Saturday, September 18, 2010

The Fine Structure Constant Isn't

Ira Flatow's Science Friday on NPR's Talk of the Nation yesterday had a mind blowing story titled "Strange Physics: Dark Flow, Fine Structure Constant". Part of the story was how the fine structure constant (conventionally denoted as α or alpha) appears to vary over space but not over time.

The fine structure constant is a dimensionless number derived from some fundamental physical constants like the speed of light in a vacuum. Its value is roughly 1/137. It was established in the first few moments of the big bang as matter solidified and reality as we know it more or less settled out. If the fine structure constant differed by just a few percent in either direction, the laws of nature would differ to the extent that the chemical reactions that life as we know it depends upon could not take place. The anthropic principle is a philosophical argument that says these fundamental constants are what they are because if they weren't we couldn't be here to measure them.

We can in fact measure these fundamental physical constants, and so compute alpha, not just in any well equipped laboratory, but also elsewhere at any number of observatories around the world by pointing telescopes at distant stars and using very accurate spectroscopes. We know about how distant these stars are from the amount the light from each is red-shifted.

But when we do this, we get different numbers for alpha, and the numbers we get do not depend on how far away the stars are (which would imply that the constant changes with time, which would be less troublesome) but in what direction we look (implying that it changes with location). This is mind boggling, because either the fundamental laws of nature vary from place to place, or something else is affecting our instruments in a strange but very consistent manner.

Mrs.Overclock (a.k.a. Dr. Overclock, Medicine Woman) and I were discussing this over dinner when my science fictional lobe came up with these ideas:

1. If the constant varies across space, that could explain the Fermi Paradox: there isn't life (as we define it anyway, which determines how we try to detect it) elsewhere because there really is something very special about our region of space.

2. An ultra-super-hella-weapon that altered the fine structure constant in a region of space would be... useful... for eliminating troublesome civilizations. The term "weapon of mass destruction" seems laughably modest to describe such a device.

This is the kind of stuff I think about on a daily basis.

Update 2010-09-18

The science/fiction blog io9 had a great article on this very topic that I missed while Mrs. Overclock and I were in Australia (at the World Science Fiction Convention in Melbourne) and New Zealand (touring The Lord of the Rings filming locations on the south island near Queenstown and Wanaka). Check it out!

Update 2010-09-23

Dave Goldberg, Ph.D. physicist, wrote a detailed and very readable article on this topic, also over at io9. Check it out squared!


mcjoe said...

While they have observed variation in alpha (which will still needs to be extensively verified before we accept it as fact), none of the variations I have read about deviate far enough from the sweet spot to affect whether life could emerge. If the "constant" is changing, that change appears to be very slight. Still very intriguing!

Adam Rosien said...

In "A Fire Upon the Deep" and other books Vernor Vinge has a galaxy where the maximum speed depends on one's distance from the galactic center, and farther than a certain point you can go faster than light. A good series overall.

Chip Overclock said...

Indeed. In fact, in Vinge's "zones of thought" universe, there are parts of space where P equals NP. Mrs. Overclock (a.k.a. Dr. Overclock, Medicine Woman) and I both enjoyed those books very much.

Anonymous said...

While intriguing, it is too early to judge. There needs to be better independent verification. Since their analysis includes corrections for the expansion of the universe, the errors and uncertainty in that quantity need to be taken fully into account.

That said, there are theories about the strengths of fundamental interactions varying, and e squared is certainly on of those.