A Few Observations About Space

I recently re-found these notes in a notebook I hadn’t opened in a while (okay, in an Evernote notebook folder, but still!), and thought they were worth copying here for posterity. For writing science fiction, they’re good to keep in mind.

These are observations from the STARSHIP CENTURY conference in 2013, but they still hold true.

Three things I learned at STARSHIP CENTURY:
1. There’s a big difference between what’s actually possible with right-now technology, and what’s possible given some major leap we haven’t made yet. The people who deal with the “major-leap”-possible believe fervently in that condition being met and their idea being possible, so it’s important to apply critical thinking and listen for those hand-waving moments.
Like the astronaut mining venture: all this is exactly right-now possible IF we presume an established base on the moon. Well, we haven’t established a base on the moon yet, so none of this is exactly right-now plausible.
Figuring out the composition of interstellar matter is right-now possible. Designing ships that run on electricity or nuclear fission is right-now possible. Designing ships that run on nuclear fusion is not right-now possible.
2. Light speed is FAST. Like, really fast. Like, at just 10% of the speed of light you’d orbit the earth in one second. At just 3.75% of the speed of light, a dust particle hitting the windshield would impact with the nuclear force of a hydrogen bomb.
[Which means I seriously have to recalculate my ship and its speed. I think I can use charged particles as a shield to deflect dust (“deflector” shields, go figure), but in right-now-technology hard science fiction, 85% light speed is just not practical or plausible.]
We can theoretically right-now see our way to about 5-7%, which with exhaust propulsion becomes about 10-14%, but that’s all.
3. Other stars are far. Like, REALLY FAR. An Astronomical Unit (1 AU) is 100 million miles — the distance from the sun to the earth. A light year is 64,000 AUs. The next nearest star to our sun, Alpha Centauri, is 15 light years away.
It’s unlikely that there are other stars between here and there. We’d have seen them by now. But there may be habitable planets and moons that are, at their closest, about that far. It’s much more realistic to surmise that the other “goldilocks planets” that support life in our galaxy, if there are any, are on about the same position on their spiral arms as we are on ours. That’s, as the Californians would say, hella far.