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Black Hole Drive Could Power Future Starships

by Ryan Anderson on November 19, 2009

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Image credit: NASA

Image credit: NASA



What would happen if humans could deliberately create a blackhole? Well, for starters we might just unlock the ultimate energy source to create the ultimate spacecraft engine — a potential  “black hole-drive” –  to propel ships to the stars.

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It turns out black holes are not black at all; they give off “Hawking radiation” that causes them to lose energy (and therefore mass) over time. For large black holes, the amount of radiation produced is miniscule, but very small black holes rapidly turn their mass into a huge amount of energy.

This fact prompted Lois Crane and Shawn Westmoreland of Kansas State University to calculate what it would take to create a small black hole and harness the energy to propel a starship. They found that there is a “sweet spot” for black holes that are small enough to be artificially created and to produce enormous amounts of energy, but are large enough that they don’t immediately evaporate in a burst of particles. Their ideal black hole would have a mass of about a million metric tons and would be about one one-thousandth the size of a proton.

To create such a black hole, Crane and Westmoreland envision a massive spherical gamma-ray laser in space, powered by thousands of square kilometers of solar panels. After charging for a few years, this laser would release the pent-up energy equivalent to a million metric tons of mass in a converging spherical shell of photons. As the shell collapses in on itself, the energy becomes so dense that its own gravity focuses it down to a single point and a black hole is born.

The black hole would immediately begin to disgorge all the energy that was compressed to form it. To harness that energy and propel a starship, the black hole would be placed at the center of a parabolic electron-gas mirror that would reflect all the energy radiated from the black hole out the back of the ship, propelling the ship forward. Particle beams attached to the ship behind the black hole would be used to simultaneously feed the black hole and propel it along with the ship.

Such a black hole drive could easily accelerate to near the speed of light, opening up the cosmos to human travelers, but that’s just the beginning. The micro-black hole could also be used as a power generator capable of transforming any matter directly into energy. This energy could be used to create new black holes and new power generators. Obviously, creating and harnessing black holes is not an easy undertaking, but Crane and Westmoreland point out that the black hole drive has a significant advantage over more speculative technologies like warp drives and wormholes: it is physically possible. And, they believe, worth pursuing “because it allows a completely different and vastly wider destiny for the human race. We should not underestimate the ingenuity of the engineers of the future.”

Article available on ArXiv.
Nod to: io9

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Tagged as: black hole, spaceship

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  • Olaf

    Do we have enough resources in this solar system to actually do this? Or would this be a single event and then we need another solar system to find new resources?

    We might also try to find black hole deposits so we do not have to create them just harvest them.

    I am not an expert in black holes, but I saw this formula that you would need a 228 metric tons of black hole so it can exist for 1 second. But if we let it run in a circle near the speed of light would it stay longer like 1 hour a black hole?

  • Lawrence B. Crowell

    The Fermat theorem here is a different Fermat theorem, not the “Fermat Last theorem” which Wiles proved last decade. What I am talking about is Fermat’s principle of least time. This idea is that the time it takes a light ray to travel through a media is minimized to give the correct path

    & int dt = 0

    & = delta, and dt = dx/c, c = speed of light. Well the speed of light in a medium changes by an index of refraction c–>c/n, where n can vary with position n = n(x). The problem is equivalent to the extremization in classical mechanics and leads to the Euler-Lagrange equation.

    As for information, yes a black hole does return all its information. In fact we can say that information is generally conserved. Yet it does not remain available, or correlated. Information can be encrypted in various ways, or it can be dispersed. That is the measure of entropy. The Susskind-Preskill win over Hawking is over this matter. Hawking insisted that information was destroyed, while it has been found that it is simply encrypted by some grand algorithm of the unvierse into forms that are much harder to cypher.

    The wormhole connecting up the outside world with the interior of a black hole would reduce the area of the black hole. Entropy is by the Bekenstein-Hawking result related to the event horizon area of a black hole A = 4piM^2 with mass M by

    S = kA/(4L_p^2),

    where L_p = sqrt{G hbar/c^3} or the Planck length, k = Boltzman constant. So we can think of the entropy of a black hole as the number of units of Planck area on the event horizon. The reduction in the area of the event horizon means that entropy is reduced, but if presented to the outside world without encryption then the second law of thermodynamics is violated. For instance one might imagine rescuing an astronaut who fell throught the BH.

    Now this presents some other funny things, for you might rescue the astronaut, bring him back and you might be able to have him see himself time dilated and redshifted above the black hole horizon. This then leads to another “no-go” theorem in physics that you can’t clone quantum states. Yet a traversible wormhole would permit you to do that.

    Worm holes would allow one to solve an NP problem in P time. In fact it might well mean you could solve all P-space problems with equal efficiency. A factorization problem can be solved in a time loop so the closed timelike loop exists with the problem solved. It is like the old science fiction idea of getting instructions on how to build a time machine, building it and then sending the instructions back in time to yourself.

