The Problem with Warp Drive

by Paul Gilster on December 28, 2009

Paul Titze, who somehow finds time to write the excellent Captain InterStellar blog when not preoccupied with his maritime duties in Sydney, passed along a 2009 paper on warp drives yesterday that I want to be sure to consider before the year is over. Warp drives as in Miguel Alcubierre’s notion of a method of reaching speeds that are faster than light. The Star Trek echo in the choice of names was playful and intentional on Alcubierre’s part, and the physicist kicked off a cottage industry in exotic spacetimes and their geometries when he used it in a 1994 paper on superluminal flight.

Specifically, Alcubierre noted that although nothing can move faster than the speed of light through spacetime, spacetime itself has no such restriction. That notion is more or less built into the theory of inflation, which demands a vast expansion of the infant cosmos that would have far outstripped any lightspeed restriction. And Alcubierre saw that if spacetime could be made to contract in front of a vehicle while being expanded behind it, the craft would remain within a conventional spacetime ‘bubble’ while being carried to its destination at speeds that would allow fast human transport among the stars.

There’s always a catch, of course, and the first to be noticed was the huge demand for negative energy to support the warp drive. While that issue has been kicked around in the literature for some time (and various solutions introduced to lower the requirements), it is also necessary to take quantum effects into account, which is what Stefano Finazzi (International School for Advanced Studies, Trieste) and colleagues have done in their paper. In particular, Finazzi’s team finds that the quantum field known as the renormalized stress-energy tensor (RSET) becomes a problem. From the paper:

…it was noticed that to an observer within the warp-drive bubble, the backward and forward walls (along the direction of motion) look, respectively, like the horizon of a black hole and of a white hole. By imposing over the spacetime a quantum state which is vacuum at the null infinities… it was found that the renormalized stress-energy tensor (RSET) diverges at the horizons. Independently of the availability of exotic matter to build the warp drive in the first place, the existence of a divergence of the RSET at the horizons would be telling us that it is not possible to create a warp-drive geometry within the context of semiclassical GR: Semiclassical effects would destroy any superluminal warp drive.

The ‘bubble’ housing our starship, in other words, becomes unstable under these conditions. But this is hardly the last of our problems. Assuming that this instability could be avoided by some kind of external action on the warp drive bubble, Finazzi’s team argues that Hawking radiation at the center of the bubble will burn the occupants to a crisp with temperatures in the area of 1032 K. If this highly detailed argument is correct, the Alcubierre warp drive will remain what it has been up to this point, a useful way to study general relativity and quantum field theory in curved spacetimes, with little possibility of being translated into technology.

Is there any hope for warp drive? Perhaps, says Finazzi, though not on the level of Star Trek-style vessels making interstellar journeys in mere days:

…we think that this work is casting strong doubts about the semiclassical stability of superluminal warp drives. Of course, all the aforementioned problems disappear when the bubble remains subluminal. In that case no horizons form, no Hawking radiation is created, and neither strong temperature nor white horizon instability is found. The only remaining problem is that one would still need the presence of some amount of exotic matter to maintain the subluminal drive.

A subluminal warp drive may not sound quite the exotic note of the classic Alcubierre drive, but in any other circumstances attaining a substantial percentage of the speed of light would seize the imagination. So perhaps a subluminal warp drive will continue to play a role in interstellar thinking, even if its energy demands remain hugely problematic. The paper is Finazzi et al., “Semiclassical instability of dynamical warp drives,” Physical Review D 79, 124017 (2009). Abstract and preprint available.

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{ 42 comments }

Denver December 28, 2009 at 11:24

On the one hand, it is noted that to use this device super-luminal is to kill everything on board.

On the other hand, if the space-time bubble is kept sub-luminal, the environment is deemed safe.

On the gripping hand, exotic matter is still needed regardless of the state of the luminals.

Fond regards,
Crazy Eddie.

