More Dark Matter fun...

From Medium.com:

Dark matter has become an object for scientists that is as fascinating as it is mysterious, and whilst many cosmologists and astrophysicists firmly accept its existence there are still groups of scientists that believe that effects attributed to dark matter could be explained by modified theories of gravity.

Jolly good, stick me in the Dark Matter Sceptic Denier corner.

The only evidence for Dark Matter is that some people have tried and failed to work out the correlation between the speed at which galaxies rotate and the amount of observable mass in them, so they invented some extra mass to explain the calculation errors.

The Dark-Matter-Ists then filled their boots with $billions of funding for experiments to try and find out what Dark Matter is.

Fact is, All disk galaxies rotate once every billion years, and I'm surprised it took them until last year to work this out.

Nobody has any idea why - least of all me - but, here's a theory... maybe they just do. If a cloud of black holes, stars, dust etc didn't rotate at that speed, it wouldn't be a galaxy - it would collapse into the central black hole(s) or it would drift apart again.

In other words, there is no correlation between the rotation speed and the size, so there's no need to invent Dark Matter.