Page 1 of 2 12 LastLast
Results 1 to 30 of 47

Thread: Star Trek "physics"

  1. #1
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631

    Star Trek "physics"

    OK, so here's the idlest question of the day (so far).

    In the Star Trek universe, one pseudoscience explanation for Warp Speed (FTL) travel, is the existence of an alternate domain of spacetime called "subspace". This apparently acts as an absolute reference frame allowing simultaneity.

    My question is, does it have to be an absolute reference frame? Can it merely be a broader "local" than the Einsteinian space we're used to, but still relative?
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  2. #2
    Join Date
    Aug 2006
    Posts
    3,212
    Quote Originally Posted by Noclevername View Post
    This apparently acts as an absolute reference frame allowing simultaneity.
    How did you arrive at these two conclusions?

  3. #3
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by DaveC426913 View Post
    How did you arrive at these two conclusions?
    Because that's how it is described in the peripheral literature approved for official publication. Particularly the Star_Trek:_The_Next_Generation_Technical_Manual.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  4. #4
    Join Date
    Jun 2005
    Posts
    13,069
    Quote Originally Posted by Noclevername View Post
    My question is, does it have to be an absolute reference frame? Can it merely be a broader "local" than the Einsteinian space we're used to, but still relative?
    Sure, it could be just a broader local frame.



    Sent from my iPhone using Tapatalk
    As above, so below

  5. #5
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Jens View Post
    Sure, it could be just a broader local frame.



    Sent from my iPhone using Tapatalk
    Thank you.
    That would explain (kinda) why warp travel outside the Galaxy is so much more difficult than inside it. At least that's how my mind makes sense of the often contradictory portrayals.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  6. #6
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    OK follow up questions: What are some ways an FTL reference frame would affect causality?

    How could it affect the local measurements of travel time? IE, could you have, say, an interstellar GPS? A regularly scheduled arrival time?
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  7. #7
    Join Date
    Oct 2001
    Location
    The Space Coast
    Posts
    4,332
    In Star Trek, there's an episode where proto-Q-being "Trelane" has been watching Earth through a telescope, so he sees humanity from hundreds of years earlier. The implications of this aren't really borne out in full in the episode, though.

    For instance, say someone in the Federation sees the light/EM waves of a distant catastrophe, a planet-wide destruction. They send a starship at warp 9+ out there... and they arrive before the catastrophe happened, and might be able to stop it. I don't think anything like this is dealt with in Star Trek, is it? It doesn't have to just be catastrophes, of course. Even just "mundane" events like distant supernovae or gamma ray bursts. Just warp out there to watch their inceptions.

    Are these they types of things you're asking about?

    CJSF
    "Find a way to show what would happen
    If you were incorrect
    A fact is just a fantasy
    Unless it can be checked
    Make a test
    Test it out"
    -They Might Be Giants, "Put It To The Test"


    lonelybirder.org

  8. #8
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by CJSF View Post
    In Star Trek, there's an episode where proto-Q-being "Trelane" has been watching Earth through a telescope, so he sees humanity from hundreds of years earlier. The implications of this aren't really borne out in full in the episode, though.

    For instance, say someone in the Federation sees the light/EM waves of a distant catastrophe, a planet-wide destruction. They send a starship at warp 9+ out there... and they arrive before the catastrophe happened, and might be able to stop it. I don't think anything like this is dealt with in Star Trek, is it? It doesn't have to just be catastrophes, of course. Even just "mundane" events like distant supernovae or gamma ray bursts. Just warp out there to watch their inceptions.

    Are these they types of things you're asking about?

    CJSF

    That's backward time travel, they deal with that in many episodes and movies. Mainly by forbidding it, or showing it being misused.

    I am not educated enough in physics to ask the right questions, I guess.
    Last edited by Noclevername; 2018-Oct-04 at 05:05 PM.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  9. #9
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Let's see if I can put it better:

    In ST there's "subspace radio" signals, which never arrive before they are sent. They always take objective time to travel.