Terraformer (a.k.a Tobias Holbrook) December 28, 2009 at 11:49

One of the advantages a subluminal warp drive would have is it’s ability to attain high percentages of light speed without the gamma factor issue. I know that may not sound like an advantage, but it would aid in interstellar trade and colonization. Crew heading to Alpha Centauri would age at the same rate as their family back home, so they wouldn’t have the problem of returning back home to find their family dead. Also, the eergy requirements would be lower for reacvhing arbitarily high velocities.

andy December 28, 2009 at 15:08

I have always had this sneaking suspicion that the laws of the universe technically allow superluminal transport, but all methods of doing so are completely useless for all practical purposes owing to unfeasibly huge energy requirements (or negative energy), high enough temperatures to zap you back to quark-gluon plasma, etc.

Terraformer (a.k.a Tobias Holbrook) December 28, 2009 at 15:29

Ifm you have exotic matter, though, you might as well open a wormhole.

Mike December 28, 2009 at 15:31

Maybe we could ask the moties for advice on solar sails instead. One of my
favorite Crazy Eddie ideas.

Latest mission manager update has been added to the Kepler website.
Just next week at the AAS meeting in Washington there will be some announcements about Kepler’s discoveries so far. Perhaps Earth-size planets in the habitable zone of M-Dwarfs? Any guesses? I think Kepler has been observing long enough to detect 3 HZ transits for M-Dwarfs maybe for late sequence K-Dwarfs as well.
Might depend on the status of the data analysis software and how faint a signal they can recognize at this time.
We find out next week!

Terraformer (a.k.a Tobias Holbrook) December 28, 2009 at 16:14

Surely they would have been leaked by now, if that was the case?

Hmmm… any chance we could transmit information superluminally, though, maybe though mini wormholes?

Athena Andreadis December 28, 2009 at 17:18

I dearly wish warp drives were possible, but it seems increasingly unlikely. No, it looks like the long haul for us if we want to go out there… which means thinking seriously about self-sufficient arcships and their inherent long-term problems, from ecosystem balance to biological and psychological integrity of the occupants.

Terraformer (a.k.a Tobias Holbrook) December 28, 2009 at 18:09

You don’t think good fractions of c are possible? Or stepping stone colonization is infeasible?

I’m still holding out for brown dwarfs, super-Jovians, and interstellar cyclers.

Bounty December 28, 2009 at 18:33

Wow, then there must have been some serious Hawking radiaion devestating all matter in the universe during the expansion then right? Note to self, don’t put space ship in center of warp bubble.

Paul Titze December 28, 2009 at 19:32

Anyone wondering about FTL travel read this excellent page:

http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html

Since we still don’t have a relativistic quantum theory of gravity and a somewhat limited understanding of the quantum vacuum, at this stage it is too early to rule out FTL travel completely (without using the warp bubble or worm holes) , it is more productive to think about the last sentence in the above page:

“FTL travel of the sort science fiction writers would like is almost certainly impossible. For physicists the interesting question is “why is it impossible and what can we learn from that?”

Cheers, Paul.

Terraformer (a.k.a Tobias Holbrook) December 28, 2009 at 19:50

Where else are you going to put it? Wherever you put it’s going to be frazzled.

Ryan December 28, 2009 at 20:27

@ Terraformer (a.k.a Tobias Holbrook):

If I understand correctly, that time dilation factor at near-lightspeed effectively slows the occupants aging – it’s not speeding up time back home, despite the astronaut’s perception. If it takes 100 years to make a two-way trip 43 ly out and back, the astronaut’ s family will be just as dead whether he experienced his own 100 years pass or just 50 with time dilation. If I’m stuck on a tin can out in the Cold Black, I’d like the trip to go by as fast as possible. The low-velocity people at home can probably do something more constructive during those 100 years.

In one of the Ender’s Game novels, there’s a reference IIRC to the Park Shift which takes a starship from rest to near-c almost instantly, without any goo-ifying inertial effects. This would be a great way to avoid a few years of simply accelerating and decelerating at 1g during a two-way trip.

