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Comment by poszlem | Hacker News Reader

In a world with faster than light drive, isn't that a possibility, though?

Well yes and no… though there’s a deliberate faster-than-light mode of travel, we see no evidence of natural disaster phenomena propagating faster than the speed of light (obviously), so… let’s say that this places the absurdity of the notion into perspective.

If you mean in ST specifically, there are plot phenomena propagating at warp speeds on numerous occasions. That ENT episode comes to mind:

> Enterprise is hailed by a trio of aliens, who warn that a deadly neutronic wavefront, many light years across, is approaching at a speed close to warp 7. Since the ship is capable of only warp 5 and cannot outrun the storm, everyone must shelter in order to survive the storm's radiation.

https://en.wikipedia.org/wiki/The_Catwalk

Also the plot speed radio of course:

> By transmission of a subspace radio signal, which travelled through subspace rather than normal space, subspace communication permitted the sending of data and messages across interstellar distances faster than the speed of light.

https://memory-alpha.fandom.com/wiki/Subspace_communication

Yeah… I’m a trekker… but stuff like this really riles me up… ‘neutronic’ radiation sounds a lot like neutron radiation, and neutrons are massive and cannot travel at the speed of light far less exceed it.

Clearly an omega molecule has pushed the neutrons' mass out of phase and the released chroniton particles resulted in the neutrons experiencing no passage of time.

It's just basic warp theory :P

I say we use the hallowed Navigational Deflector to emit a tachyon pulse.

The midichlorians developed a neutron-sized warp core, fueled by zero-point energy and fabricated by Replicators. Sorry, did I cross streams?

You mean Replicants, I’m sure.

I had meant the Replicators from the Stargate universe, but yeah, let's go with Replicants instead.

We also know spatial anomalies can move FTL.

The graviton ellipse which consumed the Ares IV Mars orbiter in 2032 was in the Delta Quadrant by 2376. https://memory-alpha.fandom.com/wiki/Graviton_ellipse

Faster-than-light travel is basically ruled out by our current understanding of physics, AFAICT.

Keeping an open mind about it, our understanding of physics is based on light-enabled observations, so if there is something that moves faster than light, we wouldn't be able to detect it anyway, yes?

If it can have causal effects then we can detect it. If it can't, who cares.

If there was something that moved faster than light, that still interacted with regular matter in some way, then yes, we would be able to detect it by the effects.

You can hear things that are going faster than the speed of sound, so I don't see why something that is outrunning its own light would be invisible. You wouldn't see it coming, but you would see it leaving. If it's not transparent then you'd see its shadow, if it smashed its way through a planet you'd see the hole, etc.

You would actually see it departing both forward and backwards.

https://en.m.wikipedia.org/wiki/Tachyon

FTL is baked in to the expansion of the universe. Just not in a useful way so you can’t get somewhere faster than light could.

there is the proposed Alcubierre drive that would allow you to get from point A to point B faster than light. The reason is that you are not traveling through space-time but you are causing space-time to move. It is a clever way around "the rules" but it does require some exotic (and unproven) concepts like negative energy to work. It even sounds like a "warp drive".

https://en.wikipedia.org/wiki/Alcubierre_drive

More recently we have the work of Erik Lentz to make these viable with positive energy (a bunch of it AFAIR) using Solitons[0].

The funny thing is there's actually a TNG episode, New Ground, where the crew test a Soliton wave for warp propulsion.

[0]: https://arxiv.org/abs/2201.00652

My understanding is that they have yet to come up with a warp solution where you can cause the warp to accelerate. So, at this point drive is a bit of a misnomer.

my suspicion is that FTL travel wouldn't work with this drive because of what the wikipedia article states here:

"Another possible issue is that, although the Alcubierre metric is consistent with Einstein's equations, general relativity does not incorporate quantum mechanics. Some physicists have presented arguments to suggest that a theory of quantum gravity (which would incorporate both theories) would eliminate those solutions in general relativity that allow for backward time travel (see the chronology protection conjecture) and thus make the Alcubierre drive invalid."

My fun layman conjecture based on absolutely no credible knowledge of this area beyond reading articles like this is:

-- the universe has a forward direction of time & causality that is as unbreakable as exiting from a black hole is

-- in a black hole space & time are so warped they sort of switch roles - any direction you try to move in X,Y,Z only brings you closer to the singularity. In much the same way I think the outside universe operates in Time - no matter what you do, you move forward in time.

-- My somewhat unpleasant belief here is the reason you and everything in the universe can only move forward in Time is because of the Block universe[1] concept: all of X,Y,Z,T are already set & predetermined, so it makes no sense to actually try to change your path through it.

-- All of these things put together invalidate the concept of FTL travel, because FTL travel (even with a clever trick like warping spacetime) would violate causality & allow travelers to go back in time

[1] https://en.wikipedia.org/wiki/Eternalism_(philosophy_of_time...

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