Dark Matter!!

[Nigel (UK)]

(07-31-2014 09:45 PM)Namir Wrote:  I may have an idea that can answer the Dark Matter issue in cosmology. My idea is that the basic sub-atomic particles have an enumerated (i.e. finite) property, call it Helkitron, that connects them to other particles. Particles with the same Helkitron values see each other and interact with each other, and vice versa. Since the mass of dark matter makes up five times the mass of the visible universe, I estimate that the Helkitron property has 6 (1+5) states. This means that there are 5 more parallel universes that exists right among us!!! We cannot see them or interact with them (except for gravity) because of the Helkitron property.

Namir

I like this idea, but I'm not sure that it is consistent with observations. One of the things that dark matter is used to explain is the way in which the rotation speed of stars in galaxies changes with distance from the centre of the galaxy. This requires the dark matter to be distributed in a way that is quite different to the visible matter. For this to happen I believe that dark matter particles cannot interact strongly with each other and so the dark matter sector cannot simply be a series of copies of the particles that we can observe directly.

(08-01-2014 03:42 PM)Joe Horn Wrote:  <rant> Everybody tells me that The Scientific Method insists on empirical verification before it accepts any claims. Oh yeah? Then why are the existence of dark matter and dark energy taken seriously even though they have never been -- and never can be -- measured? I'm told, "Oh, it's ok, because their existence is deduced from proper scientific observations of OTHER things." Bad answer! That's EXACTLY the same way that the existence of the "luminiferous ether" was deduced, until the fact that it does NOT exist was proven in 1887 by the famous Michelson-Morley experiment. There are countless web pages that claim to explain why the existence of Dark Matter and Dark Energy is NOT AT ALL like the existence of the Luminiferous Ether, but they all sound fishy to me. I hold the Scientific Method in too high regard to violate Occam's Razor this way. I would rather assume that our models of physical reality are flawed, and in need of revision. After all, that is the proper way to make scientific advances, not by explaining away things with pure speculations. Dark matter? Dark energy? Unicorns and Pixie Dust! I hope a new Michelson and Morley come forward and discredit this highly unscientific fantasy. Bottom line: the scientific method never allows untestable hypotheses, but the existence of dark matter and dark energy is by definition untestable, and therefore must be rejected as a hypothesis, Q.E.D.</rant>

I'm not quite sure why you are saying these things! Dark matter isn't "accepted"; it's a working hypothesis that does a good (though not perfect) job of explaining a wide range of different phenomena, from galactic rotation curves to the structure in the microwave background. There is at least one alternative hypothesis - the modified Newtonian dynamics idea of Milgrom - which is certainly taken seriously. I believe it explains galactic rotation curves better than dark matter does, but doesn't do such a good job in other areas. Until dark matter of the right sort is definitely detected or ruled out both ideas will continue to be considered.

Dark matter is testable - it could, for example, have failed to explain the patterns in the microwave background or the distribution of galaxies in space, or it might simply fail to be detected at all. I think it is rather like the luminiferous ether in this regard - a perfectly reasonable hypothesis, until experiments that should have detected it failed to do so.

Even dark energy, which is really peculiar, is still not untestable - for example, the supernova observations that indicate that the expansion of the universe is accelerating might turn out to be wrong.

Nigel (UK)