Physics of Romulan Engine cores

[betazed]

I promised DP a thread on the physics of Romulan engine cores. So here goes. Hopefully it will provide some of us some distraction while we cool down from all those arguments in the hotly debated politics threads.

A lot of the physics ideas in Star Trek are right, some are a maybe and some are downright bs.

So let's dwell on a "maybe" here.

In the episode "Time's Arrow" Commander Data says that the Romulan warbird is powered by an engine that relies on "forced quantum singularity". And we are left wondering what that might be. Well, the jury is still out on that one.

But if we attempt to design an engine on "similar" principles could we create such an engine? The answer turns out a tentative "Yes". We could, if only we can harness a...

...rotating black hole. A Kerr black hole.

All energy extraction process from Kerr black holes originate from a peculiar property it has. Outside the event horizon of a rotating black hole is a region called the ergosphere. Inside the ergosphere you must move in the direction of the rotation of the black hole since that is the timelike direction. However, you can enter and exit the ergosphere as many times as you wish. This is the key physics that we need for energy extraction.

{By the way this is called the Lens Thirring effect or the dragging of inertial frames. It is one of the predictions of Einsteins GR that has not been tested yet. Gravity Probe B is supposed to test this result fully. }

Roger Penrose showed how you can extract energy from a rotating black hole. The process is called Penrose Process. The energy comes from the angular momentum of the black hole.

But it is not the most efficient process of energy extraction.

The most efficient process that we know of is the BZ process {the betazed process j/k the Blanford-Zaeneck process } Very simply, You immerse the black hole in a magnetic field. You throw a lot of plasma in the ergoshere. That will make it a conductor. Then as the conductor rotates in the magnetic field it creates an induced voltage from which current can be extracted. In fact this is the process that is theorized for the immensely powerful jets of x-rays that we see in some black holes. {I could not find any nice and simple explanation of this process on the web. }

Once again the energy comes from the angular momentum of the black hole. So obviously you are not getting something out of nothing. But the point is that the angular momentum of a black hole even a few cms wide would be enormous. I guess enough to power a starship.

BTW, if you are interested of how known physics matches up with what is shown in star trek an excellent (and concise) book is
Physics of Star Trek by Lawrence Krauss. It is completely non technical and hence understandable by everyone.

 

[Bozo Erectus]

Great thread Interesting, I wonder how much power a starship would require? How many gigawats for all those far out systems they employ? Also, when they disable an enemy starships engines with phaser fire, whats stopping the blackhole from consuming the ship? Presumably, the magnetic fields containing the black hole would dissapear and all hell would break loose.

 

[Flak]

Originally posted by Dumb pothead
Great thread ...when they disable an enemy starships engines with phaser fire, whats stopping the blackhole from consuming the ship? Presumably, the magnetic fields containing the black hole would dissapear and all hell would break loose.

I'm kind of thinking that you would need energy to maintain the existence of the black hole. You would have containment fields to keep it in place. But if you loose the system that is maintaining the existance of the black hole itself, by creating the quantum singularity and keeping it stable through the process of converting its rotational energy into usable power, then the black hole will simply dissipate.

How that dissipation would occur would be interesting. In fact, it might be catastrophic, though controllable i.e. similar to purposely exploding a mine inside a detonation container.

 

[betazed]

db & flak: I have just detailed how you could use a theoreticial model of energy extraction from a black hole. How you would actually put it in an engine is far from obvious.

For example just one problem. If earth were turned into a black hole its radius would be .83 cms. Hence even a tiny black hole would have enormous mass. While it would be eminently possible to build a ship around it imagine the energy required to move it. You would need to move the mass of large planets!

 

[Flak]

betazed,

I was actually thinking along a different set of lines: What if you had a small amount of rather specialized quantum particles? Particles that you could, through some means, coax into coalescing into a singularity? Now, you don't have the mass problem, or atleast not as bad of one. You just have to figure out if the thing can actually generate enough power to be useful and if the system as a whole is efficient enough to be worth all the trouble.

