View Full Version : The Alcubierre/broeck Warp Drive

2004-Jun-19, 11:15 PM
In 1994, Physicist Miguel Alcubierre published a paper entitaled "The Warp Drive: Hyper-fast travel within general relativity" in the journal Classic and Quantum Gravity. This singal paper that took someone perhaps an hour to read, changed the status of "Warp Drive" from science fiction theme used in Star Trek, to a possible faster-then-light propulsion system that worked within the confines of relativity. Science fiction's warp drive had now been given a consistent theoretical and mathimatical basis.

Alcubierre devised a "metric", a mathimatical specifacation for the curvature of space-time. Alcubierre's warp drive used space-time it'self as a propulsion system. Somehow, the space-time in the front of the ship would be contracted, like in a mini-big crunch. The space-time in the aft of the ship would be expanded, like in a mini-big bang. While in the middle of the two distortions would be a region of normal space-time for the ship to be in. This contraction and expansion of space-time would in theory, propel the ship at speeds far in exess of c. And because the bubble is moving and not the ship, the crew experience no time dialation or super fast accelleration. However, calculations showed that negative mass-energy would be required on the sides of the "warp bubble" to keep the rest of the bubble from "collapsing." This negative mass-energy is not only theoretical, but the amount needed just to create a non-moving bubble that can hold a 100 meter ship, would require 10 times the amount of all the positive mass-energy in the universe. This was not the only problem.

In addition to the energy requirements, because the ship cannot have direct contact with the bubble's outer super-distorted space-time "wall", once the bubble is on, there's no way to turn it off. And there is no way to manuver the bubble while it's on. In a matter of speaking, the only way to get out is to hope that your ship collides with something and it's atoms are ripped apart at the sub-atomic level, not very attractive. However, Dr. Van Den Broeck has solved at least two of these problems, one, the energy requierment, two, turning off the bubble.

Broeck has discovered that many of these problems of Alcubierre's drive can be solved by useing a trick of general relativity. Broeck has created a new "Broeck Warp Metric" with out throwing away Alcubierre's original metric. Broeck has essentially given the warp bubble "layers."

Broecks new metric looks somewhat like a bull's eye on paper with four layers of space-time. The point in the center of the bubble is where the ship restes. The flat space-time around the ship is layer number 1. Beyond this layer is layer number 2, a layer of the bubble with relativly distorted space-time. Still further beyond this layer is layer number 3. Layer number 3 is a "connecting layer" of space-time that is flat like layer 1, it connects layers 2 and 4. The fourth and final layer is the standered Alcubierre metric layer, except in Broecks bubble this layer is very, very thin, still this layer of space-time is super-distorted. By changing to bubble design to this, Broeck has greatly reduced the ship's need for negative mass-energy. In fact, to attain 10 times the speed of light, the ship requires only -0.06 grams of negative mass-energy, at 100 times c, the ship needs only -56 kilograms of negative mass-energy. Also, Broeck calculates that by reducing the bubble's speed to near zero, it might be possible to expand the bubble and turn it off. However this has problems. Expanding the bubble's layers would cause the "walls" of some layers to come dangerously close to the Planck lengh. And also, because these walls are so thin (thinner then any known wave-lengh), when the bubble is on, nothing would be able to get into the bubble or leave it, not even photons or radiation, the ship would be flying blind. And there's still the problem of manuvering the bubble.

Alcubierre and now Broeck have layed down the path for future Warp Drive research, and perhaps implenmentation, but there is still alot of work ahead. To me Warp Drive has the best chance of becoming a FTL propulsion system. While the first Warp flight may still be far off, have the works of Alcubierre and Broeck dramatically increased the chances for a functioning FTL Warp Drive?

2004-Jun-20, 12:07 AM
Ziggy, you are turning, however slowly, into StarShip1 and Oliver, the Iron Man; how so? Because your posts are getting longer and longer! :unsure: :rolleyes: My heads now spinning every time I read one of your new posts! :blink: :( :angry: :ph34r:

2004-Jun-20, 12:49 AM
I have a new energy in me. It's great :D ! For some reason I'm more focused. I can write longer posts. I AM ALIVE :rolleyes: !!!

2004-Jun-20, 02:17 AM
Well, your newfound ability to make longer posts is making me less focused! :lol: ;) :ph34r:

2004-Jun-20, 07:41 PM
I'm not giving up my new ability just becuase it's de-focusing you, StarLab :lol: :P ;) !

2004-Jun-21, 12:01 AM
Then I'll have you know, BigZig, that I'm the only responsive poster in this string right up till now....so, bon chance BZ! :lol: ;) :P :rolleyes: :ph34r:

2004-Jun-21, 12:06 AM
We need to get more people to post in this forum. HELLO PEOPLE!

