Arthur T Knackerbracket has processed the following story:
Motion at speeds beyond the speed of light is one of the most controversial issues in physics. Hypothetical particles that could move at superluminal speeds, called tachyons (from the Greek tachýs — fast, quick), are the ‘enfant terrible’ of modern physics. Until recently, they were widely regarded as creations that do not fit into the special theory of relativity.
At least three reasons for the non-existence of tachyons within quantum theory were known so far. The first: the ground state of the tachyon field was supposed to be unstable, which would mean that such superluminal particles would form `avalanches’. The second: a change in the inertial observer was supposed to lead to a change in the number of particles observed in his reference system, yet the existence of, say, seven particles cannot depend on who is looking at them. The third reason: the energy of the superluminal particles could take on negative values.
[...] It turned out that the ‘boundary conditions’ that determine the course of physical processes include not only the initial state but also the final state of the system. The results of the international team of researchers have just been published in the prestigious journal Physical Review D.
To put it simply: in order to calculate the probability of a quantum process involving tachyons, it is necessary to know not only its past initial state but also its future final state. Once this fact was incorporated into the theory, all the difficulties mentioned earlier completely disappeared and tachyon theory became mathematically consistent. “It’s a bit like internet advertising — one simple trick can solve your problems,” says Andrzej Dragan, chief inspirer of the whole research endeavor.
“The idea that the future can influence the present instead of the present determining the future is not new in physics. However, until now, this type of view has at best been an unorthodox interpretation of certain quantum phenomena, and this time we were forced to this conclusion by the theory itself. To ‘make room’ for tachyons we had to expand the state space,” concludes Dragan.
The authors also predict that the expansion of the boundary conditions has its consequences: a new kind of quantum entanglement appears in the theory, mixing past and future, which is not present in conventional particle theory. The paper also raises the question of whether tachyons described in this way are purely a ‘mathematical possibility’ or whether such particles are likely to be observed one day.
According to the authors, tachyons are not only a possibility but are, in fact, an indispensable component of the spontaneous breaking process responsible for the formation of matter. This hypothesis would mean that Higgs field excitations, before the symmetry was spontaneously broken, could travel at superluminal speeds in the vacuum.
Reference: “Covariant quantum field theory of tachyons” by Jerzy Paczos, Kacper Dębski, Szymon Cedrowski, Szymon Charzyński, Krzysztof Turzyński, Artur Ekert and Andrzej Dragan, 9 July 2024, Physical Review D. DOI: 10.1103/PhysRevD.110.015006
(Score: 2, Insightful) by Anonymous Coward on Friday August 02, @10:35PM (1 child)
: They don't.
There's been no observation of tachyons. No extension of the standard model. No mass estimate. There's no more challenge to Modern Physics than is offered by negative-mass particles.
"Wouldn't it be cool if..." sure.
(Score: 4, Insightful) by HiThere on Saturday August 03, @12:22AM
Maybe they do. Not because of observation, as you're right, they haven't been observed, but if they ARE necessary for the standard model to engage in symmetry breaking, then there ARE a challenge.
I think that's what the summary meant by "an indispensable component of the spontaneous breaking process responsible for the formation of matter".
FWIW, I know that I'm not competent to judge those claims, and I really doubt they'll hold up, but if they do, there we end up either with tachyons or with the standard model being "adjusted" in some way.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by loonycyborg on Saturday August 03, @12:28AM
Of course such groundbreaking models could be fun or even useful, but there's just too many of them out there and most of them are garbage. Sadly, fundamental questions involving elementary particles and formation of universe are hard to test experimentally rending most of this work intellectual masturbation.
(Score: 2, Informative) by pTamok on Monday August 05, @08:57AM
At the level of subatomic physics, the direction of time is pretty much irrelevant. Most interactions are time reversible - which means that the future and the past are interchangeable.
It's the exceptions to this that are interesting - and you get into what breaks this symmetry, and why subatomic physicists talk about CPT-conservation [wikipedia.org] (charge-parity-time)
See also: CP-violation [wikipedia.org]
CPT conservation is related to the observed imbalance in the quantities of matter and antimatter in the universe:
Wikipedia: Matter-Antimatter imbalance [wikipedia.org]
It is 'easy enough' to posit that tachyons 'exist'. What is needed is testable predictions of behaviour dependent on the existence of tachyons, not currently seen in experiments. This is one of the criticisms of many formulations of String Theory: that they do not make predictions testable by current human technology, and so are not particularly 'useful'.