For everyone who isn't an astrophysicist, and ESPECIALLY for everyone who is:

1-Without spectral lines, you aren't doing spectroscopy.
2-And without spectroscopy, you cannot reliably measure or confirm a galaxy's redshift, distance, and age.
3-Come back when you have a spectrum. https://t.co/NTZ5x1xZl5

— Ethan Siegel (@StartsWithABang) July 21, 2022