posted by fun times

ly = light years

Stars P and Q have the same luminosity, but P is 30 ly from Earth and Q is 40 ly from Earth. What is the ratio of their brightness as viewed from Earth?

  1. Scott

    their brightness ratio is the ratio of the inverse of the square of their distances

    bP / bQ = (dQ / dP)^2

  2. fun times

    So it would be 900:1600
    = 9:16?

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