Author Topic: I don't think we understand the gravity of the situation  (Read 5339 times)

Offline Mader Levap

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Re: I don't think we understand the gravity of the situation
« Reply #20 on: 06/18/2017 02:42 PM »
well on that note:  https://www.google.com/search?q=dark+matter+search+comes+up+empty&ie=utf-8&oe=utf-8

It is enough to search in Google.

Links to Google Search are utterly useless as "evidence" for anything*. This is "it is on internet so it must be true!" inane logic.

I guess it is why certain kind of people like them so much.

* One of reasons is that results can and will change in future. Other is that you never know what exact results they had in mind. I guess it also prevents their "evidence" from being scrutinized and criticized, since you cannot do that for something that is not provided in first place.
Be successful.  Then tell the haters to (BLEEP) off. - deruch
...and if you have failure, tell it anyway.

Offline gospacex

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Re: I don't think we understand the gravity of the situation
« Reply #21 on: 06/18/2017 04:41 PM »
The existence of antimatter was first predicted theoretically,
and later it was also directly detected experimentally,
in addition to being even artificially created.

However, the existence of dark matter has neither been
directly detected experimentally, nor has dark matter been
theoretically predicted in quantum physics
by any mathematical equations.

It is even worse than that.

If the existence of matter is naturally accompanied
by antimatter, then shouldn’t we also expect
the existence of anti dark matter?

Actually, currently known particle physics has one dark matter particle type: neutrinos. And note that they do have antiparticles.

Neutrinos have all necessary properties for DM, and the only thing which "does not fit" is that according to current knowledge, we are pretty certain neutrinos created during Big Bang had so much energy that they were relativistic for several billions of years (until expansion of space "redshifted" them to non-relativistic (but still large) velocities).

IOW, primordial neutrinos are moving too fast. They are "hot" dark matter. To explain structure formation, a "cold" dark matter is necessary. Unfortunately for neutrinos, our knowledge of Big Bang physics is surprisingly advanced by now and it is hard to come up with some weird modification of it which would somehow generate cold neutrinos.

So there must be something else too. Some DM proposals latch onto neutrinos and extend that sector of Standard Model, adding "heavy neutrinos" as DM particle. For an example of one such theory, google "neutrino Minimal Standard Model".
« Last Edit: 06/18/2017 04:43 PM by gospacex »

Offline IRobot

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Re: I don't think we understand the gravity of the situation
« Reply #22 on: 06/18/2017 05:28 PM »
Calling dark matter a "fudge factor" is not particularly useful. It's currently the model that gives the best match to a broad range of observations. If you think it's wrong, that's fine, but to replace it you have to come up with a model that does a better job. To date, the alternatives have had a lot of trouble doing that.
Unfortunately dark matter is also the most non-scientific thing about XXI's century science. Almost everybody talks about it as if it was proven to exist. And that does not leave a lot of research funds for other candidate theories.

So "fudge factor" is not that far off, as an equal counter reaction to the assumption that it is a fact.

Offline as58

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Re: I don't think we understand the gravity of the situation
« Reply #23 on: 06/18/2017 05:37 PM »
And that does not leave a lot of research funds for other candidate theories.

Could you give some examples of these ignored, unfunded theories?

Offline gospacex

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Re: I don't think we understand the gravity of the situation
« Reply #24 on: 06/19/2017 01:03 PM »
Calling dark matter a "fudge factor" is not particularly useful. It's currently the model that gives the best match to a broad range of observations. If you think it's wrong, that's fine, but to replace it you have to come up with a model that does a better job. To date, the alternatives have had a lot of trouble doing that.
Unfortunately dark matter is also the most non-scientific thing about XXI's century science. Almost everybody talks about it as if it was proven to exist.

Let's look at neutrinos again. They were proposed circa 1930 but detected only in 1956. It required 26 years. My understanding is that immediately before 1956, there was not much doubt that neutrinos do exist (please correct me if I'm wrong).

"Dark matter" became a thing around 1980 - previous observations pointing to excess mass existed for decades, but they were not sufficiently numerous and thorough to be definitive. We are now 37 years after 1980 and did not detect DM particles yet. Does not look too different when compared to historical neutrino "detection gap".
« Last Edit: 06/19/2017 01:06 PM by gospacex »

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