I blogged about the Higgs particle before, in posts 17 and 116. This could be almost as fundamental as it gets: How does matter obtain the property of mass? As the article below states, without mass the universe would be a sea of particles zipping around at the speed of light(the natural condition of any massless object). Read on........
Particle physics
Higgs may fly
Mar 8th 2007
From The Economist print edition
Physicists in America may have scooped their counterparts in Europe in the hunt for the source of universal mass.
BUMBLEBEES cannot do it. Fly, that is. Or so physics is said to have shown. That the insects routinely become airborne demonstrates the shortcomings of some theoretical accounts of the world. Particle physics is in a similar state. The Standard Model that scientists have devised to describe the building blocks of nature is incomplete. One failing is the lack of a proven explanation for the existence of mass. Finding exactly what bestows this vital property on matter is the quarry of a global hunt.
Without mass the universe would be a sea of particles zipping around at the speed of light (the natural condition of any massless object). It would be hard for such particles to get together. Even molecules would be rare; galaxies, stars and planets would be impossible. So would life. So physicists want to find what enabled the universe to evolve in the way it has.
What they seek is a particle called the Higgs boson. Its existence was proposed in 1964 by Peter Higgs of the University of Edinburgh. He was trying to explain why some bosons (the particles that convey the fundamental forces which hold things together) have no mass whereas others have plenty of it. Photons, for example, transmit the electromagnetic force and are massless; W-bosons, which carry a short-range force in the atomic nucleus, are massive. So far, though, the Higgs has proved elusive.
To find it, scientists at the European particle-physics laboratory, CERN, in Geneva, are building what will, when it starts up later this year, be the world's most powerful particle smasher. This machine, known as the Large Hadron Collider, is designed especially to look for the Higgs boson. But the Europeans may be pipped at the post by rivals working at what is the highest-energy collider working today, the Tevatron, at the Fermi National Accelerator Laboratory (Fermilab) near Chicago.
Mass action
Several interesting results have emerged from the Tevatron over the past few months. Last December physicists working on it announced that they had measured precisely the mass of the W-boson, which theory suggests is intricately linked to the mass of the Higgs. The W-boson turned out to be heavier than expected, which implies that the Higgs may be lighter than previously thought. A measurement of the mass of another particle, the top quark, also made by physicists working at the Tevatron, showed that this particle, too, is heavier than theory had predicted—again implying a light Higgs.
One way of modifying the Standard Model to accommodate these observations is to add an idea called supersymmetry. This decrees that each of the known types of particle the model describes has an as-yet-undetected partner type that serves to balance its properties in a mathematically pleasing way. Some versions of supersymmetry predict several Higgs bosons, each with a different mass—and one version, called the “minimal supersymmetric model”, also predicts a relatively light Higgs to be among them.
The heavier a particle is, the more energy is needed to make it (E=mc2). Hence the desire of physicists to build a more powerful machine than Fermilab's Tevatron. But a really light Higgs might be within the old workhorse's energy range.
In recent weeks a number of physicists have got excited about bumps in the data taken at two experiments at the Tevatron. A bump is usually a sign that something has gone awry, but if all possible sources of error have been eliminated, it can indicate the presence of a particle. That both experiments on the Tevatron ring have their new bumps at precisely the same energy is particularly intriguing.
Physicists are naturally cautious—at least in their public statements—and there are certainly not enough data to decide whether these bumps really are the first sighting of the Higgs. There is, nevertheless, a suppressed air of excitement at the laboratory. It still rankles among some American physicists that their own giant instrument-to-be, the Superconducting Super Collider, was cancelled for being too costly. If they have truly found the Higgs before CERN did, and have done so using a piece of fairly elderly kit, you may expect a few sardonic smiles on the lips of whomever it is from Fermilab that gets nominated to pick up the inevitable Nobel prize alongside Peter Higgs himself.
easynash
Islam, eminently logical, placing the greatest emphasis on knowledge, purports to understand God's creation:Aga Khan 4.
The God of the Quran is the One whose Ayats(Signs) are the Universe in which we live, move and have our being:Aga Khan 3
