New Warp Drive Concept Does Twist Space, Doesn't Move Us Very Fast (arstechnica.com) 69
An anonymous reader quotes a report from Ars Technica: A team of physicists has discovered that it's possible to build a real, actual, physical warp drive and not break any known rules of physics. One caveat: the vessel doing the warping can't exceed the speed of light, so you're not going to get anywhere interesting any time soon. But this research still represents an important advance in our understanding of gravity. [...] In a paper accepted for publication in the journal Classical and Quantum Gravity, [an international team of physicists led by Jared Fuchs at the University of Alabama in Huntsville] dug deep into relativity to explore if any version of a warp drive could work. The equations of general relativity are notoriously difficult to solve, especially in complex cases such as a warp drive. So the team turned to software algorithms; instead of trying to solve the equations by hand, they explored their solutions numerically and verified that they conformed to the energy conditions.
The team did not actually attempt to construct a propulsion device. Instead, they explored various solutions to general relativity that would allow travel from point to point without a vessel undergoing any acceleration or experiencing any overwhelming gravitational tidal forces within the vessel, much to the comfort of any imagined passengers. They then checked whether these solutions adhered to the energy conditions that prevent the use of exotic matter. The researchers did indeed discover a warp drive solution: a method of manipulating space so that travelers can move without accelerating. There is no such thing as a free lunch, however, and the physicality of this warp drive does come with a major caveat: the vessel and passengers can never travel faster than light. Also disappointing: the fact that the researchers behind the new work don't seem to bother with figuring out what configurations of matter would allow the warping to happen. The findings have been published in the journal Classical and Quantum Gravity.
The team did not actually attempt to construct a propulsion device. Instead, they explored various solutions to general relativity that would allow travel from point to point without a vessel undergoing any acceleration or experiencing any overwhelming gravitational tidal forces within the vessel, much to the comfort of any imagined passengers. They then checked whether these solutions adhered to the energy conditions that prevent the use of exotic matter. The researchers did indeed discover a warp drive solution: a method of manipulating space so that travelers can move without accelerating. There is no such thing as a free lunch, however, and the physicality of this warp drive does come with a major caveat: the vessel and passengers can never travel faster than light. Also disappointing: the fact that the researchers behind the new work don't seem to bother with figuring out what configurations of matter would allow the warping to happen. The findings have been published in the journal Classical and Quantum Gravity.
I speak for everyone when I say (Score:2)
"Gravity"
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Gravity or no gravity, TFA says what they appear to propose is a
constant-velocity subluminal warp drive
Which is, let's say, uninspiring, especially given that it is not an engineering proposal, but an untested theoretical hypothesis.
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"Practical" isn't a word you want to use in this context :)
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"Practical" isn't a word you want to use in this context :)
"More practical" sounds quite reasonable. Doesn't mean we're close to doing it. Two people eating an entire elephant is more practical than just one.
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Practical means it is something you can put into practice, per the definition, that is capable of being turned to use or account; useful, in distinction from ideal or theoretical. . The paywalled TFA is about the latter.
Any time soon? (Score:2)
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Fusion drives can get you to 0.05c, fission drives can get you to 0.1c. And that's 'just' engineering - we could probably do either if we wanted to throw trillions into the effort.
At those velocities, you really have to worry about even the smallest impacts - a bit of dust in your path and maybe you're toast.
And it still isn't fast enough to get you any significant time dilation, you're going to have to experience the trip pretty much in real time. Even the next nearest star isn't a trip you could do with
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Ugh. I mixed up my fission and fusion. Fission is 5%, fusion is 10%.
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You mixed more things up.
The final speed is simply v = a * t^2.
As long as you can accelerate with a ... you gain speed.
Has nothing to do with solar sails, photon engine, ion engine, fusion or fission.
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You mixed more things up.
Speaking of mixing things up...
The final speed is simply v = a * t^2.
t, not t squared.
