1. We have added a Gift Upgrades feature that allows you to gift an account upgrade to another member, just in time for the holiday season. You can see the gift option when going to the Account Upgrades screen, or on any user profile screen.
    Dismiss Notice

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

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

  1. Lexicus

    Lexicus Deity

    Joined:
    Aug 28, 2007
    Messages:
    24,885
    Location:
    Sovereign State of the Have-Nots
    Space is big. Space-faring civilizations could occur once every 100 galaxies. That would mean there are 1 billion space-faring civilizations in the known universe, and our chance of detecting one, let alone coming into contact is still essentially zero.

    edit: and i should note that this is assuming the nearest space-faring civilizations use technologies that are recognizable to us and detectable by us.

    really i think the problems we face in detecting alien life are more akin to this classic xkcd:
     
    Last edited: Aug 6, 2019
    Gorbles, tjs282 and hobbsyoyo like this.
  2. El_Machinae

    El_Machinae Colour vision since 2018 Retired Moderator

    Joined:
    Nov 24, 2005
    Messages:
    44,917
    Location:
    Pale Blue Dot youtube=wupToqz1e2g
    Out of my butt. It's just showing how most people's Fermi explanation really only accounts for one or two of the zeros
     
  3. Perfection

    Perfection The Great Head.

    Joined:
    Apr 9, 2002
    Messages:
    49,809
    Location:
    Salisbury Plain
    There is no faster than light speed.
     
  4. Hygro

    Hygro soundcloud.com/hygro/

    Joined:
    Dec 1, 2002
    Messages:
    23,314
    Location:
    Montana
    But we may yet traverse greater distances in time than light travels.
     
  5. Fippy

    Fippy Mycro Junkie Queen

    Joined:
    Mar 17, 2013
    Messages:
    11,657
    Gender:
    Female
    Ironically we should be more concerned about nature balance and our planet, if it's about the future of humanity.. ;)
    But if somebody wants an example of Universe magnitude:

     
    Narz likes this.
  6. AdamCrock

    AdamCrock Polish Pudding

    Joined:
    Jul 4, 2012
    Messages:
    5,168
    Gender:
    Male
    Location:
    Nibylandia
    I'm no expert but if we can't go faster than light we just might have a shot at making the light go slower than us. It isn't the same thing You see, it is all in an observer view. Black holes mastered the light sucking techniques using gravity so if a body moves towards them he appears to go slower and slower so maybe there is a chance that we can find out a way to bend the light speed rule by using gravity, the problem is we don't understand gravity yet.
     
  7. TheMeInTeam

    TheMeInTeam Top Logic

    Joined:
    Jan 26, 2008
    Messages:
    25,713
    For now that is true.

    Eventually, living on Earth will be impossible no matter how ecologically pristine humanity is, so this is still a fun thought experiment with at least SOME practical value in principle.

    We already have a means of making light travel more slowly than other things can travel, by forcing light to travel through mediums that competing things don't.

    This doesn't allow the other things to exceed the speed of light in a vacuum, however.

    We don't understand gravity, but so far we're not observing anything that alters the apparent max rate of getting from point A to point B. TECHNICALLY, parts of the universe can expand away from each other faster than the speed of light, but neither hits a velocity greater than light speed.

    So sure, if we had a way to leave and re-enter the universe we could win a race against light to a distant galaxy. It's basically the same thing as saying "if wormholes exist...". Sure, if we are allowed to create negative energy or put white holes into the universe then some rules we presently observe could be overcome.

    But those are big "ifs". I could do a lot of things people can't do if I had magic, too.

    Then again, if #3 in Hobbsyoyo's list pans out we could just make a computer with power we couldn't even envision right now and simulate ourselves a reality to live in where these things are allowed, among others. That would bypass the "speed of light in a vacuum" barrier pretty soundly, as we'd bypass the need. Though "biological immortality" would in principle do the trick too.
     
  8. Hehehe

    Hehehe Emperor

    Joined:
    Feb 17, 2006
    Messages:
    1,391
    Location:
    Finland
    While I agree that the "radio-heavy phase" is indeed decreasing, the point was that these technologies still see marginal use. Same is true for older technologies which have long since passed their usefulness. For example, the post office still delivers physical letters to you (even if it it's mostly bills). Armies, and probably some other applications, still use messengers and even a (sort-of) telegraph alongside newer communication technologies. It's true that their usage is marginal, but they exist nonetheless. I expect that radio waves will continue to be used by radio amateurs or walkie talkies, if nothing else (the technology is at least relatively cheap).

    There was a paper that talked about this. Maybe I should go check the range of our current receivers
     
  9. Akka

    Akka Moody old mage.

    Joined:
    Nov 14, 2001
    Messages:
    13,365
    Location:
    Facing my computer.
    The law of the universe makes actually moving FTL impossible. We might find a way, but I don't buy it.
    If it's possible to just "translate" from a point to another (like a wormhole or whatever), we could get the actual functionality of moving FTL without ludicrous kinetic energy.

    Also, if you're wary of terrorist attacks, no need for FTL. A simple array of metal rods in high altitude would work just as well, without even requiring any initial speed.
     
  10. Phrossack

    Phrossack Armored Fish and Armored Men

    Joined:
    Oct 26, 2008
    Messages:
    6,045
    Rods may have a lot of KE behind them, but it's nothing compared to a relativistic kill vehicle or an FTL weapon. Still, either way, humanity is coming up with increasingly deadly and widespread weapons beyond its ability or will to control.
     
