Ways To Travel Faster Than Light Without Violating Relativity

StartsWithABang writes: It's one of the cardinal laws of physics and the underlying principle of Einstein's relativity itself: the fact that there's a universal speed limit to the motion of anything through space and time, the speed of light, or c. Light itself will always move at this speed (as well as certain other phenomena, like the force of gravity), while anything with mass — like all known particles of matter and antimatter — will always move slower than that. But if you want something to travel faster-than-light, you aren't, as you might think, relegated to the realm of science fiction. There are real, physical phenomena that do exactly this, and yet are perfectly consistent with relativity.

Comments

Medium.com Alert!

[weilawei]

Danger Will Robinson, Danger! This article doesn't actually provide what its title claims. Clickbait, pure and unadulterated. Plus, it's not even that informative. All stuff we see in Slashdot comments any time anyone mentions FTL travel.

Re:Medium.com Alert!

[sectokia]

Terrible click bait, doesn't mention a single way to go faster than light. Most nerds would already know all of this.

Re:faster than light never violates Relativity

[catmistake]

Relativity requires that nothing can move through space faster than light.

Relativity requres that nothing can move through space as fast as light (c). Nothing with mass moving slower than c can reach c by moving faster, due to increase in mass and infinite energy required to reach c, and nothing moving faster than light can slow down to c, for the same reasons. The quote from teh article is at best misleading and at worst, false.

Light speed

[ArcadeMan]

The fact that there's a universal speed limit to the motion of anything through space and time, the speed of light, or c. Light itself will always move at this speed.

Except, you know, cases where we slowed down light itself. By a lot.

TL;DR

[Lord Duran]

You can go faster than light goes in certain materials because then it travels slower than c. If you do that, badass things happen.

That said, the article is pretty well written IMHO, so if you've never heard of this before, go ahead and read it.

Article's summary

[m.alessandrini]

Light goes slower than c in any medium different from vacuum. Some objects can go faster than light in that medium (but not faster than c of course).

Don't bother reading

[gsslay]

The whole thing hinges on the phrase in the first paragraph; "depending on what you mean by a "thing", "faster-than-light", and "travel""

If you want to play around with semantics and definitions, then you've got an article. Otherwise, nothing new here. Speed of light unchallenged.

Light speed also depends on time

[ArcadeMan]

And time itself is also quite complex. Here's a quote from someone who explains time:

"People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff." - The Doctor.

The Usenet Physics FAQ did it better

[AdamHaun]

For a more thorough and slightly more technical approach to the same subject, check out the Usenet Physics FAQ's article "Is Faster-Than-Light Travel or Communication Possible?". Here's the conclusion:

To begin with, it is rather difficult to define exactly what is really meant by FTL travel and FTL communication. Many things such as shadows can go FTL, but not in a useful way that can carry information.

There are several serious possibilities for real FTL which have been proposed in the scientific literature, but these always come with technical difficulties.

The Heisenberg Uncertainty Principle tends to stop the use of apparent FTL quantum effects for sending information or matter.

In general relativity there are potential means of FTL travel, but they may be impossible to make work. It is thought highly unlikely that engineers will be building space ships with FTL drives in the foreseeable future, if ever, but it is curious that theoretical physics as we presently understand it seems to leave the door open to the possibility.

FTL travel of the sort science fiction writers would like is almost certainly impossible. For physicists the interesting question is "why is it impossible and what can we learn from that?"