How do we determine the size of the Universe? How do we know how far away the planets and stars are? How can we measure it without ever being there? The answer, as it always is in Astronomy, is light! More Photons = More Science! Here’s my video explaining the concepts of Parallax, spectroscopic parallax, and type 1a supernovae!   Space is big, and although we can figure out how big it is, its another challenge all together to understand and comprehend its sheer size.