A Conference on Warp Drive

by Paul Gilster on April 28, 2007

If we ever develop a true ‘warp drive’ that can take us to the stars well within a human lifetime, we’ll probably look back at Miguel Alcubierre as the theorist who took a science fictional idea fully into the realm of scientific calculation. The physicist’s 1994 paper (reference below) suggests that manipulating the spacetime continuum itself could allow a spacecraft to move within a ‘bubble’ enclosed by the warp. It would never break the light barrier but would ride on the spacetime distortion to arrive at its destination as if it had. “A propulsion mechanism based on such a local distortion of spacetime,” wrote Alcubierre, “just begs to be given the familiar name of the ‘warp drive’ of science fiction.”

It’s quite a notion, isn’t it? In essence, you want to create more spacetime behind your bubble while contracting what’s in front of it. The British Interplanetary Society notes that Alcubierre’s original paper has inspired about fifty publications probing the intricacies of the concept. One of the most troubling is a paper by Michael Pfenning and Larry Ford which raises the question of energy. In their view, the Alcubierre drive would demand more energy than is available in the entire universe. Chris Van den Broeck later produced a variation demanding no more than the energy output of a single star, so I guess we’re making progress of sorts.

Clearly, we have a long way to go before any spacecraft powered by a warp drive becomes feasible, if it ever does (and we haven’t even started talking about negative energy yet). It’s heartening, though, to see that the BIS is putting out a call for papers for a symposium on the matter to be held later this year. From the announcement:

In an effort to generate interest in solving some of the technical problems a symposium is being organised with the intention of focussing on four main themes: The Current Status of the Warp Drive Proposal; Quantum Field Constraints; Photon Propagation through the Warp Field; Alternative Faster than Light Drives. Where the latter may be based upon alternative versions of Einstein’s gravity such as Brans-Dicke theory or Yilmaz theory, or based upon alternative suggestions for interstellar travel such as the Krasnikov tube and wormholes.

The address for submissions: 27/29 South Lambeth Road, London SW8 1SZ, or via email to mail@bis-spaceflight.com; full details are in the link above. Needless to say, this is the kind of effort that the Breakthrough Propulsion Physics program would have mounted if NASA had continued its funding, and it is a reminder of how far the space program in the US has wandered away from theoretical subjects like these in its quest to keep Space Shuttles and the ISS flying. But that, I suppose, is an argument for another day.

The papers mentioned above are Alcubierre, “The Warp Drive: Hyper-Fast Travel Within General Relativity,” Classical and Quantum Gravity 11 (May 1994): L73–L77; Pfenning and Ford, “The Unphysical Nature of ‘Warp Drive,’” Classical and Quantum Gravity 14 (1997): 1743–51; and van Den Broeck, “A ‘Warp Drive’ with More Reasonable Total Energy Requirements,” Classical and Quantum Gravity 16 (1999), 3973–79.

Related: New Scientist looks at another way to travel vast distances quickly (in this case, perhaps between individual universes): the wormhole. Are black holes now under study actually wormholes? Physicists Thibault Damour (Institut des Hautes Etudes Scientifiques, France) and Sergey Solodukhin (International University Bremen, Germany) make the case for this interpretation. Click here for more.

{ 8 comments }

Adam April 29, 2007 at 4:35

The prospects for warp-drive are currently doubtful and we haven’t heard anything much lately about the Heim drive/s. Is it reasonable to hope? Or are the laws of physics so well known we can rule out FTL?

We don’t yet know the Universe’s topology. We don’t know if the other dimensions are macroscopic and we’re just on a brane. We really haven’t got a clear picture of quantum gravity yet either.

Another point is that while we have non-FTL explanations for apparent super-luminal motion in the distant cosmos we don’t really know we’re not seeing real FTL motion or just an illusion. And we’ve no idea if wormholes or blackholes are the compact objects at the centre of galaxies.

Personally I think we’re less certain about FTL than we were a few decades ago.

Chris Wren April 29, 2007 at 13:58

I’ll go out on a limb and say that yes, we can definitely rule out FTL for massive objects in normal space. There’s just too much experimental evidence demonstrating that it’s not just some trick of math. I’ll go further and say that accelerating a large object to even near relativistic speeds is so impractical from an energy consumption curve perspective as to be virtually impossible for all practical purposes.

