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A new model for faster-than-light travel that uses conventional physics

popularmechanics.com

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Re: A new model for faster-than-light travel that uses conventional physics

#111

What's your opinion on this? Do you believe we are ready for such technology? Imagine at our current state of global politics are we ready to start venturing into space and possibly into planets with life? And I'm not even considering possibilities of Intelligent life.

My opinion is that if and when we are able to harness the energy of 100 Jupiters our society will be completely unrecognizable compared to what it is today.

Re: A new model for faster-than-light travel that uses conventional physics

#112

What's your opinion on this? Do you believe we are ready for such technology? Imagine at our current state of global politics are we ready to start venturing into space and possibly into planets with life? And I'm not even considering possibilities of Intelligent life.

My opinion is that if and when we are able to harness the energy of 100 Jupiters our society will be completely unrecognizable compared to what it is today.

It was a hypothetical question, in case tomorrow we woke up and somehow we had a feasible warp drive invented.

Re: A new model for faster-than-light travel that uses conventional physics

#113

Link to one of the referred papers « Introducing Physical Warp Drives» https://arxiv.org/abs/2102.06824

That one, at least, doesn't claim to allow faster than light travel using known physics: "We show that a class of subluminal, spherically symmetric warp drive spacetimes, at least in principle, can be constructed based on the physical principles known to humanity today." (emphasis added)

Re: A new model for faster-than-light travel that uses conventional physics

#114

Since we have never been visited by aliens, or witnessed time travel, these things must not be possible. It they were, there would be proof and it would be documented. It's as simple as that.

Hand-wavey sci-fi explanation - time travel being observed causes a divergent reality (think many worlds), we're in the branch that didn't notice. Seems like not much more of a leap than aliens/time travellers would definitely visit us _and_ we would notice.

Re: A new model for faster-than-light travel that uses conventional physics

#115
post #77

Earlier quoted context omitted.

But isn't the entire thing that it appears faster than c to an outside observer? Like, that's the definition? In which case an outside observer would have less than 200 years until the thing went 200ly.

To the outside observer, they would be time travelling. "Appear to" and "actually" are two very different things. A traveller with a different procession of time will appear to be going faster or slower than they really should. There are galaxies moving faster than c away from us right now.

It's a bit mindblowing to apply relativity to that. To any observer, it'll seem like they're time traveling. (any sublight observer, or just any outside observer?)

Re: A new model for faster-than-light travel that uses conventional physics

#116
I really don’t understand why people are so hung up on the clocks back home. I mean, sure it would be nice to take a trip to Alpha Centauri, come back home, and boast about it to all of your friends, but really wouldn’t getting to see a few tens of thousands of years go by be even cooler?

To the constantly accelerating interstellar traveler distances get really small after a year or so. You’d be able to make it to the edge of the universe and back in a lifetime. Well, ‘back’ is probably not going to have a lot in common with this place, so maybe stick to distances in our local group or something.

https://en.m.wikipedia.org/wiki/Space_travel_using_constant_...

Re: A new model for faster-than-light travel that uses conventional physics

#117

Earlier quoted context omitted.

> Literally any method of getting from A to B faster than light would, has a causality paradox. Pretty much every explanation I've seen as to why this would ostensibly be so would - when applied consistently - consider the average thunderstorm to be full of causality violations because you can see the lightning before you can hear it. It shouldn't matter how long it takes me to go from Point A to Point B. As long as…

Here's the problem: Event A at location X at time T1 causes event B at location Y at time T2 > T1. If I can travel FTL, I can find a frame of reference where T2 before the cause. This leaves a few possibilities, and they're all bad: - There is no real cause and effect. - Cause and effect are real, but effects can come before causes. - The laws of physics are not the same in all frames of reference. Our current unders…

> If I can travel FTL, I can find a frame of reference where T2 How? Sure, it's possible that the light from an event happening at T2 arrives before the light from an event happening at T1, but that says nothing about when those events actually happened - just like how if we hear one lightning strike before another, that doesn't mean the one we heard first actually happened first.

That is: this notion that all superluminal travel somehow magically necessitates the possibility of backwards time travel doesn't seem to be logically sound, and seems to be one of these things that people keep repeating without bothering to actually explain why that is. Specifically, this "FTL necessitates backwards time travel" argument seems to depend on some notion that light is infinitely fast (because the only way to go back in time is to have a speed greater than infinity - i.e. one where the t component in d/t is negative), which is empirically false (we can measure light's speed, and it's clearly finite).

Re: A new model for faster-than-light travel that uses conventional physics

#118
post #99

Earlier quoted context omitted.

Perhaps but that doesn't bring one side of a circle closer to the other, or help you get out faster. Why would being able to move through higher dimensions help you travel faster through the 3 we're familiar with?

Viewing a 2D space from a higher dimension can make it obvious that the 2D space is not a flat plane, but is curved and warped. Some pairs of points in the 2D space may be closer together in 3D space than they appear while confined to the 2D space. There is a 3D/4D equivalent, but it can't be visualized, and it's unknown whether it has any possible physical meaning.

>Some pairs of points in the 2D space may be closer together in 3D space than they appear while confined to the 2D space.

This would be the coordinate system on a crumpled piece of paper analogy, yes? I can't help but feel this is highly unlikely.

Do we have any reason to believe this would be the case? Wouldn't we experience this crumpled space or is momentum crumpled as well?

Why would we expect new dimensions to be bent through our dimensions when the 3 we experience do not exhibit this behavior?

Re: A new model for faster-than-light travel that uses conventional physics

#119

Earlier quoted context omitted.

> Literally any method of getting from A to B faster than light would, has a causality paradox. Pretty much every explanation I've seen as to why this would ostensibly be so would - when applied consistently - consider the average thunderstorm to be full of causality violations because you can see the lightning before you can hear it. It shouldn't matter how long it takes me to go from Point A to Point B. As long as…

https://en.m.wikipedia.org/wiki/Tachyonic_antitelephone

That doesn't answer the question. The hypothetical existence of a tachyonic antitelephone presupposes that superluminal communication causes backward time travel. The question is why superluminal communication (allegedly) causes backward time travel, and by what mechanisms.

And no, just because some arbitrary frame of reference is slow to receive information doesn't mean the events creating that information have scrambled causality. Just like how just because I heard lightning strike B before lightning strike A doesn't mean B struck before A.

Re: A new model for faster-than-light travel that uses conventional physics

#120

Earlier quoted context omitted.

> Since we have never been visited by aliens This is a rather large assertion to make.

So is the "if it's possible, they certainly would have done it to visit us " leap of (non)logic.

Eh, I just feel that there's more "evidence" of ET's being seen than not - albeit just through religious texts, historical paintings, eyewitness accounts etc. Plus it's more entertaining to consider it as a possibility than to be a wet blanket and write it off completely.
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