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I was wondering about the specific differences between matter and antimatter. How would you tell the difference between a positron and an electron?
- Mike (age 31)
There are several ways:
1. Put them between two metal plates connected by a battery. The electron will be attracted to the positive plate (anode) whereas the positron will be attracted to the negative plate (cathode).
2. Let a beam of them pass through a magnetic field. A beam of electrons will be deflected one way, the beam of positrons will be deflected the other way.
3. Put an electron and a positron in with a crowd of electrons. The electron will shun the other electrons. A positrons loves electrons. It will be attracted to the nearest one and embrace it. Both will die a miniature annihilation explosion releasing a pair of gamma rays.
Methods 1 and 2 depend on the fact that they have opposite charges and so the electric and magnetic forces on them are opposite. Method 3 depends on the fact that the positron is an anti-particles of an electron and so can annihilate:
--> γ + γ
for some interesting facts.
(published on 01/27/2010)
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