4 ms·

OT but, is there any good reason why "parsecs" are used as distance units rather than "light-[time units]" ? The latter enjoys broad familiarity in the general

• lou1306 2y ago
  Not a physicist but it seems to be part of astrophysics culture, and it's a good "base measure" for interstellar space (i.e., if something is < 1pc away it's likely within your same star system). A parsec is ~3.26 lys, for context.
  • hnuser123456 2y ago
    At the stellar density in our region of the galaxy, sure. The density is hundreds of times higher closer to the center.
    • lou1306 2y ago
      Yeah it is obviously informed by our local environment, the very definition of parsec is tied to the structure of our solar system.
• vikingerik 2y ago
  It's customary in astronomy because it correlates more directly with observation. An object 10 parsecs away exhibits a parallax shift of 1/10 arcsecond.
• sulandor 2y ago
  supposedly not besides being a good shibboleth