Duncan Ivry December 28, 2009 at 21:10

andy: “… the laws of the universe technically allow superluminal transport, but all methods of doing so are completely useless for all practical purposes owing to unfeasibly huge energy requirements …”

Well, Andy, I would say, that the “laws of the universe” are about “practical purposes” — if we take this term serious; the universe is the location we are *practically* in. And — “unfeasibly huge energy requirements” — this and the other obstacles occur just because of the “laws of the universe”. By the way, I would recommend saying “physical laws” — this is not so over the top.

Adam December 28, 2009 at 21:56

The subluminal Alcubierre warp-drive is the “field drive” of old SF, which has surely got to be good news, even if it’s sub-light all the way. I very much doubt, though, there’s any advantage to doing away with time-dilation. Starflights are one-way except when to near neighbours surely?

andy December 29, 2009 at 6:05

Duncan Ivry: Yeah possibly I could have chosen a better phrase but it should be fairly obvious what I meant to anyone except a tedious bore with nothing better to do than quibble over semantics.

Incidentally I do like the way you quote me to make it look like I was saying that the laws of physics state that superluminal transport is impossible due to unfeasibly large energy requirements, when this is not what I said at all. Rather dishonest argument strategy, no?

T_U_T December 29, 2009 at 8:34

Oh noes ! Another ultraviolet catastrophe ! Like the one that threatened to blow the universe apart when physicists last used semi-classical approximations to compute the black body radiation. Fortunately, Max Planck came to help, otherwise the entire universe would be destroyed by infinitely hot gamma rays.
But seriously. I think, that such divergences indicate nothing more than limits of the semi-classical approximation. You also would get divergences if you tried to describe subsonic->supersonic transition using low energy approximations, yet there are no infinite pressures when you go above mach 1.
I suspect, that the alcubierre drive would also work, though it can not be properly described by the semiclassical approach.

andy December 29, 2009 at 9:31

Also your assertion that the laws of physics are about practical possibilities is flawed. Balancing a (sharpened) pencil on its point is perfectly consistent with the laws of physics, however it cannot be realised in reality because this corresponds to an unstable equilibrium: the slightest perturbation will cause the pencil to fall over, and in the real world there are always these perturbations.

george scaglione December 29, 2009 at 11:09

athena,yes what you point out above may be very true but i come from the “never say die” school and feel sure that if we keep trying we just might come up with something really good! what i mean is that is it not about 98% of what we try to do here for the most part to find that way!(?) respectfully with my thanks your friend george ps do you recall the original star trek episode for the earth is hollow and i have touched the sky?sort of underlines your point :) george

Duncan Ivry December 29, 2009 at 12:23

andy: “Balancing a (sharpened) pencil on its point is perfectly consistent with the laws of physics, …”

Er … just let me think … no.

“… however it cannot be realised in reality because this corresponds to an unstable equilibrium: the slightest perturbation will cause the pencil to fall over, and in the real world there are always these perturbations.”

The perturbations happen according to physical laws too, e.g. because of thermal particle movement.

Cool it down. From now on, I will ignore your comments. I promise! Do everybody a favour and ignore my comments too.

Athena Andreadis December 29, 2009 at 12:31

Paul T. — the link you supplied is an excellent summation of the difficulties of both defining and achieving FTL with real physical objects (like starships and their crews).

The experimental verifications of both special gravity and quantum mechanics are too robust to challenge and the causality violations of FTL won’t go away no matter what paradigm we choose. At the same time, it’s clear that we need a grand unified theory and/or a reconciled system of quantum gravity before we can make definitive conclusions of what is possible and how to make it happen in terms of engineering.

andy December 29, 2009 at 13:35

i come from the “never say die” school and feel sure that if we keep trying we just might come up with something really good!

