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How Can Gas Particles Stick Together to Ultimately Form Stars and Planets?

-- | July 21, 2015

Question: There is a lot of acceptance that when the gases of the universe began to join and spin because of the impact of those collisions. That would mean that all particles hit in the same direction, like using your hand to spin a basketball on your finger. When one questions this I just get blank stares as if I’m suggesting some sort of heresy. But, apart from the difficulty I have with the Big Bang being possible on it’s own (Quantum Physics suggests you need an outside force) the answers I read about the formation of planets and gravity seems absurd yet I can’t find anyone to explain it without theory and conjecture. Can someone help me. Just to make it clear what I’m asking, please help me understand how gas particles flying in every possible direction as can form into a rotating ball that turns into rock because physics itself suggests that is impossible. I use the theory that is used for the formation of planets as….

“…there was a massive cloud of hydrogen gas left over from the Big Bang. Some event, like a nearby supernova explosion triggered a gravitational collapse of the cloud, causing the hydrogen atoms to attach to one another through mutual gravity. Each individual hydrogen atom had its own momentum, and so when the atoms collected together into larger and larger clumps of gas, the conservation of momentum across all the particles set these clumps of gas spinning.”

Now that is a lot of conjecture – considering collisions from every possible direction…let alone how those hydrogen gas particles, once collected together formed everything we have on and in the planet.

— Brent

Answer: I think that the slight misunderstanding in your logic is the equate “sticking” with the gravitational attraction between particles such as atoms, molecules, and dust particles, which ultimately results in the formation of more massive objects like asteroids, comets, planets, and stars. It is not necessary for objects to collide and “stick” to each other immediately. A stable cloud of massive particles that is affected by a nearby event that “pushes” on it, such as a nearby supernova, will potentially be pushed in such a way that gravity causes objects to slowly move closer to each other and ultimately coalesce. This slow collapse of massive objects toward other massive objects ultimately builds on itself, collecting larger and larger massive objects. This ultimately is a mechanism for forming objects like planets, stars, and galaxies.

Jeff Mangum

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