I would probably have titled it "I think FTL travel might not be impossible". She does not propose a mechanism for FTL travel, just addresses claims that it's impossible.
But I feel like she takes a contrarian view just for the sake of being contrarian, so it's hard to tell which of her ideas actually have merit, and which simply exist to challenge the status quo, even when the status quo is conclusively proven.
Edit: that said, I really do want to believe this! The speed of light being an absolute limit to how fast we can travel (or even communicate), means most of the universe (even most of the galaxy) will be forever out of reach to us. And that's kinda depressing. Unfortunately, physics doesn't care if I'm sad or happy about it.
Edit2: on the other hand (I wrote the above after only having watched have the video, shame on me), I do find compelling her idea that some mathematical constructs (like special relativity) inherently cannot fully describe reality (in SR's case, SR doesn't include gravity). So saying "special relativity says FTL travel causes time paradoxes and thus cannot be possible" may be true, but since SR can't fully describe reality (hell, neither can GR), maybe it just doesn't matter. That doesn't prove that FTL travel/communication is actually possible, but at least suggests that we shouldn't be so adamant about it being impossible. But who knows, IANAPhysicist, etc.
That, or yes - clickbait contrarian. This seems to get a lot of loud followers though.
Which I guess shouldn't be surprising. Loud followings are usually created by saying things that are controversial, or offensive.
One-way space travel would still be possible using constant acceleration:
>A spaceship using significant constant acceleration will approach the speed of light over interstellar distances, so special relativity effects including time dilation (the difference in time flow between ship time and local time) become important.
>At a constant acceleration of 1 g, a rocket could travel the diameter of our galaxy in about 12 years ship time, and about 113,000 years planetary time.
https://en.wikipedia.org/wiki/Space_travel_under_constant_ac...
This one isn't particularily bad and the content is fine.
When in reality, she’s a bona-fide professional physicist, whose knowledge of physics is why she’s a YT personality. Before she was a YTer she had (and possibly still does) have one of the better physics blogs on the internet as well.
Nothing wrong with making a living being popular on YouTube for making physics videos. Even if you have to occasionally bend titles to the algorithm.
I’m happy having watched it. The argument about particles travelling at light speed and then suddenly having mass and travelling below light speed is one that I haven’t heard before. The note about 0/0 being finite rubbed me the wrong way, but I see the point.
She’s deconstructing absolutist nonsense into something less absolutist. It’s almost anti-clickbait.
(They don't necessarily circumvent the problems around infinite energies and/or zero/negative masses being apparently necessary, to be clear - I can't imagine the amount of energy needed to create and stabilize a wormhole or warp bubble to be all that trivial - but it's pretty obvious from their very premises that they would not inherently produce causal paradoxen).
1. This isn't a two valued system, you can think it may be possible without believing it's possible.
2. Rhetorically these are very different statements, and I believe GP was referring to the rhetorical difference between them.
Stated another way, if something is "not impossible", then what is it?
> I would probably have titled it "I think FTL travel might not be impossible".
(Emphasis added)
Belief isn't binary, ergo no LEM.
LEM doesn't apply to all logical systems, it only applies to two-valued logic. In practice lots of logic is 3 valued or otherwise non-binary (such as partial equality or when we have a probability distribution over a set of outcomes). Some schools of mathematics (the constructivists and intuitionalists) actually reject the LEM.
I personally, as a PhD in having internet opinions, wouldn't go so far as to reject it, but relying on the LEM or proof by contradiction is a risk. You've shown `~X`, and you're betting that a proof of `X` does not exist. But it could be that `X and ~X` is the paradox that reveals your axioms are flawed. But I digress.
The criticism is that X isn't shown to be true, it's just not shown to be false. That would be sufficient if the only values were true and false, but that's not the case here. What the original commenter was saying was, even if you accept her argument in full, it moves the needle to "maybe".
> I would probably have titled it "I think FTL travel might not be impossible".
Again, what does “not impossible” mean? The only meaning, logically, is “not impossible = possible.”
The fact that you’ve used the word “not” implies a two state system. LEM applies.
The original title made sense. Your proposed change to the title is either: equivalent to the original title or logically inconsistent.
- known possible
- not known to be possible or impossible
- known impossible
"Is possible" suggests case 1, if "is known" is implied (we are talking about science here, so that should be the case). "Is not known to be impossible" covers 2&3.
Can we flip the question around? Under what scenario would you accept the middle condition of, "we do not know whether X is or is not possible" to exist?
For instance, we don't know whether God exists or not (just a contrived example). Now consider the statement: "It's not impossible for God to exist." That's equivalent to saying "It's possible for God to exist." The two statements are totally equivalent. Sure, we don't know whether or not God exists, but that doesn't make the statement "It's not impossible for God to exist" fundamentally different from "It's possible for God to exist."
Now consider the headline: "I think faster than light travel is possible." And the suggestion is to change this to "I think faster than light travel is not impossible." Again, the two statements are totally equivalent because whether or not something is possible is a binary state and the law of the excluded middle.
> I was trying to explain why the arguments saying it's impossible are inconclusive and we shouldn't throw out the possibility too quickly
Specifically the point is that the author believes that impossibility has not been adequately proven. Not that possibility has been proven.
My entire life, as I imagine has been the case for many older nerds, has been one of imagining traveling to the stars, but to only have that possibility become more and more clearly shown to be impossible. Impossible because faster than light travel is impossible. Impossible, because the time-dilation makes the travel a one way trip. I canna break the laws of physics cap’n!
If the laws of physics do not forbid it, it changes everything! It provides hope, it means the search is worth the effort. It allows my kids to dream!
I am very happy about this article!
I’m also very excited about the proposal to use the sun’s gravitational lensing as a method of imaging distant planets. Might even see that one in my lifetime.
Actually doing the thing may be impossible for other reasons.
The second is that it reframes the speed of light limit as a “barrier”, and more clearly defines why accelerating mass to the speed of light is impossible (while explaining what mass actually is).
It doesn’t give the answer of “well you just need to do this”, but by removing artificial constraints “causality says no”, it will hopefully allow more young smart people to get interested in studying more in this area.
I strongly applaud Sabine in her attempts to demystify General Relativity and Quantum Mechanics (across other videos). We should introduce these (particularly Quantum Mechanics) into the later school curriculum. It’s a shame that the majority of people never get to study this, as it’s so fundamental to our current knowledge of physics.