How’s the perpetual motion machine coming along? :-)

Dan Dawson December 29, 2009 at 14:29

Hello all. This is my first time posting here. I’ve been following this blog for quite a while. I’m a research meteorologist (not TV weatherman or operational forecaster!) by profession, and my specialty is in numerical simulation and prediction of severe thunderstorms and tornadoes, but I have a strong interest in astronomy, astrophysics, and aerospace engineering, and have a basic scientific literacy in these areas, although they lie outside my field.

Anyway, after reading the overview of this paper and several others regarding warp drive, one thing that is clear to me is that we are still in babyland in our understanding of it, and any pronouncements on the ultimate practicality or even possibility of really engineering such a device for effective FTL travel is premature. The instabilities and prohibitive Hawking radiation this paper talks about remind me of some problems in meteorology where an approximate mathematical framework that is meant to describe simplified atmospheric flows is naively applied to a more complex problem. I won’t go into details, but you can easily get absurd answers, such as tornadoes with infinite velocity. If you didn’t know any better, you might therefore conclude that tornadoes are impossible, but we all know that they aren’t. Similarly, I wouldn’t be at all surprised if some future advanced technology, armed with better theoretical understanding of the underlying physics, would be able to control such instabilities and radiation, in regards to the warp drive bubble, or even show that such instabilities and radiation are not nearly as bad as our current theories (such as outlined in this paper), seem to indicate.

Note, I’m not trying to diminish this work. I think it is useful in at least constraining the playing field a bit more, and improving our understanding of what we have to work with and overcome if something like an FTL warp drive could ever become a reality. But, this and related papers are just the first flashlight beams piercing through a huge, dark cavern full of secrets.

george scaglione December 29, 2009 at 14:33

andy- lol i’m still working on it! expect some results any day now! but seriously,maybe i did overstate.sure meant no disrespect to anyone at all here . if warp drive does not turn out to be possible then i am still sure that ways will be found to propel fleets of spacecraft all over our solar system and at least reasonably well beyond in some other way using things that even now we think we will be able to do – like fusion drives. i do not – can not dismiss the vaaaast interstellar distances! only meant that i never loose hope for the future and all it can bring.funny thing i was just talking this morning to another friend who wondered aloud…what will the real star trek years be like? imho undoubtedly fantastic containing things of which we cannot yet dream was my answer.this was really all i meant by my earlier answer to our esteemed friend athena. respectfully yet again to one and all, george

andy December 29, 2009 at 14:48

Of course the thermal motions and other random perturbations might just so happen to be symmetrical and cancel out. It (almost certainly) isn’t going to happen, but if it did it would not violate the laws of physics… the probability is vanishingly small but still technically nonzero. Just because the probability is so low that we can safely go along with the assumption that it will never happen in the entire history of the universe does not mean it is disallowed.

(This reply is purely here in case some people are misled by Duncan Ivry’s mistaken statements, as he has stated he is going to ignore this)

drpayton December 29, 2009 at 19:35

Hmmmm…after reading part of http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html
The author said that shadow could be made to go faster than the speed of light but since shadow was not matter then we could not use it to travel or communicate… It instantly occurred to me that if the shadow was shaped into a discernable image or message wouldn’t that be classified as communicating via shadow?

Lucy December 29, 2009 at 20:21

Ever since I’ve been reading about these problems with warp drives I’ve been thinking that since they can’t be used for superluminal flight, perhaps they could be used for spacecraft launches.

With only a little bit of exotic matter, a spacecraft could use a warp drive like the sci-fi antigravity devices.

Just speculation.

parmanello December 30, 2009 at 3:55

I think Dan Dawson absolutely nails the point here and reminds me of an awesome quote from the master and actually the first of his three “laws” :

‘When a distinguished scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. ‘

Pat Galea December 30, 2009 at 14:21

“The author said that shadow could be made to go faster than the speed of light but since shadow was not matter then we could not use it to travel or communicate… It instantly occurred to me that if the shadow was shaped into a discernable image or message wouldn’t that be classified as communicating via shadow?”

No. The problem is that a shadow (or a light spot) is not a ‘thing’ that is travelling, so you can’t use it to communicate faster than light.

