Friday, May 7, 2021

Sabine Hossenfelder Evolves on Dark Matter

 

At her blog, Backreaction, Sabine Hossenfelder once again addresses the nature of dark matter. Is it a particle or is it a modification of gravity? Her latest conclusion?

So, the conclusion that I have arrived at is that the distinction between dark matter and modified gravity is a false dichotomy. The answer isn’t either–or, it’s both. The question is just how to combine them.

This isn’t news to me. I’ve been saying for years that dark matter and modified gravity are the same thing (see here, here, here, here, here, and here). What Sabena and her colleagues don’t know is that this phenomenon is a remnant of inflation. Only a small part of the oscillatory energy at the end of inflation decayed into standard model particles. The rest is still there in space, where it causes curvature and mimics matter, although it isn’t matter. You can find a paper here that explains how spacetime curvature without matter can look like space with matter.

So when will physicists learn what dark matter is? I don’t know. Maybe never. They certainly won’t learn it from me because they get very angry and refuse to listen when a nonphysicist tries to tell them anything.