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.
