Are warp drives science now?(backreaction.blogspot.com)
backreaction.blogspot.com
Are warp drives science now?
http://backreaction.blogspot.com/2022/01/are-warp-drives-science-now.html
80 comments
An AI capable of colonizing the galaxy seems a lot more far fetched than a practical warp drive.
Why? AI has limited lifespan too.
1. Computing machinery is made of physical matter, which means it degrades.
2. The large scale economy required to support, repair and upgrade it also requires many input materials.
3. Those materials are exhaustable and finite, which means, the AI will eventually exhaust its supply of "stuff". If that happens before it's able to expand into new areas, then it dies.
1. Computing machinery is made of physical matter, which means it degrades.
2. The large scale economy required to support, repair and upgrade it also requires many input materials.
3. Those materials are exhaustable and finite, which means, the AI will eventually exhaust its supply of "stuff". If that happens before it's able to expand into new areas, then it dies.
I'd say they're getting closer to becoming science, but aren't there yet.
BTW I wonder what they're going to do about the possibility of plowing into a small rock fragment at several times the speed of light?
If they can't solve this problem traveling at these velocities would essentially mean playing Russian Roulette with the probability of the crew dying at any moment.
BTW I wonder what they're going to do about the possibility of plowing into a small rock fragment at several times the speed of light?
If they can't solve this problem traveling at these velocities would essentially mean playing Russian Roulette with the probability of the crew dying at any moment.
I know next to nothing about anything, but my assumption would be that the solution would probably be bi-directional canary probes. If the probe didn’t ram into anything on its warp travel and makes it back, it’s a reasonable assumption that you can make the same journey.
The thought did occur to me that the the probe may even map the entire route using sensors and develop a temporal computer model for just how much time the route will still be safe to travel. But then I realised that the warp drive bends space-time, distorting photographs and other sensors.
Failing this, we decide to only use warp drive in parts of space that are very well mapped. It would allow instantaneous travel throughout the solar system, which would facilitate trade and colonisation. But warping into the dark unknown would be foolish.
The thought did occur to me that the the probe may even map the entire route using sensors and develop a temporal computer model for just how much time the route will still be safe to travel. But then I realised that the warp drive bends space-time, distorting photographs and other sensors.
Failing this, we decide to only use warp drive in parts of space that are very well mapped. It would allow instantaneous travel throughout the solar system, which would facilitate trade and colonisation. But warping into the dark unknown would be foolish.
This assumes that objects in space are static, but they move, so the dust/pebbles/boulders one ship would hit, would be different from the ones another ship would hit.
This largely depends on a lot of the properties of what “warp” actually is.
Could you fly the ship at 5*warp and then have a drone canary in a squiggle/back and forth pattern at 50*warp in front of the ship?
If it hits something, depending on how warp works, you may be able to instantly stop the ship?
Could you fly the ship at 5*warp and then have a drone canary in a squiggle/back and forth pattern at 50*warp in front of the ship?
If it hits something, depending on how warp works, you may be able to instantly stop the ship?
Travelling at any interstellar velocity seems to also be so, because even pretty tiny dust specks can take out a space ship at appreciable fractions of c. So you'd need extremely good radar to avoid/deflect/destroy it (and you don't have long to do so).
Though I suppose at least you can conceivably hope to detect them since you can actually see them at all since the approach is subluminal.
Though I suppose at least you can conceivably hope to detect them since you can actually see them at all since the approach is subluminal.
>> BTW I wonder what they're going to do about the possibility of plowing into a small rock fragment at several times the speed of light?
They will use superintelligent AI to pilot the ship and it will avoid obstacles automatically.
[Edit: jokes aside, a warp drive doesn't move the ship. It only distorts the spacetime around it. So there's no danger of hitting anything. Effectively, the ship remains immobile inside its little warp bubble and the warp bubble is displaced along space without actually moving. You know, like cats.]
They will use superintelligent AI to pilot the ship and it will avoid obstacles automatically.
[Edit: jokes aside, a warp drive doesn't move the ship. It only distorts the spacetime around it. So there's no danger of hitting anything. Effectively, the ship remains immobile inside its little warp bubble and the warp bubble is displaced along space without actually moving. You know, like cats.]
