4 ms·
Let's back-of-the-envelope this a bit... Let's say that there are 10 big interstellar rocks with a volume of 1 km^3 each that are currently within 30 au of the
by dandelany 7y ago
Let's back-of-the-envelope this a bit... Let's say that there are 10 big interstellar rocks with a volume of 1 km^3 each that are currently within 30 au of the sun (roughly Neptune's orbit). If we assume this is a good estimate of nearby galactic space, then if you chose a random 1km^3 "voxel" in our neighborhood of the galaxy, the odds that it would contain a 1km interstellar asteroid would be roughly (10 * 1km^3) / ((4/3) * pi * 30^3 au^3) ~= 3 in 10^29.
Now imagine a spaceship that travels 100 light years. It's going to pass through roughly 10^15 1km "voxels" on its journey, which means the chances of it hitting one of those 1km rocks is ~(10^15/10^29) or 1 in 100 trillion. Space is biiiig.
The real danger, though, is the smaller stuff. It's hard to know the distribution of interstellar dust size, but there are a LOT more small things than big things, and it only takes a grain of sand at relativistic speeds to cause a really bad day. If sand-sized rocks turn out to be 100 trillion times more common than these big ones, well, that's going to be a problem...
- willis936 7y agoNever tell me the odds.
- misrab 7y agoShields, duh...
- willis936 7y agoWouldn’t star trek’s polarized hull work better? Just electrostatically repel neutral objects.
- 7thaccount 7y agoI think the "polarized hull" is only in the Star Trek Enterprise prequel which takes place prior to the founding of the federation and takes place where humanity had just achieved Warp 5 and has pathetic weaponry. Every single other Star Trek show (Original Series, The Next Generation, Voyager, Deep Space 9, and the later movies) use shields as in "shields up" or "raise shields". I believe the new Star Trek Discovery should also have shields.
- willis936 7y agoYeah but shields are sci fi and were used as a storytelling device. Electrostatic repulsion is a real thing.
- Angostura 7y agoWouldn’t a grain of sand, even at relativistic speeds, Bournemouth up instantaneously with a small >tffffop<!
- simonh 7y agoIt’s impact energy would be similar to that of a bullet. The penetration power would be relatively high though due to its small size and extremely high velocity. Of course as the size of the particle goes up the impact energy goes up too. A pebble the size of a fingernail would be pretty bad news at about a million times the energy and many of them will be mostly iron.