    I guess there's a Light Cone of normal space, and a slightly wider Faster Than Light cone of subspace. Starships and signals slide in the areas between the 2 cones. Am I using that right?
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  10. #10
    Join Date
    May 2003
    Posts
    5,947
    It's in principle possible for there to be some kind of absolute reference frame without causing any problems with our current understanding of physics (although, given the way relativity works, there would be no way to determine just what reference frame that was). However, any method by which you can communicate faster than light (which would include both travelling at warp speed and sending "instantaneous" messages via subspace channel) also means that you can send a signal backward in time, at least relative to some possible observers. Here's a nice explanation of why that is.
    Conserve energy. Commute with the Hamiltonian.

  11. #11
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Grey View Post
    It's in principle possible for there to be some kind of absolute reference frame without causing any problems with our current understanding of physics (although, given the way relativity works, there would be no way to determine just what reference frame that was). However, any method by which you can communicate faster than light (which would include both travelling at warp speed and sending "instantaneous" messages via subspace channel) also means that you can send a signal backward in time, at least relative to some possible observers. Here's a nice explanation of why that is.
    If the FTL reference frame is not absolute, does that still apply? And if it is not back-time travel relative to the sender, or to an observer on the FTL ship, does it still "loop" that observer's timeline?

    ADDED: Here's a (non-canon) POV on subspace's phictional physics and reference frame. http://www.physicsguy.com/subphys/Su...Physics.html#2
    Last edited by Noclevername; 2018-Oct-04 at 10:31 PM.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  12. #12
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Let me reword again:

    Given the above, can an author come up with a plausible sounding physics excuse to prevent practical/personal timeline violations in "everyday" Warp travel usage? Beyond just saying "I'm the author, so there!"
    Last edited by Noclevername; 2018-Oct-04 at 10:44 PM.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  13. #13
    Join Date
    May 2003
    Posts
    5,947
    Quote Originally Posted by Noclevername View Post
    Given the above, can an author come up with a plausible sounding physics excuse to prevent practical/personal timeline violations in "everyday" Warp travel usage? Beyond just saying "I'm the author, so there!"
    The problem does still exist even if there is not an absolute reference frame, and there is no simple workaround. Simply put, if relativity is correct, then any kind of FTL travel or communication will allow signals to travel backward in time for some observers (and if you can send relativistic radio beacons around, you can make that happen for any observers you'd like). Conversely, if you want to have both FTL communication or travel, and also no violations of causality, then relativity has to be wrong. Of course, if you're writing fiction, you can just declare that relativity is wrong, and have done with it.
    Conserve energy. Commute with the Hamiltonian.

  14. #14
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Grey View Post
    The problem does still exist even if there is not an absolute reference frame, and there is no simple workaround. Simply put, if relativity is correct, then any kind of FTL travel or communication will allow signals to travel backward in time for some observers (and if you can send relativistic radio beacons around, you can make that happen for any observers you'd like). Conversely, if you want to have both FTL communication or travel, and also no violations of causality, then relativity has to be wrong. Of course, if you're writing fiction, you can just declare that relativity is wrong, and have done with it.
    But as long as those observers are no in a position to do anything about it, does it matter if it is "technically" time travel?
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  15. #15
    Join Date
    Mar 2003
    Posts
    2,986
    Quote Originally Posted by CJSF View Post
    For instance, say someone in the Federation sees the light/EM waves of a distant catastrophe, a planet-wide destruction. They send a starship at warp 9+ out there... and they arrive before the catastrophe happened, and might be able to stop it. I don't think anything like this is dealt with in Star Trek, is it? [snip] Even just "mundane" events like distant supernovae or gamma ray bursts. Just warp out there to watch their inceptions.
    Definite missed opportunity. Star Fleet could have waited to see a distant supernova, then have Wesley Crusher take a ship solo to the star at Warp 9 to observe the inception very, very locally.... maybe cross over to the Star Wars universe on the way and take JarJar on board as a "comic relief" crewman.