Sounds like a great way to get yourself a Butlerian Jihad.
Yeah, we’re going to need a lot of spice melange…
Warp drives even if they one day are implemented, almost certainly won't allow FTL speeds, because it will break causation. According to Special Relativity, any way of transmitting information faster than light is equivalent to passing it into the past in some frame of reference. Warping space-time doesn't really solve it, provided you plan to unwarp it back once you've reached your destination.
Some version of warp travel depicts that the ship itself is stationery but the space around the ship is warped to propel the ship forward. So there is no debris to hit as it would also be warped around the ship.
The trick is precursor vehicles.. basically fire a stream of bullets at space and expect the precursors to annihilate any obstacles.
Is that a solution though? unless you send your ship instantly after those bullets another objects could still just come in from the side after they've passed, unless these bullets cover significantly more than the front facing area of your entire ship it won't work, and if you do send it directly in front of your ship immediately before your flight then you've just invented metal shields, and if they do hit something you're still going to be hitting shrapnel and spalling at appreciable fractions of the speed of light.
Yeah, we could use the same simple trick clear space debris from Earth's orbit!
Since pieces of rock move this wouldn't be a foolproof solution.
obviously an energy shield
I've experimented with warp drives in theory and simulation, and what they could theoretically do is to "scale" the space so that every item in space appear to be closer to you so you just have to walk 10/30th of the distance to reach 30/30 of the distance.
|---o------o------------o------| normal distance
|o--o---o--| warped distance
What happens if you as matter plow into a spec of matter (dust) at beyond light speed?
In terms of an Alcubierre drive, particles would collect along the perimeter of your space time bubble. As soon as you stop and the bubble collapses the collection of particles would explode outwards and more than likely vaporize anything immediately in front of you.
First use case that comes to mind is "Alcubierre torpedoes" or "Alcubierre shaped-charge" (if the bubble could be focused in such a way). Possibly a mechanism for disrupting any orbital objects on a collision course with earth? Hit it at an oblique angle to its orbit and poof!
Any mass moving faster than light and still able to interact with matter that isn't, will necessarily have enough kinetic energy that any warhead would be an afterthought. That also doesn't necessarily improve matters in the Earth impactor case, since shattering a single large impactor without changing its vector only creates many small impactors. Some models make that look a little worse than the status quo ante, while more optimistic ones just say it's exactly as bad, but either way, if the mission is to see that zero rocks hit Earth then it isn't really a win.
I'm more interested in the idea that, the longer your FTL leg, the less well you're able to see where you're going - not that that's likely often necessary for starships any more than for sailing vessels, but you can think of circumstances in which it might matter. Too, it might come to be considered unneighborly to take too direct a course anywhere, lest you inadvertently Kessler-spray your destination.
Insystem use of the drive would be most complicated by this in general, especially since there's rarely much point in visiting stars without lots of rocks around them. You might also not be able to make sharp maneuvers in FTL, hence needing to plan legs with care not only for safety, but to minimize time and reaction mass spent on slow thruster rendezvous maneuvers. This has implications for travel time, navigation in general, and thus implicitly for supply chain logistics, travel time, and thus what's feasible both economically and politically - especially should it coincide with the absence of any FTL comms cheaper and faster than "record a message and then have a packet boat take it where it needs to go".
I'm more interested in the idea that, the longer your FTL leg, the less well you're able to see where you're going - not that that's likely often necessary for starships any more than for sailing vessels, but you can think of circumstances in which it might matter. Too, it might come to be considered unneighborly to take too direct a course anywhere, lest you inadvertently Kessler-spray your destination.
Insystem use of the drive would be most complicated by this in general, especially since there's rarely much point in visiting stars without lots of rocks around them. You might also not be able to make sharp maneuvers in FTL, hence needing to plan legs with care not only for safety, but to minimize time and reaction mass spent on slow thruster rendezvous maneuvers. This has implications for travel time, navigation in general, and thus implicitly for supply chain logistics, travel time, and thus what's feasible both economically and politically - especially should it coincide with the absence of any FTL comms cheaper and faster than "record a message and then have a packet boat take it where it needs to go".
