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Old 01-23-2018, 09:27 PM   #54
Johnny1A.2
 
Join Date: Feb 2007
Default Re: Accumulators: A concept for GURPS Spaceships

Quote:
Originally Posted by YankeeGamer View Post
That is more than "Pretty good." But Kinnison's ships still had accumulators beyond just power plants. IIRC, they even had them when total conversion was only used as an exciter for "Cosmic Power Screens," a starkly amazing power supply.
Incidentally, the 'cosmic energy field' that Smith's characters tap into in those stories is 100% real. We call it 'starlight'. :lol:

Smith slides that one through by combining two facts and waiting to see who noticed. As he has a character note, any given star pours out the equivalent of at least hundreds of thousands of tons of mass converted into energy per second, there are billions of starts in a galaxy and billions of galaxies, so that energy is flowing out across the universe all the time.

Of course, that energy fills a universe so big that the energy per unit volume is starkly miniscule, unless the volume is at least many AU on a side and contains a star. So for the cosmic energy power systems to work, the intake volume for the fields must be starkly enormous, probably light-years across per ship, and efficiency must be low, so the fields have to be even bigger. (The ships don't black out the stars, after all, except by occultation.)

Now, if you can spread a spherical intake volume 100 light-years in diameter across galactic space, and soak up, say, .01% of the energy in that volume for use, and there are (let us say) about three thousand stars in the volume, (assuming a star for every 168 cubic light-years, which is one figure I've seen for local stellar density around Sol), and if we then assume for convenience that these stars are class M dwarfs like Proxima (most stars are), then we get (.0001* 3000 stars * 680000 tons (Proxima emits about .17 of Sol's output, which comes to about that) of matter converted per second)*, which gives our cosmic-energy-powered ship about 500,000 petawatts to burn.

Not bad for starlight, if you can just make your intake-field 100 light-years wide...

OTOH, if your intake fields are limited to mere AU rather than light-years, cosmic energy will work about as well as you'd expect an engine powered by starlight to work.

*ADDENDUM: I realized after I signed off last night that I had left out a factor, I was calculating based on the tons per second conversion rate in the stellar interiors, so to make the outcome correct I need to multiply by 3600, so instead of 500,000 petawatts, it's actually not quite 2 billion petawatts...
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Last edited by Johnny1A.2; 01-24-2018 at 09:14 PM.
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