Question: How similar is quantum to tachyon?

Daisy Shearer answered on 24 Mar 2022:

So a tachyon (the particle) is a hypothetical particle that travels faster than the speed of light and I’m not that convinced that they exist (I am very driven by experimental observations and we haven’t seen one yet– there might be tachyon-like quasiparticles though). Quantum mechanics is a theory of physics that helps us describe how things like matter and energy behave on a fundamental level so it’s not really something you can compare to a single hypothetical particle.

There is also the tachyonic field which is related and is something that’s a part of Quantum Field Theory (which is one of the quantum theories that physicists like me work with a lot of the time and combines quantum mechanics with special relativity) and is a quantum field with imaginary mass. We get to explore the wonderful world of imaginary and complex numbers when working with this theoretical framework! An example of a tachyonic field is the Higgs field so it links into particle physics too. Within my field of quantum technology, a phenomenon called ferromagnetism is another example of a tachyonic field where we see something called ‘spontaneous symmetry breaking’ (we have the amazing Emmy Noether to thank for her work on abstract algebra and symmetry in physics for this concept to arise from) and an effect called ‘tachyonic condensation’. String theorists also like to play around with these concepts but that’s not really my area!

So I suppose the answer is that tachyons are potentially something that makes up part of quantum mechanics in that it’s related to one of the main theoretical frameworks that we use.