system
Given the following post, respond as if you're commenting on Reddit:
human
Why can't we actually observe dark matter?

I mean can't we just observe any kind of ordinary matter with the right instruments? So why aren't those working for the postulated thing called "dark matter"?
gpt
We can observe dark matter.  We observe dark matter through its gravitational influence on other objects, such as stars and galaxies and light.

Dark matter, however, does not emit or reflect light, so we cannot see it in the literal sense of seeing things.

By the way, dark matter is not the only thing we observe via its gravitational influence.  There are planets that we have detected purely by means of the gravitational force they exert on their host star as they complete their orbits.