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Positive Energy Warp Drive from Hidden Geometric Structures

arxiv.org

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Re: Positive Energy Warp Drive from Hidden Geometric Structures

#121

Post by pa7x1 »

AnimalMuppet wrote: post #40
sigmoid10 wrote: post #15

Earlier quoted context omitted.

General relativity actually tells us nothing about whether causality is absolute. You can easily make up spacetime configurations that violate causality and still conform to general relativity. It's just that most people believe that causality should be protected, because... well it would be really weird if it wasn't. But it's just a conjecture and not like a theorem or anything.

That conjecture is one of the two foundational principles of relativity - that the laws of physics are the same in all valid frames of reference. "Violating causality" means that in some valid frame of reference A, event X caused event Y, and in some other valid frame of reference B, event Y caused event X. The laws of physics cannot be the same in A and B for both of those to be true.

This is not true. Relativity doesn't forbid and is not in contradiction with supraluminal phenomenona.

You need to impose additional constraints on the theory (e.g., real mass conditions) to get rid of them.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#122

Post by phendrenad2 »

sigmoid10 wrote: post #15
gary_0 wrote: post #9

What do the authors of these warp drive papers think will happen causality-wise when the proposed vehicle effectively moves faster than c? You can't do that without doing nasty things to your light cone[0] and effectively traveling into your own past. Is a prerequisite of entertaining the idea of a warp drive that we disregard causality? As far as I know, there aren't any plausible loopholes in General Relativity tha…

General relativity actually tells us nothing about whether causality is absolute. You can easily make up spacetime configurations that violate causality and still conform to general relativity. It's just that most people believe that causality should be protected, because... well it would be really weird if it wasn't. But it's just a conjecture and not like a theorem or anything.

So we're traveling away from one another at 0.9c. I send a paper airplane in your direction at 500x the speed of light. You receive it and send it back (at 500c). Does it not arrive before I sent it, from my perspective?

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#123

Post by analog31 »

silon42 wrote: post #101
analog31 wrote: post #78

Earlier quoted context omitted.

By the time it works well enough to be useful, we'll all know about it, perhaps as soon as 50 years ago.

If aliens decide to visit us using the warp drive today, they will still arrive tomorrow, not 50 years ago.

Depends on how good their aim is. :-)

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#124

Post by iamnotwhoiam »

gary_0 wrote: post #13
XorNot wrote: post #11

Earlier quoted context omitted.

Well for one thing, a speed-of-light limited warp drive would still be effectively a reaction-less drive we could use for travel in the solar system. But a decent way to beat Einstein would be find and implement an actual FTL engine: after all, if you can do it then obviously the theory isn't correct (alternately: the universe possible does not care about causality as much as we do in our little bubble of perception)…

> would still be effectively a reaction-less drive True, but if the energy requirements for warp drives continue to be measured in Jupiters , reaction-mass is the least of your worries.

I think with that much energy the light pressure alone would get you wherever you wanted to go.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#125

Post by moonbug »

native_samples wrote: post #114
thaneross wrote: post #85

Earlier quoted context omitted.

Funnily enough, the writers of ST:TNG had this idea too. The main computer of the Enterprise-D was huge (9 decks tall) and generated a subspace field so that optical processing ran faster than light.

Star Trek's tech vision is astounding. How many things in it have actually been built? I count: • Tablets (the padds) • VR "holodecks" • Computers that you can talk to and ask questions • "Tricorders" (smartphones?) • Turbolifts ( https://www.dezeen.com/2017/07/12/thyssenkrupp-unveils-world... ) Maybe we'll get to add a warp drive to the list by the time I die. What else?

The navigation was done by whales.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#126

Post by pbhjpbhj »

native_samples wrote: post #114
thaneross wrote: post #85

Earlier quoted context omitted.

Funnily enough, the writers of ST:TNG had this idea too. The main computer of the Enterprise-D was huge (9 decks tall) and generated a subspace field so that optical processing ran faster than light.

Star Trek's tech vision is astounding. How many things in it have actually been built? I count: • Tablets (the padds) • VR "holodecks" • Computers that you can talk to and ask questions • "Tricorders" (smartphones?) • Turbolifts ( https://www.dezeen.com/2017/07/12/thyssenkrupp-unveils-world... ) Maybe we'll get to add a warp drive to the list by the time I die. What else?