This is what I was thinking with my response about maintaining the blackhole. The mass itself might be so small that even if it did lose containment and the maintenance system failed, the resulting energy release couldn't be more than E=mc^2. Sure it would/could still be a pretty big boom. But with that kind of technology, that event might possibly still be something that could be controlled and planned for.

 

[betazed]

Originally posted by Flak
betazed,

I was actually thinking along a different set of lines: What if you had a small amount of rather specialized quantum particles? Particles that you could, through some means, coax into coalescing into a singularity? Now, you don't have the mass problem, or atleast not as bad of one.

I am not sure what exactly you are trying to say but if I am catching your drift correctly...

You may not be able to create a singularity without having thrown enough mass into it and creating a black hole. i.e. you cannot have a naked singularity. It must be wrapped with a event horizon. This is called the cosmic censorship hypothesis.

While this hypothesis has not been proven (in fact it is very hard to even write down mathematically let alone prove it) if it is not true then we will have very fundamental problems with our physics. For example causality will definitely be violated with a naked singularity (can you tell me why?).

 

[Flak]

Originally posted by betazed


I am not sure what exactly you are trying to say but if I am catching your drift correctly...

You may not be able to create a singularity without having thrown enough mass into it and creating a black hole. i.e. you cannot have a naked singularity. It must be wrapped with a event horizon. This is called the cosmic censorship hypothesis.

While this hypothesis has not been proven (in fact it is very hard to even write down mathematically let alone prove it) if it is not true then we will have very fundamental problems with our physics. For example causality will definitely be violated with a naked singularity (can you tell me why?).

I don't see why my black hole coudn't have an event horizon around it. It's just a problem of convincing my signficantly-smaller-than-critical-mass amount of matter into coalescing into a spinning black hole. It would have to have all of the properties of a black hole, period, or I don't think it works at all.

No the problem with my idea is: How on earth, or anywhere in the universe, do you manipulate matter to coalesce into a black hole? And further, how do keep it in this state? How do you ensure it's spinning? There are many, many more questions and obstacles around this concept. But I can't imagine a realistic spaceship carting around a natural-sized black hole amount of mass. That just seems to impractical. Even you suggested in your reply a conversion of a significantly smaller amount of matter, the Earth. How would you convert any amount of mass smaller than a theorized critical mass into a black hole?

 

[Perfection]

Well, first off, there has to be some impact on the black hole, if we have something taking energy from it, then energy must somehow removed (reduction of angular momentum I'd suspect). What I'm wondering is how can a singularity have angular momentum, when it's just a single point?

 

[Flak]

Originally posted by Perfection
Well, first off, there has to be some impact on the black hole, if we have something taking energy from it, then energy must somehow removed (reduction of angular momentum I'd suspect). What I'm wondering is how can a singularity have angular momentum, when it's just a single point?

In a Kerr Black Hole, the singularity itself becomes ring shaped. From some of the illustrations I've seen, it looks actually quite a lot like a torus.

There are some interesting properties, for example, the gravity is repulsive unless you approach the singularity on the equatorial plane. There is a sphere, outside of the event horizon, where spacetime itself is rotating in the same direction as the black hole, so it is impossible for anything to actually be 'still' with respect to another point in this space. Pretty wierd.

And yes, there would be a reduction of the angular momentum.

I'm thinking if you create an artificial spinning singularity, your system has to have a way of 'revving up' the angular momentum at times to keep the whole thing running. The efficiency here would really have to be worth all this effort. I have trouble imagining how this would be possible. Perhaps we'll find some natural source for a specific type of radiation that when focused and polarized works on specific materials in such a way as to cause it to collapse into matter of singularity type density, or gets us close enough that we can give a final push toward that final collapse with rather conventional means.

I don't know. It's all pretty exotic right now.