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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

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.

lll-o-lll 4y ago
No! This is the most seismic and fundamentally perspective changing news that I have heard from a physicist in my life. It needs this strong title. 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!
- maxbond 4y ago
  Not a physicist, but for what is worth, my understanding is it's fairly realistic we could send probes to Alpha Centauri within a human lifetime or so using an approach like Breakthrough Starshot (regardless of whether that particular project succeeds). https://youtu.be/fsARBnvUB2E https://youtu.be/fsARBnvUB2E
  - lll-o-lll 4y ago
    Yes, there is still plenty to explore in the near-medium term. 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.
- ben_w 4y ago
  Well, it's more of "it doesn't necessarily violate causality (but might anyway)" rather than "here's how to make a warp drive". Actually doing the thing may be impossible for other reasons.
  - lll-o-lll 4y ago
    There are multiple levels to this. One is her attacks on the current orthodoxy around arguments that invoke causality or Special Relativity (as opposed to General Relativity). The arguments seem sound, and I’m sure it will hurt egos and generate controversy (a specialty of this particular blogger/youtuber). 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.
TexanFeller 4y ago
She seems to have good credentials and mostly sticks to claims that seem to have some evidence...but her penchant for clickbait titles and other YouTube algorithm hacking commentary makes it hard to take her seriously.
- dmix 4y ago
  She's a professional YouTuber (among other work), those sites basically require you to do that sort of thing to get and maintain traction over the long term. This one isn't particularily bad and the content is fine.
  - messe 4y ago
    That’s a bit unfair toward her. She’s not just a professional YouTuber. She is also a bonafide[1] physicist, who has spent years acting as a contrarian to the mainstream ideas. [1]: https://m.youtube.com/watch?v=AuOlHBbUkX4 https://m.youtube.com/watch?v=AuOlHBbUkX4
    - blindriver 4y ago
      Professional Youtuber != Full-time Youtuber.
      - rhaway84773 4y ago
        Yeah but calling her a “professional YouTuber (among other work)” is a very blatant misrepresentation of who she actually is, considering the opinion most people, especially on this site, would have of a YouTuber. An HNer who does not know of her would almost certainly come away with the idea that much like most YTers, she doesn’t know much of what she is talking about. 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.
        dmix 4y ago
rcme 4y ago
Law of excluded middle. The two statements are equivalent.
- maxbond 4y ago
  I'd argue not for two reasons. 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.
  - rcme 4y ago
    If something is "not impossible", then it is possible. To say otherwise is to violate LEM, which is an essential part of all of our logical systems. The vast majority of mathematical proofs, many of which form the foundation of our physical understanding, would not hold without LEM. Stated another way, if something is "not impossible", then what is it?
    - maxbond 4y ago
      Sure but the claim is, "I believe X," not X. > 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".
yellowapple 4y ago
Indeed, two such mechanisms that would largely circumvent the issues around CTCs and invalid Lorentz transformations and such entirely - Alcubierre drives and wormholes - are barely mentioned. (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).

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.

lll-o-lll 4y ago

No! This is the most seismic and fundamentally perspective changing news that I have heard from a physicist in my life. It needs this strong title. 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!

maxbond 4y ago
Not a physicist, but for what is worth, my understanding is it's fairly realistic we could send probes to Alpha Centauri within a human lifetime or so using an approach like Breakthrough Starshot (regardless of whether that particular project succeeds). https://youtu.be/fsARBnvUB2E https://youtu.be/fsARBnvUB2E
- lll-o-lll 4y ago
  Yes, there is still plenty to explore in the near-medium term. 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.
ben_w 4y ago
Well, it's more of "it doesn't necessarily violate causality (but might anyway)" rather than "here's how to make a warp drive". Actually doing the thing may be impossible for other reasons.
- lll-o-lll 4y ago
  There are multiple levels to this. One is her attacks on the current orthodoxy around arguments that invoke causality or Special Relativity (as opposed to General Relativity). The arguments seem sound, and I’m sure it will hurt egos and generate controversy (a specialty of this particular blogger/youtuber). 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.

TexanFeller 4y ago

She seems to have good credentials and mostly sticks to claims that seem to have some evidence...but her penchant for clickbait titles and other YouTube algorithm hacking commentary makes it hard to take her seriously.

dmix 4y ago
She's a professional YouTuber (among other work), those sites basically require you to do that sort of thing to get and maintain traction over the long term. This one isn't particularily bad and the content is fine.
- messe 4y ago
  That’s a bit unfair toward her. She’s not just a professional YouTuber. She is also a bonafide[1] physicist, who has spent years acting as a contrarian to the mainstream ideas. [1]: https://m.youtube.com/watch?v=AuOlHBbUkX4 https://m.youtube.com/watch?v=AuOlHBbUkX4
  - blindriver 4y ago
    Professional Youtuber != Full-time Youtuber.
    - rhaway84773 4y ago
      Yeah but calling her a “professional YouTuber (among other work)” is a very blatant misrepresentation of who she actually is, considering the opinion most people, especially on this site, would have of a YouTuber. An HNer who does not know of her would almost certainly come away with the idea that much like most YTers, she doesn’t know much of what she is talking about. 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.
      - dmix 4y ago

rcme 4y ago

Law of excluded middle. The two statements are equivalent.

maxbond 4y ago
I'd argue not for two reasons. 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.
- rcme 4y ago
  If something is "not impossible", then it is possible. To say otherwise is to violate LEM, which is an essential part of all of our logical systems. The vast majority of mathematical proofs, many of which form the foundation of our physical understanding, would not hold without LEM. Stated another way, if something is "not impossible", then what is it?
  - maxbond 4y ago
    Sure but the claim is, "I believe X," not X. > 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".

yellowapple 4y ago

Indeed, two such mechanisms that would largely circumvent the issues around CTCs and invalid Lorentz transformations and such entirely - Alcubierre drives and wormholes - are barely mentioned. (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).