Particles faster than light!
Updated: Aug 19, 2021
IN 1915, One of the world’s renowned scientist, Albert Einstein, wrote legendary papers of the stirring world of physics, postulating that nothing can travel faster than the speed of light which is nearly 300000km/s. Later in the midst of 20th century, after years of research, Indian theoretical physicists named E. C. G. Sudarshan, V.K Deshpande and Baidyanath Misra were the first to propose the existence of particles faster than light and named them "meta-particles”. Later In the 1967 paper by Gerald Feinberg, the term 'Tachyons' was coined which are hypothetical paticles which are faster than light.
Enough of history and the past, now let us see something more about tachyons.
Since tachyons travel faster than light, it would not be possible to see it approaching. After a tachyon has passed nearby, an observer would be able to see two images of it, appearing and departing in opposite directions. Gerald Feinberg also proposed that tachyonic particles could be quanta of a quantum field with imaginary mass because when a particle accelerates, its mass would increase with increase in speed and would need more and more energy to accelerate with growing mass. Therefore, if tachyons had real mass, they would require infinite energy to move at the speed of light. But later, it was realized that the imaginary mass of tachyonic particles gives rise to an instability known as tachyon condensation which is a process where a system can lower its potenial energy by spontaneously producing particles .
One curious property of tachyons, unlike ordinary particles, is that the speed of a tachyon increases as its energy decreases. A tachyon with an electric charge would lose energy as Cherenkov radiation just as ordinary charged particles do when they exceed the local speed of light in a medium (other than a hard vacuum). A charged tachyon traveling in a vacuum, therefore, undergoes a constant proper time acceleration and, by necessity, its world line forms a hyperbola in space-time.
Tachyonic particles might be observed traveling backward in time due to their speed being faster than the light reaching the observer. That is if they could be observed at all, which is not the case. So far they exist only as hypothetical particles and cool science fiction stories. Unfortunately, the only cool consequence of a tachyonic field so far has been the spontaneous symmetry breaking, changing the standard model of the Universe. But that was the age of the Universe ago.
On the positive side, there is still so much we don’t know about the physics of the Universe we live in, like what is most of it (95%) is really made of. The fundamental particles that we currently know only constitute about 5% of the entire Universe.
27% of the Universe is contributed by dark matter, which we only know is something with a mass that we cannot observe (but we can observe the effects of the extra mass). It could be some exotic matter, that doesn’t interact with photons and that we haven’t discovered yet.
68% is dark energy, which we know almost nothing about, other than there is something that accelerates the expansion of the universe. We call it dark energy, because we can’t see it and because it’s expanding something, like energy usually does. But other than that — we have no idea.
One explanation using fluctuating tachyon-anti-tachyon pairs is given by two physicists, Herb Fried and Yves Gabellini, in a publication The Birth and Death of a Universe.
Herb Fried behind the original publication explains:
“If a very high-energy tachyon flung into the real vacuum (RV) were then to meet and annihilate with an anti-tachyon of the same species, this tiny quantum ‘explosion’ of energy could be the seed of another Big Bang, giving rise to a new universe. That ‘seed’ would be an energy density, at that spot of annihilation, which is so great that a ‘tear’ occurs in the surface separating the Quantum Vacuum from the RV, and the huge energies stored in the QV are able to blast their way into the RV, producing the Big Bang of a new universe. And over the course of multiple eons, this situation could happen multiple times.”
The universe is unknowing and mysterious, but with every step further in physics, we Homosapiens are uncovering every missing clue that makes this universe. So keep your thinking caps on and join us cover every fact found till this date!