Pete,
Thanks for the clarification. Good luck with your work!
I dug up the following at the CERN site.
Natalia
http://livefromcern.web.cern.ch/livefromcern/antimatter/academy/AM-travel01b.html
Why? Albert Einstein, in 1905, wrote down the famous equation E=mc^2 .
It says that mass is a very concentrated form of energy.
Energy is like the *'money'* of nature; it comes in two different
currencies, and with an enormous exchange rate - the square of the speed
of light .
1 kg corresponds to 25,000,000,000 kWh of energy; 1 gr would be enough
to supply energy to a medium-sized town for a whole day!
If you could convert all of the energy contained in 1 kg of sugar, or 1
kg of water, or 1 kg of any other stuff, you could drive a car for about
100,000 years without stopping!
*. How mach antimatter can you make in one accelerator cycle?*
Here at CERN we can produce 50 millions antiprotons in each cycle (about
once a minute), that allows us to make a few hundred antihydrogen atoms.
The number could be 10 times higher in particular configurations of the
accelerator. This sounds a lot, but expressed in grams it is a billionth
of a gram in a year.
If we count on the production CERN has done over the last 10 years
(about 1 billionth of a gram), it has cost a few hundred millions Swiss
francs.
*But how can energy be transformed into matter, or vice versa?
*
Big meteorites traverse our solar system with a typical speed of about
30 km/sec. If such a meteorite enters the Earth's atmosphere, its energy
of movement is converted into heat, reaching 100,000 C^o or more and
melting most of its material (/'shooting star')/.
We do not have the technology to make a space ship go at the speed of
light (300,000 km/sec), but it is possible - using accelerators at CERN
- to make single particles (like a proton, the nucleus of a hydrogen
atom) go that fast.
If a particle moving with this speed hits a block of material, its
energy is also transformed, producing 'temperatures' of
10,000,000,000,000 C^o or more. Under these extreme circumstances, the
energy set free in the collision will transform into matter.
*But: what kind of matter do I produce in such collisions?
*
In a coin factory, hot metal is pressed into coins. They only come in
specific sizes and values, as 1p, 2p, 5p, 10p, 50p and 1 pound.
Similarly, nature does not allow energy to be converted into just any
kind of matter. Nature has provided us with *'moulds'*, corresponding to
a precisely defined amount of energy, as well as having some other
particular properties.
These moulds are analogous to *particles*, the most important ones in
our daily lives being the *proton*, the *neutron* and the *electron*.
They have very precisely defined properties, such as their mass, their
electric charge or the way they interact with other particles.
*So can I transform energy into a single proton or a single electron?
*
Imagine a hot metal sheet in a coin factory ('energy'). When you stamp
out a coin from a metal sheet, you are left with a coin and a hole in
the sheet.You could call this hole an "anticoin".
This is similar to what happens when energy transforms into matter. Many
experiments have shown that you can only produce a pair of particle and
its mirror image, called 'antiparticle', at the same time. Nobody has
ever observed the production of only particles, or only antiparticles.
That example also shows another feature observed with particles and
antiparticles. To create them, it takes energy, and when you bring them
back together ('*annihilation*', because they disappear into a flash of
energy), this energy is released. It is like putting the coin back into
the hole, leaving the original metal sheet.
*. How do sound waves propagate in antimatter?*
If there is a difference between matter and antimatter, it is very very
tiny, that's why we are doing experiments here at CERN to investigate
it. They are so similar that sound waves, that are vibrations of matter
or antimatter, would be identical. An antimatter piano would sound
exactly as a matter one.
*. How does the gravitational field act on antimatter?*
The gravitational force depends from the energy of an object, and since
matter and antimatter have both positive energy, gravitation acts on
them in the same way.
This means that an object made of matter and one made of antimatter
would both stand on the floor, the latter one not flying off the sky...
pete wrote:
Been a bit busy and out of net access while getting established here,
but I need to correct a misapprehension here:
On Sun, 29 Aug 2010, Darryl or Natalia wrote:
If they can isolate anti-matter safely, though I don't know how that's
possible, we will have access to ayn amazing alternate energy. Then,
the world's elite can harness and exploit it.
Um, no. The ALPHA group is one of those I am involved with on occasion.
The process is pretty simple, it's just a variation on the neutral atom
trap, using the same techniques - decelerations, coolings, energy
transfers, laser cooling, magnetic trapping. The thing is, you
irreducibly must have a multi-GeV particle accelerator to generate the
anti-protons, (positrons are an easy by-product), which consumes vast
quantities of energy producing large quantities of particles, a tiny
fraction of which end up finding their way into the trap. The energy
cost per ultimately trapped particle created is vastly more than the
energy one could get out of anihilatinhg the particles in the trap; but
regardless, if you could create antimatter with 100% efficiency, you
still have to provide the energy to make the particle, and that's the
amount you get back when you anihilate it. There is no source of new
energy in this process. You just get back out what you've put in.
There is no practical value to producing antimatter whatsoever, except
perhaps as a very light and compact way of storing energy for propellant
for small interstellar probes. Figure about 200 years development time.
(Prior to that, the containment will be so massive that there will be no
advantage - unlike the nonsense in the Dan Brown novel, a gram of
antihydrogen, besides taking about 10^18 years to produce, would, in
order to transport it, require a fleet of vehicles big enough to carry a
multi-Megawatt power supply to provide power to operate the containment
system, which would dwarf the containment system itself, which would
aready be too large to fit in a semi). No, the really interesting
questions about neutral anti-atoms are about what their properties are.
How do the frequencies of the transition lines compare to those of
normal atoms? Do they behave the same under application of forces -
gravity, magnetic fields, etc? There is much to be revealed there, and
if they are the same, or different, either outcome will be greatly
illumiinating.
-Pete
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