When Galaxies Collide

We now know that our universe is filled with billions and billions of galaxies; each with billions and billions of stars in it - and often a supermassive black hole at its center devouring its stars... And when you have billions of galaxies, some will occasionally collide! As we image the universe, we see around us colliding galaxies at various stages of their collisions; we hence can reconstruct these majestic events - like a crime investigator reconstructing a crime scene. Through computer simulations, we can then model colliding galaxies and compare with observation. The first video shows a montage of a simulation superimposed with actual images from telescopes of colliding galaxies. The shear power and beauty of these cosmic dances should bring you to tears... 

Speaking of bringing you to tears, the second video is about our own galaxy's collision course with a neighboring galaxy, the Andromeda galaxy. Make sure you wrap up your life's to-do list as soon as possible...