As an analogy, imagine I have a long chain of boy scouts stretching from here to Alpha Centauri. Each boy scout is carrying a flashlight, and is wearing a very accurate wristwatch. I have given each boy an instruction to flash his light at a very specific time.

Now, by giving the boys the right set of times to flash their lights, I can make it look like a light spot is travelling down the line all the way to Alpha Centauri. In fact, by setting the times appropriately, I can make the spot look like it is travelling at any speed I like, even infinitely fast. (This would happen if I told all the boys to flash their lights at the same time.)

The point here is that each boy flashes his light without necessarily knowing what the boys nearest him have done. If we set the times for the flashes close enough together, then the flash of light from one boy’s flashlight will not have had time to reach the next boy before he flashes his light. (This is the scenario in which the light spot appears to be travelling faster than light.) So no information is being propagated along the line of boys. The light spot is indeed apparently moving faster than light, but it cannot be used to send information faster than light.

The same thing happens with shadows and light spots (such as when you shine a flashlight almost parallel to a wall, and gently swing it back-and-forth. The spot may well be ‘moving’ faster than light, but the actual things that are moving are the photons from the flashlight, and they are still travelling at the same old lightspeed (by definition!).

I hope the analogy helps make that a bit clearer.

drpayton December 30, 2009 at 16:13

If the cosmos can be discerned as having a beginning due to the fact that all matter/energy is not evenly distributed throughout space then can’t we also say that light is not the “fastest” therefor isn’t the constant due to the fact that light isn’t omnipresent? Someone please enlighten me I’m a newb. Thanks in advance.

drpayton December 30, 2009 at 16:25

Maybe omnipresent isn’t the right word… Its just that it seems obvious that the cosmos is expanding at speeds greater than the speed of light or light would have reflected and refracted so many times throughout history that the void would be full of light. Instead we observe that the opposite is true and there is actually almost a complete absence of light comparitively. I am probably missing something fundamental due to the fact that the math is beyond my knowledge base and my grasp of physics is limited by my choice of education. Incidentally does anyone know who I should speak to about donating art? My expertise actually falls into 3D graphic modeling and rendering. I would like to learn how to donate my time by creating visual representations of the ideas and concepts herein.

Duncan Ivry December 30, 2009 at 19:10

parmanello citing “When a distinguished scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.”

There is some truth in it. Let me take this one step further, going from possibility to probability: When someone (this doesn’t need a distinguished scientist) states, something is very *probably* wrong, then … er … what?

Asserting successfully that something is false may be difficult, but … seriously. Person A says “warp drive is impossible according to the laws of physics”. Person B responds by saying “there is anekdotal evidence that statements of this kind are false in too many cases”. Does this count as evidence or reason against person A’s statement? For me it counts as a warning to be careful.

Athena Andreadis December 30, 2009 at 19:36

Drpayton, look up Olbers’ paradox. The night sky is black because the universe is not infinitely old, and the physical cosmos is expanding at less than light speed.

Mike Lorrey December 30, 2009 at 21:47

TUT, you make a very good point about this indicating the limited utility of semiclassical approximations. That said, I am curious about the distribution of energy in the center of the bubble, if this high temp is merely at the center or generally whats cooking throughout. If its merely a peak in the very center then this actually bodes well for using the warp field as an energy feedback/recycling method to help feed energy into a fusion reaction in the center of the bubble.

drpayton January 2, 2010 at 13:56

Thanks very much for the comments. I love this stuff lol!

drpayton January 2, 2010 at 15:08

“Olber’s Paradox” a very interesting read…however something still bothers me about it. The universe is finite and has a beginning, which denotes size and expansion and velocity. If the expansion is less than the velocity of light and the size was very small before the expansion, I still don’t understand how the universe is not filled with light unless our big bang is not unique and there was a medium in which it existed. Sort of like a supernova only on a much larger scale. The trouble I have with that is Olber’s Paradox, the night sky is not filled with points of light so numerous that all we see is white light. It leaves me with a question that I am sure is fundamental to most of you lol… Does light have an infinate supply of energy that allows it to travel infinate distances though at a finite rate of speed?

