Main sequence stars: A starry sky with the Milky Way galaxy (thanks to Bernd Nies) What is a main sequence star? Nine out of ten stars that you see in the sky are main-sequence stars, and our sun is one of them. (More about the sun) Most main-sequence stars probably started out as brown dwarfs, and then succeeded [...]
Atomic bomb explosions make a "mushroom cloud" - this is a fission reaction Nuclear physics is the process of getting energy from the nucleus of an atom. There are two ways to release energy from atoms: fission and fusion. Fusion happens all the time in nature, mostly inside stars because fusion needs lots of heat or gravity to get it going. Fusion works with the [...]
The Sun shining from space: nuclear fusion in action. The first fusion reactions Fusion reactions are how the first stars got started. Soon after the Big Bang, hydrogen atoms began bumping into each other and merging into one bigger helium atom. Four atoms with four nuclei - centers - mixed together into one atom with a bigger nucleus. What's [...]
Build your own model of a fusion reaction: start with a regular red lego (a proton). Wrap a rubberband around it to be the strong nuclear force. Then connect a small blue lego (an electron) to the red lego to make a hydrogen atom. Make four of these hydrogen atoms. Now imagine that your hydrogen atoms are being heated up [...]
