system
Given the following post, respond as if you're commenting on Reddit:
human
The universe is said to be around 23% dark matter, 72% dark energy and 5% ordinary matter. If we don't know what dark matter and dark energy are, where do the percentages come from?

Edit: I just want to clarify, I'm aware of what dark matter and dark energy are. I'm by no means an expert, but I do have a basic idea. I'm wondering specifically how we got those particular numbers for them.
gpt
We can calculate things like gravity and energy density of the universe base on how the galaxies behave on a cosmic scale.  We can also calculate how much stuff is out there by direct observation.  When we look at the cosmos and look at how the galaxies behave, there is not enough material to generate the gravity (even when accounting for all the gas and dust that may obscuring it).  So there's some matter that doesn't emit light but still generates that gravity we see.  We call it dark matter, because that's what it is: dark.

There's also an expansion to the universe that suggests that the energy density is not what we can directly measure.  There's a bunch of stuff out there causing the universe to expand at an accelerated rate.  We call it dark energy, because, hey, we have dark matter already--why not call it "Dark Energy"; that way it sounds cool.

So there's like 5 times as much matter as what we can see, and like 3 times as much energy density as what can be explained by that matter.  So that's where the percentages come from: just add up all the stuff we know about that makes up the universe even if we don't yet know what that stuff is.