Dark Energy and the Hubble Tension

 Arnold u3a member Brian shares a proposed solution to the cosmological mysteries of Dark Energy and the Hubble Tension.

The two linked mysteries of Hubble Tension and Dark Energy have occupied many astronomers since 1998, so far without a satisfactory resolution. There is even a citizen learning group in NASA working on it called ‘Dark Energy Explorers’. Some have begun to surmise that there may be a common solution to these two mysteries but no-one as yet is able to confidently state what Dark Energy is. It is 68% of the Universe’s matter/energy content and we have not known what it is!

My colleagues in Arnold u3a, together with two other u3a members who are also Fellows of the Royal Astronomical Society, have been conducting research around this area. We arrived at a proposal that we believe offers a reasoned solution to both mysteries.

Background

In 1929 American astronomer Edwin Hubble discovered that our Universe is expanding.

He estimated an expansion speed of 170 kilometres per second per megaparsec (one megaparsec is 3.26 million lightyears distance). This was subsequently reduced but the discovery itself was ground-breaking. It was expected that eventually this rate would be slowed by gravity, for this ‘constant’ was thought to be the remnant effect from the Big Bang. But we discovered in 1998 that this rate of so-called ‘dying’ expansion had in fact increased - and noone knows why. We call this mysterious expansive force Dark Energy.

Any guesses as to what it is? ‘An ever-present vacuum energy in space’? An energy-fluid or field called ‘quintessence’? A possible flaw in Einstein’s Relativity - or perhaps in his law of gravity? Perhaps Dark Energy just doesn’t exist? Nothing made sense.

Hubble Tension arose when two main groups tried to establish the present rate of the Universe’s expansion. One group measured the recession speed of certain ‘standard candle’ stars and galaxies in the present time. The other preferred more easily found data in the Cosmic Microwave Background (CMB), a radiation relic from the Big Bang and our Standard Cosmological Model. However, the two main groups disagreed fundamentally on their results and could not reconcile their differences.

The team using ‘standard candle’ current information had calculated the expansion rate at about 74 kilometres per sec/per megaparsec, while the CMB teams arrived at a result of about 67.4 kilometres per sec/per megaparsec. The difference was unacceptable. However each team refused to change their calculations. (These figures are not speeds but acceleration rates.)

What is the size of the Dark Energy problem?

According to our best scientific information, the total of ordinary visible matter in all our galaxies is only 5% of the Universe’s total content of matter and energy. Dark Matter, invisible, unknown, accounts for 26.8% of the total, leaving the balance Dark Energy at a colossal 68.2%. This means that we don’t know what 95.0% of our Universe is.

We are no wiser now than Edwin Hubble, 100 years ago.

So where do we go from here? Well—what if both teams’ calculations are right? They used information from two totally different eras. Could something have happened in between? Something so unlikely that no-one has considered it before?

Up until very recently, it had been implanted in everyone’s mind that our Universe is fixed and infinite. Only a few months ago, if you were to ask Google if the universe rotates, the answer was, ''the assumption that the Universe is the same in all directions has been tested to the greatest precision ever, and no spinning, stretching or any form of rotation has ever been found.' In recent months, however, there seems to have been a change in opinion. If you were to ask Google that question again now, you will find many answers agreeing that the universe is rotating - but slowly. 

There is a physics law called ‘scalar invariance’. If an object has several characteristics that clearly identify it, then a similar object with much the same characteristics, but on a smaller or larger scale can normally be rightly identified with it — like dogs, or cruise ships or people. Our galaxies are full of star clusters. Some are moderate, about 1,000 to 5,000 solar masses. Many can, moving together, affect the sensitive balance of a galaxy, eventually causing the majority of them to rotate, as they do now.

