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Earth Might Have Hairy Dark Matter

nasa.gov

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Re: Earth Might Have Hairy Dark Matter

#71

Post by jerf »

jahnu wrote: post #38
deanCommie wrote: post #3

The edge of human understanding of the universe is a vague and scary place. When we dug deep below the atom level everything we took for granted fell apart. We had to invent an entirely new model of physics to make sense of our observations, which is complex and counter-intuitive (quantum mechanics) Would it be reasonable to assume that the same applies at the opposite end of the spectrum: from the sub-atomic to the…

Perhaps we don't have the capacity to understand how the universe works? I can't remember where I read it but someone made the point that no matter how hard you try you can never teach a mouse to understand French.

So I'll zig to your several replier's zags and suggest a mechanism that could potentially explain that effect. Right now we believe that the universe has an approximate spatial granularity of Planck's distance, which is ~1.6E-36, and approximate temporal granularity of 1E-43 seconds.

(Unless you can improve upon those numbers by a good 40 or 50 orders of magnitude, please don't quibble in the replies. I am aware it's not a "grid" or something, but that is the approximate resolution.)

Our best theories of the universe will have to work at that level, or even potentially below it in the case of string theory. A full theory of the universe ought to be able to describe how everything works down there. However, all the phenomena we care about and have concrete data about are literally 40 orders of magnitude bigger, at a minimum, in spatial and temporal extent.

We have proposals for how the simplest elements of the universe work. Heck, for all we know one of them may even be right. But proving that is extraordinarily difficult because of this huge order-of-magnitude gap. You'd love to be able to just plug in the theory, set yourself up a universe, and start computing, but the incredible gulf of magnitudes makes that essentially impossible. And the theories are sufficiently complicated that attempts to approximate break down in various rather distressing ways.

Even if the Great Simulator simply handed us the equations that our universe is based on, could we verify that claim?

Honestly, my guess is that with enough effort, yes... but even with the answer it could well be extraordinarily difficult. Without the answer it's even harder.

Re: Earth Might Have Hairy Dark Matter

#72

Post by fengwick3 »

trhway wrote: post #42
jahnu wrote: post #38

Earlier quoted context omitted.

Perhaps we don't have the capacity to understand how the universe works? I can't remember where I read it but someone made the point that no matter how hard you try you can never teach a mouse to understand French.

>no matter how hard you try you can never teach a mouse to understand French. humans couldn't so far teach mouse a human language. That doesn't mean that mouse doesn't have something like several thousands or tens of thousands of basic sounds and combinations of them into meaningful (for mouse) sequences. http://blogs.scientificamerican.com/running-ponies/catch-the... After all as a mouse says to another mouse - "no…

Well, the irony is that string theory IS the attempt at the elegance behind the apparent complexity of the standard model. But I agree with you that dark matter and dark energy are undoubtedly works in progress (if that's what you were trying to say)

Re: Earth Might Have Hairy Dark Matter

#73

Post by danbruc »

idlewords wrote: post #67

One thing I can't figure out from the arxiv preprint is the lifetime of these hairs, which I assume are a transient and dynamic phenomenon. Does anyone have an idea of how long a hair remains near the planet in question and retains its shape?

They are present as long as there is dark matter flowing through the earth. In essence the gravity of the earth just changes the density pattern of the stream of dark matter particles the same way a lens focuses photons in the focal point [1]. So the interesting question is how persistent the stream of dark matter particles is. Also the earth is moving all the time around the sun and the centre of the galaxy and this alone should create a continuous stream because the earth moves through the dark matter background. So the even more interesting question is how dark matter is distributed - is there a more or less uniform distribution or is it patchy and the earth alternates between moving through essentially dark matter free regions and regions filled with dark matter. Unfortunately I have no answer for that.

[1] https://en.wikipedia.org/wiki/Caustic_(optics)

Re: Earth Might Have Hairy Dark Matter

#74

Post by rthomas6 »

jahnu wrote: post #38
deanCommie wrote: post #3

The edge of human understanding of the universe is a vague and scary place. When we dug deep below the atom level everything we took for granted fell apart. We had to invent an entirely new model of physics to make sense of our observations, which is complex and counter-intuitive (quantum mechanics) Would it be reasonable to assume that the same applies at the opposite end of the spectrum: from the sub-atomic to the…

Perhaps we don't have the capacity to understand how the universe works? I can't remember where I read it but someone made the point that no matter how hard you try you can never teach a mouse to understand French.

That depends on how long the mouse has to be taught. If we had 1,000 years I bet we could do it.

Re: Earth Might Have Hairy Dark Matter

#75

Post by pierrec »

golergka wrote: post #5

This seems like something straight out of SciFi. Dark matter actually forming invisible rods that go through the Earth? Can we interact with these "hairs" if they are all around us? Can we at least detect it? It seems that all question I and any non-specialist can ask are stupid and irrelevant, but it's still so exciting to think of all the possibilities.

>This seems like something straight out of SciFi.

