Can I ask guys, how does the sun "burn" without oxygen... NASA has to do a funny mix of chemicals to get fire in space. I just couldn't figure a reason out. I know it's gasses but ultimately oxygen is needed for fire.
Sorry if I seem a bit retarded.![]()
It doesn't burn at all, really. It's basically a very large nuclear bomb continually exploding, using hundreds of tonnes of fuel per second. Hydrogen atoms are rammed together so hard by temperature and pressure that the forces repelling them are overwhelmed and they fuse into helium atoms. Incomprehensible amounts of energy are "spare" to the resulting helium atoms and radiate away. Seriously incomprehensible - if I remember correctly, one second's energy output from the sun is more than the energy usage of humanity in a hundred million years.
In case you're wondering why this mega-bomb doesn't violently disperse all over the place - the force outwards is balanced by the force inwards caused by the mavity of the sun.
This is fine until it uses up its fuel. It will then collapse under its own mavity, which will increase the pressure at the core enough to fuse heavier elements, which will make the outwards force greater than the inwards force, causing it to balloon out into a red giant and destroy much of the solar system. Which won't happen by 2012
