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Is dark matter’s “nightmare scenario” true?

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Re: Is dark matter’s “nightmare scenario” true?

#21

Post by habibur »

Dark matter and dark energy are like what if there was no Einstein to discover relativity in early 1900s. We later continue to discover that gravity can't explain planetary motions correctly and therefore search for any explanation.

There are more laws of Physics waiting to be discovered. At least two big ones from what we currently observe.

Re: Is dark matter’s “nightmare scenario” true?

#22

Post by ephimetheus »

miika wrote: post #7

Nightmare for who? How hard it is to admit that their equations are incorrect? Even amateur like myself can see that the dark matter is adhoc value that was calculated in order to patch the standard model. There are several better alternatives but do we need to wait until these stubborn believers have passed away until the world can move forward?

I guess the nightmare is more that it might be undetectable. There’s a real possibility that DM is real, but we hit the neutrino floor at some point without finding anything (maybe couplings are too weak).

Until there’s an actual convincing alternative, that indeed is not as apparent as you make it out to be, that would be pretty terrible for a lot of physics.

Re: Is dark matter’s “nightmare scenario” true?

#23

Post by taylorius »

miika wrote: post #7

Nightmare for who? How hard it is to admit that their equations are incorrect? Even amateur like myself can see that the dark matter is adhoc value that was calculated in order to patch the standard model. There are several better alternatives but do we need to wait until these stubborn believers have passed away until the world can move forward?

This is where I reference Mike McCulloch's theory Quantized Inertia, which predicts Galactic Rotation curves far more accurately than Relativity / Newton, without any fudge factors. (This is also where someone jumps in to inform me that he is "a crackpot", and should be ignored. FWIW QI seems like a promising theory to me, and I think it should be tested experimentally. )

Re: Is dark matter’s “nightmare scenario” true?

#25

Post by mr_mitm »

taylorius wrote: post #23
miika wrote: post #7

Nightmare for who? How hard it is to admit that their equations are incorrect? Even amateur like myself can see that the dark matter is adhoc value that was calculated in order to patch the standard model. There are several better alternatives but do we need to wait until these stubborn believers have passed away until the world can move forward?

This is where I reference Mike McCulloch's theory Quantized Inertia, which predicts Galactic Rotation curves far more accurately than Relativity / Newton, without any fudge factors. (This is also where someone jumps in to inform me that he is "a crackpot", and should be ignored. FWIW QI seems like a promising theory to me, and I think it should be tested experimentally. )

How accurately does it predict the CMB fluctuations? Or weak lensing observations? Rotation curves might have been first, but they're actually not the strongest evidence for DM.

Re: Is dark matter’s “nightmare scenario” true?

#26

Post by lkrubner »

account-5 wrote: post #11

Am I right in thinking no one has been able to detect dark matter despite decades of attempts and research? My understanding is that based on observations of what can be seen galaxies move as if there's move stuff in them?? If you hypothesis that this extra stuff is dark matter but can't detect it, how do you know it's real? How have you ruled out all the normal stuff that doesn't give off light or stuff we can't see…

Sort of, but gravitational lensing has been seen in places where there is no visible matter. If dark matter doesn't exist, then you'd have to come up with another explanation for the gravitation lensing:

https://kipac.stanford.edu/highlights/using-gravitational-le...

Re: Is dark matter’s “nightmare scenario” true?

#28

Post by superjan »

habibur wrote: post #21

Dark matter and dark energy are like what if there was no Einstein to discover relativity in early 1900s. We later continue to discover that gravity can't explain planetary motions correctly and therefore search for any explanation. There are more laws of Physics waiting to be discovered. At least two big ones from what we currently observe.

There is certainly new physics involved, the issue is more that for dark matter, the evidence points to matter that hardly, or perhaps not at all, interacts* with the stuff we are familiar with (standard model). It might be that the correct theory of dark matter is already found and debated, we just have no way to tell it from the false ones, as for all that we know, dark matter might be a shadow world of spaghetti monsters of which we only know its existence via their gravitation.

*) Except gravity.

Re: Is dark matter’s “nightmare scenario” true?

#30

Post by choeger »

My intuitive objection against dark matter is that it's basically an infinite amount of additional parameters to be fitted to the observations. Galaxy behaves weirdly? Add dark matter! It behaves as expected? It obviously has lost its dark matter! It stands to reason that for every possible observation, a particular DM configuration can be calculated.

I fail to see how dark matter could ever be falsified. The best potential replacement would be a theory that's simpler, but even then dark matter would probably explain the same observations.

The second question is: Is dark matter even matter if it only interacts via gravity? Wouldn't it be better named a property of space-time? That is, dark matter is a name for a recursive property of gravity?

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