Sun light traveling to earth speed

In summary, the Earth would have rotated about 8.5/(24*60) of 360 degrees from the start of the light ray from the sun to the second it hits Earth. This is due to the cancellation of aberration and velocity-dependent interactions in general relativity, which is dictated by conservation laws and the quadrupole nature of gravitational radiation. The quadrupole nature means that the source's quadrupole moment has to vary in time in order to emit gravitational radiation.
  • #1
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?
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?
 
Astronomy news on Phys.org
  • #2
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
 
  • #3
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.

what does quadrupole nature of gravitational radiation means[?] [?]
 
  • #4
what does quadrupole nature of gravitational radiation means

It means that the quadrupole moment of the source has to vary in time in order to emit gravitational radiation.

(A body pulsating in and out spherically, has a time-varying monopole moment. No gravitational radiation -- no electromagnetic radiation from a monopole, either. Two bodies oscillating closer and farther from each other along a line has a time-varying dipole moment -- this would radiate electromagnetically if they were charged, but not gravitationally. But a body being stretched or squeezed asymmetrically, or two bodies orbiting each other, or things like that -- they all have time-varying quadrupole moments and radiate gravitationally.)
 

1. How fast does sunlight travel to Earth?

The speed of light, including sunlight, is approximately 186,282 miles per second or 299,792 kilometers per second. This means that sunlight travels from the sun to Earth in about 8 minutes and 20 seconds.

2. Does sunlight travel at the same speed all the time?

Yes, the speed of light is considered to be a constant, meaning it does not change. However, factors such as the medium through which it is traveling can affect its speed, but in the vacuum of space, it travels at a constant speed.

3. How long does it take for sunlight to reach the surface of Earth?

Since the Earth is approximately 93 million miles away from the sun, it takes about 8 minutes and 20 seconds for sunlight to reach the surface of the Earth. This is because of the distance the light must travel.

4. How does sunlight travel to Earth?

Sunlight travels to Earth in the form of electromagnetic radiation, which is a type of energy that can travel through the vacuum of space. This radiation includes a range of wavelengths, including visible light, ultraviolet light, and infrared light.

5. Why does sunlight take 8 minutes and 20 seconds to reach Earth?

The speed of light is constant, so the time it takes for sunlight to reach Earth is determined by the distance between the sun and Earth. Since the sun is about 93 million miles away, it takes about 8 minutes and 20 seconds for the light to reach Earth at its constant speed of 186,282 miles per second.

Similar threads

  • Astronomy and Astrophysics
Replies
15
Views
1K
Replies
17
Views
2K
  • Astronomy and Astrophysics
Replies
27
Views
2K
  • Astronomy and Astrophysics
Replies
1
Views
1K
  • Astronomy and Astrophysics
Replies
9
Views
2K
  • Astronomy and Astrophysics
Replies
16
Views
4K
  • Astronomy and Astrophysics
Replies
5
Views
962
  • Special and General Relativity
Replies
18
Views
2K
  • Astronomy and Astrophysics
2
Replies
46
Views
9K
Replies
2
Views
422
Back
Top