Communicators would be something like Bluetooth earpieces.

You've got Tricorders wrong, they're a generalized non-contact diagnostic tool; someone was working on one but it was just a load of diagnostic devices stuck together. We've got body temperature, and pulse is doable, but not sure what else can really be added to a Tricorder, maybe a tiny mass-spectrometer gets you part way there.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#127

Post by mikro2nd »

native_samples wrote: post #114
thaneross wrote: post #85

Earlier quoted context omitted.

Funnily enough, the writers of ST:TNG had this idea too. The main computer of the Enterprise-D was huge (9 decks tall) and generated a subspace field so that optical processing ran faster than light.

Star Trek's tech vision is astounding. How many things in it have actually been built? I count: • Tablets (the padds) • VR "holodecks" • Computers that you can talk to and ask questions • "Tricorders" (smartphones?) • Turbolifts ( https://www.dezeen.com/2017/07/12/thyssenkrupp-unveils-world... ) Maybe we'll get to add a warp drive to the list by the time I die. What else?

"Computers that you can talk to and ask questions"

Pity the answers are so often rubbish and the "side-effects" so obnoxious. ST (and most other SF) seems not to have predicted that.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#128

Post by bronzeage »

gary_0 wrote: post #9

What do the authors of these warp drive papers think will happen causality-wise when the proposed vehicle effectively moves faster than c? You can't do that without doing nasty things to your light cone[0] and effectively traveling into your own past. Is a prerequisite of entertaining the idea of a warp drive that we disregard causality? As far as I know, there aren't any plausible loopholes in General Relativity tha…

As far as I understand, the point of warp drive is that you shorten the space time distance you travel by warping spacetime.

At no point do you travel in a specifical location faster than light. You simply cover less distance by warping space.

There's no causality violation. It's similar to the fact some parts of the universe travel away from us faster than light. They don't violate causality because it's space that is expanding.

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#129

Post by Aardwolf »

native_samples wrote: post #114
thaneross wrote: post #85

Earlier quoted context omitted.

Funnily enough, the writers of ST:TNG had this idea too. The main computer of the Enterprise-D was huge (9 decks tall) and generated a subspace field so that optical processing ran faster than light.

Star Trek's tech vision is astounding. How many things in it have actually been built? I count: • Tablets (the padds) • VR "holodecks" • Computers that you can talk to and ask questions • "Tricorders" (smartphones?) • Turbolifts ( https://www.dezeen.com/2017/07/12/thyssenkrupp-unveils-world... ) Maybe we'll get to add a warp drive to the list by the time I die. What else?

"The Game" episode of TNG predicted addictive viral mobile games

Re: Positive Energy Warp Drive from Hidden Geometric Structures

#130

Post by eganist »

pbhjpbhj wrote: post #126
native_samples wrote: post #114

Earlier quoted context omitted.

Star Trek's tech vision is astounding. How many things in it have actually been built? I count: • Tablets (the padds) • VR "holodecks" • Computers that you can talk to and ask questions • "Tricorders" (smartphones?) • Turbolifts ( https://www.dezeen.com/2017/07/12/thyssenkrupp-unveils-world... ) Maybe we'll get to add a warp drive to the list by the time I die. What else?

Communicators would be something like Bluetooth earpieces. You've got Tricorders wrong, they're a generalized non-contact diagnostic tool; someone was working on one but it was just a load of diagnostic devices stuck together. We've got body temperature, and pulse is doable, but not sure what else can really be added to a Tricorder, maybe a tiny mass-spectrometer gets you part way there.

> You've got Tricorders wrong, they're a generalized non-contact diagnostic tool; someone was working on one but it was just a load of diagnostic devices stuck together. We've got body temperature, and pulse is doable, but not sure what else can really be added to a Tricorder, maybe a tiny mass-spectrometer gets you part way there.

In fairness, a tricorder would probably need to be a device capable of gathering data about quantum fields within an extremely local region of space and then analyzing based on known frames of reference and data models, so we're probably a ways off on that one.

The harder part of that challenge is building a device capable of analyzing quantum fields in the most abstract sense. But once that's done, even if it's in the form of a massive machine that can only analyze spacetime in a small chamber, even if that machine is rooms-big, the race to the first tricorder begins.

(I could be completely off-base with my comment on analyzing quantum fields. I'm not at all an expert.)

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