Terraformer (a.k.a Tobias Holbrook) January 3, 2010 at 15:05

The night sky *is* filled entirely with light… if you can see the cosmic background radiation. All that energy which filled the universe has been redshifted ut of the visible.

drpayton January 7, 2010 at 1:19

Ahhhh… Now that makes sense… But I still can’t get my mind around absolute nothingness… What exactly is hypothesized to be outside the universe? What is the universe epanding through?

Ronald January 7, 2010 at 11:18

drpayton January 7, 2010 at 1:19:

“What exactly is hypothesized to be outside the universe? What is the universe expanding through?”

Nothing, the universe itself is expanding, not into something else.

Then again: bear in mind that what we call our universe is only the visible (or rather: observable) part of the total universe, unto the light (or rather: event) horizon, from where light has reached us since the beginning.
A bit like someone standing on earth can only see a small part of the total earth, as far as the horizon.

The total universe is probably vastly larger, according to the cosmic inflation theory of Alan Guth at least 10^23 to 10^26 times larger. And this is a lower bound!

But to quote the good old (late) Arthur C. Clarke: “I am only a small town boy and hardly interested in anything beyond the Milky Way galaxy” (well, make that our supercluster).

Stephen July 11, 2010 at 18:29

Overcoming these problems somehow will certainly be the biggest engineering obstacle to creating a warp drive. Deep down inside though I just KNOW somehow we will do it. We haven’t come this far in our understanding of how to create a warp drive just to be stopped by this. If we have too we will even working for centuries and keep digging for answers until we have every possible kink worked out in the building of our future warp engines! We will never give up, never give in, and never surrender to pessimism until we take flight to the stars and at last secure the survival of the human species!

ljk October 1, 2010 at 3:02

Metamaterial-based model of the Alcubierre warp drive

Authors: Igor I. Smolyaninov

(Submitted on 28 Sep 2010)

Abstract: Electromagnetic metamaterials are capable of emulating many exotic space-time geometries, such as black holes, rotating cosmic strings, and the big bang singularity.

Here we present a metamaterial-based model of the Alcubierre warp drive, and study its limitations due to available range of material parameters. It appears that the material parameter range introduces strong limitations on the achievable “warp speed”, so that ordinary magnetoelectric materials cannot be used. On the other hand, newly developed “perfect” magnetoelectric metamaterials are capable of emulating the physics of warp drive gradually accelerating up to 1/4c.

Comments: 10 pages, 1 figure

Subjects: Optics (physics.optics); General Relativity and Quantum Cosmology (gr-qc)

Cite as: arXiv:1009.5663v1 [physics.optics]

Submission history

From: Igor I. Smolyaninov [view email]

[v1] Tue, 28 Sep 2010 19:43:47 GMT (56kb)

http://arxiv.org/abs/1009.5663

neilrued October 11, 2010 at 4:44

I am an almost 50 year old Electronics Engineer and a Trekkie; which means I am excited by the possibility of the human race exploring other star systems, travelling in superluminal starships. Yet I temper my enthusiasm with the knowledge that nature/the Universe demands very hard work from us to wrestle its secrets. Sometimes this hard work stretches out over centuries; think of the first drawings and models built by Leonard Da Vinci, and the Wright Brothers’ first flight at Kitty Hawk. That took almost 500 years, then from the Wright Brothers to the Apollo spacecraft took 60-70 years.

I used to recall as a teenager being fascinated by the USS Enterprises’ ion engines, then reading how back then in the mid-1970′s how physicists and engineers regarded ion drive for use with interplanetary spacecraft as belonging to the realm of science fiction. Almost 20 years later, NASA announced it would launch a space craft with ion propulsion to explore the asteroids in the asteroid belt. In the 1980′s I recall watching an Australian TV programme called Beyond 2000, it was revealed that an Australian experimental physicist, had been experimenting with ion engine propulsion in the 1970′s, or perhaps earlier for NASA.