2004-Jun-21, 07:59 AM
alright i read all that, wow. all sounds dandy to me, whether the math and physics actually exist for this project i have no idea. but i did think it was cool to estimate these numbers. at 100 c we can travel to mars in a quick two seconds. we could go to our nearest star alpha centauri in a little over two weeks, meet some aliens on the terrestrial planets on that solar system.

or if the milky way isn't your bag, in this fantasy warp drive it takes 250 years to the canis major dwarf galaxy that is colliding with the milky way. or if you wanted to head the other direction (long trip) and find where the stars stop and the void to the next galaxy begins it would take 300 years. then once you hit the void of dark matter lean back for another 19,000 years and you hit good old spiral galaxy andromeda!

2004-Jun-21, 08:25 AM
also this post is pretty funny since in this post http://www.universetoday.com/forum/index.p...wtopic=3295&hl= (http://www.universetoday.com/forum/index.php?showtopic=3295&hl=) you declared FTL is impossible and you had given up hope. just admit it now you're a FTL junkie!

2004-Jun-21, 03:08 PM
Well, Zig, I think I understood you post, and:

1) Why crush the crew into a singularity. That'd just kill them! :o
2) Speaking of maneuvering a bubble, you know those pictures of spacetime grids? With the lines perpendicular and dipping under stars. What if we could hook the bubble onto one of those lines and let the bubble travel along those lines? What if we didn't have to turn the ship into a singularity and kill the astronauts? What if we could make it so the bubble stays intact and keeps spacetime outta the bubble, which disappears near a well of gravity? Consider these for a sec.

2004-Jun-21, 03:27 PM
I am a FTL junkie. That post was made when I let my inner skeptic get to me.

2004-Jun-21, 07:10 PM
Ok everyone, post in this forum! Tell me if it's possible or not and WHY.

2004-Jun-22, 07:15 PM
Someone, someone smart, answer my question. PLEASE I need someone elses imput!

2004-Jun-22, 07:39 PM
Let me know when you've found someone with a yoctogram of negative matter-energy. Until that happens there is nothing practical about this form of locomotion.

2004-Jun-23, 02:57 PM
Sadly, I must agree. Even a yoctogram (60% the mass of a hydrogen atom) of negative mass-energy is far beyond our current production capabilities. We need a breakthrough in negative mass-energy production for practical FTL travel. Negative mass-energy will become the dilithium of the future :lol: ! But just because production of the nessecery amounts of negative mass-energy is currently impossible, that dosn't mean we should forget Warp Drive all together. I've read many papers that talk about matter-anti-matter rockets, even though the designs require several kilos of it (far beyond our current capabilities). So let's assume that a breakthrough in negative mass-energy production has occured. With negative mass-energy production problems set aside, is a FTL Warp Drive possible or roughly possible (there's still a few "technical" problems with the drive)?

2004-Jun-23, 03:05 PM
To get all the information I have posted here in detail and more do a search engine on "Alternate View Columns by John G. Cramer." The site should be one of the first search resaults. Go there and click on the "Space Drive" section and click on the Alcubierre Warp drive and Micro Warp Drive. Theres lot's of other FTL concepts there too.

2004-Jun-26, 10:30 PM
I found this E-book after doing quite a bit of searching. It's very optimistic, blows me right out of the water. Your going to have to read it, I'm not even through 1/4 of it. Very Interesting (http://www.stealthskater.com/Documents/WarpDrive_02.doc). It takes two minutes to download, but if you don't have a high level understanding of physics, don't bother.

2004-Jun-26, 10:49 PM
Originally posted by Ziggy@Jun 26 2004, 10:30 PM
I found this E-book
404 - bad URL.
Please give the title and author to help doing a Google search to track it down.

2004-Jun-27, 06:24 PM
I knew this would happen <_< , all URLs are like this. Anyway, go to www.stealthskater.com. Then, there should be a "science section" that has "Warp Drive with Maxwell&#39;s Equations." Go down to article number 15, "The Science of Warp Drive", click on the little diamond thing to download it. You should get the E-book on your desktop.

David S
2004-Jul-12, 06:03 AM
Anyway you could explain what the heck negative matter-energy is? I&#39;ve never heard of it.

2004-Jul-12, 02:17 PM
Here (http://encyclopedia.thefreedictionary.com/negative%20matter) is a description of negative matter. It should be relegated to the artifacts of science fiction.

2004-Jul-12, 04:59 PM
Negative matter is definitely science fiction; that is why we use it in Orion&#39;s Arm (http://wwworionsarm.com) for a wide range of uses; but the Alcubierre/Broeck drive isn&#39;t one of them.

