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Travel through wormholes is possible, but slow

phys.org

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Re: Travel through wormholes is possible, but slow

#91

Post by pontifier »

logfromblammo wrote: post #35
philipov wrote: post #3

Earlier quoted context omitted.

Based on the colloquia I watched by Lenny Susskind, the problem is that you can put something into a wormhole, but to get it out the other end, you have to carry the encoding you get to the other end of the wormhole to decode the output. Because the distance to the singularity grows at the speed of light, the length of the wormhole is essentially infinite. It is only the operator you get from putting the object into…

So... Two entangled wormhole apertures function as Star Trek style transporter pads. Feed mass into one hole, scanning it as it goes in. Transmit the pattern to another aperture of the hole, using electromagnetic energy at the speed of light, and when that end ejects a mass, apply the pattern to it, so it resolves into an exact copy of what you put in. The distance the mass travels may be shorter than the distance th…

http://existentialcomics.com/comic/1

Edit:Lol, someone else also had this link as a reply to a similar thought.

Re: Travel through wormholes is possible, but slow

#93

Post by Abishek_Muthian »

>To date, a major stumbling block in formulating traversable wormholes has been the need for negative energy, which seemed to be inconsistent with quantum gravity. However, Jafferis has overcome this using quantum field theory tools, calculating quantum effects similar to the Casimir effect.

Prof. Stephen Hawking has explained the Casimir effect in hist last book 'Brief Answers to the Big Questions' in the chapter talking about Time Travel with Wormholes.

"Imaging that you have two parallel metal plates a short distance apart. The plates act like mirrors for the virtual particles and anti-particles. This means that the region between the plates is a bit like an organ pipe and will only admit light waves of certain resonant frequencies. The result is that there are a slightly different number of vacuum fluctuations or virtual particles between the plates than there are outside them, where vacuum fluctuations can have any wavelength. The difference in number of virtual particles between the plates compared with outside the plates means that they don't exert much pressure on one side of the plates when compared with the other. There is thus a slight force pushing the pates together. This force has been measured experimentally. So, virtual particles actually exist and produce real effects.

Because there are fewer virtual particles or vacuum fluctuations between plates, they have a lower energy density than in the region outside. But the energy density of empty space far away from the plates must be zero. Otherwise it would warp space-time and the universe wouldn't be nearly flat. So the energy density in the region between the plates must be negative"

Re: Travel through wormholes is possible, but slow

#94

Post by smoyer »

BartBoch wrote: post #69
lupire wrote: post #64

Earlier quoted context omitted.

Not always. Faster than light travel has never been bent.

Well, we are able to research FTL for only a few decades. Give it a few more due to complexity. Few ages ago people thought that the world is flat... Also, there are theories of FTL: https://en.wikipedia.org/wiki/Faster-than-light

And suddenly people think the earth is flat again ... we need to keep science more relatable to the general population and that starts with being realistic.

I'm not arguing with your idea ... just that it should start with a caveat ... "there are no current theories that support FTL but we're hoping ..."

Re: Travel through wormholes is possible, but slow

#95

Post by saagarjha »

soulofmischief wrote: post #33
FrancoisBosun wrote: post #16

Earlier quoted context omitted.

I thought nothing could move faster than light?

Nothing's moving. It's like if you ran a 100m but while you were running, they decided to make it a 200m. If you speed up, you can finish the race in the same amount of time. Light always finishes the race in the same amount of time from each observer's perspective. It can always speed up because it's massless, but you have mass and there is a limit to how much you can speed up. According to general relativity, an ob…

> It can always speed up because it's massless

I'd suggest clarifying this statement because it certainly gave me the wrong impression…

Re: Travel through wormholes is possible, but slow

#96

Post by stcredzero »

zspade wrote: post #87
swebs wrote: post #66

Earlier quoted context omitted.

On the bright side, due to time dilation, you can still make the trip in your lifetime.

If by the bright side you mean you would only make it there it there as pure energy. Mass is converted to energy as it approaches C (Light Speed). Though getting mass to actual light speed would require infinite energy, so that point is moot. Let's say you get to 96% C. You would experience 28% of the journey. Taking into account the the time to speed up and slow down from C, you're looking at over 290k years from th…

Mass is converted to energy as it approaches C (Light Speed).

Not so much.

https://www.youtube.com/watch?v=LTJauaefTZM

Try this thought experiment. Let's say you had a magic Bussard Ramjet rocket which scoops up energy and reaction mass from space and can accelerate forever. There are no special reference frames. So what happens if the rocket accelerates then shuts off its engine at the point where the "relativistic mass," as measured by an un-accelerated observer, should make the rocket disappear behind an event horizon?

