Rob Sheldon kindly writes to say about that:
Just getting to this news blurb.
Adam Reiss got the Nobel Prize for discovering dark energy, so of course he is going to believe in it.
The issue at hand is that the CMBR (cosmic microwave background radiation) which started at 3000K in temperature, is now 2.725K degrees above absolute zero. This cooling is simply a function of the universe expanding some 1100 times. Since we “know” the time in the Big Bang at which it was cold enough for free electrons to recombine with free protons and decouple from the photons (379,000 years after the BB), we have two times and two sizes, so we have an expansion rate = Hubble Constant = 64 km/s/Mpc (kilometers per second per megaparsec). However when we look at the rate of expansion today, by seeing how fast the galaxies are receding from us, we get 73 km/s/Mpc. Thirty years ago, these numbers weren’t known very well, and it was assumed that better data would bring them into alignment.
It hasn’t. Instead the “Hubble Tension” has increased as the numbers didn’t budge, but the error bars kept getting smaller. We are now some 8 sigma apart.
Adam Reiss got his Nobel in 2011 for proving “dark energy” by measuring the dimming of Type 1a supernovae, which recent work suggests was a data artifact due to his selective use of 74 supernovae and increasing the data set to 1200 or 2000 supernovae has removed the effect. So he needs to justify his Nobel on other grounds, and he has selected the Hubble Tension as proof of dark energy = anti-gravity = acceleration of galaxies. He reasons that if we take the two times and two distances, we get an average speed for Hubble’s constant. But if we make some measurements in the times between, say galaxy speeds only 4 billion years ago, we can show that the Hubble constant gets faster with time, it is accelerating, which means “dark energy” did it. This is where the James Webb telescope will help, getting pictures of some truly ancient (and therefore IR red-shifted) galaxies.
He claims to have exhausted all other explanations, which is use of abductive reasoning if you need an example. But he has not challenged the BB model itself.
If, as I claim, the BB did not expand very quickly at the very beginning because of magnetic tension forces, then the 379,000 years number needs to be changed upwards. say to 760,000 years. That factor of 2 shows up as the Hubble Constant, because the universe then took less time to get to our observed 1100 expansions. So naively, moving the decoupling era to later times, raises the Hubble Constant and removes the tension without any dark energy added. Or to say it another way, the dark energy is the magnetic field which assists gravity in the early universe, and its absence in the late universe appears as if it were anti-gravity. But of course, it isn’t there anymore, and looking for it now is pretty frustrating.
Which points out the whole problem of abductive reasoning in the historical sciences (which this is) — you have to be exhaustive in your theorizing. And only God is exhaustive. Which makes abductive reasoning somewhat theological.