14 dec. 2011

Mer om Higgs-bosonen

Richard Dawkins har bett professor Lawrence M. Krauss skriva en populärvetenskaplig förklaring om varför (den eventuella) upptäckten av Higgs-bosonen är så intressant.
The Standard Model of particle physics implies that there is an otherwise invisible background “Higgs field” that permeates all of space. This field interacts with other particles with varying degrees of strength. As particles move through space, they interact with the background Higgs field, and those that interact more strongly will experience more resistance to their motion, and will act heavier. Some particles, like the photon, do not interact with the field at all, and remain massless. In this way, the mass of everything we see is determined by the existence of this field, and if it didn’t exist, essentially all particles would be massless. In this case, mass is an ‘accident’ of our circumstances because we exist in a universe in which such a background field happens to have arisen.

But why a Higgs “particle”? Well, it turns out that relativity tells us that no signal can travel faster than light. Incorporating this in quantum mechanics tells us that forces which we think of as being due to fields like the electric field are actually transmitted between objects by the exchange of particles, and that these particles travel on average at the speed of light or slower. Why particles transmit forces is like thinking of playing catch. If I throw a ball to you and you catch it, then you will be pushed backwards by the force of my ball, and I will by pushed backward by the act of throwing the ball.. Thus we act like we repel each other in this case.

So, if there is a Higgs field, it turns out that there has to be a new particle associated with this field, and this is the Higgs particle.
Läs hela artikeln hos Richard Dawkins Foundation for Reason and Science.

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