  16. #16
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Noclevername View Post
    But as long as those observers are no in a position to do anything about it, does it matter if it is "technically" time travel?
    What I mean is, is there a way to have warp and not potential time paradoxes? So you have "time travel" that cannot actually affect events.

    (NOT the Novikov principle.)
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  17. #17
    Join Date
    Feb 2003
    Location
    Depew, NY
    Posts
    11,523
    Quote Originally Posted by Noclevername View Post
    What I mean is, is there a way to have warp and not potential time paradoxes? So you have "time travel" that cannot actually affect events.

    (NOT the Novikov principle.)
    Have an AI on your computer tech that obscures paradoxes, or FTL creates a physical barrier to observing period. You don't have a paradox if you don't see them. Maybe your "rule" is that you can't have FTL if there is the potential for a visible paradox. It creates an odd situation where you characters can't use FTL while someone is looking with out that filter.

    Alistair Reynolds has used this a couple of times. In House of Suns, the characters can't see the Andromeda Galaxy because someone went there using FTL. People in Andromeda can't see the Milky Way either. Kind of interesting. They are aware that both galaxies exist.
    Solfe

  18. #18
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Solfe View Post
    Have an AI on your computer tech that obscures paradoxes, or FTL creates a physical barrier to observing period. You don't have a paradox if you don't see them. Maybe your "rule" is that you can't have FTL if there is the potential for a visible paradox. It creates an odd situation where you characters can't use FTL while someone is looking with out that filter.

    Alistair Reynolds has used this a couple of times. In House of Suns, the characters can't see the Andromeda Galaxy because someone went there using FTL. People in Andromeda can't see the Milky Way either. Kind of interesting. They are aware that both galaxies exist.
    So, all you have to do to blind an enemy warship, is go to warp in their line of sight? I can see a large power flying ships all over, to prevent anyone from detecting their actions...
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  19. #19
    Join Date
    Feb 2003
    Location
    Depew, NY
    Posts
    11,523
    Quote Originally Posted by Noclevername View Post
    So, all you have to do to blind an enemy warship, is go to warp in their line of sight? I can see a large power flying ships all over, to prevent anyone from detecting their actions...
    I didn't think that through. I was thinking of the AI as being friendly and blinding you. An enemy ship is another matter. What is happening in the Reynolds story is no one has FTL, except for some very limited cases.

    The one time he actually describes a ship in FTL during combat, one side cobbled together some stuff so they don't have the ability to observer anything strange. It appears to work until their opponents detect some gravitational effects. The enemy ship doesn't know what happened, only that everything was pulled towards the ship going at FTL speeds and then suddenly it stops doing that. It appears to me that if someone going FTL can conceptualized the problems of going to FTL, they get wiped from the timeline in the Reynolds universe.

    Edit - It is hard to tell what Reynolds is saying, because the person who designed the FTL device should know that it will cause strange gravitational effects, but then puts that thought aside long enough to allow the ship to go faster than light. The moment the gravitation effect reaches the enemy, the FTL device stops working, the creator's best friend vanishes and the creator is killed. There is the implication that the creator's friend was on the ship until the moment the drive turned on and is retroactively erased from the timeline. Then the creator herself is kill/destroyed a little more slowly. Very weird.

    In House of Suns, two friendly ships are going through a worm hole (or something) and the distortion prevents seeing each other and real time communication. At the end of the day, it turns out that not only don't have the ability to see the effect of FTL travel, the ship's computers are deliberately hiding facts to protect the crew from a variety of things.
    Last edited by Solfe; 2018-Oct-06 at 02:02 PM.
    Solfe

  20. #20
    Join Date
    Jun 2007
    Posts
    5,644
    Quote Originally Posted by Solfe View Post
    I didn't think that through. I was thinking of the AI as being friendly and blinding you. An enemy ship is another matter. What is happening in the Reynolds story is no one has FTL, except for some very limited cases.