I don't believe any model that says many small impactors cause more or the same damage than one large impactor. Surface area is higher, drag is higher. V becomes lower. 1/2mv^2 becomes dramatically lower. In every single case that an impactor is split.
Also, in the case of hitting a rock with sufficient kinetic energy it will become atomized. A cloud of fast moving space dust would burn in the upper atmosphere.
Also, in the case of hitting a rock with sufficient kinetic energy it will become atomized. A cloud of fast moving space dust would burn in the upper atmosphere.
If I recall correctly, heating up the atmosphere to scorching temperatures is a major concern. It's better to heat up one spot than half of the globe.
That is true. Well, in the case of being smashed by a hypothetical FTL wave the imparted energy should be sufficient to alter the course clear of Earth.
This was used in “Another Life” on Netflix.
And so were coined the warp bombs and the warp shots, two weapons of unimaginable power against which no defenses could stand. Undetectable until arrival, unstoppable upon arrival. A very fast and saucy radiation souffle.
Perimeter? As in -outside- the warp bubble?
So the dust is now moving at beyond light speed but without the protective effects of time inside the bubble?
We know what happens to matter at those speeds, it becomes infinitely "heavy" and would experience time in relative light-years (I mean time-to-travel at light speeds) no?
So the dust is now moving at beyond light speed but without the protective effects of time inside the bubble?
We know what happens to matter at those speeds, it becomes infinitely "heavy" and would experience time in relative light-years (I mean time-to-travel at light speeds) no?
What I said is about the limit of my knowledge unfortunately.
However here’s the paper from the University of Sidney that goes into much greater detail.
pdf warning https://arxiv.org/pdf/1202.5708v1.pdf
From the paper:
> These results suggest that any ship using an Alcu- bierre warp drive carrying people would need shielding to protect them from potential dangerously blueshifted particles during the journey, and any people at the des- tination would be gamma ray and high energy particle blasted into oblivion due to the extreme blueshifts for P+ region particles.
However here’s the paper from the University of Sidney that goes into much greater detail.
pdf warning https://arxiv.org/pdf/1202.5708v1.pdf
From the paper:
> These results suggest that any ship using an Alcu- bierre warp drive carrying people would need shielding to protect them from potential dangerously blueshifted particles during the journey, and any people at the des- tination would be gamma ray and high energy particle blasted into oblivion due to the extreme blueshifts for P+ region particles.
> We know what happens to matter at those speeds, it becomes infinitely "heavy" and would experience time in relative light-years (I mean time-to-travel at light speeds) no?
I don't think we do know what happens. Relativistic mass approaches infinity at exactly c. Beyond c we obviously have no data, but if we just apply the same equations the relativistic mass would drop back to a finite value. A finite complex value.
I don't think we do know what happens. Relativistic mass approaches infinity at exactly c. Beyond c we obviously have no data, but if we just apply the same equations the relativistic mass would drop back to a finite value. A finite complex value.
That's an interesting plot device/weapon for a sci fi story..!
I can't remember the title or the author, but I remember reading a story based on a similar premise years ago - the first interstellar ship goes out from Earth to a nearby star, only to barely escape as it goes nova shortly after they arrive. They first think it's just a coincidence, but later suspect that their ship's drive might have been the cause. On their way back home they make up a desperate plan to drop out of FTL drive way out of the solar system to make sure Earth's sun would be safe. This would stretch their supplies, etc. because the flight will now take years instead of months. While traveling they realize that turning on the drive might have had the same effect as turning it off. They stop at the right distance from Earth to catch the light from the time of their departure and observe as the sun goes nova.
You remembered more details of the story than me but I manged to find it... 3 years after someone else asked about it on SE:
This is Randall Garrett's "Time Fuze", first published in IF, March 1954.
https://scifi.stackexchange.com/questions/203584/short-story...
This is Randall Garrett's "Time Fuze", first published in IF, March 1954.
https://scifi.stackexchange.com/questions/203584/short-story...