As long as you can accelerate with a
And therein lies the problem.
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True, T not squared. I think I copied it from one of your nonsense posts.
The problem with accelerating is related to the engine type. The speed is not really. It is the question of available fuel.
So claiming either Fission or Fusion gives you more speed makes no sense.
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Final velocity depends on mass, thrust, fuel, and your route.
There is a velocity limit based on acceleration, mass, how much fuel you can carry, etc.
Saying velocity has nothing to do with your propulsion system is ignorance of a very high order.
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Well... the guy is in fact the subject of my sig.
He's convinced that every new reactionless drive scam might just work this time.
When pushed, he wouldn't even accept the Newtonian limit kinetic energy equation, you know half m v squared.
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He's convinced that every new reactionless drive scam might just work this time.
I asked you already how you come to this stupid idea. But you did not have the dignity to answer.
When pushed, he wouldn't even accept the Newtonian limit kinetic energy equation, you know half m v squared.
That is a lie. Why are you lying about me?
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But you did not have the dignity to answer.
I told you, but you scream and screech and throw insults, then stop replying, yet refuse to actually follow where the maths lead. It's like you beileve you can build a starship through the sheer power of invective coupled with wishful thinking.
That is a lie.
This is not a lie. You flat out denied it last time, because you didn't like the results.
Want to try again?
Let's say you have a force of 1N acting on 1kg, starting at rest, for 10,000 seconds. What's the speed
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E = m * v * v
s = 1/2 a * t * t
v = a * t.
That is not high school physics.
That is basically the first week of physics.
So, you are lying about my physics. Why?
Oh, because you failed ten times now to explain how to get more E out of "E = m * v * v" then you have put into it.
Good luck.
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It not say irrelevant, I said it makes no sense to claim one is 'faster' because you point out: it is much more complex ...
I was to lazy to write a sermon like you did
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Final velocity of rockets depends on mass, thrust, energy source, propellant, and your route. Chemical rockets use fuel and oxidizer as both an energy source and propellant, but that's not strictly necessary.
Re:Any time soon? (Score:4)
So many high school physics dreams crushed by the rocket equation, before they could even be crushed by special relativity.
Re: Any time soon? (Score:2)
Not really, the dreams just become the delusionsof adult Space Nutters.
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I suspect anyone who uses the phrase "space nutter" had their dreams crushed and is still bitter about it. The wild eyed delusionists wave away the math. The name callers are afraid of it.
The ones who use conspiracy caps on it even more so.
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At those velocities, you really have to worry about even the smallest impacts - a bit of dust in your path and maybe you're toast.
At those velocities you don’t have to worry about objects coming in from any direction other than one. Simply design your craft with a tiny forwards cross section in a long straight line, the first 20% of the craft length are impact plates for your shields. Tiny dust grains would just vaporize a little bit at a time but a speck to grain you didn’t see from a hundred million miles out to dodge and you’re going to need some decent shield plating. But anything down stream wouldn’t
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Stick a H-bomb under your ship, preferably as large as possible, like air craft carrier or larger, and set that H-bomb off and it will move. keep throwing them under the ship and away you go. Do have to cancel a few treaties first.
Seems that with a 10 Mt ton vehicle (empty) and 30 million Mt bombs, gives a maximum speed of 1000 km/s (0.33% light speed) and Alpha Centauri is only 1330 years away, Saturn much easier. Smaller ship could do the trip in a tenth of the time with only 300,000 Mt bombs and a roughe
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The velocity limit I've read is more on the order of 10% because even using nukes you run into the tyranny of the rocket equation. At some point, your fuel gets to be such a large percentage of your initial mass that additional fuel can't even move itself.
Also, the practical (average) limit is halved because you typically want to stop at your destination rather than fly by at 0.1c.
That's why I usually just say an Orion drive tops out at 0.05c.
