Lemme talk about an old theory first, then I’ll talk about dark matter.

In the late 1600s to early 1700s, people came up with an explanation on why things burn.

It was called “phlogiston”, a substance present in everything that can be burned. Burning things release phlogiston into the air, that gets eventually absorbed by plants. This theory explains why, typically:

• you can’t re-burn the ashes of something — because the phlogiston is gone
• ashes weight less than what was burned — because phlogiston has a weight
• things stop burning in enclosed spaces — because there’s a limit on how much phlogiston the air can hold
• plant matter typically burns — because plants absorb phlogiston from the air
• things that burn faster leave less ashes behind — because they have more phlogiston

It’s a single principle. And it explains so much. Truly elegant.

…except there are some corner issues. That “typically” is key here: the theory cracks as soon as you weight a piece of metal, burn it, and then weight its ashes. It’s losing phlogiston, so why do the resulting calx (metal-ashes?) weight more than the metal?

Of course, people tried to fix the theory. For example, claiming phlogiston is lighter than air, or that it had negative weight. Neither solved the problem, only flipped it.

Then some guy called Lavoisier came up with a competing theory: that burning things combined themselves with something from the air, that he called “oxygen”.

It was a dirty theory. You’re still proposing something not directly attested (in the 1700s, at least), just like the phlogiston. But now the substances combining themselves with the “oxygen” also matter — they dictate if the combination will be a gas (so ashes weight less than the burnable) or a solid (so the calx weights more than the burnable). Or if something will burn at all, even if there’s oxygen available.

And the dirty theory worked way better than the elegant theory. Because nature doesn’t give a damn about our search for elegance; we should still look for the simplest theory (otherwise our theories will be filled with unnecessary junk!), but “simplest” is not necessarily “simple”. And data is bread and butter, if your theory doesn’t explain the real world then it’s skibidi.

I do believe dark matter will be seen in the future much like we (people from the XXI century) see the phlogiston: an outdated theory of the past, caused by our lack of understanding on nature. I wish I knew the theory to replace it, but if I did I’d be publishing it, not writing about phlogiston.