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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)

#31

Post by jerf »

macspoofing wrote: post #24
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.

Everything we know tells us that energy being conserved is a fundamental limit, but we don't know everything. For example, exotic physics that allows us to pull energy from the cosmological constant itself is still a theoretical possibility. Maybe there is some exotic aspect of reality that could violate energy conservation.

My point being that, yes, these two are comparable, which is what the claim you are replying to said.

In fact, belief in FTL is sillier that violation of conservation of energy. We have no evidence for FTL of any kind. We do have some reason to believe that conservation of energy is in fact violated at cosmological scales by the increasing rate of expansion of the universe. (Perhaps future understandings will resolve this apparent violation with a more complete picture of "energy", but at the moment, what we know of as energy is not being conserved at that scale.)

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

#32

Post by jerf »

amelius wrote: post #22
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.

You don't need that. Time dilation already does that for you. There is no apparent limit to subjective velocities.

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

#33

Post by macspoofing »

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…

>If FTL is possible then the Fermi paradox goes from being an intellectual curiosity to a near metaphysical emergency.

Maybe. Maybe not. This is how UFO conspiracy theorists reason - "Here are some phenomena I don't understand, I can't think of any plausible explanation for them, therefore, must be aliens".

There may be some hidden reasons why we can't detect FTL civilizations.

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

#34

Post by amelius »

jerf wrote: post #32
amelius wrote: post #22

Earlier quoted context omitted.

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.

You don't need that. Time dilation already does that for you. There is no apparent limit to subjective velocities.

Well, the people standing by watching the experiment still notice you are moving slower than light.

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

#35

Post by jerf »

amelius wrote: post #34
jerf wrote: post #32

Earlier quoted context omitted.

You don't need that. Time dilation already does that for you. There is no apparent limit to subjective velocities.

Well, the people standing by watching the experiment still notice you are moving slower than light.

How does that relate to your first post? Are you really focusing on what people notice?

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

#36

Post by astrowilliam »

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.

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

#37

Post by Abraln »

I agree with the link that it really depends on what you mean by FTL. At first glance refrigerators seem impossible because they would reverse entropy. The key is that it does not practically matter if they do or not, they just need to achieve the desired result. I would personally consider FTL anything that would beat light traveling through unaltered space-time.

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

#38

Post by Bombthecat »

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.

What if physics is like a computer?

You have atoms and quants and whatnot. Now you add one and one another. You keep adding and soon or matter there is a slip. Basically you get the universe to a buffer overflow. All still following the laws of physics. Like you get a cpu limited of his numbers you get the universe to a buffer overflow.

Now one could say, but the universe is endless. Which means you would need endless energy for that buffer overflow.

But who says you need to create that buffer overflow in the whole universe and not in a cube? And who says the universe is endless?

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

#39

Post by api »

macspoofing wrote: post #33
api wrote: post #21

Earlier quoted context omitted.

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…

>If FTL is possible then the Fermi paradox goes from being an intellectual curiosity to a near metaphysical emergency. Maybe. Maybe not. This is how UFO conspiracy theorists reason - "Here are some phenomena I don't understand, I can't think of any plausible explanation for them, therefore, must be aliens". There may be some hidden reasons why we can't detect FTL civilizations.

Way off in tangent land now but: while much of "ufology" is indeed silly, "the aliens are here but they are not communicating" is a valid hypothesis for the Fermi paradox (with or without FTL).

There are numerous rational reasons that an intelligence exploring the universe might choose to be very very careful about initiating communication to the point of taking steps to avoid even accidentally revealing itself. Some of these are altruistic (e.g. prime directive and contamination concerns) and some are self-interested (see game theory, and consider the apocalyptic destructiveness of conflict between really advanced intelligences).

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

#40

Post by kirykl »

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…

if a method to violate causality is discovered on Earth it probably wouldn't lead to intelligent expansion, but mass destruction
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