    Lexicus likes this.
  11. Lexicus

    Lexicus Deity

    Joined:
    Aug 28, 2007
    Messages:
    24,885
    Location:
    Sovereign State of the Have-Nots
    Not "just as well." You can do the kinetic energy calculations for relativistic impactors yourself.

    Incidentally, a far more realistic technology than FTL travel would be a constant-acceleration engine that takes a ship up to an appreciable fraction of lightspeed, like 1/3c. A kamikaze ship using that kind of engine would be an extremely powerful and all but unstoppable weapon.
     
  12. hobbsyoyo

    hobbsyoyo Deity

    Joined:
    Jul 13, 2012
    Messages:
    25,938
    You're still assuming that we're not going to phase these things out entirely, sooner or later. Even if I go with the premise that some marginal uses will continue, that doesn't mean they'll be detectable at lightyear distances. They won't.
    I mean at some level it doesn't matter if everyone is dies from the shockwave of a 20 km impactor or if the Earth gets split in two by a relativistic impactor. It's all overkill. The main difference is that one is more or less achievable right now, the other, not so much.
     
  13. Leifmk

    Leifmk Deity

    Joined:
    Jan 20, 2006
    Messages:
    3,049
    Location:
    Outskirts of Oslo, Norway
    Well yes, but then a civilization able to do that could also employ similar amounts of energy in other ways for other purposes. Basically you would either end up with a robust and advanced civilization which used just about every method to guard against every conceivable disaster (natural or otherwise), from dispersed and diversified habitats to a widespread early-warning defense network; or everything would be completely ruined by acts of war, terror or accident.
     
  14. El_Machinae

    El_Machinae Colour vision since 2018 Retired Moderator

    Joined:
    Nov 24, 2005
    Messages:
    44,917
    Location:
    Pale Blue Dot youtube=wupToqz1e2g
    With regards to radio, we are still having the problem of 20 zeros. Or maybe in this case, 10 zeros. The civilization might reduce its radio noise to the point where it's not detectable at distance. But it's more than that, you're also assuming that 0 out of 10 billion people are choosing broadcast at detectable levels. Now, I don't know how much it would cost to make a radio broadcaster that could be detected elsewhere in our galaxy, but I suspect a small dedicated group of people could do it
     
  15. Phrossack

    Phrossack Armored Fish and Armored Men

    Joined:
    Oct 26, 2008
    Messages:
    6,045
    I'm betting very heavily on the latter. Someone in the past might have said, "Any society able to produce enough necessities for eight billion people could easily be robust enough to withstand inequality, hunger, weapons of mass destruction, and climate change," but we're definitely failing to do so. In general, it's easier to destroy than to protect.
     
  16. TheMeInTeam

    TheMeInTeam Top Logic

    Joined:
    Jan 26, 2008
    Messages:
    25,713
    Do we know enough about the universe between stars to know for sure that radio noise makes it through? Legit question, I just want to make sure we can rule out the possibility of the universe having tons of radio signals all more or less blocked and/or fading into being unrecognizable over long distances. If our ability to detect radio signals like our own is limited to say 10 light years or something you'd have a lot fewer 0's.

    This still implies breaking causality as we understand it however, and while the math for what would allow (in principle) a wormhole is beyond me my impression is that you have to assume things we've never observed exist like negative energy at macro scales.
     
  17. El_Machinae

    El_Machinae Colour vision since 2018 Retired Moderator

    Joined:
    Nov 24, 2005
    Messages:
    44,917
    Location:
    Pale Blue Dot youtube=wupToqz1e2g
    Yep, for radio specifically, I don't know the answer to your question. SETI is looking for intentional broadcasts, mostly. That's still the 10 zero problem, where a dedicated group could easily intentionally send an interstellar signal. Of course, unless that civilization become interstellar itself, finding that one transmitting star is a determined task.
     
  18. TheMeInTeam

    TheMeInTeam Top Logic

    Joined:
    Jan 26, 2008
    Messages:
    25,713
    My point was that the 10 zero problem is only relevant if the activity in question is something we can detect, even if the alien(s) try. For example even if literally every alien species drinks water, we have no way to detect aliens drinking water on other planets from Earth. That isn't part of the 20 zeros question because we'd see the same things right now regardless of whether there are trillions of aliens or none.

    We have to KNOW that what they're doing is something we can detect. This allows us to rule out things like Dyson spheres, which we could actually see, but not drinking water. I'm curious where radio falls on the spectrum between those.
     
  19. hobbsyoyo

    hobbsyoyo Deity

    Joined:
    Jul 13, 2012
    Messages:
    25,938
    I don't think we could spot Dyson spheres at this time except ones that are very close. They radiate infrared in a tell-tale way but spread out over a huge surface area which means it's quite diffuse and not likely to be easily detectable from very far away with current technologies. We could stumble on them by their gravitational effects (i.e. - there's obviously a stellar mass in this region but it's hidden) but that would almost be an accidental find.

    The radio spectrum has varying penetration through interstellar dust media. There are few frequencies that do have great penetration and those are the ones we look for on the assumption ET both knows they easily penetrate the interstellar media and that they would intentionally use them to signal us. I do not know how big the overlap is between 'incidental' detection and purposeful signaling. What I mean is that I don't know how useful those spectra are for every day sorts of uses we might pick up from a society that is broadcasting without trying to signal to another society.
     
    El_Machinae likes this.
  20. Zelig

    Zelig Beep Boop

    Joined:
    Jul 8, 2002
    Messages:
    16,518
    Location:
    Canada
    Yes, this is the key point. There's absolutely no possibility for FTL (even just FTL transfer of information) without breaking causality.
     

Share This Page