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The Challenge of Relativistic Spaceflight

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Re: The Challenge of Relativistic Spaceflight

#41

Earlier quoted context omitted.

Special relativity says the speed of light is the same in all reference frames. In the reference frame of the moving CPU, it would operate correctly.

While the speed of light is the same, relativity also has a lot to say about accelerating reference frames. That said, if you were accelerating fast enough to affect the behavior of a CPU, you'd be experiencing G-forces comparable to the tidal forces of a black hole; computation would be the least of your problems.

[deleted]

Re: The Challenge of Relativistic Spaceflight

#42
post #22
post #18

Earlier quoted context omitted.

It's not quite valid anymore to say warp drive is flat impossible, given all the theoretical work on the Alcubierre drive. Whether it will ever actually be practical is still a big unknown.

you mean the drive that if it were used it would annihilate your destination in a immense-burst of gamma energy? Not to mention we have no idea how to effectively modify space-time. It is interesting, but the drive is basically "if we had MAGIC, we could do this". FTL is also exactly the same as time-travel. If you could travel 25,000 light-years in an instant, you could turn a BIG telescope back at earth from your s…

I saw a lecture from the researcher that is working on the project and he explained why there isn't a burst of deadly energy. Also they are working on those experiments, so they have at least some idea how to do it. You should really update your data.

Re: The Challenge of Relativistic Spaceflight

#43
post #22

Earlier quoted context omitted.

you mean the drive that if it were used it would annihilate your destination in a immense-burst of gamma energy? Not to mention we have no idea how to effectively modify space-time. It is interesting, but the drive is basically "if we had MAGIC, we could do this". FTL is also exactly the same as time-travel. If you could travel 25,000 light-years in an instant, you could turn a BIG telescope back at earth from your s…

Well, that is just the light. Does it count as time travel when we look at stars that are thousands of lightyears away?

yes. We see the stars today as they were thousands of years ago. It's thousands of light years away from our perspective, but from the perspective of the photons the trip took zero time as it was a zero distance. SR is weird like that.

Re: The Challenge of Relativistic Spaceflight

#44

TL;DR: Chemical propulsion is a dead end. But, the alternatives require matter/energy of ridiculous scale (hundreds of times the power output of human civilization, launching hundreds of millions of tons of matter into orbit). We're not going anywhere, any time soon.

http://en.wikipedia.org/wiki/Stellar_engine

Solves the "anywhere", but not the "any time soon".

Re: The Challenge of Relativistic Spaceflight

#45
post #39

Earlier quoted context omitted.

Uploaded minds is hardly an argument depending on cartesian duality. Arguing that there's something irreproducible about the human brain is quite close to cartesian duality. I am not arguing that uploading minds is any more feasible than a generation ship, but it is at least more plausible than hyperdrive -- based on what we think we know right now.

I guess I disagree that uploading minds is more feasible. One is more of an engineering/physics challenge, and uploading minds is dependent upon a vast set of unknown unknowns. We aren't even out of the door on the idea of biological computing let alone at the mailbox.

One key difference is that we know brains can exist. We might not know the entirety of how they work, but the important thing is we already know they can be reproduced in some fashion.

Hyperdrive or any other form of FTL travel is purely in our thoughts. Nothing currently exists that even proves it is possible in our current reality. For all we know we could spend an infinite time attempting it and never achieve it.

Re: The Challenge of Relativistic Spaceflight

#46
post #38
post #22

Earlier quoted context omitted.

you mean the drive that if it were used it would annihilate your destination in a immense-burst of gamma energy? Not to mention we have no idea how to effectively modify space-time. It is interesting, but the drive is basically "if we had MAGIC, we could do this". FTL is also exactly the same as time-travel. If you could travel 25,000 light-years in an instant, you could turn a BIG telescope back at earth from your s…

I'm not saying it will ever work, just that those sorts of objections are quite different than "relativity says it's impossible, full stop." Modifications have improved the practicality from the original design, eg. by reducing the energy requirement from Jupiter mass to the mass of a small car. The way to modify space-time would be to use negative energy, which exists in theory but maybe not in any practical way. We…

Regarding negative-energy; I think you mean "nothing in our current understanding prevents something like what we describe as negative-energy from having existed at some time in the life of the Universe". Very different from "exists in theory".

Re: The Challenge of Relativistic Spaceflight

#47

Earlier quoted context omitted.

Special relativity says the speed of light is the same in all reference frames. In the reference frame of the moving CPU, it would operate correctly.

While the speed of light is the same, relativity also has a lot to say about accelerating reference frames. That said, if you were accelerating fast enough to affect the behavior of a CPU, you'd be experiencing G-forces comparable to the tidal forces of a black hole; computation would be the least of your problems.

Hmm, suggests a vaguely related question to my mind. Generally speaking, do black holes have any implications for computations? E.g. does having a black hole at your disposal let you solve any problems you wouldn't be able to otherwise?

Re: The Challenge of Relativistic Spaceflight

#48
post #42
post #22

Earlier quoted context omitted.

you mean the drive that if it were used it would annihilate your destination in a immense-burst of gamma energy? Not to mention we have no idea how to effectively modify space-time. It is interesting, but the drive is basically "if we had MAGIC, we could do this". FTL is also exactly the same as time-travel. If you could travel 25,000 light-years in an instant, you could turn a BIG telescope back at earth from your s…

I saw a lecture from the researcher that is working on the project and he explained why there isn't a burst of deadly energy. Also they are working on those experiments, so they have at least some idea how to do it. You should really update your data.

wow, someone tell the Nobel people that this guy has experimentally tested space-time modification and shown it does not accumulate bow-energy as it covers distance. I kid, but those that claim the bow-energy problem also have to prove it for it to be a real problem, and your comment seems to indicate the lecture was much more of a grant-money pitch.

Re: The Challenge of Relativistic Spaceflight

#50
post #15

I think we'll need fusion to make intra-solar system travel (really) possible, where we just transport stuff through-out the entire system, with a speed of at least 1/100 of the speed of light. Achievable in ~50-100 years. For inter-stellar space travel, say to the closest 20-100 star systems, we'll need either an anti-matter powered ship or a black-hole powered one (a bit more likely) that can travel to these stars…

> (remember technological progress is exponential not linear) No it is not. For example, airliners fly about as fast as they did a generation ago, and if you buy a desktop computer today it won't be noticeably faster than the ~3 year-old one you're using now. Do you really think the next TV you'll buy will be exponentially bigger than the one you have today? Prepare to be disappointed. warp-engine would require FTL t…

I must say that the idea of a single human cell traveling through space at relativistic speed, with the end goal of landing on a planet and growing into a fully formed human is one of the wildest and most unique ideas I've heard in a long time. Perfect sci-fi material. Totally awesome.
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