3 ms·

What fraction of c qualifies as "relativistic" in this case?

• ineedasername 6y ago
  Generally it's whatever speed that forces you to account for relativity for you desired precision. However, I've seen 10% referenced as a lower limit.
  • jessriedel 6y ago
    That's generally true, but it's not meaningful in this case. If I say "One in 10,000 stars in the Milky way is a hypervelocity star moving at relativistic speeds", there is no context to provide a threshold for the magnitude of relativistic corrections that are important. (And if it's just about escape velocity, they should just say that. The Milky Way's escape velocity is 550 km/s = 0.002 c, for which relativistic corrections are extremely tiny: \gamma ~= 1.0000017.)
    • ineedasername 6y ago
      Yes, absolutely-- the general claim lacks enough specificity to fully evaluate it. Should there be a need for extremely high precision, even somewhat "slow" speeds would be considered relativistic in terms of the need to take such corrections into account.