I really don't see why!

"He now seated me near the machine, so that it was on my right, and turned a switch somewhere below the crowning cluster of glass bulbs.

[...]

I felt the huge animate things brushing past me and occasionally walking or drifting through my supposedly solid body [...] Suddenly I myself became possessed of a kind of augmented sight.[...] Indescribable shapes both alive and otherwise were mixed in disgusting disarray, and close to every known thing were whole worlds of alien, unknown entities. It likewise seemed that all the known things entered into the composition of other unknown things and vice versa. Foremost among the living objects were inky, jellyfish monstrosities which flabbily quivered in harmony with the vibrations from the machine. They were present in loathsome profusion, and I saw to my horror that they overlapped; that they were semi-fluid and capable of passing through one another and through what we know as solids."

- H.P. Lovecraft, From Beyond

Re: Earth Might Have Hairy Dark Matter

#76

Post by TheOtherHobbes »

lmm wrote: post #57
wlievens wrote: post #55

Earlier quoted context omitted.

True, but we've come to seek more than just predictive models, we want understanding and "truth".

I'd say the opposite; we've come to realise that accurate predictions are the truest benchmark and notions of understanding can often be misleading. But supposing you're right, so what? Unless you'd prefer a more understandable but inaccurate model, there's still no better alternative to dark matter or dark energy.

You need deep understanding to develop the next set of accurate models and - perhaps - turn them into useful technology.

Re: Earth Might Have Hairy Dark Matter

#77

Post by yxhuvud »

daveguy wrote: post #58
wlievens wrote: post #55

Earlier quoted context omitted.

True, but we've come to seek more than just predictive models, we want understanding and "truth".

Until you have a better predictive model there's no way to tell what you had before wasn't the "truth".

Yes there is. Models can be disproved by empiricism without needing another model.

However, even if a model doesn't work all the time, it doesn't mean it is useless for prediction. Newtons laws is still in use, for example.

Re: Earth Might Have Hairy Dark Matter

#78

Post by nikhilgk »

idlewords wrote: post #66
CBABIES wrote: post #17

Dark matter seems like a misunderstood component of gravity. The current explanations just seem ridiculous.

You're not the first, second, or ten thousandth person to have this thought. But dark matter fits the phenomena better than any proposed modification of gravity. See the https://en.wikipedia.org/wiki/Bullet_Cluster for a textbook example.

Also, look at the Bolshoi Cosmological Simulation (https://en.wikipedia.org/wiki/Bolshoi_Cosmological_Simulatio...). Simulating the universe with the currently accepted model of dark matter successfully predicted the large scale structure of the universe. As a model for explaining observations, dark matter does hold some merit.

Re: Earth Might Have Hairy Dark Matter

#79

Post by GFK_of_xmaspast »

trhway wrote: post #45
jstanley wrote: post #43

Earlier quoted context omitted.

No but the point is a mouse simply does not have the capacity to understand French. Maybe humans do not have the capacity to understand the complete workings of physics.

>a mouse simply does not have the capacity to understand French. we don't really know what capacity is required to do it. 1PFlops? 1P neuron synapse transfers/minute? What capacity and in what units mouse brain is? Our human brain evolution has abused low efficiency size increase approach. As result we're using only like 10% of capacity of our brain. This dog knows 1000 words in human language. That's more than i kno…

Chinese characters are not 'hieroglyphs.'

Re: Earth Might Have Hairy Dark Matter

#80

Post by poelzi »

semi-extrinsic wrote: post #51
poelzi wrote: post #24

Earlier quoted context omitted.

That is exactly which brought me to the BSM-SG model. When nothing seems to fit well and the physics appear stranger and stranger, you should ask yourself: did we do everything right ? Did we do some mistakes in measurements ? Do we have some some wrong assumptions ? Turns out: yes. If you remove those wrong assumptions, you end up with a classic logical model that makes sense in very aspect. QM is just to raw for ex…

When googling "BSM-SG", the top result is a thread (by poelzi) on a cold fusion forum... Which contains this nugget: "If Quantum Mechanics describes the Atom, why does it not provide the angles atom create for chemical bindings, every chemistry student has to learn?" Really? You couldn't be bothered to sit down with an organic chemistry textbook and discover that QM is the basis for our entire understanding of how at…

Search for Basic Structures of Matter - Supergravitation Unified Theory then, its by Dr. Stoyan Sarg

QM is a theory. There are facts and theories and they should not be confused. Who we think the universe is governed is based on theories that are derived from facts. But for nearly all facts, you can find different explanations. It is not that the BSM-SG theory will not provide you with equations that are similar to QM equations, but then they differ in the interpretation for example.

Compare the Atlas of BSM-SG model with what QM provides and you will see, that the angles of the BSM-SG model are much more precise what complex chemical structures look like.

Then, you have many different theories in condensed matter physics, there are models that have no free electrons at all, and they work for their field also extremely well.

i know the spdf hybridisation model, had it @university, still it's a theory not a fact.

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