Edgy stardrive proposal by established physicist

[Martin]

Louis Crane is a math professor at Kansas State who has published a bunch of legitimate mathematical physics research in the usual peer-review journals. He also produces research papers that don't get published, for whatever reason:

http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=a+Crane%2C+Louis&FORMAT=WWW&SEQUENCE=

 

Three years ago, Crane applied for and was awarded a $2 million grant from a foundation called FQXi which has the stated aim of supporting far-out research that would not normally be funded by the government.

 

His proposal was to study the feasibility of using black holes to power spaceships.

 

Crane did, indeed, deliver the goods. He duly performed the proposed study as he had promised FQXi he would. The result appeared in August 2009.

 

http://arXiv.org/abs/0908.1803

Are Black Hole Starships Possible?

Louis Crane, Shawn Westmoreland

20 pages

(Submitted on 12 Aug 2009)

"We investigate whether it is physically possible to build starships or power sources using the Hawking radiation of an artificial black hole as a power source. The proposal seems to be at the edge of possibility, but quantum gravity effects could change the picture."

 

Some people might be interested in checking this out. In order to be useful, the black holes need to be quite small---on the order of 1/10 of a nanometer--comparable in size to atoms--or smaller. He calls them "subatomic black holes" or SBH.

Such small black holes radiate intensely. (Hawking radiation temperature varies inversely with the size of the BH).

 

They need to be fed, because if they are allowed to evaporate and shrink down to much less than ideal size the radiation becomes too intense and they effectively explode. You want them small, but not too small. So as they radiate away mass you should keep feeding them.

 

The work is based on the same standard BH physics, the same formulas, that are used in doing normal astrophysical BH calculations. He just plugs in different size and mass numbers---instead of stellar masses, much smaller masses on the order of a few hundred thousand tons.

 

I considered putting this in Speculation, but it has considerable amount of kosher physics, and is by an established author, so decided it was borderline legit.

 

Crane also submitted a brief non-technical essay on this idea to a FQXi essay contest:

http://fqxi.org/community/forum/topic/525

 

He got his PhD from Chicago in 1985, postdoc'd at Princeton Institute for

Advanced Study, was Assistant Professor at Yale for a while, then took the tenured faculty position at Kansas State.

[Rasori]

I read about this recently in NewScientist (no claims are being made by me on validity of any source).

 

From what I read it sounded feasible and certainly interesting, but it's one of those things where "feasible" means that I understood what was being said, not that I verified the facts he used. The biggest drawback was the power needed to create the black hole. Something on the order of a gigantic solar panel pretty close to the sun being able to produce a large enough power source once every 3 years?

 

Still, more feasible than travelling the stars with the technology we're currently using.

[Mr Skeptic]

Yeah, I read about this also on new scientist, an quite a while had though up of it independently. The trick is that making a small black hole doesn't seem feasible any time soon. And of course we don't know if the numbers are right since GR is not tested on such a small scale. And I don't think Hawking radiation has been verified yet. Lots of potential problems and definite problems, but if it does work, it would kick antimatter's ass (at least if the black hole can be fed).

 

I also am pretty sure that with a small black hole you can convert some protons into positrons plus energy.

[Tranquility]

as a novice physicist I am interested to understand how electricty generated from solar panels could be used to generate a black hole. Also you mention feeding the BH, I asume, just like a large animal, this should be done using a long stick? But seriously how much would you need to feed the BH and how often, I would imagine carrying around hundreds or thousands of tonnes of "BH food" is going to be complicated. Finally I thought that BHs radiate spherically how could you channal this radiation into a driving force?

 

Sorry if these questions are dumb

[Rasori]

The electricity would be used to power a very powerful laser or something like that. I'm not entirely sure how they create black holes, but allegedly they already happen in labs on occasion, it mostly has to be scaled up slightly.

 

In terms of the radiation, the suggestion was to use a parabolic mirror I believe--anything already going away from the ship provides thrust just like any other engine, and anything going towards the ship bounces back and also provides thrust.