Down in the dark matter lab


#1

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#2

I reckon they’ll spend another 20 years searching.
My guess is on some form of Modified Newtonian Dynamics.


#3

Not really “radiation quiet”, since they are surrounded by potassium, which has a “strong” beta/gamma emitter, 40K. It is just more like being exposed to a steady strong hum rather than a cacophony of voices – which makes it easier to ignore.


#4

There are significant phenomena that can’t be explained with MOND. Notably, we can see two galaxies that collided recently, and their dark matter halos kept on moving, so we can see (through gravitational lensing) the dark matter halos, in different locations than the normal matter of the galaxies. Here’s a good summary:


#5

I would say that they are looking for stuff with higher energy than the K-40 emissions. If the background is below the energy threshold of the detectors, they are all okay. With cosmic radiation one can get quite extreme energies, with radioactive decay they are capped and often with well-defined bands easy(ish) to subtract from the results.


#6

Dark matter comes from the Nether - the only reason to mine that deep is redstone, and the occasional diamond.


#7

I agree that MOND is a fallible theory, New Scientist ran a rather good article on a different take on the theory a few months back (too late to look through a stack of magazines now), the name was similar because it essentially modified ND at larger scales, but took a different tack.
Newtonian Dynamics rest on two major assumptions; Homogeneity and Isotropicity.
The CMBR features in several cosmological theories, and with the ‘Axis of Evil’ now apparent, it’s not to be relied on as such a crucial witness.
Galactic Rotation Curves? That’s a mystery. From what we measure, the stars on the edges are travelling the same speed as the stars near the centre, yet to view a spiral galaxy, it seems apparent that the arms are being ‘dragged’ behind as the stars in the centre speed up. Surely the spiral matches the rotational direction. I may be wrong.
The Bullet Cluster is an anomaly because of the difference in the calculations between the visible mass and the result of the equations used to calculate the lensing effect. These are ND equations. I’m not anyone to call them wrong, but others more qualified than I have pointed out that if gravity does behave differently at different scales then those equations would need adjusting.
Ditto Large-Scale Structure Formation.
I don’t mean to sound dismissive. Maybe I just hope that our universe is vastly bigger and older and stranger than our knowledge can see yet.
Late. Stoned. Tired.


#8

Can we get some more pictures please? Lots more! This is an amazing lab. Let see it all. Please?


#9

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