Random Space Qs (1 Viewer)

[bleh1234]

I have 2 queries :
1) In the surfing book, they said that a spaceship in geostationary orbit is an inertial frame of reference. Why is this so? I thought it was non-inertial because even though the spaceship is travelling at a constant velocity, its direction is constantly changing, and so it undergoes centripetal acceleration.
and
2) I see many textbooks saying that the apparatus of the Michelson-Morley experiment should be rotated through by 90 degrees because the first detection of the interference pattern isn't enough due to the fact that the phase difference might be caused by the different in length of the 2 pathways taken by the light beams. I think I'm interpreting the question incorrectly? Because what I'm thinking is that if the two mirrors are at equal distances from the half-silvered mirror, then wouldn't the light rays be travelling the same distance?
Thank you to anyone in advance!

 

[Joshmosh2]

Hi Bleh,
For 2, the distance between the HSM and the two mirrors are are always constant. What was expected to change was the velocity of the light that traveled with or against the supposed "aether winds". Once the apparatus was rotated through 90 degrees, one of the perpendicular components of the light beam would now travel with or against the aether wind, for example, if the light suddenly went against the aether wind, its velocity, as observed on Earth, would be expected to decrease. Also, the other component would remain unaffected, as it is travelling perpendicular to the aether wind, and the velocity would thus remain the same (speed of light).
It is due to the differences in the speed at which the two components are travelling relative to eachother that was supposed to cause the shift in interference pattern (and it is true that the light rays both traveled the same distance).

 

[Joshmosh2]

http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/mmexpt6.htm
You can visually see it here
Notice that when you turn the aether winds on, the red component that is moving against the aether wind would have a slight decrease in velocity, and reach the HSM, and thus detector slightly after the green component.

 

[Drsoccerball]

I have 2 queries :
1) In the surfing book, they said that a spaceship in geostationary orbit is an inertial frame of reference. Why is this so? I thought it was non-inertial because even though the spaceship is travelling at a constant velocity, its direction is constantly changing, and so it undergoes centripetal acceleration.
and
2) I see many textbooks saying that the apparatus of the Michelson-Morley experiment should be rotated through by 90 degrees because the first detection of the interference pattern isn't enough due to the fact that the phase difference might be caused by the different in length of the 2 pathways taken by the light beams. I think I'm interpreting the question incorrectly? Because what I'm thinking is that if the two mirrors are at equal distances from the half-silvered mirror, then wouldn't the light rays be travelling the same distance?
Thank you to anyone in advance!

1) considered as an inertial frame of reference to us on Earth

 

[Joshmosh2]

1) considered as an inertial frame of reference to us on Earth

Adding to this, if you were to observe a geostationary satellite on Earth, it would appear to stay in a fixed position in the sky (since the periods match), so technically, it is stationary, which satisfies inertial frames

 

[bleh1234]

Thanks a lot I get it now!