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Is dark matter’s “nightmare scenario” true?

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

#11

Post by account-5 »

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 at the distances we're looking over? Like planets, rocks, dust, etc. Couldn't that stuff, which to my mind there would be vastly more of than stars, make up the extra gravity?

I'm aware I might be talking complete shit because I'm completely ignorant of the detail here. I would love an understandable explanation as to why that's wrong.

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

#13

Post by dotancohen »

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?

One funeral at a time, as the saying goes.

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

#14

Post by whoIsYou »

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?

science advances one death at a time. not the only domain in which the current experts and holding things hostage

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

#15

Post by negativelambda »

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…

> Am I right in thinking no one has been able to detect dark matter despite decades of attempts and research?

Yup [1]

> My understanding is that based on observations of what can be seen galaxies move as if there's move stuff in them??

Yup [2]

> If you hypothesis that this extra stuff is dark matter but can't detect it, how do you know it's real?

It produces certain effects in various different enviromennts or domains, which lends more support to that hypothesis. By certain different domains, I mean like Galaxy and cluster dynamics, gravitational lensing around galaxies and clusters and the precise fluctuations seen in the cosmic microwave background, these are all very different regimes but all seem to support the hypothesis of extra mass which is not interacting electromagnetically.

> How have you ruled out all the normal stuff that doesn't give off light or stuff we can't see at the distances we're looking over?

There are research efforts to look for exactly this kind of stuff; Massive compact halo object (MACHOS). However they don't see enough of it to account for the observations we see in galaxies and galaxy clusters. [3]

[1] https://lss.fnal.gov/archive/2022/conf/fermilab-conf-22-180-... [2] https://en.wikipedia.org/wiki/Dark_matter#Observational_evid... [3] https://en.wikipedia.org/wiki/Massive_compact_halo_object#De...

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

#16

Post by exmadscientist »

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…

I hate to be that guy, but many of those points are exactly the subject of this article.

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

#17

Post by heisenzombie »

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 think every physicist on the planet would love a nice elegant model of gravity that explains away “dark matter” observations. The next layer after Newton and Einstein. Clean and simple.

… but that’s just proven to be very very difficult. Evidence for dark matter comes from a wide range of observations, and while it’s pretty easy to come up with relativity replacements that could explain things like rotation curves nicely… other observations, from lensing and colliding galaxies like the bullet cluster are, just, well, messy.

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

#18

Post by exmadscientist »

dotancohen wrote: post #13
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?

One funeral at a time, as the saying goes.

There are many good reasons to think that dark matter is a good solution to certain cosmological problems. There are also a few good reasons to think that dark matter is total BS. It is a genuine open question. No theory in this area is a good fit for all available evidence.

This is not a case of "progress by funeral" like, say, the Alzheimer's situation also on today's front page. The linked article is a good summary.

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

#19

Post by mr_mitm »

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?

An amateur seeing something that almost no respectable cosmologist can see is a red flag. It's not that simple.

Pretty much the only alternative is MoND, and judging by the how well it fits the observations, it's not better.

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

#20

Post by boxed »

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?

All modified gravity theories are falsified by astronomy as far as I know. There are galaxies out there without dark matter halos for example. Or where the dark matter halo is not centered around the core. This alone shuts down modified gravity.
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