Robert J. Bradbury (
Sat, 21 Aug 1999 16:37:23 -0700 (PDT)

On Sun, 22 Aug 1999, Gabriele Betti wrote:

> I'd like to know why , if antimatter "exist" and since it react
> with matter releasing light or energy..why it doesn't exist an
> antimatter engine(like UFO to understand).

Well, generally speaking people don't build engines if there is no fuel to put in them... :-)

A number of fairly serious scientists have done preliminary designs for antimatter rockets/engines during the last 20+ years and then do calculations on how this would impact the times for interstellar travel [it still takes a long time!].

We can produce antiparticles (it is done every day at CERN, the Fermi Laboratory and a few other places). The problem currently is to take the anti-particles (which are traveling in particle accelerators near the speed of light), slow them down, combine the anti-protons & anti-electrons into anti-matter and store them in a trap (e.g. a fuel tank) for long periods without having it explode. I believe we may be at the point where we can store a few hundred anti-atoms currently.

We need a lot more anti-matter if we want to use it as fuel and the problem is that the production of anti-matter is very inefficient and therefore is very expensive. It would probably take the entire power output of nations for weeks to produce enough antimatter fuel for you to make a short trip in your car.

Then there is the problem that combining anti-matter and matter produces a lot of radiation, so we would need to redesign your car so that you have a big lead shield between you and the antimatter engine. At that point the car weighs a lot more and you need even more anti-matter fuel to make it go.

Hope that explains it.