previous approaches. So it's right? Not sure. Previously, Ethan stated that the conflicting numbers were not necessarily contradictory, and likely hint at some as-yet undiscovered "new physics." He ends the piece ambiguously.

With novel methods continually increasing this cosmic tension, new physics, not an error, provides the likeliest resolution.

New evidence is adding to "cosmic tension" - his way of saying that it seems to refute the mainstream theories he so passionately advocates.

In that light, please review this recent article from Hawaii's Keck Observatory title A Crisis in Cosmology. There, astronomers investigated three different gravitationally lensed system to find the expansion rate, and came up with three different answers: 70, 77, and 83.

The team’s results add to growing evidence that there is a problem with the standard model of cosmology, which shows the universe was expanding very fast early in its history, then the expansion slowed down due to the gravitational pull of dark matter, and now the expansion is speeding up again due to dark energy, a mysterious force. 

Boy, that sure is some "cosmic tension." Some would even call it a crisis. Not just "contrarians" like yours truly, but the actual astronomers performing the observations. In that context, reread Ethan's short synopsis to fully appreciate the degree to which he is grasping at straws here. Also note that Starts With A Bang! can't be trusted for unbiased reporting of space news. If I hadn't happened to have seen that Keck story in another context, I never would have understood the reality of the recent developments.

This Is Why Einstein’s Greatest Blunder Really Was A Tremendous Mistake (link)

I'll spare you the full treatment and pull out the two paragraphs of significance.

Today, just like every day for more than 20 years, the scientific consensus has been that there really is an effect that behaves just like a cosmological constant in the Universe: the accelerated expansion of the Universe. Only, today, we don’t demand that it must be a cosmological constant; we treat it as just another generalized form of energy with its own unique properties that must be determined observationally: dark energy.

The accelerated expansion that we see today indicates that dark energy’s behavior is indistinguishable from a cosmological constant’s behavior, which is extremely interesting. It’s no stretch to say that understanding and explaining dark energy is one of the biggest challenges facing 21st century science.

So the "tremendous mistake" is that mathematically a term gets moved, but in practice there is no difference. It hardly seems like a tremendous mistake from this vantage point, but it means that Einstein's theory is subject to the same criticisms as we've applied to dark energy here before.

LIGO’s Lasers Can See Gravitational Waves, Even Though The Waves Stretch The Light Itself (link)

Here he addresses a paradox of LIGO that no one was proposing. Supposedly, people are confused by the concept. Ethan suspects that people believe that light gets stretched by gravitational waves, thus it could not be used to measure the tiny variations in linear distances proposed be caused by the gravitational waves.

Actually, the skepticism of LIGO has more to do with it's implementation. They're taking a weak signal, eliminating noise somehow, and then comparing to a large catalog of theoretical events that would cause gravitational waves. The problem is that, no matter the observations, they'd eventually find what they were looking for. It's basically a galactic Rorschach test.