Aug 24 2009
What physicists and the Sex Pistols have in common
Alex Serpo
Alex Serpo likes particular particles in precise positions. He’s pretty sure that right now Heisenberg is playing chess with Schrödinger in the afterlife.
Let me tell you a secret. In every scientist there is an anarchist. Don’t let anyone tell you otherwise. What all scientists have in common is they really, really like to break things.
Physics is no exception.
I was at last week’s ‘Hunting for Anti-Matter’ talk by Dr Kevin Varvell of Sydney University’s School of Physics. The lecture hall was packed and latecomers were forced to sit on the stairs.
(I can vouch for this, I was one of them! And, for all you Physics-lovers out there, come to the Einstein Lecture tonight, featuring renowned U.S theoretical physicist Lawrence Krauss. There will be a LASER light show & time dilation in action, amongst other revelations. ed)
During Varvell’s talk I was reminded me of the considerable effort physicists make to smash their own discipline. Every time a theory goes up, attacks come from every side trying to bring it down. The result is a discipline that, while being highly predictive and very accurate, is also full of contradictory or incomplete theories.
For example, there is still no quantum theory of gravity. Special relativity is something of a bulwark – however it predicts both dark matter and gravity waves, and to date there has been no direct observation of either. Finally, the rather mundanely-named ‘Standard Model’ of particle physics predicts the existence of the infamous mass-carrying ‘Higgs Boson’.
But to date there has been no Boson.
Years of experiments have left physics in pieces. The four fundamental forces of nature: 1) gravity, 2) electromagnetism, 3) strong force and 4) weak force, remain in contradiction. This contradiction really bothers physicists. They like things to add up.
Enter Yoichiro Nambu, Makoto Kobayashi and Toshihide Maskawa, three Japanese-born physicists who managed to put a couple of pieces of physics back together again. Specifically, the weak nuclear force and electromagnetism.
This small achievement earned them the 2008 Nobel Prize in physics and was the topic of Dr Varvell’s talk. How did they do this? Just like Alice in Wonderland, they went through the looking glass. They entered the strange world of mirrors.
By a strange world of mirrors, I am talking about anti-matter. Anti-matter is matter’s ‘mirror image’ twin; for every particle there is an anti-particle. Dr Varvell explains that antiparticles aren’t some kind of mathematical construction on a blackboard, they are as real as toast and butter.
You can observe them, photograph them and they are even used routinely in medical procedures like Positron Emission Tomography Scans or PET Scans. (The positron is the anti-particle of an electron).
The funny thing is, it turns out that anti-particles aren’t exactly the same as their matter siblings. This has huge implications, as when matter and anti-matter meet, they annihilate in an intense burst of gamma rays. This means if the universe contained exactly equal amounts of matter and anti-matter, soon after the Big Bang all of it would have annihilated and the universe would only contain high-energy photons.
As it turns out, because anti-matter and matter aren’t exact ‘mirror images‘, the big bang created slightly more matter than anti-matter and things went from there.
Thus, the universe exists as we know it.
It may seem obvious that the universe contains matter, but it took three Nobel laureates to demonstrate why. Not only does this discovery give us a closer insight into the Big Bang, it also helps unite two previously separate forces: the weak nuclear force and electromagnetism.
In partially uniting these forces, physics has come one step closer to being unified. However many questions still remain unanswered. As you read this, engineers are busily trying to fix the Large Hadron Collider (LHC) at CERN. The LHC is expected to find the Higgs Boson and provide further evidence for Yoichiro Nambu, Makoto Kobayashi and Toshihide Maskawa’s theory.
But what if it doesn’t? What if there is no Higgs Boson? This question brings out the scientific anarchist in Dr Varvell. “If you catch physicists in their most candid moments,” he explains “they will tell you that’s exciting.”
Just like particles, science is exciting when it comes together, and exciting when it falls apart.
Now for Kate Hennessy’s brief review:
I was also at this lecture on Thursday night. I know little-to-nothing about physics. In fact, it was probably lucky for all involved I was late and had to perch on a stair in the back row with no-one beside me because there were several times I yearned to nudge my nearest neighbour and shrug theatrically, possibly followed by a ‘let’s get out of here’ thumb gesture for the door.
But I’m glad I persisted. While I exited the lecture hall with my brain actually hurting, I thoroughly enjoyed Varvell’s talk. I didn’t understand everything but the bare minimum I learnt at school remarkably flooded back to help me out. And I’m talking pre-Year 10 here. And I thought all that knowledge was gone!
In any case, who really needs to understand utterances such as this?
“When the universe was just a fraction of a second old after the Big Bang, matter started annihilating anti-matter. There was an asymmetry to begin with – a very small one – but it was enough. Otherwise, the universe would just be bathed in photons.”
I also welcomed two new phrases to my lexicon – ‘charmed quark’ and ’strange quark’. My search to use these in a context that’s not Physics begins now.
And, I don’t understand why they do it, but I like the fact that physicists measure things based on metres. To view a quark in a particle accelerator, for example, you need to magnify it to “a billionth of a billionth of a metre”. Why don’t they use millimetres as the original unit? Can anyone tell me that?
Oh and Varvell also had a movie recommendation. Angels and Demons. Check it out.
