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[RD] Will we ever travel faster than light speed?

Discussion in 'Off-Topic' started by caketastydelish, Aug 2, 2019.

  1. Akka

    Akka Moody old mage.

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    Meh.
    Of course anything relativistic would be orders of magnitude more destructive, I'm not THAT clueless :p
    But if the goal is terrorist attack about killing a whole bunch of people, between "razing anything on the surface of the world" and "fracturing the planet", the result for people is not a whole lot different, even though the second is millions of millions times more powerful.

    Regardless, the destructive energy of relativistic impact is precisely why it's considered impossible to reach (because, well, you'd need infinite energy to reach light speed) so the question is rather moot because you would still need to produce that energy to begin with (which could be used to bomb the planet too if it could be produced).
    That's already something we can theorically do, and you "just" need to mount a big thruster with enough fuel on an asteroid to do it (okay, the amount of fuel is not going to allow 1/3c, but it'll be fast enough to do a LOT of damage).
    Or a big railgun and a lot of calculation, and you fire a 100 tonnes slug from Pluto in a direction where it'll use slingshot effect to accelerate and end up hitting Earth.

    Again, if you can destroy one third of the Earth, it's functionally about the same as cracking the planet for killing people purpose.
    Well, there is a reason I started my sentence with "if" :D
    Reaching speed of light requires infinite energy according to physics, so going past that kind of violate the laws, unless you can find a way to produce "more than infinite".
     
    Last edited: Aug 7, 2019
  2. hobbsyoyo

    hobbsyoyo Deity

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    You don't even need a particularly big thruster or rail gun to set up a collision between the Earth and a large asteroid if you are content with waiting years and years for their orbits to cross after a small nudge.
     
  3. Akka

    Akka Moody old mage.

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    Well, I was aiming (ahah) at something a bit faster and with the most impact. A big railgun at least gives a few tens of km/s headstart.
     
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  4. Gori the Grey

    Gori the Grey The Poster

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    Hey wait, unless I've missed something, we haven't yet destroyed ourselves!
     
  5. r16

    r16 not deity

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    such far sightedness but the Attack on Tankograd was not glorious an achievement and it like totally achieved nothing .
     
  6. hobbsyoyo

    hobbsyoyo Deity

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    There's been enough close calls that it's a plausible explanation. :(
     
  7. Hehehe

    Hehehe Emperor

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    And you're assuming that we will completely phase them out. Of course, all of this depends on many things. How many civilizations would be in a phase where their signals would be detectable, and how close to us they are (whether or not they're within detection range)
     
  8. Lexicus

    Lexicus Deity

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    It honestly seems a bit like a psychological defense mechanism when people refuse to acknowledge how close we came.
     
  9. red_elk

    red_elk Deity

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    I'd say every species which destroyed itself, had failed the test for sentience. We still have a chance to pass it.
     
  10. Akka

    Akka Moody old mage.

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    We came close to nuclear apocalypse.
    That's a far, FAR, FAAAAR cry from actual species annihilation. Like, far.
    Mankind survived from a population bottleneck of about 50000 people spread on several continents, we'll really have to work hard to make less of that amount of us survive. We might collapse the environment and make life on Earth incredibly (and pointlessly and stupidly) hard, but to the point of killing everyone ? I doubt it.
     
  11. hobbsyoyo

    hobbsyoyo Deity

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    During various crisis points in the Cold War, there was enough nuclear weapons on hair-trigger alert to annihilate everyone on Earth.
     
  12. Lexicus

    Lexicus Deity

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    Based on what? I know there was some debate in the scientific community about how destructive a full-scale nuclear exchange would actually be, but I think it reasonable to suppose human extinction to be a plausible outcome of the detonation of thousands of warheads.

    Yeah, but we're not even necessarily talking about the total annihilation of the species. If we're talking about "filters" for civilizations that we can detect from interstellar distances, a nuclear exchange destroying our civilization and the capacity to produce and maintain advanced technology e.g. radios would be sufficient.
     
  13. Thorgalaeg

    Thorgalaeg Deity

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    I have read a good amount about this topic and i think total annihilation of humanity or even civilization is highly unlikely.

    The main factor would be the intensity and duration of nuclear winter, which depends on the number, intensity and duration of the huge fires created by nuclear explosions in cities and forests (firestorms). Only these megafires can create convective ascending currents strong enough to carry huge amounts of dust, smoke and soot to the stratosphere and darken the sky for many months or even several years, enough to annihilate vegetal life. Nuclear winter is an enigma however, while extremely optimistic models predict it would be negligible, extremely pesimistic ones predict total darkness and thereby the extintion of any life. Anyway most experts agree nuclear winter will have a significant effect depending on the number of nukes and other factors, knowing the exact degree of these effects is impossible though.

