CERN physicists Alvaro
de Rújula and Rolf Landua answer your most frequently asked questions.
What can antimatter be used for?
are several different uses for antimatter, the main one being for medical
diagnostics where positrons are used to help identify different diseases
with the Positron Emission Tomography (or PET
scan). For other uses, we are still in the first phases of development
and it's difficult to foresee what will happen in the next ten years!
Can we use antimatter to propel a car or a spaceship?
In principle, yes, but in practice
it is very difficult. You all know that the Star
Trek Spaceship Enterprise flies around powered by antimatter. But
in reality, making antimatter is so difficult that it is hard to foresee
it ever being used as a propellant fuel. In order to propel a matter spacecraft
weighing several tons up to the speed of light, you would need an equal
amount of antimatter and, using the present technology, it would take
millions and millions of years to produce a sufficient amount.
However, if you had a gram
of antimatter, you could drive your car for about 100.000 years!
Is it possible to build an antimatter weapon?
military use of antimatter has the same limitations as spaceship propulsion:
both would require a huge amount of antimatter, taking million of years
if you define a weapon as something which shoots bullets, an accelerator
could be considered an antiparticle gun! But we are talking about single
particles, so the amount of energy you release when you shoot one of these
"bullets" is so small you wouldn't even tickle your enemy.
How do you store antimatter?
either a positive or a negative electrical charge, so they can be stored
in what we call a trap which has the
appropriate configuration of electrical and magnetic fields to keep them
confined in a small place. Of course, this has to be done in good vacuum
to avoid collisions with matter particles.
Antiatoms are electrically
neutral, but they have magnetic proprieties that can be used to keep them
in "magnetic bottles".
What does antimatter look like?
and antimatter are identical. Looking at an object means seeing the photons
coming from that object; however, photons come from both matter and antimatter.
If there were a distant galaxy made out of antimatter, you couldn't distinguish
it from a matter galaxy just by seeing the light from it.
& Answers - page 1 of 2)
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