7 ms·

The lesson we should really take here is the power of wishful thinking. People dearly want to believe in FTL travel. Without it, the Universe just seems so vast

by cletus 5y ago

The lesson we should really take here is the power of wishful thinking. People dearly want to believe in FTL travel. Without it, the Universe just seems so vast, empty and distant. The truth is it is and it isn't. It's only really that on our current time scales. Not to be a broken record (there's some new variation on some old idea like every week it seems), but I'm firmly in the camp that believes FTL isn't possible. There are two prongs to that. 1. Theoretical: a lot of these theories rely on people not understanding the domain of a function (eg plugging in negative mass or energy into an equation; just because a function can operate over real numbers doesn't mean real numbers are the domain of that function); and 2. The macro evidence in that if FTL were possible it makes it that much more unlikely that we haven't detected starfaring life. Specifically, the potential volume of spacetime goes from a line cone of several million light years to the entire Universe (not just the observable Universe). We don't know how big that is of course but it's may orders of magnitude larger. So this paper tries to "solve" the negative energy/mass problem. I honestly can't speak to the soundness of this idea. I am however skeptical.

jack_pp 5y ago
Isn't there evidence starting to surface that we have actually detected alien contact?
- IdiocyInAction 5y ago
  You mean that UAP stuff? Occam's razor says this is probably some electronic countermeasure stuff by the US or something.
  - randmeerkat 5y ago
    Maybe, or what if it’s exactly what the DoD is saying? That there’s verified advanced UAPs beyond our current technological understanding.
    - stjohnswarts 5y ago
      I don't they said "there are uaps beyond..." , they said they couldn't explain all of them, that's all.
      - randmeerkat 5y ago
        “UAP clearly pose a safety of flight issue and may pose a challenge to U.S. national security. Safety concerns primarily center on aviators contending with an increasingly cluttered air domain. UAP would also represent a national security challenge if they are foreign adversary collection platforms or provide evidence a potential adversary has developed either a breakthrough or disruptive technology.” https://www.dni.gov/files/ODNI/documents/assessments/Prelimary-Assessment-UAP-20210625.pdf https://www.dni.gov/files/ODNI/documents/assessments/Prelima... I think breakthrough or disruptive technology are the key words here. They may not have said “beyond” but pretty much said everything short of that.
  - postalrat 5y ago
    Occam's razor actually says that?
    - alphachloride 5y ago
      Turing test failed.
    - Bud 5y ago
      Yes. This is actually about as clear of an example as you can find of what it says.
solarengineer 5y ago
What if we're the first species to explore FTL? What if the Universe is vast enough that FTL-capable specifies are busy in other parts of the Galaxy or the Universe?
mmazing 5y ago
Wouldn't space-faring civilizations be more likely to exist along the galactic plane, which we have a much harder time examining?
godelski 5y ago
> The macro evidence in that if FTL were possible it makes it that much more unlikely that we haven't detected starfaring life. I don't think this is a great argument. Even with FTL the galaxy (not universe) is huge. Let's just say you can go 2x (warp factor 1.25) it would still take more than 2 years to reach Alpha Centauri (our closest star, 4.37 lyr). Even at 8c (Warp 2) it would still take >6 months. At 100c it is 2 weeks. The energy to travel these different speeds presumably does not scale well and so the difference between 2c and 1000c is going to be different level of civilizations[0]. The Milky Way is 2 million light years in diameter. There's about 1000 stars within 50 light years. Here's a list of stars <5 parsecs (16 lyr)[1] or within 5 days at 1000c or 0.0008% of the Milky Way. There could be extensive networks of trade and travel with FTL civilizations and we'd probably never detect them. These routes would still be fairly local and if they aren't around us then we would have no chance of seeing them. This is basically peoples in the Western Hemisphere trying to observe people in the Eastern Hemisphere when neither civilizations have the ability to cross the ocean nor see across it to a reasonable resolution. I think a lot of people miss how huge the galaxy is (let alone Universe). Nothing is accessible without FTL. FTL is _necessary_. That, or immortality, or generational ships. The problem is that these numbers are so incomprehensibly large that we think they are magnitudes smaller than they actually are. However big you think the galaxy is, it is actually bigger. [0] https://en.wikipedia.org/wiki/Kardashev_scale https://en.wikipedia.org/wiki/Kardashev_scale [1] https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brow...
- R0b0t1 5y ago
  I don't think it's fair to say "or immortality, or generational ships." You can make a one way trip, sometimes, but you can't meaningfully communicate. FTL is necessary or the universe is kind of boring on a grand scale.
  - hallway_monitor 5y ago
    It's not boring, it's just too big and therefore too slow for our tastes. If we lived 5,000 years, taking a 100 year trip to Alpha Centauri might not seem so bad. I think extending lifespan like this is more likely than building an FTL drive.
fpgaminer 5y ago
> Theoretical: a lot of these theories rely on people not understanding the domain of a function We thought it was an aberration of mathematics when Einstein's equations blew up into singularities. A singularity couldn't exist in the real world, they said. Must just be an artifact of us using "real numbers", and we needed to be careful to respect the domains of those functions. Well, turns out singularities do exist and the math led us right to them.
- liminvorous 5y ago
  Event horizons exist, I don't think we have any evidence singularities really exist inside them, or any way gather such evidence.

by cletus 5y ago

jack_pp 5y ago

Isn't there evidence starting to surface that we have actually detected alien contact?

