# Sun light traveling to earth speed

H_Dog

## Main Question or Discussion Point

As light travels at X km/h (pretty fast), and Earth is 155,000,000km away from the Sun, How much would the Earth have rotated from the start of the light ray from the sun to the second it hits Earth?
Another way of explaining: Looking from Earth, how many degrees would the Sun have moved in the time the light ray left the Sun and reached Earth?
Or does it point to where the sun is actually located, not it's delayed position?
I had an answer saying "The best and probably the accurate description, is that when the gravitomagnetic components due to the spin of the sun and earth are included into the calculations, they shown that the earth is attracted towards the actual position, not the delayed one."
Is this correct?

Related Astronomy and Astrophysics News on Phys.org
Originally posted by H_Dog
As light travels at X km/h (pretty fast), and Earth is 155,000,000km away from the Sun, How much would the Earth have rotated from the start of the light ray from the sun to the second it hits Earth?
It takes about 8.5 minutes for the light to reach the Earth, so it will have rotated about 8.5/(24*60) of 360 degrees.

Or does it point to where the sun is actually located, not it's delayed position?
You're thinking of the direction of the electromagnetic attraction due to a charged body (or the gravitational attraction of the Sun). See:

http://arXiv.org/abs/gr-qc/9909087

from the article:
By evaluating the gravitational effect of an accelerating mass, I show that aberration in general relativity is almost exactly canceled by velocity-dependent interactions, permitting cg = c. This cancellation is dictated by conservation laws and the quadrupole nature of gravitational radiation.