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Seems I've read somewhere that even that 10% is under ideal conditions that likely would not exist in reality. Then you have the problems with your "fuel" for slowing down, nukes deteriorate.
Given the energy requirements, it is hard to see how interstellar travel would happen.
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The treaty prohibits weapons, not Fission reactors.
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>No fusion reactors capable of producing more energy than they require exist,
You have flawed assumptions: I didn't say you'd use a fusion reactor with an over-unity requirement.
You can actually use a leaky fusion reactor to fire a particle stream out of the magnetic confinement chamber and use that for thrust. It's supposedly very efficient, and results in twice the theoretical velocity of riding the shockwaves of fission bombs.
>the Outer Space Treaty prevents nuclear weapons in space
When we're talki
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Most people forget how fast even a small fraction of the speed of light is (for example 1/100th the speed of light). For example, the Voyager 1 is travelling at ~17.08km/s aka ~0.000057 times the speed of light. Dropping even a couple of zeros from that fraction would make multi-decade missions reach much further.
But at these low warp speeds, how long will it be until we encounter V'ger?
Re: Any time soon? (Score:2)
I think the problem is that most people think let the speed of light is fast. Sure it's incredibly fast in terms of what humans typically think of as speed but if you want to get practically anywhere interesting the speed of light is incredibly slow.
That said being able to move at say even 0.5c and not having to deal with acceleration would still be fairly interesting for exploring the solar system.
Unsurprising and impractical (Score:5, Informative)
It appears to roughly translate to: "if you put a large mass in front of the ship, the ship will fall towards it".
This is indeed possible and does not require exotic mass or negative energy, and it does not violate relativity. It would seem to require a mass that's already moving in your desired direction at your desired velocity, and then matching pace with it... which would be incredibly impractical.
I'm sure the paper is mathematically interesting, but in terms of a reactionless drive (even a sublight one would be awesome), it's not terribly practical.
Re: Unsurprising and impractical (Score:4, Funny)
A practical solution would be to find a suitable habitable planet, moving at high speed, and live on it. For example, the planet "Earth." Last I looked, "Earth" is moving approximately one MILLION miles per hour, which can get you somewhere very quick.
Re: Unsurprising and impractical (Score:5, Funny)
It goes nowhere, and it takes a whole year to do it!
Re: Unsurprising and impractical (Score:2)
We move around the Milky Way galaxy. And we're also moving toward the Andromeda galaxy. I hope that's where you wanted to go and I hope you can wait a very long time.
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Sounds like it’s once again time for the Galaxy Song:
https://www.youtube.com/watch?... [youtube.com]
Re: Unsurprising and impractical (Score:1)
u say u want a rev-olution
we-eellll u know...
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A practical solution would be to find a suitable habitable planet, moving at high speed, and live on it. For example, the planet "Earth." Last I looked, "Earth" is moving approximately one MILLION miles per hour, which can get you somewhere very quick.
Sure, but I can't say I like where it's headed.
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Sure, but I can't say I like where it's headed.
To Hell in a handbasket?
Re: Unsurprising and impractical (Score:2)
Back before the full scope of his crazy came to light, Sonny White was playing with the idea of curvature in space being a function of energy density, not just mass density. We have to way of materializing an arbitrary mass into being, but we can create energy density in the form of EM flux.
I remember reading about him trying to do a tabletop experiment measuring the curvature of space interferometrically through a region of high electric or magnetic flux that got turned on or off.
That's where the crazy cam
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I suspect that if your EM flux is dense enough to noticeably warp space, you will find it has converted itself into matter. And maybe anti-matter, but I believe the process is weirdly asymmetrical.
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Einstein played with the same idea. He called it "General Relativity." Incidentally, today the most famous equation in the world is the first term of an ancillary result: E = mc^2.
Re: Unsurprising and impractical (Score:2)
Yes, and you need roughly Earth-sized objects or bigger to measure the curvature. New physics would be required to build your star trek warp drive gizmo.
