Outer space…the great empty nothingness with a few big things floating around in it, right?
Interstellar space is not empty.
Between those objects we refer to as stars, planets, moons, asteroids, etc. there is a lot going on. It is a giant “soup” of atoms and molecules – mostly, but not exclusively, hydrogen and helium.
Thin, yes. But empty, no.
Connected, yes. But, how?
All of the atoms in the universe interact with all others gravitationally. Every atom exerts some gravitational pull on every other atom, no matter how great the distance between them.
And with the slightest perturbation in the randomness of the motion of all those atoms, some of them begin to congeal (“clump up”) into a gaseous cloud of molecules.
Over time, as this process continues, the “fuzzy globe” of gaseous matter gains significant particle density. As gravitation continues to pull the atoms toward the center, the mutual attraction gets stronger and stronger.
If there is the slightest spin in their coming together, which there often is, the congealing mass flattens and forms into a spinning disk with a bulge in the center.
A “vicious circle” ensues.
As the density of the central region accelerates its concentration, gas pressure rises and heat goes up. Eventually, nuclear fusion occurs and a new star is born!
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Perhaps this explains, from another perspective, the human desire to huddle together against the cold, boundaryless void surrounding our tiny planet and our separate, individual lives.