Electromagnetism and Light Questions

[appplejack]

Hello,
I want to know the right answers to these questions.
I will try to state my answers but I want to know if they are right or wrong.
Thanks.

Homework Statement

1.Does the Sun's mass decrease due to its radiating electromagnetic waves?
2.Does the speed of a light beam change as it travels away from the surface of the Earth? Ignore the Earth's atmosphere.

Homework Equations

The Attempt at a Solution

1.The sun gives off radiation and energy. Hence yes. (I'm not quite sure but that's the best answer I could come up with)
2.No, light has no mass. If the Earth's atmosphere is ignored. It wouldn't make any difference in the outer space.

 

[Hells]

1. The sun's mass decreases when it fuses lighter elements into heavier elements (and thus giving off radiation). I think it's on the order of 0,4% of the mass that gets converted into energy when 2 hydrogen fuses to helium, but don't quote me on it,

2. if the Earth's atmosphere is ignored then no, the speed of light in a vacuum is always the same, C. The Earth's gravity would however redshift the wavelength of the light.

 

[appplejack]

Thanks hells

For #2. How does the gravity affect the wavelength of the light? Does that mean a bending of the light?