(via Sabine Hossenfelder) Is the universe really infinite? Or could it close back on itself like a sphere? If it’s infinite, how can it expand? And is it true that there might be copies of you in it?

This NASA/ESA Hubble Space Telescope image features the spiral galaxy Messier 77, also known as the Squid Galaxy. CREDIT: ESA/Hubble & NASA, L. C. Ho, D. Thilker. Get the Popular Science daily ...

Modern cosmology reveals a universe expanding uniformly without a spatial center or edge. The Big Bang wasn't a localized explosion but a simultaneous ...

Whenever we look out at the Universe, no matter how powerful our tools or how clever our techniques, there’s always a limit to what we’re capable of observing. No photons, or quanta of light, can be ...