The vast amounts of negative energy required for Alcubierre&#39;s original proposal are detailed here, in this study by Pfennig and Ford;
http://xxx.lanl.gov/PS_cache/gr-qc/pdf/970...702/9702026.pdf (http://xxx.lanl.gov/PS_cache/gr-qc/pdf/9702/9702026.pdf)

Cramer himself casts doubt on the likelyhood of Broek&#39;s warp
essentially Broeck&#39;s warp shrinks the ship inside a baby universe-like bubble until it is smaller than an proton; then it can be flung around the universe using trivial amounts of negative energy.

But getting it into the bubble and out, and steering, are all real problems, and the new multidimensional theories of gravity probably rule this multilayered bubble out altogether.

But the real reason we don&#39;t use FTL is considerations of causality; if relativity is correct, travelling faster than light will lead to time paradoxes.

Especially when used in conjuction with wormholes; the ends of wormholes can have completly different frames of reference with respect to time, and by flying between wormhole mouths in your FTL ship, you could easily create a time machine.

For this reason among many others, we do have wormholes but not FTL ships in the Orion&#39;s Arm scenario.

2004-Jul-22, 06:05 PM
Eburacum45, both Warp Drives and Wormholes take advantage of the same loopholes in physics, wormhole travel is as speculative as warp drive. You don&#39;t need a faster-then-light ship to make a wormhole a time machine. Say you create a wormhole, somehow, one end of the wormhole is placed on Earth, while the other end on a ship that can travel at speeds close to the speed of light, not faster, say 99.49% light speed. As soon as the wormhole is created, the ship starts heading towards the star Epsilon Eridani, roughly 11 light-years away. The trip to Epsilon Eridani takes roughly 11 years in the view point of someone standing still on Earth. However, because of time dilation, the crew of the ship would have experienced only a little more then one year going by. Now, because the people on the ship experienced only one year going by, so did the end of the wormhole on the ship. Therefore, if someone on the ship stepped through there end of the wormhole, they would emerge on the other side having traveled 11 light-years of space, and also, 10 years into the future in time. And also, someone on Earth could step through Earth&#39;s end of the wormhole and travel 10 years into the past, a direct violation of the law of casulity. I&#39;ve been to the Orion&#39;s Arm website, if it is to be a "hard science" website, both warp drives AND wormholes cannot exsist.

2004-Jul-22, 06:44 PM
Wow thats cool i just came to this foroom to day with thorie i had about spacetime waping wich opend the door 4 faster then light travel aswell i figerd u would sipmely copmpess spacetime at wich point the speed of light would increse but thats as far as i got. but thats like the kit and kaboodel right there also i belev it may be posabel to do it without crusing tidel forces &#092; ;)

2004-Jul-26, 06:21 PM
stars and bars forever/ solami. SPISH AKA ZIGGY YOU KNOW WHAT THIS MEANS.


2004-Jul-28, 10:56 AM
There is nothing a priori impossible about FTL travel, wormholes, and stuff like that; i.e. this stuff does not defy logic.

However, any way of traveling faster than light (reaching a destination before a light beam could have reached it through normal space) entails the following dilemma. Either, the machinery cannot be Lorentz-invariant, or the machinery makes it possible to travel to one&#39;s own past.

If I am traveling faster than light relative to a certain inertial frame, there is always an other inertial frame where I am arriving at my destination before I left.
This is not a problem if this other inertial frame has a great speed relative to Earth, because I cannot visit my own past that way, merely some distant location whose time coordinate happens to agree with the time coordinate of some moment in my past.

But Special Reletivity says that whatever I may do in one inertial frame, I may repeat in any other inertial frame.So I can board a spaceship with exactly the opposite speed as the frame where I seemed to go back in time. And while on this spaceship I may travel faster than light relative to the ship. Now I have traveled back in time relative to Earth. If another spaceship now returns me to Earth, I may arrive before I ever left, and create all kinds of paradoxes.

To prevent this, we must restrict the possibilities of traveling faster than light to those which do not travel back in time within a certain, priviliged inertial frame. (For example the frame where the cosmic background is isothermal.) Now we cannot follow a closed loop in spacetime, and therefore we cannot create paradoxes (like reading a message before it has been written, and thereupon writing a different message).

However, with a priviliged inertial frame, our machinery is no longer Lorentz invariant. It can travel back in time relative to some (unimportant) frames, but not relative to other (important) ones. If such a machinery can be nuilt, Special Relativity must fail.

Interestingly, a trip around the universe would cause Special Relativity to fail for similar reasons. Therefore, if the universe is "round", and if it is possible to travel "äround" it in any epoch, there must be a priviliged frame of reference; in any other frame the arrival may precede the departure.

