Talk:Black hole starship

Math Issues
Greetings, In this article, and in the 3rd source, it says that a black hole that would survive a 3.5-year journey "would have a radius of 0.9 attometers, would have a mass of 606,000 tonnes, and a power output of 160 petawatts." However, I did the math and got different answers. Using the mass of 606,000,000 kg as a standard, I solved $$r_s = \frac{2GM}{c^2} \;$$ for the radius and got the same 0.9 attometers, but I got a power output of ~27 GW when I solved $$P = \frac{\hbar c^6}{15360 \pi G^2 M^2} \;$$ and a lifespan of ~567 years when I did $$t_{\operatorname{ev}} = \frac{5120 \pi G^2 M_0^{3}}{\hbar c^4} \;$$. My answers may be incorrect, but I really think that the values are false whether my answers are right or wrong and I think this merits immediate attention. Carbon6 talk 20:06, 17 October 2013 (UTC)


 * I've calculated 25.6 gigawatts and 593 years. —  Reatlas  (talk)  03:24, 19 October 2013 (UTC)

Confirmed, I've calculated the mass of a black hole that would last 3.5 years, and it's 109,522.7 tonnes. It has a radius of 162.625 zeptometers, and a power of 29.7072 Petawatts.

in all honesty, the 29-PW black hole is probably the better option of the two if the technology to pump matter into it is available. If the reflector could handle it, I'd even argue that 10,000 tonnes is a good size, as it allows for a much better Thrust/weight ratio of ~120, assuming ideal efficiency. At that point, you could maintain 1 G acceleration on a craft of 1.2 megatonnes mass.

Even if you want a larger ship, as long as it can handle the thrust, it's better to have multiple black holes powering it over a shorter period.

As for the power from the 606 kt hole: L=1/M^2*hbar*c^6/15360/pi/G^2, so we get 97 Terawatts, with the correct diameter already listed.207.62.170.211 (talk) 17:47, 20 February 2015 (UTC)

Fictional
IRIC, fictional Star Trek's impulse engines rapidly generate micro black holes that evaporate just as fast. The ship 'rides' the resulting gravitational disortions. The hawking radiation from the evaporation of each black hole is used to help created the next black hole. — Preceding unsigned comment added by 208.106.46.59 (talk) 02:50, 8 October 2015 (UTC)

According to the StarTrek Technical Manual, impulse engines are pretty standard fusion rockets (I know, booooring!), no exotic physics required.178.15.151.163 (talk) 14:54, 22 February 2016 (UTC)

Dr Who
Also fictional use of black hole, see http://tardis.wikia.com/wiki/Eye_of_Harmony please add with quality standard — Preceding unsigned comment added by 95.89.75.46 (talk) 09:13, 27 November 2016 (UTC)

hello
i did the math about black hole evap time with the hawking radiation formula and it gave me 600 years instead of 3.5 years. i read the reference and im still confused. >:(

any help is aprecciated ! :D 46.97.176.251 (talk) 21:42, 10 June 2022 (UTC)

Moving the blackhole
Regardless of the method of extracting energy to make the ship move, what makes the blackhole move with the ship?

You can’t push it (it eats whatever cones into contact with), and you can’t pull it (unless you’re lowering a weight into near-contact, and even that will give you a miserable acceleration).

You could use a magnetic field to pull a rotating charged blackhole, but you’ll probably be subjecting the crew to a huge EM signal… and it’s still a very heavy thing to pull. 81.84.206.158 (talk) 00:08, 6 August 2022 (UTC)
 * I was about to ask the exact same thing. How do you hold on to it? 92.6.145.235 (talk) 20:42, 16 October 2022 (UTC)