That doesn’t mean I’d love to be proven wrong of course, and it doesn’t mean that there might not be other ways of getting around. The really great aspect of the concept of warp drive is that it doesn’t violate the speed of light. “Velocity” becomes irrelevant inside the warp bubble. And if all we need to warp space is the energy output of a star, then that makes harnessed black holes a possible drive-source – albeit one for the FAR distant future.

Eric James April 29, 2007 at 16:46

Since light does indeed enter and exit warped space (gravitational gradients), wouldn’t a warpdrive that allows an interior object to exceed the speed of light violate causality? How would this problem be reconciled? Must it also travel backwards in time?

Lubo April 30, 2007 at 0:41

Like I said before the hyperdrive is more feasible than warp drive because the less energy it need. Heim’s theory MUST be proved no later than a decade or so if we want to explore first our solar system than the stars. I personally think that both propulsion deserve more attention than now from US government and nongovernment organizations! Megacorps should invest more capitals in these projects because one day they will replace NASA and the true interstellar travel will begin!

Stephen May 1, 2007 at 12:07

It’s still possible that ideas like this will have applications even if a WARP drive isn’t one of them.

george scaglione July 7, 2007 at 13:11

hi all just read the above and its a funny thing,it mentions manipulating space time.well ijust finished reading something which implied that the negative energy needed to hold a wormhole open is implicit in the nature of space! so then i have said that “all” it is necessary to do therefore is engineer space itelf…not far from the concept of “manipulating space time” is it !? well for what it might be worth i have had my say.thanks and with great respect to all, your friend george

Jessika August 5, 2008 at 14:33

Any time you speak of the Alcubierre Warp Metric you should also link to the Van Den Broeck modification which makes it much more practical and eliminates many objections of the critics. 1) The new bubble is created around a space ship at sublight speeds and then is shrunk down to microscopic size (including the spaceship! How’s that for a new take on a fantastic voyage). According to critics quantum fluctuations would destroy the bubble after a period of time.
2) the size of the new bubble is smaller than a proton when surpassing light speed and is unsteerable and opaque to light meaning you can’t control it once it exceeds the speed of light and you can’t see out of it.

Andrew December 30, 2008 at 7:18

I believe that FTL or “Superluminal” speeds are more than achievable, albeit not with todays technology. Let us use a few real world examples to explain why i say this.

Let us say that the fastest a human being can move under his own power (the use of muscle power only) is 40 kph (25 mph). If i am observing (according to Einsteins Theory of Relativity) a person running away from me (assuming perfect conditions) i will see him to be travelling at the aforementioned speed.
If i was to run backwards at the precise same speed the other person would be observed to be travelling at double the aforementioned speed ie. 80 kph (50 mph).

Now if we (myself and this other person) were in cars that had a limit of 320 kph (200 mph) and the same experiment is performed as above, the latter result would be that the other vehicle would be seen as travelling at 620 kph (400 mph).

Now lets assume that I stand perfectly still while the other person in the vehicle is travelling away from me at the vehicles maximum velocity, however it then produces a “warp field”, that causes me to be pushed away from the vehicle at the speed of Light and the vehicles destination to be brought towards it at the speed of light (as stated by Alcubierre), the vehicle would then appear to me to have travelled at the speed of light.

As a warp field is a function of subspace and not nomal space, the vehicle and occupant in the second example have in fact NOT travelled faster than the speed of light as they never left their normal space. They merely arrived – through the use of spatial distortion – at their destination at an equivalent time as that which light would have taken. Therefore there was no necessity to acclerate the vehicle or the occupant, the necessity was to bend – the already curved – space in front of them.

As for the question of the vehicle and occupant travelling through time, this will not occur. The reason for this is that time is not moved backwards, it remains in forward motion, it is only the time taken to reach the destination that has been shortened. Let us say that at the speed of light it will take 11 minutes to reach mars (this is the effective time delay in microwave communications experienced by NASA). Travelling at twice the speed of light means that we would reach mars in 5 minutes and 30 seconds. We have not gone back in time at all, although we will view earth as it was 5 minutes and 30 seconds ago we ourselves will not have travelled back in time. The only counter effect of travelling at these speeds would be that if we had to directly turn around and return without losing a single second, we would arrive just in time to see ourselves leave.

Your kindly, Andrew

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