Pondering the Possibility of Non-constant 'Constants'
IRA FLATOW, host: In physics, there are certain numbers that just are. They're numbers like the speed of light. We can't explain why it has that value, but it does. There are those constants like pi and Planck. And we take for granted that these numbers would be the same all over the universe. But now, researchers are reporting that their measurements, another of those physical constants in those measurements known as alpha, the fine-structure constant, well, that constant may not be constant after all.
It's a surprising finding and definitely falls into the "extraordinary claims require extraordinary evidence" category. But the team says that it's having trouble finding other explanations for their work, published this week in the journal Physical Review Letters. Joining me now is Michael Murphy. He is the QEII research fellow in the Centre for Astrophysics and Supercomputing at Swinburne University of Technology. That's in Melbourne, Australia. He's one of the authors of the paper. Welcome to SCIENCE FRIDAY, Dr. Murphy.
DR. MICHAEL MURPHY: Hi there, Ira. How are you?
FLATOW: Tell us what's wrong with the universe here? What did you find?
MURPHY: Well, we found, I guess, this alpha constant, that you've referred to, measures really the strength of electromagnetism that we're all familiar with. Electromagnetism is probably one of the four forces of nature that most people are most familiar with, maybe apart from gravity. But the strength of electromagnetism as measured by alpha seems to be different on one side of the sky and into deep space compared to the other side of the sky. So when we look in one direction, we find that it's stronger electromagnetism there, just a little bit. And then, when we look in the other direction, we see that it's weaker. And so we have this kind of dipolar universe when it comes to electromagnetism, we think.
FLATOW: We think - you think.
MURPHY: Yeah. Well, that's what the measurements say. And as you say, we've been trying to find reasons why those measurements could be wrong. They're obviously pushing the limits of what we can do in astronomy. We're making very precise measurements using distant quasars. And as I said, we're pushing the measurements to their limit, and it's possible that some things are wrong. We haven't found any of those things, and we're opening now up - by publishing these results, we're opening that debate up and - up to other astronomers and other scientists.
FLATOW: Well, what would that mean if you're correct and the constant changes?
MURPHY: Well, the find - well, the constants of nature are assumed to be constant. We don't actually know for sure that they are constant - that they are actually constant throughout the universe. And that's why we're going and doing these measurements. We actually want to test that assumption. But if they're not constant throughout the universe, then it really means that - well, our current understanding of physics, our entire understanding of physics is really relying on those constants being constant, and that means that understanding is wrong.
There's, probably, therefore, a more fundamental set of laws that we have to discover, and that's exciting. That's a great opportunity. It means that our conceptual idea of the universe will completely change. And it might be that there's something like string theory or M-theory or one of these what we call unification theories, something that unifies the four different forces of nature into just one theory or concept. Maybe one of those theories is correct. We don't know at this point. But they're the sort of implications we're - that we're talking about, here.
FLATOW: How different, how - your measurements, how far off are they from what you would think they are, they should be?
MURPHY: Well, so when we look in one part of the sky, as I say, we see a stronger value of alpha characterizing the strength of electromagnetism, and that's greater by about one - about 10 parts in a million on one side of the sky. And when we look to the other side of the sky, we see that it's weaker by about the same amount. And so we're not talking about large differences, here. But it doesn't matter how small the change is. If there's any change at all, it really means a revolution in physics is required - in our understanding of physics is required.
FLATOW: You know, we've heard, in the last couple of weeks, two different revolutions in physics, possibly, first with the neutrino, right, going faster than the speed of light.
MURPHY: That's right. Yes.
FLATOW: And now your work that shows that the measuring of magnetism, electromagnetism is different in different parts of the sky. If this is true, I mean, are there any practical applications? Of course, people like to hear...
MURPHY: Well, I think the main practical, you know, result of this is that our concept of the universe would completely change. So, for example, electromagnetism is what holds you together. It's what holds atoms together. And so everything around you is really governed by electromagnetism and also subject to gravity. But if you start playing around with the strength of electromagnetism, even just by a few percent, it would turn out that, for example, carbon atoms might become unstable and water molecules might fall apart. These are the sorts of consequences of changing the strength of that electromagnetic force.
