Tuesday, July 31, 2007

The End of the World As We Know It?

I really enjoy nuclear physics and at one time wanted to get into particle physics. In fact, before I became a theology major, I was on the path to nuclear physics. I even helped my professor do some nuclear experiments to study the structure of the Ce-142 and Nd-144. Admittedly, I didn't understand much about the "IBM model," but it sure sounds cool to say you helped with research in the Interacting Boson Model and the shell model of the N=84 isotones.

The actual experiment was kind of cool. Getting to play with one of those van de graaff generators. You know the one where you put you hand on the ball and it makes your hair stand on end:

Well, imagine having a van de graaff generater that was two stories tall! We used it to shoot protons into a block of something I can't remember. But the protons would collide with the substance and shoot neutrons of a specific energy at the sample (either Ce-142 or Nd-144). The neutron would hit the nucleus of the atom and transfer some of it's energy to the nucleus of the sample, making it go to a higher energy level. It would then decay, releasing a photon. We would measure this photon's energy and be able to use that data to see various energy levels. My job was to help babysit the experiement, then crunch numbers and do computer analysis to find the energy levels as accurately as possible. It was pretty cool how you could predict some things just by the data. Anyway, science has always interested me.

So why the title to this post?

I came across a documentary on the Large Hadron Collider at CERN in Geneva, Switzerland.

I love the "frightful" opening squence of the video. Will it destroy the world?

I guess there has been concern. In looking at the LHC web page, if you look at the public web pages of CERN and it's description of the LHC, tucked at the end of the pages is a page that deals with the "safety concerns."

Are LHC collisions safe?
Microscopic black holes will not eat you...
Massive black holes are created in the Universe by the collapse of massive stars, which contain enormous amounts of gravitational energy that pulls in surrounding matter. The gravitational pull of a black hole is related to the amount of matter or energy it contains – the less there is, the weaker the pull. Some physicists suggest that microscopic black holes could be produced in the collisions at the LHC. However, these would only be created with the energies of the colliding particles (equivalent to the energies of mosquitoes), so no microscopic black holes produced inside the LHC could generate a strong enough gravitational force to pull in surrounding matter.

If the LHC can produce microscopic black holes, cosmic rays of much higher energies would already have produced many more. Since the Earth is still here, there is no reason to believe that collisions inside the LHC are harmful.

They even point out other articles that deal with this from other experiments:

Review of Speculative "Disaster Scenarios" at RHIC (pdf file)

The video is a pretty good video about the purpose of the LHC at CERN and the physics behind it. It also gives a very good overview of the relationship between cosmology and particle physics; two seemingly opposite areas of physics: study of the whole universe and study of the basic building blocks that make it up.

There's also some interesting video of just one of the detectors on the LHC the Atlas detector (sort of a crash course in particle physics ... pun intended ... "crash" course ... super collider ... nevermind)

I can't embed these particular videos, but you can see the videos on youtube:

The ATLAS Experiment - Mapping the Secrets of the Universe 1

The ATLAS Experiment - Mapping the Secrets of the Universe 2

It looks like the November 2007 date has been pushed back, so I think the LHC won't go online until 2008. Still, interesting stuff.



On the side of the angels said...

spooky, because my three kids have asked for a van de graaff generator or a whimshurst machine for christmas ;

Can I be rude enough to ask two questions you may be able to help with ?

Can you prove to me that Gravity is a pulling force and not a pushing force ?
My 13 year old son is adamant that after reading about Tesla and science articles about the 'suspect' heat of stars etc that gravity is not what we think it is...

I'm not exactly backward [did Physics to 'S' level at school and avidly read Pinker, Sheldrake and Ramachandran but in this field I'm dumbstruck [apart from the old ewton/Einstein stuff]; so I'm having great difficulty in responding.

secondly my friend [scarily the chief military officer of the river severn - God help us if there's an invasion ]and I have an ongoing argument regarding chess and future quantum computers - do you think there will be an ultimate always-winning game discovered in the quantum infinitudes ? [redolent of the russian story of the 19 moves?]

Roman Sacristan said...

Well, for the first question: I didn't study much about the forces four fundamental forces, but I would say that gravity is an attractive force. I don't think I have seen anything to the contrary. I would think that what your son read about is related to other forces or phenomena (probably electromagnetic) or maybe something related to "gravitational radiation" but I wouldn't say that means gravity itself is a "pushing force" since gravitational radiation is a result of the bending of spacetime by moving object(s).

As for the second, I could only say maybe. Since we are talking about infinity, if an infinite amount of monkeys played an infinite amount of chess for an infinite amount of time ... LOL.
Seriously, I would doubt it, because if you move the same way each time, you opponent can move several different ways each time. I would think you would always have to adapt to your opponent's moves, so I would guess you could never have a guaranteed win.