Frequently asked Questions about Antimatter
1)
Is antimatter a new source of energy?
- it is true that
the annihilation of 1 kg of antimatter with matter would generate an enormous
amount of energy (9 · 1016 J, corresponding to a 1 GW power plant running
for 3 years);
but:
- there is no natural
‘mine’ (on Earth or even in the Universe) where antimatter can be dug out
- antiparticles have
to be made by using accelerators for concentrating (kinetic) energy in particle
beams and then colliding them with a block of matter (E = mc2)
- making antiprotons
costs about 10 billion times more energy than is finally stored in their
mass
- to make a kilogram
of antimatter would therefore take all the energy produced on Earth for 10
million years.
2)
Can antimatter be used for energy storage?
- Yes. For storing
small amounts of energy in an extremely compact way, antimatter is very useful.
The energy density stored in antimatter is about 1 billion times higher
than in batteries.
- But: the amount of antimatter that is
produced each year in big accelerator labs such as
CERN or Fermilab corresponds to an energy that would allow a 100 W light
bulb shine for 15 minutes.
3)
Can antimatter be used for medical applications?
- Positron Emission
Tomography has been in use for more than a decade.
- Antiproton irradiation
might be useful for cancer therapy, and will be studied at CERN.
4)
Are there everday applications of antimatter?
- Not for our daily
life at home in the foreseeable future, may be for medical applications (see
question 3).
- Producing antiprotons
requires high energy accelerators which exist only in a few places. Keeping
antiprotons away from ordinary matter requires electromagnetic
particle traps inside ultra-high vacuum vessels at very low temperatures.
5)
Why is the production of cold antihydrogen important?
- Our method has
proven to be useful for producing large quantities of slow moving anti-atoms.
- This technology
is the first step on the road to high precision comparisons of hydrogen
and antihydrogen. This is presently a purely scientific objective, with
the goal of understanding our Universe and its preference for matter
over antimatter.
6)
Antimatter as rocket fuel?
- There are indeed
researchers in the U.S. working with NASA on futuristic concepts for
antimatter induced fission engines. Antimatter would not be the main source
of energy, but would be used instead to split heavy nuclei (antiprotons
would be the ‘matchstick’). However, even for this applications
about 1 milli-gram of antiprotons would be needed, about 100,000 times
more than the present annual production on Earth. In addition, many
serious technical problems (capture, storage, transport) would have to
be overcome.
7)
Extra-terrestrials made from antimatter?
- According to the
Big Bang theory, equal amounts of matter and antimatter have been produced
in the first instants after the Big Bang. It is still not clear why
the Universe has developed a preference for our kind of matter, and
why all the antimatter has apparently disappeared.
- The most commonly
agreed model predicts that all antimatter disappeared in the first
microseconds after the Big Bang. However, it is not completely excluded
by observation that some parts of our Universe are made entirely of antimatter,
with anti-suns, anti-planets, etc. On these anti-planets, it
is quite conceivable that (intelligent) life has evolved like on Earth.
However, these anti-E.T.s would of course define their kind of matter as
‘ordinary’ and would consider us as being made of antimatter.
8) How many people
work on antimatter production at CERN?
- Officially, the
operation of the AD takes 12 FTE (full-time equivalents).
- In the three experiments
studying antimatter, there are about 100 physicists.
9) How much does the
antimatter research at CERN cost?
- The operation cost
of the AD is about 1 million CHF per year (not including the salaries).
- Overall cost including
salaries about 2.5 MCHF per year. (CERN budget only, not including
physicists from outside CERN)
10)
Does antimatter fall up - i.e. does antimatter involve anti-gravity?
- We do not know,
since no experiment has been feasible to test it experimentally. We hope
that our method will one day lead to such a measurement.
Theory says that
antimatter and matter should fall equally in gravitational fields. However,
there are several aspects of gravity which are not understood,
in particular in connection with cosmological effects (dark matter, cosmological
constant) and quantum effects. The final answer will therefore
come from experiment (as usual).
11)
Can we destroy waste (also radioactive waste) with antimatter?
A: In principle:
yes, but it would be very expensive (and dangerous) to destroy kilograms of it
(see question 1)
12) Can you build
antimatter bombs?
A: No. The destructive
power of a 10 MT hydrogen bomb (of which several thousand exist) corresponds
to about 250 g of antimatter. It would take 2.5 million years of the
entire energy production of the Earth to produce this amount.
13) Can positrons
annihilate with protons?
Only (fundamental)
particles and their corresponding (fundamental) antiparticle can annihilate
? they must be ‘mirror’ images. Therefore, positrons can only annihilate
with electrons, and antiprotons with protons.
However, protons
and neutrons are not fundamental, but composed of 3 other particles, called
quarks. When e.g. an antiproton hits a neutron, the anti-quarks from the
antiparticle can annihilate with the corresponding quarks contained
in the neutron.
LVJ - Last modified
September 19, 2002