Antimatter: pro or anti?
In the April 2007 edition a letter was printed debunking the idea of antimatter-powered spaceships. The argument was that since antimatter is so difficult and expensive to produce, this use is impractical.
But do we know that our present method of making antiprotons is the only one possible? Or might some future scientist find a different way to produce or capture antimatter? After all, at one time transistors were too expensive to be used in computer memories.
Ed Foster, Geneva, Illinois
Dave McGinnis, a physicist at Fermilab, responds:
Obviously, I cannot predict the future and it might be possible that some future scientist will discover a more efficient way to produce antimatter. But the transistor analogy is more the exception than the rule. In the case of antiproton production, a better analogy would be to ask the car industry to develop a vehicle that can get 5 billion miles per gallon.
The current state-of-the-art efficiency for making antiprotons is about 0.0000004 percent. At Fermilab, it requires 20 megawatts of electric power to produce an 80 milliwatt antiproton beam. This is about 10 times better than it was 15 years ago, but it is still a drop in the bucket compared to what would be needed for powering a spaceship.
Nevertheless, antiprotons are an exceptional scientific tool. They have been used to make very important discoveries at Fermilab and CERN.
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