Against dark matter

Vera Rubin in One Hundred Years of Rotating Galaxies (Astronomical Society of the Pacific, 2000)

"Surprisingly, we cannot yet rule out a modified gravitational potential, rather than dark matter, as the explanation of our observations. We have learned much about galaxies in the last 100 years. I think that we still have major surprises to uncover."

Pavel Kroupa, University of Bonn

"The existence of dark matter particles can never be disproven

by direct experiment because ever lighter particles, and/or ever smaller cross sections just below the current detection threshold may be postulated for every non-detection. There exists no falsifiable prediction concerning the DM particles."

John Moffat, University of Toronto, in his book Reinventing Gravity

"It may be that ultimately the search for dark matter will turn out to be the most expensive and largest null-result experiment since the Michelson-Morley experiment [an 1887 experiment that failed to find the hypothetical ether substance supposed to fill space]."

Mordehai Milgrom Weizmann Institute of Science, Israel

"Recent years have seen the advent of several relativistic formulations of MOND. These account well for the observed gravitational lensing, but do not yet provide a satisfactory description of cosmology and structure formation… [I]t may well be that none of them point to the correct MOND theory."