Laws of Nature May Not Be Constant After All — Dare to Know
The Laws of Nature are said to be constant throughout the universe. Find out how a new study challenges this fundamental principle of science.
I remember learning in grade 5 that the laws of nature were the same everywhere. This was true no matter where you looked. They applied everywhere in the world and even out in space.
That’s been a mainstay of my fascination with science. I’ve always been awestruck by the idea, for example, when I look at the Andromeda galaxy. The laws of nature that apply in that galaxy and here in the Milky Way are identical.
The general principle of uniformity of the laws of nature is essential to the philosophy of science and theology as well. All of the constants underlying the laws of physics seem meticulously fine-tuned. They seem designed to support the formation of stars, planets and living things.
Had These Natural Laws Varied, None of Us Would Exist
Had these physical laws varied in the slightest degree, none of us would exist. It’s a profound mystery scientists call “the anthropic principle.” It leads many to conclude that the universe has some sort of intention behind it.
Now, this almost sacred scientific principle about the laws of nature is facing new scrutiny. Researchers from the University of New South Wales, Sydney (UNSW), suggest that one of the cosmological constants in our universe is not so constant.
There are four physical forces in the universe. These are gravity, electromagnetism, the strong nuclear force and the weak nuclear force. This new study, published in the journal Science Advances, is about electromagnetism.
New Science Advances Study on Electromagnetism
To explain why the discovery is significant, we need to go back to the year 1916. A German scientist named Arnold Sommerfeld was the director of the Theoretical Physics Unit of the University of Munich.
His colleagues remember Sommerfeld as one of the most respected mentors in his field. Albert Einstein told him, “What I especially admire about you is that you have, as it were, pounded out of the soil such a large number of young talents.”
Four of his former students won the Nobel Prize. Many others also went on to become leading physicists in their day. Like most professors, he combined his world-class teaching with instrumental research in his field.
Fine Structure Constant AKA Sommerfeld’s Constant
The important discovery for our story on the laws of nature is the “fine structure constant.” Scientists also call it “Sommerfeld’s constant” in his honour. Sommerfeld became one of the early pioneers of quantum mechanics.
Sommerfeld’s constant describes the strength of the electromagnetic interaction between charged particles. Readers will recall that protons have a positive electrical charge, and electrons have an equivalent negative charge.
Physicists call that charge the “elementary charge.” Sommerfeld’s constant is one of the mathematical terms that define the elementary charge.
Sommerfeld’s Constant Part of Defining Elementary Charge
Niels Bohr’s model of the atom that we all learned in school, was a leap forward in understanding the big picture, or “coarse structure” of atoms. Even so, it wasn’t consistent with measurements of hydrogen that the 19th-century scientists Michelson and Morley had made. These measurements were highly accurate and had been around for a long time.
Sommerfeld resolved this problem by introducing a mathematical constant that he based on the ratio of the speed of light, the electron charge and Planck’s Constant. This new fine structure constant refined Bohr’s model to reconcile the discrepancies. It also better explained the laws of nature for the subtler fine structure of atoms.
Professor John Webb led the present day research team at UNSW. As he puts it, “The fine structure constant is the quantity that physicists use as a measure of the strength of the electromagnetic force.”
Fine Structure Constant is Different in One Direction
Webb and his colleagues found that the fine structure constant is different in one direction versus the rest of the universe. Professor Webb explains, “We found a hint that that number of the fine structure constant was different in certain regions of the universe. Not just as a function of time, but actually also in direction in the universe, which is really quite odd if it’s correct.”
The researchers studied the light from a distant quasar. The quasar was about 12 billion years old. This means that the photons they were examining originated when the universe was in its infancy.
Professor Webb’s team made four measurements of the fine structure constant along the line of sight from Earth to the quasar. Comparing these measurements to a range of other quasar measurements from different experiments, they detected the discrepancy.
“Universe May Not Be The Same In All Directions”
“So the universe may not be isotropic in its laws of physics — one that is the same, statistically, in all directions,” Professor Webb explained. Counterintuitive as this claim is, there’s evidence to support it.
A team of researchers led by Konstantin Migkas of the University of Bonn studied the x-rays emitted by distant galaxy clusters. Their work was completely independent of Professor Webb’s team. In fact, he was completely unaware of their study until he read the findings in the journal Astronomy and Astrophysics.
In Professor Webb’s words, “They’re testing the properties, the X-ray properties of galaxies and clusters of galaxies and cosmological distances from Earth. They also found that the properties of the universe in this sense are not isotropic, and there’s a preferred direction. And lo and behold, their direction coincides with ours.”
“Lo and Behold, Their Direction Coincides With Ours”
The results from these two studies aren’t enough evidence to conclude that scientific laws are somehow directional. Even Professor Webb is skeptical about that.
Even so, if this hypothesis turns out to be accurate, it would explain the profound mystery of the fine-tuning of the cosmos. It could be that the laws of nature are more flexible than we have always assumed.
That would mean that all of those narrow parameters that seem to create a “goldilocks universe” that’s “just right” could vary depending on where you sit. That would explain why natural laws in our region of the universe conform so precisely to the anthropic principle.
Maybe Nothing fine-Tuned Natural Laws After All
Maybe nothing fine-tuned them after all. Perhaps we just happen to be in a part of the universe where the prevailing natural laws accommodate solar systems and ecosystems like ours. It’s always preferable to seek out an explanation based on a naturalizing philosophy rather than relying on “god in the gaps” explanations.
In 1927, English biologist J.B.S. Haldane wrote, “The universe is not only queerer than we suppose but queerer than we can suppose.” Professor Webb seems to share that sentiment.
As he described his study, “It seems to be supporting this idea that there could be a directionality in the universe, which is very weird indeed.” Weird as it is, it’s not any stranger than Bohr’s model of the atom being inconsistent with experimental measurements.
A Lot of Things in the History of Science Were Weird
A lot of things in the history of science were weird. Had Sommerfeld ignored Bohr’s inconsistency as just “noise,” he would never have made his fundamental discovery.
The UNSW researchers are calling for a far larger study that explores the universe in a wide range of directions. Today’s telescope technology makes that possible in ways that weren’t feasible even a few years ago.
We always have more to learn if we dare to know.
University of New South Wales, Sydney
Four direct measurements of the fine-structure constant 13 billion years ago
Probing cosmic isotropy with a new X-ray galaxy cluster sample through the LX-T scaling relation
The 5 Big Questions We Need Cosmology to Answer
Are We Inside a Hubble Bubble
Primordial Universe Made of Strange Particles
Originally published at https://daretoknow.ca on May 5, 2020.