Did scientists at some point believe that everything is made out of atoms? Or were atoms always accompanied by other "elementary particles"? I myself did not realize that there existed other "elementary particles" besides atoms until quite recently. I assumed that both solid objects, liquids, th...

With Big Bang, one would expect distribution of mass be somewhat uniform but we have galaxies that has billions of stars and there are huge distances between galaxies? Why is there is so much emptiness between galaxies? Like nearest galaxy is 25,000 light years from the sun. Why is there so muc...