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No Dark matter needed (mind blown)

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#1 Adun

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Posted 09 August 2019 - 03:03 PM

Nature published an interesting paper with a theory that uses entropy to explain the galactic phenomenons (such as edge stars moving fast, or "missing" energy/mass) that had originally being explained via dark matter.

Here's the paper:
https://www.nature.c...598-019-46765-w

Here's a secular, more digestible version for mortals:
http://theconversati...research-121017

I'm not a physicist, but what I could grasp did blow my mind.
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#2 fcathell

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Posted 09 August 2019 - 03:31 PM

I would have to agree that this is a more elegant and simpler solution to the galactic motion/shape problem, but would be harder to test than dark matter.  I do have a degree in physics and try to follow the arguments and research on this problem (and others) and I have always thought that "dark matter" was an easy, ad hoc solution to a phenomena that has a more simple and subtle solution. Nature usually adopts the more simple solution (Occam's Razor).

 

Frank

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#3 Astrojedi

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Posted 09 August 2019 - 03:49 PM

Still a long way to go. I don't think it is appropriate to call this a theory, more like a hypothesis. But very fascinating nonetheless. I wonder how you empirically test it.


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#4 Simcal

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Posted 09 August 2019 - 10:39 PM

Very interesting.  Thanks for sharing.


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#5 Adun

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Posted 10 August 2019 - 08:59 AM

Trying to understand better, this part caught my attention:
 

The stars in the galaxy are simply choreographed by an entropic force to line up into a pair of such spirals to maximise entropy.

 
Made me wonder about that "entropic force" concept. The paper says it doesn't introduce a new form of physics, but I'd never heard of "entropic force" before.
 
So far, the most digestible explanation I've found comes from Wikipedia (worth reading!). Here's a small subset, but if you're interested I recommend you read the Wikipedia link for the examples of entropic forces in action:
 

In physics, an entropic force acting in a system is an emergent phenomenon resulting from the entire system's statistical tendency to increase its entropy, rather than from a particular underlying force on the atomic scale. The entropic force can be considered as an emergent of the .... mutual influence of open thermodynamic systems on each other by means of transferring information about their states, changing their entropies and translation of these systems into more probable conditions.

 

The entropic interaction is not a consequence of existence of some entropy charge and a field accompanying it. It should not be referred to as a distribution of the entropy in the space. Entropy interaction reflects only an “order” and “structure” of the space, the state of the space and physical systems in it and, ultimately, affects the energy, behavior and evolution of such systems as well as the space as a whole.

 

The entropic interaction results in the alteration of symmetry, free energy, and other characteristics of the physical system.


Despite the convincing examples and confident wording, this "entropy interaction" seems to me like a work-in-progress thermodynamics interpretation of everything physics. Which is cool, and has quite a lot of potential. Emergent behaviors are observable (so, real), and perhaps studying new ways to explain them might shed light on things in ways reductionism hasn't been able to. It's very refreshing from the casual-amateur science reader perspective.


Edited by Adun, 10 August 2019 - 09:16 AM.


#6 Simcal

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Posted 10 August 2019 - 09:10 AM

Sorry officer, Entropy made me do it.  twitch.gif

 

Personally, I feel Entropy is singling me out for some reason...  

 

I wonder if there is a limit to the speed of Entropy, and if so, what happens when you're travelling at or close to it..  hmmm..


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#7 Todd N

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Posted 10 August 2019 - 02:15 PM

I had to bookmark this one. This idea may fit into some more recent evidence that some galaxies seem to be missing dark matter based on velocities of globular clusters. Is it because they may have smaller central black holes/smaller galactic entropy?


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#8 llanitedave

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Posted 11 August 2019 - 11:06 AM

Sorry officer, Entropy made me do it.  twitch.gif

 

Personally, I feel Entropy is singling me out for some reason...  

 

I wonder if there is a limit to the speed of Entropy, and if so, what happens when you're travelling at or close to it..  hmmm..

Hmmm, I think some of us are already there.


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