# QuestionIs Gravitational time dilation due to gravity?

Page 2 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.

#### Greenlight

If you were to stop the shaft at one end from rotating, eventually everything would catch up and it would look straight.
lets point the rod at the Sun

the time dilation is ~1 min per year at the surface of the sun.

lets say i rotate the shaft at 60 rpm

after one year there should be 60 winds in the rod?

If you fixed a laser to the shaft and shot a pulse of light down the shaft would it follow that winding? (Anyone at any location would see their area perfectly straight.)

would the path of the light depend on the duration the rod rotated?

if you rotated it for another year would the light path be different and have twice the windings in it?

#### billslugg

Yes, there would be 60 turns. Do it for another year and there would be 60 more turns. The light would not follow the helix, the light would come straight at us, only taking 8 minutes.

#### Greenlight

Yes, there would be 60 turns. Do it for another year and there would be 60 more turns. The light would not follow the helix, the light would come straight at us, only taking 8 minutes.
i guess im caught up on the "Anyone at any location would see their area perfectly straight."

after a million years there will be 60 million winds. yet still look straight?
if the lazer is fixed and rotating with the shaft but doesnt follow the helix , how can both look perfectly straight ?
light travels in a straight path and any location would see their area perfectly straight.

Last edited:

#### Greenlight

I think i would measure both ends at the same RPM. and if someone was near the Sun they would measure both ends to be the same but faster than my measurement. The only Helix seen would be that from the 8 min SOL trip. And that light would follow that helix.

#### billslugg

I think I got it wrong. The amount of twist in the rod would be limited to that which would occur due to time dilation ONLY during the amount of time it took for the 8 minutes it takes for light to get to us from the Sun, which would be about 0.3 degree. It would remain constant and not increase as time went on.
My original statement that the twist would continue indefinitely would only apply if there was a black hole at the far end of the rod, with infinite gravity at the event horizon.

Replies
34
Views
1K
Replies
35
Views
2K
Replies
14
Views
2K
Replies
0
Views
1K
Replies
5
Views
629