    These things simply don’t happen, at least if the universe is at least not logically self contradictory.

    LC

  • Aodhhan

    The problem with using black holes is the same with other conventional methods of propulsion… weight. Even a relatively small black hole weighs a lot. In this case… more than anything else proportionally.

    Then there is the little problem being, the faster you go, the more mass you have… which means you need more propulsion.
    Why can light move as fast as it does? …because it doesn’t have mass.
    In theory, you would be better off using some sort of fission device, and make the most of E=MC^2 to move around in space. The heck with black holes, lets use the strong nuclear force.

    Even better… find a way to compress the space you want to move into; then you wouldn’t need to travel quite as fast, since you are basically making space come to you.

    Shielding a ship from harmful radiation is simple… you simply do the same thing Earth does. Something we’ve been able to do for over a hundred years. Create a magnetic field.
    Shielding a ship from particles using energy or a form of plasma is probably within our reach now, and I would bet we see something feasible within the next 10-20 years.

  • Dark Gnat

    It would need to be a very powerful magnetic field of you are traveling at such speeds, as even optical light would be blueshifted to dangerous frequencies, right?.

    Such a strong magnetic field would also interfere with sensory equipment and communications, assuming there would be anyone to talk to out there. I suppose during the high speed travel, all cell phones would need to be turned off!

    I kind of think that navigation at near light speeds would be very difficult. I suppose you could have predetermined “jump points” and hope there are no objects in the way.

    Lastly, wouldn’t it need to be a gradual acceleration to keep the crew from being splattered all over the back of the bridge?

  • http://www.spaceward.org CrazyEddieBlogger

    @Lawrence (staying off-topic – I know a lot less about black holes than I do about SEs)

    You are correct with the linear mass density figure, but start with a Carbon Nanotube material that has a specific strength of 40 GPa-cc/g, and see how much cable is required to carry a 20 ton climber… you’ll be surprised, as I was a few years ago. I used to have in mind the multi-megaton Arthur C Clarke vision, but it’s a mazing what a little bit of math can cure. :)

  • Lawrence B. Crowell

    I can’t comment too much on space elevator ideas. I will be honest I have regarded the idea as utterly daft. I am aware that there are ideas about carbon nanotube composite materials and the like, but I had not thought that this would involve as little as a few 100 kg per km of the “cable.” EVen if the thing can be made to only a few thousand tons I have a heard time seeing how all that mass is going to be lofted up.

    LC

  • Andrew

    How large would the parabolic electron-gas mirror need to be such that the radiation from the black hole doesn’t destroy it?

    And how large would the particle beams need to be to “anchor” the ship to the black hole?

  • Lawrence B. Crowell

    As I indicated two days ago there are maybe more subtle ways of working with this physics. Thieapproach presented here is pretty much a sledgehammer approach. Yet if you were to do this and had this mini-black hole you would need to control it by putting a charge on it. The Kerr-Neumann metric for a charged black hole would permit one in principle to hold the BH with large electric fields. You would need to keep pumping charged particles into the BH as it will tend to radiate away quanta to equilibrate its charge to zero. If you run some numbers you will find that the field energy density required to hold the BH is enormous.

    This goes into a general problem of how to put a black hole in a “box.” It turns out there is no perfect box, except one which general relativity provides — the anti-de Sitter (AdS)spacetime. This is a whole universe of sorts. This is a theoretical setup, where the AdS is a field theoretic map of sorts from our entire universe. So we are not going to be doing that obviously in some engineering sense.

    LC

  • Vanamonde

    My gawd, Mr. Crowell can you actually do the math on these ideas? I am in awe of such skills. Me brain seizes at the very word, Calculus. I must take it all on faith.

    My first thought when I read the title was “What Clarke novel had those black hole powered space ship, only they were for interplanetary use.” Or was it a Varley novel? I am have a foggy mental over this, once again.

    And then I thought of Anderson’s “Tau Zero”. Okay, less us say Mr. Crowell’s math is off or someone is motivated to actually build this puppy. You pointed it, i dunno, that third star on the left and go until morning. And you get to .9999999 C or whatever.

    Can you turn it off and restart it at will? You are going to have to a 180 and restart it to decelerate. Is that possible?

    Maybe you will two of these boosters (like two SRB pointer together). Fire one to get to speed and throw it away when you get there and then fire number two to slow it down.

    What, you wanna come home? Then you will need four. Do these things even have a “shelf life”?

    Tricky

  • Anaconda

    After reviewing the comments, I can see that a solid majority of commenters realize this is fanciful (fun to talk about, but not practicable)..

    That’s a good thing.

    Because when you are talking about propulsion systems, you are talking about real engineering and physics that have been confirmed in a laboratory, no if’s, and’s, or but’s.

    That’s where the “rubber meets the road”.

    And as much as the “black hole” crew believes in the reality of “black holes”, there is NO laboratory confirmation that any of the supposed scientific principles that support “black holes” actually exist.

