Monday, 15 September 2008

What do atom smashers do?

I am very indebted to Shastree J.C .Philip a physicist of great repute who has written this article on my request for Sciblog .The aim of the article is to communicate the intricacies of the Geneva 's so called dooms day experiment in a lucid manner so that the same could be easily understood by even a lay person.In this backdrop,now its for you to read and decide yourself as to what extent Shastree ji has done justice to this artile .
Smashing or taking apart a thing to explore it is usually done by curious children, but not always. Even self-respecting scientist on the cutting edge of physics also do this, particularly if they are working in nuclear or particle physics.
The value of crashing particles at the atomic level or below became known when in 1909 when Hans Geiger and Ernest Marsden performed the gold foil experiment under the direction of Rutherford. They took an extremely thin gold foil and bombarded it with alpha particles. Conventional wisdom in physics of that time told them that all the alpha particles should comfortably penetrate the gold foil and should keep going in a near-straight-line from the source of alpha particles. Only minimal and random deviation from a straight-line path was expected.
However, the actual deviation was very high and eventually they noticed that many alpha particles simply bounced back. This was similar to a machine-gun bullet getting bounced back from a paper tissue, and told them that the picture of matter that was popular in physics at that time needed radical modification. Rutherford solved the puzzle by proposing a model of atom which was close to truth. From this time onwards physicists discovered that colliding particles against each other and studying the after-effects is a great probe into the unseen.
Atoms are so tiny that no microscope in the world can show an atom, and thus collisions have become our microscope, telescope, and everything to see into the atoms. By 1960 it became clear that even protons and neutrons have inner structure, and scientists once again realized that if one cannot see the atom using a microscope, one might as well forget seeing these smaller particles. Thus smashing protons and neutrons against each other became all the more important to study their inner structure and working.
Particle-accelerators were built in early twentieth century for performing collision experiment with mathematical precision, and almost all information in sub-atomic physics comes from these experiments. They soon realized that the greater the energy with which particles are smashed, the greater will be the possible fragment and the information gleaned from these. This resulted in an ever increasing demand for collision-power and the contemporary result is the Large Hadron Collider in Switzerland. This 27 kilometer machine accelerates protons and makes two such beams collide. September 2008 is the month this machine is getting tested. Once the initial tests are over, the machine might be used for the next 20 to 30 years for ever-increasing ambitious projects. There is also talk of a 100 kilometer accelerator to be built in the USA.
The September run of the LHC attracted worldwide attention when two scientists made bizarre claims about the possible doom from these experiments. Common man, not familiar with the experiments that have been taking place in physics, became disturbed quickly. The media, ever hungry for juicy bit of presentation, only added fuel in the fire. Thus there was worldwide fear among common people. But the experiment came and went away, exactly as those in physics knew would happen.
There is a long way to go. Perhaps the machine will be used for the next 25 years. Meanwhile the 100 kilometer machine might come up in the USA, helping physicists to probe deeper into sub-sub atomic matter.
Shastri JC Philip: The author has done work in quantum-nuclear physics, and did research on the quark structure of protons and neutrons (the hadron family). His website is a


arun prakash said...

a very informative work reminds us to past when we studied modern physics.

Shastri said...

Like Arun Prakashs, who made the first comment, the article did transport me also into the past!!