National Public Radio’s David Kestenbaum, who’s quite reliably an excellent reporter whose field reports I always enjoy, did a report on CERN’s (soon to be switched on) Large Hadron Collider (see also a Wiki here) today! Or rather, it was played on this morning’s Morning Edition. Here’s the site where you can listen to an archived version of the report, and read a transcript of some of it. It’s rather well done.
(Image: A simulation from the CMS experiment – part of the LHC – showing the decay of the Higgs particle after being created in one of the high energy collisions.)
It starts with a few theoretical physicist clichÃ©s in the introductory remarks leaving up to talking to Alvaro De Rujula, but it’s fine – not really too over the top, and done with good humour. Really good is that fact that once the physics issues start being discussed and described, he focuses on doing that well. The bottom line is that if your subject -the science- is good, that should take center stage in forming the core of the report for attracting and holding the audience’s attention.
And report does it well. Through interview and Kestenbaum filling in with further explanatory remarks, he does a pretty good job of describing the point of the 16 mile-long LHC, bringing out back story of the huge success of the Standard Model of particle physics for the last 30 years and why that has left a lot of remarkable quiet in elementary particle physics, and why this is a hugely important experiment. This is motivated nicely by describing some of the mysteries still remaining in the Standard Model, the chief one being the question “What is Mass?”. This is the prime purpose of the LHC, and this is properly emphasized in the report.
There’s rather nice imagery used here and there. The tiny particles being collided – protons (one of the particles that normally helps constitute the nucleus of an atom) – will each have the energy of a city bus [update: No they won’t! See below] as they whiz around the 16 mile track that runs underneath parts of France and Switzerland. Then they’ll collide them together. So the resulting energy released from each collision (and there’ll be umpteen of them per second) will allow physicists to probe the “structure of the vacuum”. That latter phrase means that via Einstein’s E=mc2, other particles can and will be created in the collisions – lots of them will be ones we know, but unknown and unexplored stuff has a chance to be created too. It is that unknown stuff that will tell us about the new physics.
Correction from two commenters (thanks Bob and Bee!) on the energy, and from the update on the NPR site:
This story stated that each proton in the accelerator carries the energy of a bus. This is wrong. But added together all the protons in the machine will carry the equivalent energy of 100 10-ton buses moving at 200 mph.
The new physics includes (it is hoped) clues as to the origin of mass – perhaps the Higgs particle (as it is called – this is the particle which is expected to mediate the interaction which gives the property of mass to (nearly) every particle that is known), or perhaps a family of such particles performing this mission.
There’s also a bit of chatter about other things which might be seen (and for which physicists are keeping an eye out): The issue of the making miniature black holes, which would be a direct signature of certain scenarios involving extra dimensions of spacetime. De Rujula talks about this for a bit, emphasizing (for the nervous and critical) the harmlessness of this by distinguishing them from large astrophysical black holes that gobble everything up – these subatomic-sized holes would simply evaporate, leaving a characteristic (and hugely exciting!!!!) signature in the experiments. (And, I should mention, would open up a completely new frontier of direct experimentation in quantum gravity in concert with particle physics….)
More likely than black holes (De Rujula says, interestingly) is the finding of particles that would constitute the Dark Matter that we know is present from numerous cosmology and astrophysics observations. Recall that about 85% of the matter in the universe is in an unknown form! One way to determine its nature is to use E=mc2 to create it directly in the laboratory and study it. (This would be a huge achievement too, of course, if you think about it.)
I like that the article ends with them considering possibility of finding nothing:
Derujula says this would actually be the most interesting outcome.
“That would tell us we really haven’t understood anything about the vacuum,” he says. “Although that is the most interesting possibility. Suppose we don’t find it and don’t find anything else. How do we explain that not finding anything is the best possible thing? It would be very difficult.”
Yes, is a possibility that is both scary and exciting (in a way, as it tells us that there’s even more to be understood about some of the basics)…. Kestenbaum speculates that the LHC would then probably be the last big particle physics experiment of its type.
So have a look at NPR’s site (there are some interesting images and video as well as the article’s audio and transcript). I think there’ll be a second report tomorrow, when Kestenbaum goes down into one of the experimental halls and probably the LHC tunnel. So listen out.