NASA spacecraft launched since 1964 with ion propulsion drives were called: SERT 1; SERT 2; Deep Space 1; and Dawn.

I have been fascinated and interested in the comments everyone has been posting here.

With regards to the use of exotic matter for a working warp drive, I stumbled across a website http://www.stealthskater.com/Documents/WarpDrive_01.pdf
in which a pdf published document titled “Warp Drive within Maxwell’s equations” by Todd J. Desiato and Riccardo C. Storti working for Delta Group Engineering, claims to reduce the need for negative energy and hence exotic matter.

Quoting from the Introduction of their paper:
“… It is now understood that all space-time shortcuts may require a negative energy density [2]. This is referred to as “exotic matter”, which implies something that is mysterious and unknown. In this paper, the existence and nature of exotic matter is demonstrated so that the negative energy density problem may be solved.

In recent years, the negative energy density requirements that violate the energy conditions have been steadily reduced [3, 4, 5, 6, 7]. The most recent works would seem to indicate that faster-than-light travel can be achieved with a vanishing amount of negative energy density [6, 7]. It is well known that electromagnetic (EM) fields do not violate any of the energy conditions. However, the interaction between the EM field and an array of real sources of charge and current densities does possess a welldefined, negative potential energy density as is presented in Section 5. This may be nterpreted as a violation of the Weak Energy Condition — though not necessarily.”

In their highly technical and mathematical paper, Desiato and Storti derive an electro-magnetic (em) version of the Alcubierre warp drive, by mathematically combining Maxwell’s equations with “the Quantum Mechanical phase shift known as the Bohm-Aharonov Effect”, and em field Relativistic Lagrangian energy density. Their equations result in a model implementing the Lorentz force to produce thrust.

Their theory is an attempt to devise Engineering solutions to building a practical Warp Drive, within our current understanding of the laws of Physics. One aspect is that they claim that superluminal speeds may be achieved without Einstein’s Special Relativity consequences of time dilation or length contraction.

The validity of the Desiato and Storti theory can only be proved by experiment, and this theory may be the best one devised so far that may be experimentally tested because it may be the first that allows Engineering methods to be included in its formulation, that allows a modification of the vacuum polarizability by applying em fields, to affect space-time curvature.

Whilst they do not claim this is the best or only way to make a working Warp Drive an engineering possibility, at least they are attempting to find a way to get around the negative energy limitations of the Alcubierre warp drive theory, as reported by Stefano Finazzi and his colleagues.

Hawking Radiation as has been reported by Finazzi et. al., is due to the spacecraft travelling so fast, that atoms, ions or electrons naturally occurring in the interstellar medium, would be colliding and enough would pass through the walls and bulkheads at high speeds to pose a radiation hazard for the crew.

In Star Trek’s technical manuals, the USS Enterprise and other Starfleet vessels/spacecraft solve this problem through the use of their Navigational Deflector, that effectively pushes such atoms, ions and electrons out of the way of the starship. The Navigational Deflector could even deflect or push larger space debris out of the way, such as small asteroids.

An embryonic version of a Navigational Deflector has been already devised by DARPA; an em shield to deflect the molten copper resulting from the detonation of an RPG (Rocket Propelled Grenade), to provide additional protection to APCs (Armored Personnel Carriers) and military tanks. The last I read on this invention, was that it had not yet been implemented in actual US combat vehicles because of the enormous power requirements for this shield. One may imagine that a starship of a reasonable size may generate enough power to run the Navigational Deflector and the Warp Drive. Of course improvements in the energy efficiency for the shield may in the future reduce the power required.

As Alfred, Lord Tennyson once wrote: What some men can imagine, other men can make real.

Scott M December 3, 2012 at 15:09

“and in the real world there are always these perturbations.”

Finally an explanation as to why the divorce rate is so high.

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