Thanks for finding it! I'm certain this is the story I remember reading.
This plotline sounds familiar to me, too. I hope someone will remember the author... are you thinking golden age SF, 60s/70s?
Wow
Let's say hypothetically we find a way to create all of the weird matter necessary to create a warp bubble...
Changes to the shape of space-time willl still only travel at the speed of light, so I don't see how that would enable you to travel faster than light for any meaningful distance, as the warp bubble itself would be unable to keep up with the vehicle.
Changes to the shape of space-time willl still only travel at the speed of light, so I don't see how that would enable you to travel faster than light for any meaningful distance, as the warp bubble itself would be unable to keep up with the vehicle.
Perhaps when we discover why the universe is expanding, then we may have or not a solution for this.
The expansion of the universe can be faster than the speed of light. Would it be possible to use that to create FTL travel?
The expansion of the universe can be faster than the speed of light. Would it be possible to use that to create FTL travel?
Within the event horizon of a black hole, spacetime seems capable of "moving" towards the center faster than the speed of light. That's why light cannot escape, right?
No, speed of light will not move faster inside in the event horizon. It is still at the same speed.
But the spacetime is so distorted that a photon will start orbiting the singularity, thus it doesn’t get out of the event horizon.
https://phys.org/news/2014-03-orbit-black-hole.html
But the spacetime is so distorted that a photon will start orbiting the singularity, thus it doesn’t get out of the event horizon.
https://phys.org/news/2014-03-orbit-black-hole.html
The speed of light in a patch of space does not change but space itself can warp faster than the speed of light.
The link you post describes a region in certain conditions where light can orbit not that that is the fate of all light falling into a black hole.the end talks about the always orbitally unstable regions beneath that being referred to here.
The link you post describes a region in certain conditions where light can orbit not that that is the fate of all light falling into a black hole.the end talks about the always orbitally unstable regions beneath that being referred to here.
General relativity permits changes in the geometry of space time to propagate faster than the speed of light.
tl;dr:
Mathematician: "Absolutely."
Physicist: "Sure! actually no."
Engineer: "No way in hell. Go play with a blockchain."
Zefram Cochrane: "I already built it."
Mathematician: "Absolutely."
Physicist: "Sure! actually no."
Engineer: "No way in hell. Go play with a blockchain."
Zefram Cochrane: "I already built it."
Hah, Sabine Hossenfelder again. I found out about her via HN, when she’s not researching, or making pop-science articles and videos [0], she also does some fun music videos [1]
[0]: https://www.youtube.com/watch?v=YdVIBlyiyBA
[1]: https://www.youtube.com/watch?v=PX0k0WfMSi0
[0]: https://www.youtube.com/watch?v=YdVIBlyiyBA
[1]: https://www.youtube.com/watch?v=PX0k0WfMSi0
My favorites are „last real man“ and „outer space“ and „I can’t forget“(remix)
tldr sub-light speed warp drives are not ruled out yet. still could be pretty useful
I've never considered subluminal warp drives, but it'd be really exciting if we can create warp drives that are some healthy fraction of c.
Some healthy fraction of c seems to be possible with current technology also. If you consider 3% healthy that is.
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
There's a big difference in that conventional propulsion will leave the traveller subject to relativistic effect of a slowed clock, while the traveller with a warp drive will not.
I’m not sure this is a benefit? The time dilation means the passengers subjectively get there faster than they would without the time dilation.
Why would removing this be a benefit? It means when you arrive at your destination you are older than you would have been if you had the normal time dilation, and if you head back, the people will have aged just as much in your round trip as normal, the only difference is that you’ve also aged as much as they have.
Right?
If you have a non-accelerating subliminal warp bubble, and you shift to a frame of reference where it is not moving, then wouldn’t you just get a region where time moves more quickly? Or.. ?
Why would removing this be a benefit? It means when you arrive at your destination you are older than you would have been if you had the normal time dilation, and if you head back, the people will have aged just as much in your round trip as normal, the only difference is that you’ve also aged as much as they have.
Right?
