Particle of the Month: TACHYON

Feel like going faster than the speed of light? Time travel? Spaceships from another dimension? If you start investigating these sci-fi concepts, sooner or later tachyons come up. Tachyons are hypothetical and as far as we know, do not physically exist because they can’t exist. But that makes them even more fun to think about!

Physicists and mathematicians actually do use tachyons in equations and thought experiments. According to Wikipedia, a tachyon is a “hypothetical particle that always moves faster than light and has imaginary mass.” That is, imaginary in the mathematical sense, meaning a multiple of the square root of -1. It is this imaginary mass that defines a tachyonic field which indicates that a system is unstable. Tachyons and tachyonic fields turn up in quantum field theory, string theory and astrophysical models of cosmic inflation. Even the famous Higgs boson can be associated with a tachyonic field.

Tachyons are just bizarre compared to any other particle and are hard to wrap your mind around. They are contrarians! Their speed increases as their energy decreases. Tachyons are in fact, forbidden to go any slower than the speed of light. They are in danger of getting a traffic ticket for going too slow instead of too fast!

Probably the coolest thing about tachyons is the idea of the tachyonic antitelephone. Yes, you read that right. It’s a telephone that sends signals into the past! Einstein was even thinking about this in 1907.

Basically, a tachyon goes against all the givens for any other particle. Whether or not they actually exist in the universe (and many have tried to detect them, most notably Australian Physicists Roger Clay and Philip Crough in 1974), tachyons sure do come in handy when you need to make a telephone call to the past.