system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does the universe keep expanding if no energy can be created.

They teach in science classes that all energy is conserved and you can only transfer energy to something else, possibly making something have kinetic energy or potential energy. However, we are also taught that the universe is always expanding. Wouldn't that need infinite energy to make that possible?
gpt
Think of it this way; if you slowed down a bomb exploding, you could see all of the dust, dirt, particles, detritus, and shrapnel moving away slowly.

Now imagine being created out of that explosion. Maybe your a little fire guy living on a speck of dust and your life happens super fast. From the time your people are created until they die off thousands of fire people generations later is less than a 10th of a second.

The entire time, that bomb explosion is still happening. The parts are flying away farther and faster.

After several seconds or minutes, all the fire is finally out and all the dust has settled.

We live in the Big Bang. The explosion is still happening. The dust hasn't settled yet.