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It seems easy to imagine a universe in which dark matter, particles or otherwise, have literally no interactions with regular matter except via gravitation. Al
by angiosperm 3y ago
It seems easy to imagine a universe in which dark matter, particles or otherwise, have literally no interactions with regular matter except via gravitation.
All the efforts to spot such an interaction seem to be based purely on wishing that it is not true, so that fancy expensive detectors can defensibly be promoted and somebody might get a prize. It seems of a piece with string theory. Maybe astrophysics, like particle physics, has lost its way, and needs to return to investigating phenomena that answer to experiment. Solar photosphere physics has yet to be elucidated in any detail. Jupiter's liquid-electrolyte moons orbit well within its magnetosphere. And planetary nebulae favor a long axis parallel to the galactic plane. Lots of crunchy physics has yet to be done, even without descending to low-status solid-phase phenomena.
On a completely different note: why does the author think a dark star would necessarily explode before turning into a black hole? A rotating pair of black holes seems like an efficient way to sweep up billions of solar masses of perfectly serviceable mass, and dynamical friction with it seems like a nice way to bleed off momentum.
- wswope 3y ago> It seems easy to imagine a universe in which dark matter, particles or otherwise, have literally no interactions with regular matter except via gravitation. Very much a valid hypothesis https://en.wikipedia.org/wiki/Sterile_neutrino https://en.wikipedia.org/wiki/Sterile_neutrino
- mikhailfranco 3y agoNeil Turok has recently proposed cosmological models based purely on the existing Standard Model with sterile right-handed neutrinos. No new forms of Dark Matter required. One RH neutrino must be massless, and another must be 4.8 x 10^8 GeV. https://arxiv.org/abs/1803.08930 https://arxiv.org/abs/1803.08930
- ssivark 3y ago> All the efforts to spot such an interaction seem to be based purely on wishing that it is not true, so that fancy expensive detectors can defensibly be promoted and somebody might get a prize. That's incredibly short-sighted. There are many other falsifiable hypotheses and due diligence directs us to make measurements to test those hypotheses. More generally, it makes zero sense to assume the worst case that cannot be ruled out and use that as an excuse to not pursue science. For example, it is impossible to "falsify" superluminal/nonlocal influence -- and not being able to screen for that renders the whole scientific process fundamentally useless (because there could always be something happening in a neighboring galaxy that is influencing your experiment -- how do you rule that out or control for it?). We simple continue doing science with the optimism that the the universe is not perversely adversarial to our attempts to understand it (and give that optimism fancy names like Occam's razor).
- dventimi 3y agoWell put
- angiosperm 3y agoIt makes plenty of sense to spend on a multitude of cheap experiments in place of vanishingly few super-expensive ones, and on a multitude of disparate, poorly understood phenomena instead of hammering away at just one.
- dventimi 3y ago"Plenty of sense" is a subjective measure that can't be quantified. A person could just add easily state that it makes plenty of sense to concentrate some resources on a few or even just one line of inquiry, because of the perceived payoff. Nobody would be in a position to tell that person they're wrong.
- angiosperm 3y agoDollars have always been strictly quantitative. A dollar spent on experiment A is a dollar not spent on experiments B through Z.
- dventimi 3y agoI was talking about the value of the outcomes.
- angiosperm 3y agoYou miss the point that the value of the outcomes correlates poorly with the expense of the experiment. Therefore, a hundred cheap experiments promise a hundred times the value of one expensive experiment. Compared to dark matter detection experiments, an infinitely greater value, as against the conspicuously zero denominator.
- 3y ago
- dventimi 3y agoNobody has a perfect understanding of which phenomena won't answer to experiment, not even you.
- angiosperm 3y agoThat is strictly true. However, it is not hard to gauge which phenomena are cheaper to experiment on. I would rather see a hundred independent phenomena pursued than just one. Since significance correlates so poorly with cost, odds favor more results.