    At the peak of the cold war in the 80s there were about 60,000 warheads deployed, enough to destroy every city in the world several times (for city i mean anything bigger than 100,000 habitants). Of course nuclear war doesn't work that way, most nukes are not pointed to cities but to enemy ICBM silos and other military targets, industrial centers and cities being third and fourth level targets, anyway with 60,000 warheads there are enough to spare and destroy every single meaningful city in the world easily. Today however there is only a fraction of the nuclear stockpile of the 80s, warheads are smaller too due to higher accuracy, so leaving aside future nuclear proliferation, (something very likely looking at current world politics) effects of a global nuclear war would be smaller than in your typical cold war scenery.

    On the other hand, firestorms like the ones in Dresden, Hamburg or Tokyo are not that common and are not very well understood. There was a brief firestorm at Hiroshima and nothing at all in Nagasaki, maybe because nukes obliterate buildings in such a complete way that nothing able to burn for some significant time remains, also modern cities are mostly concrete and steel, unike the beautiful medieval cities of Dresden and Hamburg, which were mostly wood made.That said, forest firestorms like the ones happened in California last year seems the major source for nuclear winter, however some calculations indicate that only very dense woods can provide enough fuel density for firestorms to develop. So all appears to indicate that nuclear winter would not be so intense like some experts thought at first and would mostly affect the northern hemisphere only.

    Meanwhile, nuclear fallout will spread radiation poisoning and all kind of illnesses across the whole world and it will be unstoppable, but like Chernobyl proves, radiation only immediately kills at very high doses, so at short range and in the short term, in the mid/long term it soften and spread and makes life shorter, more difficult and much more miserable, but life finds its way anyway. Otoh direct destruction or mismanagement of nuclear power plants could be a major source of nuclear contamination too, maybe several times more significant than nukes themselves making things much worse in this regard.

    Of course there are other factors to have in mind apart of nuclear winter and fallout, like the total collapse of industry and large scale agriculture, infrastructures, services, transportation, healthcare, government, public order, etc... As a result countless millions would die of thirst, hunger, violence and all kind of easily treatable illnesses.

    I think the result of a global nuclear war would be the total destruction of civilization in most northern hemisphere, most of the population would die. Russia, USA, China, Koreas, Japan, India, Pakistan, Israel, Middle East and most of Europe would experiment almost total annihilation due to countless direct nuclear hits and subsequent effects, the worse the more urbanised the country is, other less involved countries would suffer the effects of radiation and more or less severe nuclear winter and possibly most people would die of radiation poisoning and starvation but many millions would survive too. OTOH, most models show that Southern hemisphere would suffer a more mild nuclear winter and fallout, but collapse of world economy will reach them too, and several millions may also die in famines and epidemics. Society and civilization may not crumble in these countries thought and governments would probably survive.

    So, for the TLTR, preferred tourist destinations for ww3 are Australia and Argentina.
     
    Last edited: Aug 10, 2019
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  14. uppi

    uppi Deity

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    Ultimately, a Dyson sphere should reach a steady state in which it radiates as much energy as the star within, only with a shifted spectrum. The surface area would be huge, but for a telescope looking at it from a long distance this would not matter, because from a 1000 light years away, a telescope could not resolve it anyway and would make it look the same size as a star.

    It could only be hard to detect if the wavelength was in a range for which we don't have any (good) telescopes. Otherwise a Dyson sphere which has reached the steady state should be fairly easy to detect, even at large distances.
     
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  15. hobbsyoyo

    hobbsyoyo Deity

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    I immediately facepalmed when I read that. Thanks for the correction!
     
  16. El_Machinae

    El_Machinae Colour vision since 2018 Retired Moderator

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    Wait, you could cause your Sphere to radiate in spectra that get absorbed most easily by interstellar dust ... that would help obfuscate it
     
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  17. red_elk

    red_elk Deity

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    They can just use quantum anti-entropy thermal absorber instead of primitively radiating heat into space.
     
  18. Akka

    Akka Moody old mage.

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    Even total darkness for years wouldn't spell the end of life. There is lots of life in places where absolutely no light goes (deep caverns and deep oceans). Extremophiles live close to ocean vents where water is at 300 to 600 °C.
    Life will continue as long as the planet doesn't explode or melt entirely.
    I don't think Dyson spheres would ever be built. Not only the engineering feat is mind-boggling, but even more than that, it's just pointless - it's pretty incredibly inefficient to harvest energy this way.
     
  19. El_Machinae

    El_Machinae Colour vision since 2018 Retired Moderator

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    Well, except that it's all at the margin. Each individual addition to the Swarm makes short-term sense. Unless you actually mean 'Sphere', not Swarm. My impression is that most people just immediately mean 'Swarm' once pressed. The Sphere itself makes little sense
     
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  20. hobbsyoyo

    hobbsyoyo Deity

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    Also, probably pointless. A society that can build such an energy-collecting device will have surely mastered fusion or more exotic energy production techniques such that they don't need to harvest every drop of solar energy. A sphere would create a massive amount of livable space but it's such a monumental amount of space that I can't imagine a use for it all.
     

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