It’s been said that the loophole to nothing being able to travel beyond c is if the particular particle was created faster than c. Not that this might be likely, but is the amount of energy required the genuine limitation or can that at least be partially circumvented? One might not be able to create an infinite source of energy, but if one had a means to absorb extremely large amounts of energy very quickly, or even instantly, could this be utilised to achieve something respectable against the physical c barrier? To my basic comprehension of electrics, a particle collider seems to resemble an incomplete capacitor?

if you want to accelerate a massive object towards c, the energy required asymptotically approaches infinity as the velocity approaches c..

Dropbear said:

if you want to accelerate a massive object towards c, the energy required asymptotically approaches infinity as the velocity approaches c..

yes, this I am aware of. I am wondering if being able to absorb immense amounts of energy can be directed.

I guess it depends on what you mean by “absorbing” energy..

Things don’t tend to absorb energy without changing somehow …

Dropbear said:

I guess it depends on what you mean by “absorbing” energy..

Things don’t tend to absorb energy without changing somehow …

I’ll give it a think

Riff-in-Thyme said:

It’s been said that the loophole to nothing being able to travel beyond c is if the particular particle was created faster than c. Not that this might be likely, but is the amount of energy required the genuine limitation or can that at least be partially circumvented?

It takes infinite energy to get a particle with non-zero mass to speed up to c, but if you could create a particle that naturally travels faster-than-light, then it’d take infinite energy to slow it down to c. If you take (kinetic) energy away from such a FTL particle it speeds up, with no limit to its upper speed.

The impossibility of reaching c from below is often explained in terms of the energy problem, but the real explanation is more fundamental: according to the relativistic formula of velocity addition, it’s not possible to get a speed of c (or greater) by adding two sub-light speeds together.

That formula is a logical, mathematical consequence of the structure of spacetime, although strictly speaking, the formula is only exact in flat spacetime. Fortunately, General Relativity says that we can analyse curved spacetime by breaking it up into lots of small patches that are approximately flat (similar to how we can make a flat atlas of a curved Earth).

Sure, we don’t yet have a final theory that combines GR & QM, so there is some wiggle room, but it’s unlikely that a working theory of quantum gravity will disagree with the current results of relativity in non-extreme regions of spacetime.

FWIW, Gerald Feinberg, who coined the word tachyon is almost certain the tachyons are not possible.

probably should have allowed a little more leeway by stating ‘approaching c’

PM 2Ring said:

FWIW, Gerald Feinberg, who coined the word tachyon is almost certain the tachyons are not possible.

Sorry but I’ve seen them on many of Gene Roddenberry’s docos.