    The one time he actually describes a ship in FTL during combat, one side cobbled together some stuff so they don't have the ability to observer anything strange. It appears to work until their opponents detect some gravitational effects. The enemy ship doesn't know what happened, only that everything was pulled towards the ship going at FTL speeds and then suddenly it stops doing that. It appears to me that if someone going FTL can conceptualized the problems of going to FTL, they get wiped from the timeline in the Reynolds universe.

    Edit - It is hard to tell what Reynolds is saying, because the person who designed the FTL device should know that it will cause strange gravitational effects, but then puts that thought aside long enough to allow the ship to go faster than light. The moment the gravitation effect reaches the enemy, the FTL device stops working, the creator's best friend vanishes and the creator is killed. There is the implication that the creator's friend was on the ship until the moment the drive turned on and is retroactively erased from the timeline. Then the creator herself is kill/destroyed a little more slowly. Very weird.

    In House of Suns, two friendly ships are going through a worm hole (or something) and the distortion prevents seeing each other and real time communication. At the end of the day, it turns out that not only don't have the ability to see the effect of FTL travel, the ship's computers are deliberately hiding facts to protect the crew from a variety of things.
    This cure seems worse than the disease, since you're essentially erasing huge swathes of the universe from your reality every time you go FTL, and even handling that consistently seems improbable. You're better off if FTL just puts you in a different timeline.

  21. #21
    Join Date
    Feb 2003
    Location
    Depew, NY
    Posts
    11,523
    Quote Originally Posted by cjameshuff View Post
    This cure seems worse than the disease, since you're essentially erasing huge swathes of the universe from your reality every time you go FTL, and even handling that consistently seems improbable. You're better off if FTL just puts you in a different timeline.
    Strangely, you'd think that he would put lots of characters out of play, but it doesn't happen.

    I admit, the idea is bonkers. For 99% of his stories, he happily explains that c is the limit. Then he pulls out the math and says, "well, it's more like a guideline, you can go faster if only...". The characters don't have the inclination to do math or think about it deeply, so Reynolds gets a strange scenario to describe and the characters move really fast.

    The interesting thing is, just as you say, the characters have limited access to other timelines. Apparently several of them and maybe another universe or two.
    Solfe

  22. #22
    Join Date
    May 2003
    Posts
    5,947
    Quote Originally Posted by Noclevername View Post
    What I mean is, is there a way to have warp and not potential time paradoxes? So you have "time travel" that cannot actually affect events.

    (NOT the Novikov principle.)
    The only way is for relativity to be wrong. But again, for a fiction story where you have warp drive in the first place, there's nothing wrong with deciding that relativity is wrong. You can even decide that it's wrong the same way that Newton's laws of motion are wrong: that it's a very good approximation under most circumstances, but breaks down under certain extreme conditions (probably the circumstances under which it breaks down are exactly the thing that allows warp travel in the first place...). FTL travel probably isn't actually possible in our universe, so if you write a story that includes it, you're already adding new physics that likely doesn't exist. Just try to make the rules consistent enough that it isn't too jarring, and all will be well.
    Conserve energy. Commute with the Hamiltonian.

  23. #23
    Join Date
    Jun 2007
    Posts
    5,644
    Quote Originally Posted by Grey View Post
    The only way is for relativity to be wrong. But again, for a fiction story where you have warp drive in the first place, there's nothing wrong with deciding that relativity is wrong. You can even decide that it's wrong the same way that Newton's laws of motion are wrong: that it's a very good approximation under most circumstances, but breaks down under certain extreme conditions (probably the circumstances under which it breaks down are exactly the thing that allows warp travel in the first place...). FTL travel probably isn't actually possible in our universe, so if you write a story that includes it, you're already adding new physics that likely doesn't exist. Just try to make the rules consistent enough that it isn't too jarring, and all will be well.
    Well, there is the approach I mentioned, where FTL travel puts the traveler into a different universe. You could end up in a time and place equivalent to your past in that timeline and sabotage your alternate's FTL drive, but it's not your past you'd be interacting with. In the original timeline, you presumably just disappear, but that seems preferable to, say, having all photons originating from the Andromeda galaxy do the same mid-flight.