IdiocyInAction 5y ago
You mean that UAP stuff? Occam's razor says this is probably some electronic countermeasure stuff by the US or something.
- randmeerkat 5y ago
  Maybe, or what if it’s exactly what the DoD is saying? That there’s verified advanced UAPs beyond our current technological understanding.
  - stjohnswarts 5y ago
    I don't they said "there are uaps beyond..." , they said they couldn't explain all of them, that's all.
    - randmeerkat 5y ago
      “UAP clearly pose a safety of flight issue and may pose a challenge to U.S. national security. Safety concerns primarily center on aviators contending with an increasingly cluttered air domain. UAP would also represent a national security challenge if they are foreign adversary collection platforms or provide evidence a potential adversary has developed either a breakthrough or disruptive technology.” https://www.dni.gov/files/ODNI/documents/assessments/Prelimary-Assessment-UAP-20210625.pdf https://www.dni.gov/files/ODNI/documents/assessments/Prelima... I think breakthrough or disruptive technology are the key words here. They may not have said “beyond” but pretty much said everything short of that.
- postalrat 5y ago
  Occam's razor actually says that?
  - alphachloride 5y ago
    Turing test failed.
  - Bud 5y ago
    Yes. This is actually about as clear of an example as you can find of what it says.

solarengineer 5y ago

What if we're the first species to explore FTL? What if the Universe is vast enough that FTL-capable specifies are busy in other parts of the Galaxy or the Universe?

mmazing 5y ago

Wouldn't space-faring civilizations be more likely to exist along the galactic plane, which we have a much harder time examining?

godelski 5y ago

> The macro evidence in that if FTL were possible it makes it that much more unlikely that we haven't detected starfaring life. I don't think this is a great argument. Even with FTL the galaxy (not universe) is huge. Let's just say you can go 2x (warp factor 1.25) it would still take more than 2 years to reach Alpha Centauri (our closest star, 4.37 lyr). Even at 8c (Warp 2) it would still take >6 months. At 100c it is 2 weeks. The energy to travel these different speeds presumably does not scale well and so the difference between 2c and 1000c is going to be different level of civilizations[0]. The Milky Way is 2 million light years in diameter. There's about 1000 stars within 50 light years. Here's a list of stars <5 parsecs (16 lyr)[1] or within 5 days at 1000c or 0.0008% of the Milky Way. There could be extensive networks of trade and travel with FTL civilizations and we'd probably never detect them. These routes would still be fairly local and if they aren't around us then we would have no chance of seeing them. This is basically peoples in the Western Hemisphere trying to observe people in the Eastern Hemisphere when neither civilizations have the ability to cross the ocean nor see across it to a reasonable resolution. I think a lot of people miss how huge the galaxy is (let alone Universe). Nothing is accessible without FTL. FTL is _necessary_. That, or immortality, or generational ships. The problem is that these numbers are so incomprehensibly large that we think they are magnitudes smaller than they actually are. However big you think the galaxy is, it is actually bigger. [0] https://en.wikipedia.org/wiki/Kardashev_scale https://en.wikipedia.org/wiki/Kardashev_scale [1] https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brow...

R0b0t1 5y ago
I don't think it's fair to say "or immortality, or generational ships." You can make a one way trip, sometimes, but you can't meaningfully communicate. FTL is necessary or the universe is kind of boring on a grand scale.
- hallway_monitor 5y ago
  It's not boring, it's just too big and therefore too slow for our tastes. If we lived 5,000 years, taking a 100 year trip to Alpha Centauri might not seem so bad. I think extending lifespan like this is more likely than building an FTL drive.

fpgaminer 5y ago

> Theoretical: a lot of these theories rely on people not understanding the domain of a function We thought it was an aberration of mathematics when Einstein's equations blew up into singularities. A singularity couldn't exist in the real world, they said. Must just be an artifact of us using "real numbers", and we needed to be careful to respect the domains of those functions. Well, turns out singularities do exist and the math led us right to them.

liminvorous 5y ago
Event horizons exist, I don't think we have any evidence singularities really exist inside them, or any way gather such evidence.