A significant development

Much later in 2020 an otherwise ordinary annual meeting of the American Astronomical Society featured a presentation by Lior Shamir of Kansas State University, citing an examination of about 200,000 galaxies. His conclusion declared that "Since the spin patterns of a galaxy as visible from Earth are also an indication of the actual spin direction of the galaxy, the large-scale patterns in the distribution of the spin directions can be an indication of a rotating Universe."

His observations mainly examined galaxies within about the last 9 billion years. When adding data from more distant galaxies, their results shifted to 68 – 70 kms/sec per megaparsec. This better agrees with the CMB results from the Hubble research. He also maintained that the Universe was not rotating on a single axis, but on 4 axes in a complex alignment.

However, this observation is critically important and meaningful. In 2020, this astronomer Lior Shamir had already realised that for about the last 9 billion years our Universe has apparently been rotating. Not only that, his data from ‘more distant galaxies’ gave a similar result to the CMB data from the Planck satellite (68-70 kms per sec. per megaparsec) before that period, also showing that the Universe was not rotating from about 13.8 to 9 billion years ago.

Hubble Tension

It should be clear now that the early relic data from the Cosmic Microwave Background could not contain any information on the universe’s rotational. There was no rotation. What was shown there would likely be the remaining ‘explosive’ energy from the Big Bang. But those other calculations based on current evidence from ‘standard candle’ sources include the additional energy derived from matter now propelled away by unrelenting pressure from Dark Energy—or rather the now rotating Universe’s centrifugal force. Could there be a simpler solution to the Hubble Tension enigma?

Those cumulative ‘speed’ rates are simply how much faster we shall be moving outwards each time our galaxy is thrown out another 3.26 billion lightyears by that centrifugal force.

The acceptance of a rotating Universe would be a simple, if novel means of solving the persistent enigmas of Hubble Tension and Dark Energy—in one fell swoop. For Dark Energy, the concept is far simpler than the outlandish, mystifying alternatives previously offered. It has proved impossible for 27 years to devise a logical, acceptable theory explaining these two enigmas. Nevertheless, the majority of astronomers may still find it difficult to accept universe rotation as a simple but radical solution to this missing part of our Standard Cosmological Model. Its a reminder of the experience of Copernicus, trying to convince the authorities of his own revolutionary Sun-centred system. This is a similar huge leap now—and necessary.

Others may well be working on it, but no-one has yet declared that Dark Energy is the Universe’s centrifugal force that is driving our galaxies out to its expanding edges. I predict that will come very soon.

Sharing the theory with u3a members

My involvement in the search for Dark Energy began in May 2024, after reading a fascinating article by science writer Marcus Chown in a popular science magazine. Although already suspecting that the Universe may well be rotating, I had then no interest in pursuing the Dark Energy mystery. But I became nevertheless suddenly aware that a rotating Universe would probably develop a centrifugal force, thereby behaving exactly as Dark Energy appears to do. It was an unexpected revelational moment, but it would require considerable research to shine a light on this 26 year-old persistent enigma. Not only NASA , but many famous scientists had already failed in the attempt.

By October 2024, I had made enough progress to make a presentation on Dark Energy to Arnold u3a’s Astronomy Group of which I am a member. The idea made logical sense to me and the group members, but at the time I had no supportive evidence. That arrived in January, when Chair of Arnold u3a, Hazel, passed me presentations from the American and our own Astronomical Society, citing from them the first real evidence from other like-minded astronomers of their evidence for possible Universal rotation.

Hazel had already been helping me to present my complex ideas more coherently. Another keen astronomy member, Kate, has also ensured that some of the unusual and difficult concepts were understandable to our members.

This enabled me to design a PowerPoint presentation of 36 slides which is easier for ordinary members to follow. With the help with the u3a Astronomy Subject Adviser Martin, I circulated copies of this to many u3a Astronomy Groups, receiving thoroughly supportive encouragement from many of them. I particularly mention Andrew Makin, Guy Consterdine, Steve Fletcher (FRAS) and Cat Stevenson.

This is a truly combined work that showcases how effectively u3a members can work together on a complex scientific issue.