2004-Sep-01, 03:42 AM
Originally posted by StarLab@Jun 21 2004, 03:08 PM
Well, Zig, I think I understood you post, and:

1) Why crush the crew into a singularity. That&#39;d just kill them&#33; :o
2) Speaking of maneuvering a bubble, you know those pictures of spacetime grids? With the lines perpendicular and dipping under stars. What if we could hook the bubble onto one of those lines and let the bubble travel along those lines? What if we didn&#39;t have to turn the ship into a singularity and kill the astronauts? What if we could make it so the bubble stays intact and keeps spacetime outta the bubble, which disappears near a well of gravity? Consider these for a sec.
I just found this group and this is the first page that I read through.

At the risk of repeating someone else:

1) Has anyone found a metric to create a Tardis?
2)Since I doubt that the astronauts inside the bubble would be able to see outside of it (flying blind), in order to navigate, I would assume that a computer would calculate the direction to pull/push the bubble and create the effect based on a time limit (i.e. it takes 2 seconds to travel to Mars at 100C). Keeping the astronauts out of space-time sounds hard (and sounds like &#39;subspace&#39; to me), and sounds interesting since the warp drive would need the vessel, if I understand it correctly, to create an immense gravity field to work. A question that I would think of would be if an external gravity well would destabilize the vessels gravity field? I would like to hear thoughts about that.

Mild mannered
2004-Sep-01, 05:44 AM
:D warp drive - man I like the sound of that - if only they can come up with a way for me to live a thousand years so I&#39;ll be around to see it&#33;

2004-Sep-15, 03:21 PM
Here&#39;s a new paper on this topic. It clarifies a few things about Alcubierre&#39;s work.

Fundamental limitations on “warp drive” spacetimes (http://www.arxiv.org/PS_cache/gr-qc/pdf/0406/0406083.pdf)

2004-Sep-15, 04:25 PM
If spacetime contracts in front of the ship, it will contract other spacetime at
speed c in all directions of that spacetime..

If spacetime expands behind the ship, it will expand spacetime at speed c in all
directions of that spacetime...

Apparently, there is some mechanism that brings everything back to normal after
the ship is transmitted.

So spacetime that was contracted needs to expand as some rebound effect as
well as the expanded space in the exhaust of the ship needs to recontract..

All of that needs to occur without any energy dissipation or the rest of us back on
Earth are going to experience a sonic boom or something akin to Chernkov
radiation...on a very massive scale...

All of that just because someone wants to get from point A to point B faster....

What for?

Is some damsel in distress across the universe in need of our help right at this moment?

Aren&#39;t we killing ourselves because we are in such a big rush?

Hasn&#39;t every failure in science been due to methodologies that tend to finish things up at the expense of waiting and finding out?


2004-Sep-23, 09:49 AM
My understanding of the Alcubierre warp drive is this...but first a little background. The universe is expanding as seen by distant galaxies receding from us faster and faster as the distance increases. However, these galaxies aren&#39;t moving in the conventional way but space itself is expanding and simply carrying them along with it. In other words, space adds more space to itself and the larger the distance you look at the more this affect can be seen. A gravitationally bound system (Earth/moon, Sun/Milky Way galaxy, galaxy clusters) overpowers this expansion and keeps them stable.

Now to the Alcubierre warp drive. It harnesses the principle that allows the universe to expand but in two ways. In the direction you want to move it REMOVES some space (let&#39;s say a foot) and simultaneously ADDS the same amount behind it. The ship then has "moved" forward by one foot. Repeat the process and it "moves" forward another foot. Of course, you could remove a light year from in front and add it to the rear. Done simultaneously there&#39;s then no affect on the distance between where you left (Earth) and your destination. The "warp bubble" around the ship is to insulate it from the removal and addition of space around it. The wave it&#39;s supposed to be riding on can then be thought of as the trough of less space in front and the rise of more space behind.

2004-Sep-24, 09:46 AM
warp bubbles this and "remioving spact-time" that - all nice therioes but a bit to complex.

the easy way to do FTL is so simple you will kick yourselves.

Take the basic prinicpal of acceleration and forget it. Take relativitly, and forget it. All you need to do is travel "through" space-time and not on it. The only walls in this universe are the ones we impose upon it. the only rules are the ones we write for it. that said, you will have to make a black hole to go FTL &#33; a somewhat hazerdous occupation.

Step one - first of all, stuff one quantum particle into another, the chain reaction will create your balck hole - easy &#33;

Step two - make another and stuff that inside your first black hole. not so easy but in a controlled enviroment it will probably be eaiser than you think. your first black hole will be tiny and controled by a magnectic field. the second ( created after so smaller) will be sucked in.

step 3 - the result of the above will create spacial paradox, a white hole. a source of infinite energy. nothing sucking in nothing = everything - simple but true. basically, instead of sucking in matter, it pumps matter out, forever. A matter making machine(MMM).

step 4 - utilise this energy by use of matter to energy transformer. build an engine similar to the ion drive but not energy limited.

step 5 - mount it on the back of your space craft and hit start &#33; and your off. In theory, you will accelerate forever. taking you to speeds FTL and beyond.