Louis Crane and Shawn Westmoreland co-authored the paper Are Black Hole Starships Possible? (http://arxiv.org/abs/0908.1803) that suggested that one could use Small Black Holes to propel starships close to the velocity of light for interstellar travel. To give them credit, they stated that this is at the “edge of possibility” and would only be possible in the very distant future:
“The purpose of this paper is to investigate whether it is possible to build artificial BHs of the appropriate size, and to employ them in powerplants and starships. The conclusion we reach is that it is just on the edge of possibility to do so, but that quantum gravity effects, as yet unknown, could change the picture either way… Many questions which arise in this program lead to calculations in general relativity which have not been done. Whatever the other merits of our proposal, we are confident it will pose many interesting problems for classical and quantum relativity.”
Note, BH = Black Holes
That is it. Crane & Westmoreland were presenting an academic exercise to pose “many interesting problems for classical and quantum relativity”.
However, others like James Messig and Paul Gilster and Marcus Chown have taken this to mean a real engineering problem that can be solved . . . Read their articles.
I only found out about Marcus Chown because Paul Gilster says “Chown does a good job with this material” quotes him, and I reproduce here,
“The resulting million-tonne black hole would be about the size of an atomic nucleus. The next step would be to manoeuvre it into the focal range of a parabolic mirror attached to the back of the crew quarters of a starship. Hawking radiation consists of all sorts of species of subatomic particles, but the most common will be gamma ray photons. Collimated into a parallel beam by the parabolic mirror, these would be the starship’s exhaust and would push it forward.”
What a parabolic mirror … with black holes in the same paragraph? This I must see. I traced Marcus Chown comments to his article Riding a black hole to reach the stars. Chown actually states this paragraph above.
Here are the problems with Marcus Chown statement & Paul Gilster’s unquestioning nod of authority to Chown’s statement.
1. How do you control a black how?
Small Black Hole radius = 0.6 x 10-18 m, in comparison assuming a spherical shape (Illinois University), the typical space between particles in the gas is 2×10-9 m, and the average distance between two bonded atoms in water is 2X10-10 m, and generally speaking the space between two bonded atoms is around 10-10 m. That is one can fit 108 or 100 million Small Black Holes between two atoms in an average chemical compound.
So how does one control a 1,000,000 ton black hole that is more than million times smaller than an atom?
James Messig had suggested “Now imagine that a 1,000 metric ton rest mass ship could be coupled to the black hole via electrically charging the black hole or otherwise setting up a coupling field between the ship and the black hole”
Funny, James Messig contradicts Crane & Westmoreland. Crane & Westmoreland write “Note that if an isolated SBH is initially endowed with an electric charge, then it will quickly, and almost completely, radiate this charge away”.
But wait, there is another problem. Even if you could somehow electrify this black hole contraption the electric field breaks down into a discharge in air at 3kV/mm or about 1kV/mm in vacuum. So you cannot hold an black hole in a container with an electric field.
If you try, one whiff of the electron cloud on the atom and the electron cloud is gone. Another whiff. Another whiff… and before you know it there are millions of naked nuclei without their electron clouds, and an electric force based explosion, because the black hole (BH) of this size could whiz past matter striking down electron clouds in its path without ‘colliding’ with their nuclei.
Crane & Westmoreland write “As to confinement, a BH confines itself. We would need to avoid colliding with it or losing it, but it won’t explode.” They weren’t thinking about massively ionized matter because they had already stated “need to avoid colliding with it”. In their paper they were comparing black hole with antimatter.
Never mind the naked nuclei explosion that is a small matter. The real problem is that the black hole gets lost (because it is 0.6 x 10-18 m small) and it sucks out the air or the Earth, maybe the Sun. Don’t forget black holes love a good meal and will consume anything in their path and get bigger, and bigger … Need a black hole in our neighborhood? No thanks.
2. How do you maneuver the spacecraft?
Remember you are lugging around at least 1,000,000 tons of black hole matter to your 1 ton. Oops, I misspoke, the laws of physics require that it is actually the other way around. 1 ton of spacecraft is lugged around by 1,000,000 tons of black hole matter.
So how does one alter the direction of the Hawking Radiation that this 1,000,000 ton black hole is producing? Archimedes is reported to have said that if you give him a fulcrum long enough he could move the Earth. So what would be the equivalent of a “large enough fulcrum”? Hmmm. I know! Another black hole!
3. How do you collimated gamma rays with a parabolic mirror?
Really? Gamma radiation passes through everything we know of, if the material is not thick enough. Maybe Chown was reporting science fiction? Remember this was 2009. What do you think?
In all fairness I think the gamma ray problem is a more realistic problem than the black hole control & maneuvering problem.
No wonder, Prof. Adam Franks stated in his July 24, 2012 New York Times Op-Ed, Alone in the Void, “Short of a scientific miracle of the kind that has never occurred, our future history for millenniums will be played out on Earth”.
Done. Black hole interstellar drive debunked.
The next blog post in this debunking series.
Benjamin T Solomon is the author & principal investigator of the 12-year study into the theoretical & technological feasibility of gravitation modification, titled An Introduction to Gravity Modification, to achieve interstellar travel in our lifetimes. For more information visit iSETI LLC, Interstellar Space Exploration Technology Initiative.
Solomon is inviting all serious participants to his LinkedIn Group Interstellar Travel & Gravity Modification.