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Old 1st April 2010, 01:08 AM   #14 (permalink)
Chinook
Science fiction fantasy
 
Join Date: Nov 2009
Location: Nepal
Posts: 130
Re: When two particles collide

So, folks have been throwing terms around like the Chef’s throw food at Beni-hana’s.

Here is a fairly accurate description of the current understanding that most physicists agree upon. Now, what is not mentioned here is the crazy half-sister of the standard model: String theory. Essentially, the notion of string theory is that all of these particles – both mass-less, and massed, are composed of tiny vibrating bits of energy. The issue is that the “strings” would be so un-measurably small (Planck length = 1.616252 x 10−35 meters – about 10 to the power of 20 times smaller than the size of a proton) That we have no hope of “seeing” a string anytime soon.

CERN - The Standard Model

What physicists have “seen” are some of the missing pieces of the “standard model”. Here is a proposed example of the standard model puzzle:

http://web.infn.it/superb/images/sto..._fermi_lab.jpg



For example, with existing particle colliders, they have seen “anti-electrons" (AKA positrons), and plenty of others.


Clues to the early Universe

The Universe has changed a great deal in the 13.7 billion years since the Big Bang, but the basic building blocks of everything from microbes to galaxies were signed, sealed and delivered in the first few millionths of a second. This is when the fundamental quarks became locked up within the protons and neutrons that form atomic nuclei. And there they remain, stuck together by gluons, the carrier particles of the strong force. This force is so strong that experiments have not been able to prise individual quarks or gluons out of protons, neutrons or other composite particles.

Primordial soup

Suppose, however, that you could reverse the process. The current theory of the strong interaction predicts that at very high temperatures and very high densities, quarks and gluons should no longer be confined inside composite particles. Instead they should exist freely in a new state of matter known as ‘quark-gluon plasma’.

Such a transition should occur when the temperature goes above a value around 2000 billion degrees - about 100 000 times hotter than the core of the Sun! For a few millionths of a second after the Big Bang the temperature of the Universe was indeed above this value, so the entire Universe would have been in a state of quark-gluon plasma – a hot, dense ‘soup’ of quarks and gluons. Then as the Universe cooled below the critical value, the soup condensed into composite particles, including the building blocks of atomic nuclei.

The thing to realize here is that a particle accelerator such as the LHC only smashes tiny beams of particles together, like the nuclei of atoms. For the size of particles we are talking about, yes it is an immense amount of energy, but in terms of the size of everyday things, it’s easy to contain. From a published paper on the LHC: “The total energy stored in each beam is about 360 MJ.” The MJ stands for “Mega-Joules” in layman’s terms we can first see the relationship to something we are familiar with: the watt.
A Watt is power. A Joule is Energy. A Joule is 1 Watt X 1 Second. Watts are units of Power, whereas Joules are units of Energy. Power is Energy in accordance to time: P = E/t. So One Watt of Power is equal to one Joule per second. P=E/t

1 Watt = 1 Joule/ 1 second

The whole colliding process is over in about 85 micro-seconds. (85 millionths of a second). So the power released is roughly 360,000,000 J / .000085 s = 4 trillion watts.

But, the beam is deflected by magnets within 89 micro-seconds of the initial collision, and travels through a 700 m long transfer line towards the graphite block located about 940 m downstream from the deflection magnets. Each beam hits a separate location on the graphite block, limiting the maximum temperature inside the graphite to about
700 0C.


Each fundamental force has its own corresponding boson particle – the strong force is carried by the ‘gluon’, the electromagnetic force is carried by the ‘photon’, and the ‘W and Z bosons’ are responsible for the weak force. Although not yet found, the ‘graviton’ should be the corresponding force-carrying particle of gravity. When it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when we have matter in bulk, such as in ourselves or in planets, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.

Now, all of this crazy-making that has physicists in such a frenzy is to combine all four of the known forces The strong nuclear force (holds nuclei together) the weak nuclear force (holds atoms together), the electromagnetic force (carries all of the energy from place to place) and gravity (holds the universe together – sort of). There is a theory that combines the first three forces. The Standard Model includes the electromagnetic, strong and weak forces and all their carrier particles, and explains extremely well how these forces act on all the matter particles. However, the most familiar force in our everyday lives, gravity, is not part of the Standard Model. The following is one attempt at a “Unification theory” (AKA - Theory of Everything AKA - TOE):

Loop quantum gravity - Wikipedia, the free encyclopedia

Each fundamental force has its own corresponding boson particle – the strong force is carried by the ‘gluon’, the electromagnetic force is carried by the ‘photon’, and the ‘W and Z bosons’ are responsible for the weak force. Although not yet found, the ‘graviton’ should be the corresponding force-carrying particle of gravity. When it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when we have matter in bulk, such as in ourselves or in planets, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.
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