Has science just discovered that the multiverse is us? That our very own universe is not only one of many, but it connects directly to other ones with very different physical laws and we can sense the borderlands via a tiny gradient in the visible cosmos? It depends – but over the last week a trickle of stories has spread news that an arcane, but quite vital and mysterious, pillar of physics may work differently in other places with a variation that itself varies by what direction one looks. Thus the fine structure constant that is the protagonist in this tale, aka alpha in equations in physics, may be a variable.
Avid followers of physics news, as well as just about every serious physicist, know that the constant’s constancy has been debated for years. Now fresh data, with an asserted statistical accuracy of 4 sigma that means chances are slim it’s just noise in the system, have perked up the conversation.
Initial reports in media triggered, it appears, by pre-publication of the paper at the on line arXiv site (link in Grist below):
- Economist, Aug. 31 (no byline, as is its way): Ye cannae change the laws of physics / Or can you? ; First out and best dressed, with a keen summary of what the constant is and why it matters. Dunno why the outbreak of Scottish Gaelic in the hed, but it gives it the air of a wizardly declaration.
- PhysicsWorld – Hamish Johnston, Sept.2: Changes spotted in fundamental constant ; Explained for the cognoscenti who read this specialty outlet’s news.
- Science News – Ron Cowen, Sept. 3: Changing one of nature’s constants / If correct, new finding could upend physicists’ view of universe ; Particularly solid on the maybes and caveats – these data, on tiny effects seen in things very far away, are a bit too squishy for some.
- USA Today – Dan Vergano, Sept 3: Astronomers: Quasars upend fundamental physics constant ; Dan pulls one quote, with proper attribution, from the PhysicsWorld story.
Yesterday, Sept. 6, an astronomy meeting in Portugal issued a press release on the paper (in Grist below). This was followed by other story or stories, but whether this is due to the release or was in the works anyway is not clear:
- ABC Science (Australia) Stuart Gary, Sept 6: Meaning of life changes across cosmos ; Makes no stab at all at explaining what the fine structure constant, alpha, is. And in a stretching of the term, he calls the arXiv paper-sharing site a physics blog. Is that correct by any definition of ‘blog’? The story overall seems hasty – what’s he mean writing that in one direction the universe seems to be growing, and in the other, shrinking? If he meant the constant does so, fine, but that’s not what he wrote and perhaps should have re-read more carefully.
This is exciting news, but awfully nebulous in the literal meaning of clouds in space as well as metaphorically as in fuzzy. Because consequences of over-reporting it – nobody gets hurt – are so small, reporters are in a sense free to emphasize the far end of responsible speculation.
Let’s back up. This constant is necessary to calculate how electric particles interact – including the energies of electronic orbitals in atoms. It is famous because physicists can write down its value in terms of other constants, but they have no idea why it has that value. It’s a philosophical conundrum that has led many scholars to pace the floor. There is, for one, its anthropic angle. If its value were not pretty darned close to what it is, fusion reactions in stars would be quite different (such as, no production of carbon), and maybe there’d by no fusion at all. No stars, no us, not much of anything. Hence, it is key to serious discussions of the fine-tuning problem and the anthropic principle, the one that has no explanation for why the universe seems delicately and inexplicably perfect for eventual evolution of life.
The news is from a team of astronomers, led by one in Australia, that for years has said the fine structure constant appears to be slightly larger, judging by detailed spectra of gases pierced by quasar light getting here from more than 10 billion light years away, looking into the northern celestial hemisphere. Now,using data from another telescope looking the other way, they report it gets smaller in that direction. Not by enough to make fusion run much differently, one gathers. But it is enough to raise eyebrows.
I in my layman’s stupor am betting on systematic errors in the two telescopes that gathered the data, but am hoping for new physics.
Grist for the Mill:
arXiv paper ; Joint European and National Astronomy Meeting Press Release ;
– Charlie Petit
Leave a Reply