If you have a non-accelerating subliminal warp bubble, and you shift to a frame of reference where it is not moving, then wouldn’t you just get a region where time moves more quickly? Or.. ?
Not being affected by relativistic problems such as time dilation and mass increases would be a benefit for travel at relativistic speeds within the Solar System.
Isn't getting where you're going in less time the whole point of going fast? Why would you want to use a device that made your journey take longer?
Because it'd probably be better for you at the end of your journey if everyone you ever knew hadn't died of old age, including your great grand relatives. If you just want to go to the future, you can do that. But if you'd like to travel large distances at great speed without losing everyone you care about, then warp will help with that because you will age at the same rate as those you've left behind, and everything will be as expected when you return.
> and everything will be as expected when you return
Either what I said is completely wrong, or this is completely wrong. I think it is the latter.
You experiencing time dilation doesn’t make it so when you get to your destination, people have aged more. It makes it so you have aged less. If the round trip takes 2 years from the perspective of an external stationary observer, because it is a round trip of like, 0.9 light years in both directions, Then by the time you get back, people have aged 2 years. Removing the time dilation in the ship just makes is so the people on the ship also aged 2 years instead of less than that.
That’s not really helpful.
Unless you can go faster than c, you can’t go 50 light years away and come back to people having aged less than 100 years. If you did, you would have gone faster than c. Basically by definition of speed?
Either what I said is completely wrong, or this is completely wrong. I think it is the latter.
You experiencing time dilation doesn’t make it so when you get to your destination, people have aged more. It makes it so you have aged less. If the round trip takes 2 years from the perspective of an external stationary observer, because it is a round trip of like, 0.9 light years in both directions, Then by the time you get back, people have aged 2 years. Removing the time dilation in the ship just makes is so the people on the ship also aged 2 years instead of less than that.
That’s not really helpful.
Unless you can go faster than c, you can’t go 50 light years away and come back to people having aged less than 100 years. If you did, you would have gone faster than c. Basically by definition of speed?
But for distances travelled within the Solar System, and many trips taken, it would be advantageous if traveling 0.7c because conventional propulsion will have time dilation occur at those speeds, and the effect is cumulative. Who cares for a 5 hour trip to Jupiter's moons, or wherever, but if you're spending all your time traveling around the Solar System and back to Earth with conventional propulsion at 0.7c, you'll hardly age, and everyone will get old around you. So again, warp is great for sublight relativistic travel within the Solar System.
Assuming you aren’t communicating with those not on the ship while in the ship, the only difference with warpfield is that the trips take longer for you? (Your trips take same amount of time for others)
If you go to Europa and then head back, Joe here on earth will have aged the same amount by the time you get back. The only difference is whether you aged the same amount as Joe, or less than Joe did.
The warp bubble doesn’t make you miss any more of Joe’s life. It just changes what ages you are when you experience the parts of Joe’s life that you do. (Specifically, warp bubble makes you age more quickly, same rate as Joe)
If you go to Europa and then head back, Joe here on earth will have aged the same amount by the time you get back. The only difference is whether you aged the same amount as Joe, or less than Joe did.
The warp bubble doesn’t make you miss any more of Joe’s life. It just changes what ages you are when you experience the parts of Joe’s life that you do. (Specifically, warp bubble makes you age more quickly, same rate as Joe)
Pointing lasers at solar sails on small probes is theorized to get to 15-25% c:
https://en.wikipedia.org/wiki/Breakthrough_Starshot
To me this seems like the logical next step after using chemical rockets to populate a moonbase. Plop some big lasers on the moon and use them to push things really fast. No weird physics needed, just improvements on what we already have.
To me this seems like the logical next step after using chemical rockets to populate a moonbase. Plop some big lasers on the moon and use them to push things really fast. No weird physics needed, just improvements on what we already have.