    The collider might bring some, who knows, or bosons from the future might sabotage it again :-)

    What this little exercise should do is concentrate the mind on the lack of ANY laboratory evidence that “black holes” exist.

  • Anaconda

    And readers should note the number of comments on the respective posts, one a “black hole” fantasy, the other, plasma propulsion reality.

    Apparently fantasy is more interesting and enjoyable than reality for this crew.

    (Universe today deserves credit for the juxtaposition of the two posts.)

  • Lawrence B. Crowell

    @Vanamonde, I seem to remember reading a short story by Varley about a spacecraft tracking a miniblack hole, but where the black hole starts talking to the woman running the ship, and deludes her into destruction. It had that PK Dick sense of not distinguishing between reality and delusion.

    Making and controlling a micro black hole would be a daunting problem. To see that it is hard to build a box, all one needs to appeal to is Gauss’ law. A shell of material that is the source of a static field, whether gravity or electric, has a constant potential inside. Force is the gradient of a potential, so enclosing a charge or a gravitating point-like object with a shell does not induce a force on it. So you can’t confine it and guarantee it will not drift and eventually bump into the shell. So dynamic control is required which would be tough.

    LC

  • http://www.spaceward.org CrazyEddieBlogger

    @LC – keeping the off-topic theme, the since the SE is a linearly-scalable transportation system, the plan is to build a 10% scale unit, which will lift only 2 tons at a time, and there are several methods proposed for using it to bootstrap, carrying more tether material.

    A key parameter in a Space Elevator design is the Characteristic Time Constant, which is a measure of how long the system can transport its own weight into orbit.

    Read more at http://www.spaceward.org/elevator-feasibility

    Ben

  • http://www.spaceward.org CrazyEddieBlogger

    Anaconda – There’s a simpler explanation than that…

    One article is about a highly hypothetical device relying on extreme physic and that has at its core an astronomical phenomena.

    The other article is about a comparatively “straight forward” engineering implementation.

    This is a web site for Astronomers and Astro-physicists… Which do you think will be of more interest ?!

    That said, you need to be careful, since you’re moving from the purely delusional phase to the paranoid.delusional phase. That’s not good for your credibility… If everyone thinks you’re out to lunch, you should carefully consider the possibility that indeed maybe breakfast’s over and dinner is not yet served.

    just my 2c, of course. :)

  • Hon. Salacious B. Crumb

    CrazyEddieBlogger

    Anaconda has been black banned as a troll in this group.

    Just ignore the jackass, please.

    Thanks

  • Anaconda

    @ CrazyEddieBlogger:

    Sure, I got you: Fantasy is more fun than reality.

    But that ain’t Science.

    Of course, Crumb jokes about “burning” heretics at the stake.

    Oops, I meant “deflagation”, how careless of me:

    As in, “Pity deflagration doesn’t work with some people, here. It’s probably illegal to do so”.

    What do you say when somebody reveals their religious fervor?

    “Science has nothing to do with it.”

  • Lawrence B. Crowell

    @CrazyEddieBlogger: I’ll think about his. The space elevator idea has always struck me as way over the top.

    This article is not a judgment about the physics of black holes, but rather about engineering concepts for black hole power.

    Don’t feed trolls. Anaconda is a pseudo-science exponent. Plasma cosmology has been rejected by the scientific community.

    LC

  • http://www.spaceward.org CrazyEddieBlogger

    Yeah, I slipped.. it’s not like I had a rational thought going that he will process it logically. He must not be leading a very happy life.

    The irony is in the feeling of scientific prosecution that he feels… At an age where the scientific community has for more than a century created an environment where challenging existing notions is protected and encouraged..

    All of modern physics is a result of people completely revising or upending the prevalent understanding of the world..

    What some folks don’t get, however, is that not every view that revises or upends the current understanding is necessary valid – it might just be a completely unfounded pet theory advocated by a NUT.

    NUT NUT NUT NUT NUT!!.

    There, did it again.

  • Homme du Sud

    @CrazyEddieBlogger

    I concur 100% with Hon. Salacious B. Crumb and Lawrence B. Crowell.

    Don’t feed this troll Anaconda (which should be the prerequisite by other users here.)

    I mean. What fool would label himself a “heretic”? To me he is more like a sick-in-the-head zealot? To me it sounds like this individual just wants to be a martyr and victim towards his personal cause.
    It is clearly not about science, religion, or anything else, it is all about him and his self-centered egocentrism
    Science?

    “Anaconda has nothing to do with it.”

    Yes he is a NUT, but I’d add, he is really still in his narrow-little shell. Pity.

  • InvaderXan

    Sorry… I’m a little confused about something.

    As the shell collapses in on itself, the energy becomes so dense that its own gravity focuses it down to a single point and a black hole is born.

    …but photons are massless and therefore have no gravitational influence. :

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