Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

math.ucr.edu

Post reply on HN
Print view View original

21–30 of 88 posts

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

#21

Post by api »

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 possible then the Fermi paradox goes from being an intellectual curiosity to a near metaphysical emergency. If there is FTL then either we are absolutely alone or there are aliens everywhere and they are hiding from us or for some reason we can't see them. That's because the first expansionary intelligence to discover FTL will fill at least the galaxy if not the entire universe in a geological eye-blink. Since ubiquitous aliens hiding seems less likely, if a pathway to FTL were discovered I would immediately conclude that we are alone in the galaxy at least and possibly beyond.

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

#22

Post by amelius »

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.

But you can still create the illusion of moving faster than light by freezing everybody for the duration of the experiment. That might be good enough.

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

#23

Post by 3pt14159 »

snarfy wrote: post #12
sevenless wrote: post #7

The thing is that subjectively "FTL" travel, a la Star Trek, is totally possible thanks to special relativity contracting distances between objects. A little math shows the relative velocity in which you travel one light year measured in a rest frame, in one year in your spaceship's frame, is 70.7% of the speed of light. If you happened to be moving at the ludicrous speed of the "Oh-My-God" cosmic ray recorded in 199…

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.

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 cosmopolitan place ever.

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

#24

Post by macspoofing »

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.

You are way too sure about this. Everything we know tells us that this is a fundamental limit, but we don't know everything. For example, wormholes are still within theoretical possibility. Maybe there is some exotic aspect of reality that could imply FTL travel, causality be damned.

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

#25

Post by ceejay »

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…

Possible doesn't necessarily mean easy.

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

#27

Post by mikeash »

dec0dedab0de wrote: post #18
sevenless wrote: post #14

Earlier quoted context omitted.

This explains the famous line from Star Wars about the Millennium Falcon "making the Kessel run in less than 12 parsecs". George Lucas was obviously hip to the implications of special relativity.

I think the retconed explanation is that the kessel run involves going around a black hole. Bragging about parsecs is because the slower ships had to completely steer free of the blackhole, while faster ones could get closer and break free of it's gravity, thus shortening the overall distance traveled.

I prefer the explanation that Han Solo thought they were total rubes, and gave them some nonsense just to impress them.

Indeed, the fourth draft of the script has this comment after the "twelve parsecs" line: "Ben reacts to Solo's stupid attempt to impress them with obvious misinformation." The final draft says he's "obviously lying."

I feel like this ridiculous retcon involving black holes, rather than sticking to the simple human explanation of braggadocio, is a microcosm of everything that subsequently went wrong with the prequels.

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

#28

Post by yoz-y »

dec0dedab0de wrote: post #18
sevenless wrote: post #14

Earlier quoted context omitted.

This explains the famous line from Star Wars about the Millennium Falcon "making the Kessel run in less than 12 parsecs". George Lucas was obviously hip to the implications of special relativity.

I think the retconed explanation is that the kessel run involves going around a black hole. Bragging about parsecs is because the slower ships had to completely steer free of the blackhole, while faster ones could get closer and break free of it's gravity, thus shortening the overall distance traveled.

After seeing Interstellar and some Black Science Man explanations this would also mean that the fastest ships would get to the finish decades after the slow ones due to gravity shenanigans.

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

#29

Post by vslira »

3pt14159 wrote: post #23
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.

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…

It's not a party, it's a restaurant :)

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

#30

Post by mikeash »

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 theories are subject to refinement and replacement as better data is obtained.

It is not known that perpetual motion or FTL are impossible. It is believed that they are impossible, because the best theories to explain current data say they are impossible. But there is room for new data and new theories.

It was not all that long ago that it was "scientific fact" that atoms were indivisible (that's what the word means, even), that velocities add linearly, that light propagates through a fixed medium, that matter is conserved, and that gravitational force is proportional to mass and inversely proportional to the square of distance.

I also don't see much "acceptance" of FTL as physical fact. I see it accepted a lot as a story device, but that's just because it's handy for making entertaining stories, not because there's any basis in physical fact. There's some "acceptance" of FTL as physical fact in that people don't completely rule it out, but that's entirely justified.

Post reply on HN