# Astronomy (space science) explained

We don't exactly know how stars are formed. This is contested based on philosophical cosmological beliefs:

1. Mathematicians say atoms erupted out of a singular point in space very rapidly, then slowed down and drew together to form stars.
2. Religious people say God formed the universe with the stars fixed in a starting location already.

Stars fuse elements together to create light. The highest element ever recorded from a star is iron because by the time it reaches iron the atoms are so tightly bound that there's not enough room to fuse any further.

When a star doesn't have enough energy to keep fusing, it collapses. Depending on its size, it can become a red dwarf, a white dwarf, have a supernova (i.e., explode), or become a black hole.

Black holes are extremely dense objects. They're *so* dense, in fact, that even visible light can't escape it. For that reason, the only way to measure black holes is to track the stretched-out photon waves that became x-rays.

Further reading:

- [How does the earth's spinning around the sun make seasons and years?](https://ciechanow.ski/earth-and-sun/)

Obvious questions that remain unanswered:

- What's at the bottom of a black hole?