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Rule IVIn experimental philosophy we are to look upon propositions collected by general induction from phenomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other phenomena occur, by which they may either be made more accurate, or liable to exceptions.This rule we must follow, that the argument of induction may not be evaded by hypotheses.
Dunno bout dark energy but dark matter might well be rather more mundane than some would like. It could be ordinary matter in the form of brown dwarfs and maybe other large but not particularly bright objects like gas giants that are not orbiting visible stars.
So there you are. The MACHOS project DID find a significant amount of dark matter in the form of stars too dim to see BUT an unwarranted assumption was made in estimating the combined mass to 20% of required. It could very easily be 100%, or I admit very much less than 20%. The simpler explanation would be the 100%.
Unfortunately, no, ordinary matter cannot account for the amount of dark matter in the universe. The relative abundances of the light elements in the universe put pretty tight constraints on the maximum amount of "ordinary" matter in the universe. And the other forms of cosmological investigation but a much higher lower limit on the amount of matter in the universe. Any contemporary textbook on cosmology, and many contemporary general introductions to astronomy, should go over these limits.
There is no unwarranted assumption here: evidence points to a great deal of non-baryonic matter and very little baryonic matter. While the Millenium simulation may not make any claim about what dark matter is, it uses parameter values for matter density that are inconsistent with the possible amount of baryonic matter in the universe.
Really. We are THAT sure how the universe is put together?
The problem here is that MOST of the mass of our galaxy is unaccounted for - along with most of the mass of other galaxies. We should be surrounded by the stuff even if the bulk is toward the edges of our galaxy. Yet the only dark matter we have actually detected is MACHOs. It might well be inconvenient for theory but in terms of actual evidence baryonic matter is all there is. Are you telling us that if dark matter turns out to be 100% MACHOs the theoreticians won't be able to come up with a convincing explanation?
There is much more evidence for dark matter than looking at galaxies. If all the dark matter in galaxies is MACHOs then there is a serious problem in cosmology, something that could not possibly be expected.
Quote from: PhysBang on 08/08/2016 17:02:46 There is much more evidence for dark matter than looking at galaxies. If all the dark matter in galaxies is MACHOs then there is a serious problem in cosmology, something that could not possibly be expected.Err. All the evidence for dark matter involves looking at galaxies.
Please tell that to the people who won Nobel prizes for their work on type Ia supernovae. Tell that to everyone who worked on WMAP. Tell that to the people working on the Sloan Digital Sky Survey.I'm sure they'll be happy to hear about your pop astronomy.
Pop astronomy? Hoo OK um er.. so lets take a look.Type 1a supernovae..... speculative to say the leasthttp://physicsworld.com/cws/article/news/2015/oct/07/dark-matter-may-power-supernovae
WMAP.... gives a calculation for mass/ density of the universe and accounts for it thus: 4.6% atoms we can spot as stars/gas clouds & dust. 24% dark matter because the galaxies contain that much more mass than we can account for.... and 71.4% dark energy because that's how much more would be needed to flatten the universe if the WMAP data has been correctly interpreted. In short it relies totally on the galaxy evidence for dark matter. All it says is that dark matter isn't enough.
Sloan Digital Sky Survey...... an assessment of Galaxies.
If all dark matter was made of MACHOs and dust, it would be observable due to the huge quantity of it.
Dark energy is possibly due to black holes jets.
All these dark forces are confusing everything. What effect do the electrostatic and electromagnetic 3D spin forces have on galaxies?? When will the electric effects be looked into by astronomers??
Some time ago, these forces were examined as having potential at these scales and then, on the weight of evidence, rejected. Cranks continually try to make the case for these forces without, of course, actually doing the work to make the case.