Dark matter isn’t based on simulations, it’s entirely observational.
We observe here that matter generates a gravitational force proportional to the amount of matter present, and we know that to an extreme degree of precision, but when we look at big things like galaxies the force required to shape and move them in the ways we observe would require more matter than we observe within them.
Dark matter isn’t based on simulations, it’s entirely observational.
We observe here that matter generates a gravitational force proportional to the amount of matter present, and we know that to an extreme degree of precision, but when we look at big things like galaxies the force required to shape and move them in the ways we observe would require more matter than we observe within them.