The conversation between human and AI assistant.
If universe expands without limit is there infinite potential energy that transforms into kinetic energy (of expansion) all the time?
That's fascinating. Can you tell me more about redshifts?
Sure. When light travels through space, its wavelength is stretched if the space it's traveling through is expanding. This stretching increases the wavelength and decreases the frequency of the light, producing a redshift. By studying the redshifts of distant galaxies, astronomers can measure the rate of expansion of the universe.