From the POV of people on the rocket, they accelerated, then stopped accelerating. From the observer's POV, the rocket turned into a black hole? One reference frame now seems "privileged" or different somehow. How do we square this with relativity? Also, what happens if the rocket turns around, then decelerates? Wouldn't that constitute them returning from inside of an event horizon?

The answer, is that "relativistic mass" is actually just a pedagogical fiction.

(EDIT: Also, a lot of the redonkulousness in the thought experiment sneakily comes from rockets that can magically accelerate without worrying about where the fuel and energy come from. If you worked out how much fuel and reaction mass would be needed by a real rocket to perform such a feat, you'd get "unphysical" amounts of matter.)

Re: Travel through wormholes is possible, but slow

#97

Post by PaulHoule »

noobermin wrote: post #71

I'm not sure if this is the researchers' issue or is an issue with the scientific press, but it would help if the "discoveries" theorists made with their hitherto unestablished and untested theories like various string and QG based theories were not touted as discoveries about the real world.

QG is funny.

There are some results around QG, such as holography, which seem to be universal. That is, they make sense with strings, loop quantum gravity or any of about ten other lines of work that people can do quantum gravity calculations with today.

If you can prove that all of those have to say the same thing, that is a powerful result and probably means something about our world.

It seems pretty reasonable that wormholes could exist so long as they don't form closed-timelike curves, so I think these people are getting at the quantum roots of the "cosmic censorship principle".

Re: Travel through wormholes is possible, but slow

#98

Post by stcredzero »

saagarjha wrote: post #90
zspade wrote: post #87

Earlier quoted context omitted.

If by the bright side you mean you would only make it there it there as pure energy. Mass is converted to energy as it approaches C (Light Speed). Though getting mass to actual light speed would require infinite energy, so that point is moot. Let's say you get to 96% C. You would experience 28% of the journey. Taking into account the the time to speed up and slow down from C, you're looking at over 290k years from th…

> Mass is converted to energy as it approaches C (Light Speed). Uh, I think it's the other way around: the energy you pump in becomes additional mass.

Look at my sibling comment to yours. Relativistic mass is mostly just a pedagogical fiction.

Re: Travel through wormholes is possible, but slow

#99

Post by lisper »

lupire wrote: post #75
jaequery wrote: post #6

When ever I think of traveling through a wormhole/blackhole, I imagine you would be squished and crushed and come out the other end as pure vaporized energy. This makes me wonder, if there is the potential for our beings (or things) be able to be vaporized and then recreated to original form. If we are just mass and particles, this should be possible?

Uncertainty principle says...probably not. It's impossible to make a complete copy of the pattern. Even aside from that -- it's unlikely to be practical to scan something down to the smallest level level of matter, because the tools we use to manipulate things can't manipulate things smaller than their own finest details. So there's a "glass wall" in that you can only replicate things less finely detailed than the re…

> Uncertainty principle says...probably not. It's impossible to make a complete copy of the pattern.

That depends on what "the pattern" is. You can make an "exact" copy of a digital file, but that's because the semantics of digital data don't depend on the fine details of the physical representation (that's the whole point of going digital). We don't yet know what level of detail of our physical state actually matters. If you take a single atom in your brain and move it somewhere else, does that matter? Probably not. What about ten atoms? Again, probably not. But at some point as the number goes up the answer must change. We don't know where the boundary is, and we don't know how close it is to the theoretical and technological limits of copying. But I don't think we can rule out the possibility of cloning a human brain in principle based on current knowledge.

Re: Travel through wormholes is possible, but slow

#100

Post by therein »

nine_k wrote: post #81
piker wrote: post #51

Earlier quoted context omitted.

So that's it, then? Some thing, say, a million light years away from another thing is in practice entirely inaccessible to civilizations existing on that other thing, requiring a minimum of a million years to reach?

This depends on what do you mean by 'inaccessible'. Going there and back again, and telling your pals how things are 1000LY away is likely impossible. Expanding your civilization to more and more habitable celestial bodies, slowly but relatively surely, is entirely possible. This is how e.g. plants colonize vast spaces, being limited by the speed of their growth often by inches per lifetime. (You should also consider…

But aren't there massive gaps where an intermediate celestial body to perform this jump on will be simply too far away for traditional space travel?
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