4 ms·

Makes me wonder, if a relativistic star passes through a decently thick dust cloud could its bowshock achieve fusion and glow brighter than the star? That would

• jcims 5y ago
  I did some napkin math and a star the size of our sun passing through intergalactic space (not a dust cloud obv) at the speed of light would only encounter about 1kg of matter per second on average. (pi1.3e9m^2 cross sectional area 3e9 m/s velocity) / (1e-27 kg/m^3 density)
  • EForEndeavour 5y ago
    Your result is only about twice my own napkin math, so it checks out. That formula as written has a typo: to get mass per unit time, multiply (not divide) cross-section-speed by mass density. Other fixes: - solar radius is 7e8 m, not 1.3e9 m - c is 3e8 m/s, not 3e9 m/s I get about 0.5 kg/s https://www.wolframalpha.com/input/?i=%28pi*%287e8m%29%5E2+*+c%29+*+%281e-27+kg%2Fm%5E3%29 https://www.wolframalpha.com/input/?i=%28pi*%287e8m%29%5E2+*...
    • jcims 5y ago
      Thanks for the correction, in either case the number is way way smaller than I would have ever imagined.