Monday, 8 September 2008

Physics Experiments

There's a lot of press going around about how when CERN brings up the Large Hadron Collider (LHC) this week, the planet will vanish into a newly-created black hole. As someone who has worked in Beam Control at CERN in the very distant past, and whose code may be used in some of the post-processing phases it is worth reassuring the readers that this will not happen.
The LHC has been built to collide Hadrons, large particles that have been spun up to very high speeds/masses, so that when they hit the other particles head on there is a lot of energy in the collision, energy which may, sometimes, result in the appearance of previous hypothesised but never seen particles.

This is what the fear is about -that humanity will create new particles that will destroy us. It will not happen. The duration of these particles will be incredibly small, otherwise there would be many leftover particles from the time of the big bang. Furthermore, any new ones created from cosmic-ray collisions with the planet in the distant past would have left some traces. Therefore it is believed that the to-be-created particles will only exist within one of the detectors (ATLAS being the primary UK experiment) long enough to be picked up, and even its evaporation measurable.

Yes, CERN may finally create evidence that the hypothesised "FirstBus No.77 Bus" does actually exist putting to rest forever the Copenhagen Interpretation of this long standing physics problem, namely that cities are only for bicycles.

7 comments:

Chris said...

You can confidently assure us that nothing will happen at CERN because if it does there's not going to be any come back. Ever.

Much as I admire your work Steve, knowing that you may have written some of the code involved "in the very distant past" isn't going to make me sleep any easier. Sorry.

SteveL said...

My code was on the previous experiment. All of my work here is downstream. So no, neither my competence/incompetence is a factor here.


That said, in the loughran-guijarro scale of system disasters, a screwup in the physics would be a level 10 event "end of humanity", so you really have to ask "is it worth knowing". Do you know when the manhattan project set of the first explosion, Trinity, they were worried that it could set off a chain reaction in the atmosphere. The allies clearly felt the risk was worth it there. But now?

Karl On Sea said...

OK, I was with you all the way. The Copenhagen Interpretation was fine, as was the idea that some code written by someone I know as "some bloke who obviously has more time on his hands than even I do, and likes taking photos of traffic ejits in Bristol" actually having something to do with making sure this all works. But the No. 77 bus? C'mon - everyone knows that's a myth. Even the Tooth Fairy.

SteveL said...

Karl. The whole reason I cycle round bristol with a camera is the hope that one day I will discover a #77 bus and get photographic proof. With my luck I will end up being run over by it.

Actually, that would make for a good variant on the Schroedinger's cat experiment. Put a cat in a box on a bus stop for a #77 bus and suddenly the cat may-or-may-not get run over. Until you open the box, it will be in a undetermined state. Yes, we could do this...

thebristolblogger said...

At least the LHC isn't owned by Bristol City Council. David Bishop would've sold it off to First to run tube trains down by now.

SteveL said...

You are right, they would sell it off, especially once they discovered that when the beam is off, CERN are happy to let staff cycle round the tunnels. He'd probably also try to sell the fields nearby full of deer for housing, without checking that they weren't above the Beam Dump Pit, and therefore exposed to bursts of radiation whenever they shut down the LHC and redirect the hadrons into the dump target.

SteveL said...

@Chris,
looking at the beam dump docs, it appears that anyone can shut down the LHC, from any web browser inside the CERN network. If you really want to stop it, get down there, get your laptop on the wifi net, search for "LHC beam dump" to find the page you need, and start shutting the beam down.