[qam1]

Dark Matter is to the 20th and 21st century what Ether was to the 16th and 17th.

[Doctor Stochastic]

It's more like what neutrinos and neutrons were in the 1920s to 1930s. Both were inferred to exist, but neither had been seen.

[Colinsky]

Dark Matter is to the 20th and 21st century what Ether was to the 16th and 17th.

I think it's more like phlogiston--a colorless, odorless, invisible, indetectable substance that has whatever attributes are needed to explain the observations.

The observations show that the structure and rotation of galaxies do not fit our theories of gravity. Our theories of gravity also cannot be reconciled with the successful theory of quantum mechanics.

Heaven forbid that the theory of gravity should be re-examined. It's lots easier to think up fudge factors that would save the existing theory.

Two favorite kinds of dark matter are MACHOS (Massive Astrophysical Compact Halo Objects) and WIMPS (Weakly Interacting Massive Particles). I don't see how this new evidence can be reconciled with these theories. The inferred particles are way too small to be massive WIMPS, and the direction of the signal rules out the MACHO idea of invisible clumps of stuff orbiting the galaxy.

Even though we know less about gravity than any other force in the universe, people who question the standard theory are dismissed as crackpots, while those who propose ever more intricate imaginary structures and epicycles are considered the front edge of the field.

[RightWhale]

Dark Matter is to the 20th and 21st century what Ether was to the 16th and 17th.

It might be so. Then there could be an experiment that would do to Dark Matter what Michelson-Morley did to the aether.