My understanding of gravitational waves is that very large objects try to move. It's easier if the universe sees more or less of their particles than if they moved. So the universe sees more or less of their particles. Instead of creating a warp drive, do that. Find some cosmic structure big enough, and manipulate it until the universe sees more or less of it's particles in a way that you are now where you want to be. Very difficult to do, but it happens:
> After years of producing null results, improved detectors became operational in 2015. On 11 February 2016, the LIGO-Virgo collaborations announced the first observation of gravitational waves, from a signal (dubbed GW150914) detected at 09:50:45 GMT on 14 September 2015 of two black holes with masses of 29 and 36 solar masses merging about 1.3 billion light-years away. During the final fraction of a second of the merger, it released more than 50 times the power of all the stars in the observable universe combined. The signal increased in frequency from 35 to 250 Hz over 10 cycles (5 orbits) as it rose in strength for a period of 0.2 second. The mass of the new merged black hole was 62 solar masses. Energy equivalent to three solar masses was emitted as gravitational waves.
> After years of producing null results, improved detectors became operational in 2015. On 11 February 2016, the LIGO-Virgo collaborations announced the first observation of gravitational waves, from a signal (dubbed GW150914) detected at 09:50:45 GMT on 14 September 2015 of two black holes with masses of 29 and 36 solar masses merging about 1.3 billion light-years away. During the final fraction of a second of the merger, it released more than 50 times the power of all the stars in the observable universe combined. The signal increased in frequency from 35 to 250 Hz over 10 cycles (5 orbits) as it rose in strength for a period of 0.2 second. The mass of the new merged black hole was 62 solar masses. Energy equivalent to three solar masses was emitted as gravitational waves.
> My understanding of gravitational waves is that very large objects try to move. It's easier if the universe sees more or less of their particles than if they moved. So the universe sees more or less of their particles. Instead of creating a warp drive, do that. Find some cosmic structure big enough, and manipulate it until the universe sees more or less of it's particles in a way that you are now where you want to be.
I'm not sure where you're getting this from, but it is nothing like our current understanding of gravitational waves. Nor did the black hole merger you describe, which was detected by LIGO, do anything like what you describe.
I'm not sure where you're getting this from, but it is nothing like our current understanding of gravitational waves. Nor did the black hole merger you describe, which was detected by LIGO, do anything like what you describe.
My son Zeph is working on it.
Well he better hurry up because he only has 41 more years before it needs to launch.
[deleted]
Shoo-Be-Doo-Be-Doo-Da-Day
TheDudeMan(2)
That moment when we become able to measure the speed of light in only one direction is the realization moment that this warp speed technology becomes tenable … or not.
So they took the phrase "science fiction" as what warp drives used to be. Then they just dropped the word "fiction" but that is the noun.
"Are warp drives science?" does not make grammatical sense, as the word "science" was previously describing what type of fiction it was.
The new sentence should read something like "are warp drives science fact now?"
Science is a process, not a thing. The term science fiction describes fictions based around the process, or a faux process that seems realistic or may be in the future.
If we were to take the same meaning of science as ascribed by the author here, my interpretation is they are equating the word "science" with something like "fact, truth, or reality". Following this, if the then ask what the phrase "science fiction" means in this context, we get "truth fiction"? "reality fiction"? These things don't make much sense to me.
https://en.m.wikipedia.org/wiki/Science_fiction
"Are warp drives science?" does not make grammatical sense, as the word "science" was previously describing what type of fiction it was.
The new sentence should read something like "are warp drives science fact now?"
Science is a process, not a thing. The term science fiction describes fictions based around the process, or a faux process that seems realistic or may be in the future.
If we were to take the same meaning of science as ascribed by the author here, my interpretation is they are equating the word "science" with something like "fact, truth, or reality". Following this, if the then ask what the phrase "science fiction" means in this context, we get "truth fiction"? "reality fiction"? These things don't make much sense to me.
https://en.m.wikipedia.org/wiki/Science_fiction
If/When AI takes over, it will likely be quite content with taking 10,000 years to go to the distant stars. It will also likely be more capable of breaking off a piece of itself and launching it at 1/10th C in order to get around relatively quickly.
It could "colonize" the entire galaxy in 10 million years - which is an acceptable time scale for it given that it has no finite lifespan.
It is our biological limitations that fixate us on faster-than-light travel. ...something the rest of the universe probably doesn't think too much about.