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Not new physics, just an awful lot of existing physics.
Re: Unsurprising and impractical (Score:2)
Assuming it exists and we've only to discover it, yes.
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I don't think so. They start with a mass shell and optimize it into something that looks pretty distinctly different. Section 5.1 discusses a test that differentiates warp bubbles of different types from mass shells.
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The paper and ones on the Warp Factory calculator are on Arxiv, search for Jared Fuchs.
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Just stick the paper title in google scholar and it provides a link right to it.
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Sounds Familiar (Score:2)
FTA by George R. R. Martin
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Did he finish that one?
An analogy (Score:1)
We chuckle at real (and fictional) historical figures dreaming about going to the moon in a balloon or an artillery shell.
We laugh at cargo cultists attempting to lure in planes onto grass landing strips using coconut radios.
And yet we treat at serious intellectual endeavors the attempt to invent interstellar travel given that launch into LEO costs tens of thousands per kilo and rocket launches are so expensive as to be rare events that draw an audience.
Fascinating.
Re: An analogy (Score:3)
Planets, suns, and galaxies provably exist. It's not a stretch to imagine what kind of math needs to exist before we attempt to send anything out there.
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In the same way they view God as whatever the latest technology is.
A wheel with a wheel, a clockmaker god, a machinist, a weilder of energy, a programmer, a simulation, and now an AI.
Because saying "I don't know" is the most painful thing for a materialist.
The secret is: I have a goal and am willing to work hard to iterate. The best SciFi authors can do this in their minds - it's amazing.
Don't wormholes work? (Score:3)
If exiting objects through a wormhole in a given reference frame maintain the same time, direction and speed as when entering, causality isn't violated right? (Lets pick the CMB frame for convenience, it's special not special.)
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We've got no reason to believe that a wormhole connecting two pieces of space-time would be shorter than the distance outside the wormhole. It would probably be longer. And wormholes aren't stable without unobtainium. (In this case I think that's strong construction materials made from stuff with negative energy content, but I can't remember for certain.)
Star Trek was Almost Right (Score:3)
Still of potential use (Score:2)
Even if it doesn't allow FTL travel, it would allow accelerating is squishy humans much faster, which could let us get to nearby stars without a generation ship.
Re: Still of potential use (Score:2)
Solve (Score:2)
Equations of gravity hard to solve. No, it's not like finding the answer to an equation. The problem is finding a solution that conforms to constraints, or has certain properties. A solution. Not THE solution.
"don't seem to bother" (Score:3)
The researchers don't seem to have satisfied the impetuous author.
He better get to work on solving that next problem and publishing a paper since it's so damn easy.
But it only works for ... (Score:1)
so instead of Trek's warp drive, (Score:2)
They've discovered the principles behind Larry Niven's inertialess drive. That's still something.
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Unfortunately no. They consider the constant velocity case. Their discussion of acceleration is a few paragraphs at the end saying you might be able to do it with a rocket,
In *theory* (Score:2)
These researchers didn't actually prove that it's possible to build such a "warp drive." They just proved it *on paper.*
The team did not actually attempt to construct a propulsion device. Instead, they explored various solutions to general relativity that would allow travel from point to point without a vessel undergoing any acceleration or experiencing any overwhelming gravitational tidal forces within the vessel, much to the comfort of any imagined passengers
As every engineer knows, you haven't proved that anything can be built, until you actually construct it, and then test it.
Not exciting, really? Actually very exciting! (Score:2)
I've got a bone to pick with the article, namely on perspective. In the article they say:
> We already have plenty of methods for traveling slower than light (rockets, walking, etc.), so adding one more to the list isnâ(TM)t all that exciting.
And I really have to disagree with that. Sure, a full-on break-the-speed-of-light warp drive would be awesome, but let's be realistic: The current record holder for fastest human-made object is currently at something like 0.5% of C, I think? And that took years