The document calculates the deflection angle of light from a distant star as it grazes the edge of Earth as observed from the Moon according to general relativity. It uses the formula for deflection of light in a gravitational field along with known constants for Earth's mass, radius, gravitational constant, and the distance from Earth's surface to the Moon. The calculated deflection angle is 2.8 x 10-6 radians.

1. 1
Compute the deflection angle for light from a distant star that would,
according to general relativity, be measured by an observer on the Moon
as the light grazes the edge of Earth.

Solution

2. 2

3. 3

4. 4
2
3
11 24 8
2
6
We know that in connection with deflection of light in a gravitational
field,
4
---- (1)
using
6.67 10 , 5.98 10 , 3.00 10 ,
.
6.37 10 , in eq.(1), we get
GM
c R
m m
G X M X kg c X
s kg s
R X m



  


5. 5
3 3
11 24 13
2 2
9
3
8 2 6 22
2
4 6.67 10 5.98 10 159.5 10
.
2.8 10
(3.0 10 ) 6.37 10 57.33 10
m m
X X X X kg X
s kg s X radian
m m
X X X m X
s s



  