/sci/ - Science & Math

>>6917510
>will a photon's wavelength change near a black hole?

Yes, gravitational dilation does changes the frequency of light. Its called gravitational redshift.

>does this redshift make it will it lose/gain energy

Yes

>does this violate the conversation of energy?

No. If I drop a ball from the top of building, does it violate conservation of energy when it falls? No... It gets potential energy from the gravitational field, and turns it into kinetic energy. Same with the photon moving through gravitational changes.

>will a photon's wavelength change from the universe expanding

Yes. They lose energy.

>doesn't this violate the conversation of energy

No. There is no conversation of energy (the way you are used to it) when space stretches in that manner. Conservation of energy is not a "first principle". It is derived and only applies to certain kinda of spaces.