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Is Faster-Than-Light Travel or Communication Possible? (1997)

math.ucr.edu

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Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#51

Post by akshayn »

zxexz wrote: post #48
3pt14159 wrote: post #23

Earlier quoted context omitted.

This is one of my theories about why there isn't any alien life around. There is some party far in the future with a beacon or message that shouts "JOIN US HERE IN THE MIDDLE OF GALAXY R345Q2 10 BILLION YEARS IN THE FUTURE!" After about 10 thousand years of hearing the beacon and being alone we finally get restless and just build a couple thousand giant spaceships and join the rest of the universe in the most cosmopo…

Huh, this is a really fun thought experiment. Does anyone know any scifi books that explores this (or a similar) concept?

As vslira alluded: https://en.wikipedia.org/wiki/The_Restaurant_at_the_End_of_t...

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#53

Post by nwah1 »

zxexz wrote: post #48
3pt14159 wrote: post #23

Earlier quoted context omitted.

This is one of my theories about why there isn't any alien life around. There is some party far in the future with a beacon or message that shouts "JOIN US HERE IN THE MIDDLE OF GALAXY R345Q2 10 BILLION YEARS IN THE FUTURE!" After about 10 thousand years of hearing the beacon and being alone we finally get restless and just build a couple thousand giant spaceships and join the rest of the universe in the most cosmopo…

Huh, this is a really fun thought experiment. Does anyone know any scifi books that explores this (or a similar) concept?

https://en.wikipedia.org/wiki/The_Restaurant_at_the_End_of_t...

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#54

Post by dogma1138 »

dcherman wrote: post #44
snarfy wrote: post #12

Earlier quoted context omitted.

The center of the galaxy is 32,000 light years away. 32,000 years will have passed at the center of the galaxy by the time you get there in your 3.2 second journey. If you then turn around and go back, another 32,000 years will have passed before you get home. It might feel more like time travel than space travel.

What I've always found interesting (not sure if there's a name for this) is kind of the idea that if you made such a trip, you might find by the time you arrive there in 3.2 seconds, the rest of humanity has figured out true FTL travel with the technology that was developed during those 32,000 years. As a result, you arrive in what might be the equivalent of a horse and buggy at the center of the galaxy versus what e…

There was an Episode in Andromeda that dealt with that same thing.

There was also an point in that episode since the FTL method they used was tethered to massive objects and hence only allowed for travel from on star system to another (or from one galaxy to another) the old fashioned non FTL method allowed them to explore many more things than with FTL travel the downside that 10,000's years would pass for everyone else every time they take a trip.

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#55

Post by andrewla »

api wrote: post #21
aaron695 wrote: post #16

Thinking you can go faster than light for communication is the same as believing perpetual motion or even being a flat earther. You can't do it, there are no hacks to do it. It's a law of the universe. No matter how many SciFi movies tell you other wise. I just don't get the acceptance of this anti-scientific concept.

We've only been doing this science thing in a serious organized way for between 100 and 200 years depending on how you count it. It's only since WWII that we've done it in a really big heavily funded way (cold war and all that). You're probably right, but I can't bring myself to be quite as dogmatic about it. I do very much doubt FTL, not only for the physics reasons but for other circumstantial ones. If FTL is possi…

Our galaxy is estimated to be at most around 180,000 light years in diameter.

Even at a fraction of the speed of light, the amount of time to expand and fill the galaxy is still an eye-blink in geologic time. Even in evolutionary timescales it's still an eye-blink -- the Cretaceous era ended about 66 million years ago.

I think the depressing truth is that we are alone in this galaxy. See [1] for Michael H. Hart's extremely compelling discussion of this idea.

[1] http://adsabs.harvard.edu/full/1975QJRAS..16..128H

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#56

Post by zxexz »

akshayn wrote: post #51
zxexz wrote: post #48

Earlier quoted context omitted.

Huh, this is a really fun thought experiment. Does anyone know any scifi books that explores this (or a similar) concept?

As vslira alluded: https://en.wikipedia.org/wiki/The_Restaurant_at_the_End_of_t...

Oh, I've read that five part 'trilogy' several times :) I guess I should have said...

Douglas Adams' books have been a major fixture of my life since I was 12. He really was ahead of his time. Actually I don't think said time he was metaphorically ahead of has come yet :)

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#57

Post by michaelmrose »

astrowilliam wrote: post #36
aaron695 wrote: post #16

Thinking you can go faster than light for communication is the same as believing perpetual motion or even being a flat earther. You can't do it, there are no hacks to do it. It's a law of the universe. No matter how many SciFi movies tell you other wise. I just don't get the acceptance of this anti-scientific concept.

And in the early 1000s humans believed that we would never fly a few people strapped to a giant rocket to the moon. They believed that because the technology to do it hadn't been invented yet and we had no idea it was possible. We have to learn how to do it and then we will do it.

Flying didn't violate the basis premises of physics. Also it exacerbates the issue wherein space doesn't appear to be full of aliens. Even a few races in the galaxy expanding with slower than light travel could fill the galaxy in tens of thousands of years. Now imagine how fast the universe fills up with ftl travel

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#58

Post by Jach »

mikeash wrote: post #30
aaron695 wrote: post #16

Thinking you can go faster than light for communication is the same as believing perpetual motion or even being a flat earther. You can't do it, there are no hacks to do it. It's a law of the universe. No matter how many SciFi movies tell you other wise. I just don't get the acceptance of this anti-scientific concept.

Flat earthers are a totally different thing. The shape of the Earth is a fairly simple physical fact about the universe. To deny it is to essentially deny even the most basic human ability to gather facts. Perpetual motion and FTL travel are about physical laws, which are not known in full . We've got some really good theories with a lot of data to back them up, but the facts lie in the data, not the theories. The th…

http://arxiv.org/abs/1005.4172

c is a bit more established than "scientific fact" like the behavior of atoms were once thought to be, it is very mathematical, as is the curvature of the earth being > 0. In principle new data could come in showing these things to be false, in the same sort of way twice 2 may not be 4.

Another similar fact almost beyond experimental disproval is https://en.m.wikipedia.org/wiki/Identical_particles

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#59

Post by SerLava »

mariodiana wrote: post #47
jandrese wrote: post #17

Earlier quoted context omitted.

This is exactly right given our current understanding of the universe. FTL travel violates causality, which is a fundamental principle of the universe. I wouldn't go quite so far as to say it's totally impossible though. There is a whole lot about the universe we don't understand and I can't rule out the possibility that there are entire branches of mathematics and physics that we don't know about.

Can you or someone else "explain to me like I'm five" why faster-than-light travel violates causality?

To travel faster than light, you'd have to skip places in space instead of moving through them continuously. So you'd be constantly appearing out of nowhere.

Other reasons.

Re: Is Faster-Than-Light Travel or Communication Possible? (1997)

#60

Post by bla2 »

zxexz wrote: post #48
3pt14159 wrote: post #23

Earlier quoted context omitted.

This is one of my theories about why there isn't any alien life around. There is some party far in the future with a beacon or message that shouts "JOIN US HERE IN THE MIDDLE OF GALAXY R345Q2 10 BILLION YEARS IN THE FUTURE!" After about 10 thousand years of hearing the beacon and being alone we finally get restless and just build a couple thousand giant spaceships and join the rest of the universe in the most cosmopo…

Huh, this is a really fun thought experiment. Does anyone know any scifi books that explores this (or a similar) concept?

"A Fire Upon the Deep" explores a related concept.
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