3 ms·
Neutrinos already move at relativistic speeds, so they aren't much of a problem. The real possible problem would be massive dark matter particles. These would
by pfdietz 2y ago
Neutrinos already move at relativistic speeds, so they aren't much of a problem.
The real possible problem would be massive dark matter particles. These would be traveling now at around 300 km/s, so a relativistic spacecraft would boost their speeds by three orders of magnitude and their energies by six orders of magnitude or higher. And, of course, the number passing through a given area in the vehicle per unit of time would also be orders of magnitude higher. If the interaction cross section is high enough (and not so high they could be shielded) then travel at that speed becomes impossible.
- rbanffy 2y agoI wasn’t thinking of the speed of the neutrinos, but the increase in encounter frequency. From a passenger’s perspective, the number of interactions per second will be much higher, not just because the ship is covering large distances and hitting more particles (although I’m not sure about that - it might cancel out) but hitting them more frequently from the crew’s perspective because of time dilation.
- pfdietz 2y agoNo large amount of time dilation is likely to be practical, even with laser propelled light sails or antimatter. And the heat load on the vehicle from running into interstellar matter would be very high. The more massive DM particle issue I discussed might be problematic even with very little time dilation.
- rbanffy 2y agoWhatever tech is used, it'll need to be something really fancy (as in new, fancy laws of physics being bent in fancy ways) to make near light-speed travel feasible. Even Alcubierre-White warp drives would create interesting problems because compressing spacetime in front of the ship would heat up whatever matter is there. Unless something miraculous happens, I don't think we'll live to see these problems in real life, but, if we do, it'll be fun to work in solving them.