  24. #24
    Join Date
    Sep 2004
    Location
    South Carolina
    Posts
    1,605
    I could almost live without FTL drive as long as we could get FTL communication, like an ansible.

    https://en.wikipedia.org/wiki/Ansible
    There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
    Mark Twain, Life on the Mississippi (1883)

  25. #25
    Join Date
    Jun 2005
    Posts
    13,069
    Quote Originally Posted by Noclevername View Post
    What I mean is, is there a way to have warp and not potential time paradoxes? So you have "time travel" that cannot actually affect events.

    (NOT the Novikov principle.)
    It seems to me that a fairly easy solution is to have a Newtonian universe where mass does not warp space and light just happens to travel at the speed it does. So time passes equally for all observers, and all you have done is found a faster way to get from A to B.


    Sent from my iPhone using Tapatalk
    As above, so below

  26. #26
    Join Date
    Aug 2006
    Posts
    3,212
    Quote Originally Posted by Jens View Post
    It seems to me that a fairly easy solution is to have a Newtonian universe where mass does not warp space and light just happens to travel at the speed it does. So time passes equally for all observers, and all you have done is found a faster way to get from A to B.


    Sent from my iPhone using Tapatalk
    So, a sort of "Return to the Flash Gordon Era - where space is just space" answer. Not sure that would fly.

  27. #27
    Join Date
    Jun 2007
    Posts
    5,644
    Quote Originally Posted by Roger E. Moore View Post
    I could almost live without FTL drive as long as we could get FTL communication, like an ansible.

    https://en.wikipedia.org/wiki/Ansible
    Unfortunately the limitations have nothing to do with anything material passing from point A to point B, but arise from the transfer of information between those points.

  28. #28
    Join Date
    Apr 2007
    Location
    Nowhere (middle)
    Posts
    35,631
    Quote Originally Posted by Grey View Post
    The only way is for relativity to be wrong. But again, for a fiction story where you have warp drive in the first place, there's nothing wrong with deciding that relativity is wrong. You can even decide that it's wrong the same way that Newton's laws of motion are wrong: that it's a very good approximation under most circumstances, but breaks down under certain extreme conditions (probably the circumstances under which it breaks down are exactly the thing that allows warp travel in the first place...). FTL travel probably isn't actually possible in our universe, so if you write a story that includes it, you're already adding new physics that likely doesn't exist. Just try to make the rules consistent enough that it isn't too jarring, and all will be well.
    Well, the Star Trek solution is to have another domain of space that temporarily overlaps this one to enable Warp, in a way that does not normally happen in nature (unless the next writer decides it does). So I suppose that counts as extreme circumstances.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  29. #29
    Join Date
    Feb 2005
    Posts
    10,995
    The "Janus" model seems all the rage these days:
    https://forum.nasaspaceflight.com/in...?topic=43501.0

    Can't help you with Spore drive, other than saying it may have something to do with coupling to Voyager's fluidic space--likly home to the giant space protist from Immunity syndrome.

  30. #30
    Join Date
    Jul 2018
    Posts
    46
    Quote Originally Posted by Noclevername View Post
    Thank you.
    That would explain (kinda) why warp travel outside the Galaxy is so much more difficult than inside it. At least that's how my mind makes sense of the often contradictory portrayals.
    I don't think that in Star Trek travel outside the galaxy is any different from inside it. The only reason they don't travel outside the galaxy is travel times. If I remember my Voyager correctly, they estimated it would take them 75 years to travel back home? Something like that. And that was about 2/3 of the galaxy. So if it takes 100 years to travel across the entire galaxy that would take 2,000 years to get to Andromeda. I think that alone is why they stay in the Milky Way, I don't believe there are any contradictory portrayals of this (maybe in the original series?.......).

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •