Jump to content

Warp drives

Pugspaceprogram
 Share

Recommended Posts

Pugspaceprogram

Pugspaceprogram

Posted
Posted (edited)

According to the theory of relativity, if we were to travel at the speed of light, we would create a natural time machine. But; with a theory made by the same guy (Einstein); if we were to travel at the speed of light, we would need an infinite amount of energy. That's quite a big number. As we speak, NASA is working on these 'warp drives' which, according to them, could accelerate anything with mass to the speed of light. Not just the speed of light though, they also claim that they can accelerate anything with or without mass to 10x the speed of light! How is this possible? As explained earlier, not only can nothing with mass reach the speed of light, it would require an infinite amount of energy to do so; also, the same theory dictates whether we can go beyond the speed of light too.

So what are your opinions? What do you think should be done? Should we make Einstein spin in his grave (and attach him to a generator for infinite electricity *trollface*) Or just leave him be?

It's up to you.

Poll to be added soon. We want to know your opinions! -Cheers, NotYorkie

(Here there would normally be a message from OP [PugSpaceProgram], Sadly there is currently none), Have fun - PugSpaceProgram

Edited by Pugspaceprogram
Admin message
Link to comment
Share on other sites
Awaras

Awaras

Posted
Posted (edited)

There was a big hubbub about these news a few months ago:

http://beforeitsnews.com/space/2013/05/nasas-warp-drive-project-speeds-that-could-take-a-spacecraft-to-alpha-centauri-in-two-weeks-even-though-the-system-is-4-3-light-years-away-2459620.html

To OP:

The whole point of the proposed 'Warp Drive' is that it would warp the space around the ship, while the ship would practically remain stationary inside it's own 'bubble' of space-time. That means that there would be no relativistic effects on the ship (no time dilation). It still needs strange stuff to make it work, things like negative energy and negative mass, and as far as we know at this time, those things are pretty much impossible...

Edited by Awaras
Link to comment
Share on other sites
tek_604

tek_604

Posted
Posted

God, what a horrible site. Anyway, at least it gave me the name of the guy involved, Harold White. And to calm everyone down, this is what he has proposed doing White–Juday warp-field interferometer.

As far as I can see, currently not funded.

Link to comment
Share on other sites
Awaras

Awaras

Posted
Posted
God, what a horrible site. Anyway, at least it gave me the name of the guy involved, Harold White. And to calm everyone down, this is what he has proposed doing White–Juday warp-field interferometer.

As far as I can see, currently not funded.

Yeah, sorry about the site, it was on all major news sites at the time, but it was the first one that popped out at me when I did a quick google search right now.

Link to comment
Share on other sites
nyrath

nyrath

Posted
Posted
As we speak, NASA is working on these 'warp drives' which, according to them, could accelerate anything with mass to the speed of light. Not just the speed of light though, they also claim that they can accelerate anything with or without mass to 10x the speed of light! How is this possible?

No, that is the entire point. Relativity makes it impossible to accelerate anything with a rest mass to the speed of light. So the warp drive does not accelerate the ship to the speed of light.

Instead it accelerates a bubble of space to a speed faster than light. The ship is stationary inside the bubble, as far as relativity is concerned. And nothing in relativity says you cannot accelerate a patch of space faster than lightspeed.

http://en.wikipedia.org/wiki/Alcubierre_drive

Link to comment
Share on other sites
Galacticruler

Galacticruler

Posted
Posted

Its a trick, they are not accelerating anything, the principal is spatial distortion, taking point A and B, then removing, say, 150k light years from their distance temporarily, alternatively they move the ship by expanding/contracting space around them, again, not moving the ship at all.

Did not read above post.

Link to comment
Share on other sites
Bunsen

Bunsen

Posted
Posted

Short version: Ain't gonna happen.

Long version: Physicists like to play with impossible ideas sometimes. It's sort of the scientific version of telling stories about elves and wizards, and it's easy to do on paper. You can write down equations that describe magnetic monopoles, then see what consequences their existence would have. You can write down equations that describe a universe with no mass in it, and see what would happen. You can examine the consequences of changing the speed of light to ten miles per hour, or making Planck's constant a billion times bigger, and all sorts of crazy sh*t comes out of the equations. It's fun, it stretches the mental musculature, and it has no implications whatsoever concerning the actual existence of any of those phenomena. There are no magnetic monopoles, the universe does contain mass, the speed of light is not ten miles per hour, et cetera.

One of the more amusing fictions turns out to be the existence of matter with negative mass. You can write down Einstein's field equations for a metric that incorporates negative mass, and find that crazy sh*t happens -- specifically, certain arrangements of it cause pockets of spacetime to do very strange things, like drag matter along at speeds greater than c relative to matter outside that odd little pocket, which then breaks causality. Miguel Alcubierre did that, and published a paper about the curious consequences of that particular nonexistent universe.

Attention whores like Harold White seized upon this and started trumpeting "Warp drive can be real! Give me money and I'll have Captain Kirk banging green chicks by this time next year! Just don't look to closely at the part where none of it works without a galaxy's worth of negative mass packed into a cubic meter, which you have to conjure into existence and then make disappear at will." More recently, further media attention was attracted when they figured out that if you make the nonexistent stuff magically appear and disappear really fast, then you can get by with a lot less of it.

White et al. are very careful to downplay the fact that the entire concept is built upon fiction. In their papers, they will very occasionally mention "exotic matter," which is their preferred euphemism for things that don't exist, but will otherwise treat it as granted that you can drive down to Costco and buy the stuff by the pallet. In the recent paper, they never even get as far as admitting that mass-energy (negative or otherwise) tends not to appear and disappear, despite the proposed scheme depending on exactly that.

Most physicists, sadly, tend to enable them due to a tendency to be exceedingly precise about what we can prove mathematically, and what is mere empirical fact. When asked about the Alcubierre scheme and its negative mass, they say things like "Well, negative mass has never been observed, but there's nothing in the equations that explicitly prohibits it." This is true, but possibly misleading -- there's nothing in the equations that prohibits the existence of magnetic monopoles, or Planck's constant from being a billion times bigger than it is, but those situations are quite solidly not the case. Journalists, naturally, translate that quote as "Warp drive is real! Physicist says negative mass can be made," which is utterly wrong. And as agencies like NASA are populated with people who know sh*tloads about turbopumps, electronics, metallurgy, and hypersonic aerodynamics, but are usually no more familiar with general relativity than the journalists, this occasionally results in research funding for the Unicorn Fart Warp Drive.

To be clear, my beef with White is not that he's continuing to examine the implications of metrics with strong local negative curvature. That's fine and dandy, and wild hypothesizing is even worth funding sometimes. The problem is that he's selling it (quite literally, I've heard his funding pitch disguised as a conference talk) as practical technology, which is a flat-out lie.

Link to comment
Share on other sites
OdinYggd

OdinYggd

Posted
Posted
the Alcubierre drive is theoretically possible, but sadly an engineering impossibility as the energy inside the bubble would destroy anything inside the bubble very very quickly.

I was under the impression that they aren't too sure of that part. Though I wouldn't particularly want to be the first one to find out, an unmanned ship should be sent first on a short hop to Mars and back to verify the theories and see if it survives.

As far as the energy thing goes, at the present time they are indeed relying on effectively an unobtanium to make this system work.

But the fact remains that they have successfully found a warp drive theory that is in fact valid with current scientific knowledge. In time people will figure out a means of providing the required amount of energy- which would be kind of hilarious if it actually was Dilithium. I've heard that dilithium actually does exist, just it refuses to form crystal structures and does not match the properties outlined in Star Trek.

Link to comment
Share on other sites
Bunsen

Bunsen

Posted
Posted
But the fact remains that they have successfully found a warp drive theory that is in fact valid with current scientific knowledge. In time people will figure out a means of providing the required amount of energy...

The problem is not with the quantity of energy. Simply burning an entire star in a few seconds is trivial in this context, because it actually sorta happens. Not that supernovae are easy to harness, but they do exist. Negative mass does not, and only the most unreasonably charitable definition of "valid" would encompass a scheme that depends on it.

Link to comment
Share on other sites
Inspector Gadget

Inspector Gadget

Posted
Posted
Since you're going faster than light, couldn't you violate causality?

As stated by others, the ship doesn't technically move faster than light by the space around them does (I'm not going to explain it since everyone else has)

Also I see very few people considering wormholes. We already have discovered micro-wormholes that appear on an atomic level. While they only exist for micro seconds they have been proven to develop naturally and the alcubier drive is still at a theoretical level. I think people are to hyped about the warp field idea and we should invest more time in making stable artificial wormholes.

Link to comment
Share on other sites
Flavius Aetius

Flavius Aetius

Posted
Posted

Warp Drive is indeed viable - I've personally done the (some of, not all I don't have enough time) calculations and looked at the issues with it, and all of them are "solvable." (Although we have yet to test anything at all)

First of all, the mass-energy requirement of the negative matter is only that of the mass of the voyager space probe, and even then you don't actually need negative matter. A scaled up version of the quantum casimir effect would generate the expansion of spacetime behind the ship needed, not to mention the (although highly remote) possibility of harnessing dark energy.

The energy required to power the ship could be done with antimatter - we only need to find a more efficient process of creating and storing it. But you are right in that anti-matter wouldn't still be efficient enough to power a warp drive, as it would take an inpractical amount of it. We'd have to find something more advanced, dark energy has been suggested but is still only theorized.

The build up of energy and heat inside the warp bubble can be counter-acted by metamaterials, which refelect all kinds of elctromagnetic radiation and are in development by the U.S. military.

Stopping the ship is the only real problem, as you need to have the exotic matter projected in front of the warp bubble, which would require it to be tachyonic in nature. However, it might be possible to use quantum entanglement to make exotic matter stop the ship, although I'm not entirely sure if it would work.

I will not dispute that Dr. White is indeed "selling" this idea as something practical, when it's nothing more than a viable possibility in the future. But I am excited by the fact that in a few centuries it could be possible, provided our civilization doesn't collapse by then.

Link to comment
Share on other sites
Bunsen

Bunsen

Posted
Posted
Also I see very few people considering wormholes. We already have discovered micro-wormholes that appear on an atomic level. While they only exist for micro seconds they have been proven to develop naturally...

[citation needed]

I say that because while there are lots of hypotheses about microscopic effects of general relativity (i.e. anything having to do with curved spacetime at the quantum level, including microscopic wormholes), none of them have been observed. Such observations would be huge news for the field of quantum gravity -- like Nobel Prize huge. Many of those hypotheses conflict with each other, too, so we can't even make reasonably precise predictions about whether spacetime even forms closed loops, or their size and duration if it did, or much of anything else in the absence of some observational evidence.

As for the causality question: If you can use it like everybody thinks of using faster-than-light travel (i.e. you can start in one place, turn on the warp drive, go somewhere, turn it off, and be somewhere else before a beam of light would have gotten there), then it violates causality. This is a trivial consequence of any information or energy going from point A to point B faster than light, no matter what the mechanism.

Link to comment
Share on other sites
K^2

K^2

Posted
Posted

Yes, warp drive violates global causality. But there is absolutely no law stating that causality must be obeyed globally. It is a local property, and warp drive does preserve local causality.

As for wormholes, there is no known mechanism for a change in topology of space-time, and one must alter space-time topology to create a new wormhole. Of course, it's possible that there are enough microscopic wormholes around that we don't need to create one from scratch. Only manipulate it to make it traversable. That we can do with known physics, at least, if not with known materials. But we haven't discovered any actual wormholes, so that's a bit of a moot point.

Warp drive is currently the only FTL method which we actually understand the physics of. There are still some major theoretical hurdles, like requirement for negative energy densities, but these are a problem for traversable wormholes as well.

Link to comment
Share on other sites
Redjoker

Redjoker

Posted
Posted

The warp drive does not actually break the speed of light. The distance it travels is simply compressed so that to an observer it appears to have broken the speed of light, similar If a laser beam is swept quickly across a distant object, the spot of light can move faster than c, although the initial movement of the spot is delayed because of the time it takes light to get to the distant object at the speed c. However, the only physical entities that are moving are the laser and its emitted light, which travels at the speed c from the laser to the various positions of the spot.

Link to comment
Share on other sites
K^2

K^2

Posted
Posted

There is an important difference here. If a spot of light appears to be moving faster than speed of light, it still can't convey information from one point to another faster than light. A ship under warp drive can.

Link to comment
Share on other sites
K^2

K^2

Posted
Posted

Sure it can. There is no event horizon in the warp bubble, so in principle, you can communicate with ship under warp. There can be some engineering difficulties associated with extreme red/blue shifts, order reversal, and lensing that signal undergoes, but you can send a message across the bubble.

Link to comment
Share on other sites
K^2

K^2

Posted
Posted

It can't catch up from the rear. Correct. But it wouldn't be encountered at FTL speeds from the front. That's the whole point of the statement that warp drive does not result in local violations of the speed of light limit. Warp bubble is going to frame-drag anything it encounters. That includes "tugging" on the light shining from the front so that it is still traveling at precisely the light speed when encountered by the ship. That will result in severe blue shift, and angles are going to be all distorted. In fact, observer on the ship will be able to look around and see the outside universe in every direction. Except that the light that seems to be coming from behind is also going to be actually from the front.

Hm. Maybe I should write up a simulation of what the sky is going to look like when you are traveling under a warp drive.

Link to comment
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing
×
×
  • Create New...