> Galactic spectra, which JWST started to send back in earnest at the end of last year, are useful for two reasons.
> First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefore when it originally emitted its light.
Won't a photon climbing out of a huge gravity well have a huge redshift, thus confounding estimates of distance from us and estimated age?
> First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefore when it originally emitted its light.
Won't a photon climbing out of a huge gravity well have a huge redshift, thus confounding estimates of distance from us and estimated age?