If a fire burned a large part of a medieval city 1000 years ago, approximately how far out in space has some of that light now reached? (Note to instructors: This question must be modified yearly.) A)1000 × (3 × 10⁸) m = 6.04 × 10¹¹ m B)1000 au C)1000 ly D)1000 pc

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The speed of light is approximately 3 × 10^8 m/s. In one year, light travels about 9.46 × 10^12 km (or 9.46 × 10^15 m). Therefore, in 1000 years, light would have traveled 1000 × 9.46 × 10^15 m, which is equivalent to 1000 light years. Choice A is incorrect because it calculates the distance in meters, which is not a typical unit for measuring astronomical distances. Choice B and D are also incorrect because they are units of distance used in astronomy, but they are much larger than the distance that light from a medieval city would have traveled in 1000 years.

If a Fire Burned a Large Part of a Medieval