And so, for example, our life, obviously, depends - life as we know it depends on carbon and water. And so if you move into a universe, into a region of the universe where electromagnetism has a significantly different strength to here on Earth, then you might cease to exist. It might also mean that there's parts of the universe where life cannot exist - life, at least as we know it.
So, if you like, we're in a Goldilocks zone of the universe, a Goldilocks - a very, very large Goldilocks zone, where the values of the fine-structure constant is just about right for us. Of course, we're probably tuned for the fine-structure constant rather than the fine-structure constant being tuned for us. Of course, we're going to find ourselves in a part of the universe where things are just right. But it might also mean that there's other regions of the universe where our sort of life just cannot exist.
FLATOW: You know, it's more fascinating is that the more we're learning, the less we know, you know. Instead of thinking we're getting to know more about the universe, we're finding this dark energy that we don't know what it is. We're finding that maybe electromagnetism is not the same everywhere. It seems to be more - a more exciting, interesting place than just...
MURPHY: I'd say it's more exciting and interesting. I don't know we're - I don't know if we're learning that we don't know as much as we did, or we thought we did. But the - it's certainly an exciting time in astronomy. One of the main reasons for that is that we can do these sorts of precise measurements. So we couldn't have done these with, you know, photographic detectors and things like that. The technology in astronomy and the size of our telescopes these days really enables us to do fundamental physics that we would otherwise do in the laboratory here on Earth. We can do that sort of physics in distant galaxies, and that's how we've done these measurements.
We've looked with the - two of the largest telescopes in the world, the Keck telescope in Hawaii and the very large telescope, European telescope in Chile, all over the sky at different quasars and investigate galaxies along the lines of sight to those quasars. And that's what actually allows us to probe the fundamental physics into deep space.
FLATOW: And so you've - so other people will need to recheck this, and you'll probably be rechecking this yourself.
MURPHY: Well, we're certainly rechecking it ourselves and...
FLATOW: Is it possible to come up with more accurate checks or other equipment, something like that?
MURPHY: Well, equipment's always advancing and technology's always advancing. We're certainly cross-checking this result in as many ways as we can find time to do by looking at - using the same method and using the same sort of instruments. Those instruments are getting better. There's also new instruments being designed and starting to be built now for existing telescopes. And, of course, we all look forward to the new era of the extremely large telescope - not very large telescopes, but extremely large telescopes, 30-meter and 40-meter telescopes that will be able to really nail this question with very highly stable spectrographs that can look at these distinct galaxies in a lot more detail.
But I think if you're to believe these results, finally, if what we find in further experiments confirms what we've already found, then I think that the endgame of this is that you really have to confirm this somehow in the laboratory. And there are hopes for that, using very, very precise atomic clock experiments. And these things might be able to detect different values of alpha just in our solar system. As we go around the sun, we might experience a different strength of electromagnetism in the laboratory. And we just have to have precise enough measurement to find that. But we don't know yet.
FLATOW: But you'd then need an explanation for it, too.
MURPHY: Oh, you absolutely would, and that's the exciting part. You know, the explanations have to meet the observations, and currently, our current theories cannot explain this. Actually, our current theories can't even explain why the values of the - the value of the fine-structure constant is what it is. We have no idea where this number comes from. Richard Feynman was, you know, famously said that this is one of the greatest damn mysteries in the universe, and it is that. We just don't know where this number comes from. And if it started to vary, we wouldn't have an explanation for that, either. But it would point the way, I think, to a new understanding, or the start of a new understanding of more fundamental laws of physics that we just don't have any idea about right now.
FLATOW: That's exciting. I love it. Thank you.
(SOUNDBITE OF LAUGHTER)
MURPHY: No problem.
FLATOW: You must hate your job, I'm sure.
MURPHY: Oh, it's terrible.
(SOUNDBITE OF LAUGHTER)
FLATOW: Thank you very much for joining us, Michael Murphy.
MURPHY: Thanks, Ira.
FLATOW: Dr. Murphy is the QEII research fellow in the Center for Astrophysics & Supercomputing at the Swinburne University of Technology - that's in Melbourne, Australia - and one of the authors of the paper that appears in Physical Review Letters. I'm Ira Flatow. This is SCIENCE FRIDAY, from NPR.
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