Rømer calculated that the eclipses were observed 17 minutes earlier when Jupiter was in opposition compared to when it was close to conjunction. This was attributed by Rømer to the finite speed of light. From Rømer’s data, compute the speed of light, first inAU min−1, and then inm s−1.
In the 1670s, Ole Rømer observed eclipses of the Galilean satellite Io as it is plunged through Jupiter’s shadow once per orbit. He noticed that the time between observed eclipses became shorter as Jupiter came closer to the Earth and longer as Jupiter moved away. Rømer calculated that the eclipses were observed 17 minutes earlier when Jupiter was in opposition compared to when it was close to conjunction. This was attributed by Rømer to the finite
When earth and Jupiter is in the position of opposition and conjunction then the Speed of light is the ratio between the distances from the earth to the Jupiter, to the difference in times taken by light to reach the earth in these two situations.
Here is the difference in the distance from the Earth to Jupiter when it is at opposition and conjunction, and is the difference in time taken by light in these two situations to reach the Earth.
Orbital radius of the Earth = 1 AU
Orbital radius of Jupiter = 5.2 AU
At opposition, distance between earth and jupiter is
(5.2 - 1) AU = 4.2 AU
At conjunction, distance between them
(5.2 + 1)AU = 6.2
so the difference in the distance in these two positions is
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
