science – astrophysics

Robyn Williams: In fact that’s what I was going to ask you because in this era of astronomy, 400 years since Galileo, it’s somewhat embarrassing that the laws of physics are, putting it frankly, in a mess. There are so many black holes of understanding, you’re really looking for something fundamental to come along to sort it all out, aren’t you.

Michael Murphy: That’s right, and that’s why we have these big experiments in the Large Hadron Collider. These are all aimed at a deeper understanding of the physics, and trying to look into those little black holes of understanding that you mentioned, trying to peer through a little window into the new physics that we think exists there, we think there’s an underlying set of physical laws that we’re just missing at the moment that brings all of those four forces of nature together into one simple unified law. That’s kind of the Holy Grail of physics at the moment. And part of the motivation for doing this work with quasars is that maybe it’s best not to look in Large Hadron Collider, maybe it’s best to look on much larger timescales in the universe…

Robyn Williams: Especially as they can’t get it going yet.

Michael Murphy: They will. It’s a bit embarrassing that they haven’t, but this is an enormous experiment. If any one of us tried to do it, it would be much more embarrassing. But looking on all sorts of timescales and distant scales in the universe I think is important when you’re trying to address these fundamental questions. It’s actually remarkable that we can do fundamental physics with astronomy, which it’s only in this century that astronomy has really become a proper science in the sense that you can make reproducible observations.

Robyn Williams: When will you know you’ve got it right?

Michael Murphy: That’s a good question. We are at the moment basically repeating our experiment on a different telescope that we have been using in Chile, that’s called the Very Large Telescope. The other telescope we used in the past was the Keck telescope in Hawaii that actually at Swinburne we have some access to now. So we’re actually trying to compare the data now between the two telescopes and try and understand whether it’s something about the telescopes themselves that is leading to this very strange result or whether it’s really correct. Of course if we find the same result, I don’t think anyone will believe us even then. We really have to go and do this with many other experiments because it is such a fundamental result. Extraordinary claims require extraordinary evidence, and certainly the evidence at the moment is good and strong but it’s not extraordinary.

Robyn Williams: And when you have got it, I presume the world will jump up and down like…I wonder when they last did that, 1919 I think when the word came back that Einstein had got it right.

Michael Murphy: I guess so, it would be a similar kind of change in our understanding. It would require a conceptual change. Of course Einstein actually understood that change, and if our experimental results are really right that doesn’t mean we understand why the fundamental constants are changing, why the laws of nature are different in different places in the universe. That will require I think a much deeper understanding of the underlying set of physical laws that we’ve all been striving to do. In fact Einstein himself spent the latter part of his life looking for a unified theory. He didn’t know about the nuclear forces then, so he was probably doomed to failure, but at the very least it’s a very difficult problem.

But we do need some experimental guidance, and that’s why the Large Hadron Collider is there, that’s why we’re doing these experiments with quasars, and there’s many other experiments in physics, all aimed at basically trying to punch a hole in physics. And that’s maybe something that a lot of people don’t understand, is that we’re not satisfied just thinking we know everything. We know that we don’t know everything and we’re tyring to find out what we don’t know.

Robyn Williams: Sounds like the Donald Rumsfeld conundrum, doesn’t it! Big physics from Swinburne with Michael Murphy, senior lecturer there. Put their findings together with a little physics from the LHC and hope that they match.

Guests
Michael Murphy
Senior lecturer Astrophysics Swinburne University of Technology Melbourne Victoria
http://astronomy.swin.edu.au/staff/mmurphy.html

Presenter
Robyn Williams

http://www.abc.net.au/rn/scienceshow/stories/2009/2663067.htm