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Earth Might Have Hairy Dark Matter

nasa.gov

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Re: Earth Might Have Hairy Dark Matter

#101

Post by jp555 »

jstanley wrote: post #43
trhway wrote: post #42

Earlier quoted context omitted.

>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…

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.

Does a human have the capacity to understand the complete workings of an Intel CPU? I doubt it.

But we augment our capacities with tools, something mice don't do.

Re: Earth Might Have Hairy Dark Matter

#104

Post by Balgair »

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…

Interesting point. Also, if you look at the time scales, QM wasn't really discovered until we could get tech to go that fast. We had to 'see' it at the 'speed' it was going, otherwise it just blurred out (not just speed but distance and many other units had to be very very finely tuned).

Perhaps with the super large, everything seems to be more static than we'd like it to be. To get a good sense of the systems, we need to let it happen for longer than we have thus far. Dark Matter is an example. We had to watch the stars to figure out they were not spinning at the right rates, and that took a long time to be certain of.

There is a balance here though. With QM it was just a few things, with astro, it is a universe of things and that takes a lot more 'eyes' to be certain of stuff.

I leave out black holes and the interface of QM and GR, because that is a hell of a lot of stuff happening really fast at really small sizes. Granted, it's the interesting stuff, but I feel we have to get real experiments going first before it is prudent to look at. That means some really big telescopes looking for really tiny variations for a really long time. Something funding bodies are not able to justify as of yet.

Re: Earth Might Have Hairy Dark Matter

#105

Post by Freaky »

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…

You'd probably be better off linking to something like this: http://www.rifters.com/crawl/?p=6116

Or this: http://rifters.com/real/2009/01/iterating-towards-bethlehem....

Less than a million neurons and Portia's interpreting complex visual scenes and making detailed attack plans.

While "we only use 10% of our brains" is clearly bollocks, the implication that our brains may not be particularly efficient for our level of intelligence doesn't seem too unlikely given the way evolution works - our brain's a crudely scaled-up pile of accidental hacks guided by endless local maxima it can't readily escape from, it'd be very surprising if you couldn't improve on it.

You might draw parallels with modern computers. All these transistors to play with, but we're certainly not using them as well as we could - we're limited by the software we want to run and know how to write using our existing tools.

Re: Earth Might Have Hairy Dark Matter

#106

Post by kamaal »

trhway wrote: post #70
pavel_lishin wrote: post #61

Earlier quoted context omitted.

> After all as a mouse says to another mouse - "no matter how hard you try you can never teach a human to understand mouse language". But mice don't say that. They can't . jahnu's statement wasn't a parable.

>But mice don't say that. check the various articles on animal language decoding. Mice and other animals do say that or similar complexity things. >They can't. That just an empty statement of belief unsubstantiated by facts. Again check the articles. In general, the "only humans have language" is simply the religious "only humans have soul" dogma in disguise.

>>check the various articles on animal language decoding. Mice and other animals do say that or similar complexity things.

You aren't stating the solution, you are stating the problem.

You didn't get the point. If all of humanity had limited capabilities to speak and express. Say we could all utter only 3 kinds of sounds namely x,y,z- due to that sheer limitation our language and written systems have to be expressed in permutations and combinations of x, y, z.

That sort of stuff works only for simple things. The moment you start venturing into any complexity, trying to express those concepts in only 3 ways will lead to verbosity and interplay that will blow up beyond practical ability to grasp, given limited resources to interpret them.

And take note if the animal has no means of recording information somewhere and check over time, keeping that level of verbosity in one's brain and workout complex physics is just out of question.

Re: Earth Might Have Hairy Dark Matter

#107

Post by kamaal »

hliyan wrote: post #12
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.

As I understand, we can detect them through their gravitational effects and not much else. If we fully account for the pulls of all the non-dark bodies in the vicinity (Earth, Sun, Moon) and then manage to measure an anomalous gravitational pull (say on a mass connected to an extremely fine sensor) that changes with the motion of the measuring apparatus, that (I think) ought to do it. Disclaimer: not physicist.

Not a physicist either. But from what I understand from Lawrence Kraus's lecture 'A universe from nothing' is they found light bending(A phenomenon similar to gravitational lensing) around a massive start cluster, the amount observed and the mass in that area was insufficient to explain how that kind of phenomenon was possible.

When looked at from the perspective of Gravitational lensing[A phenomenon that bends light] there is some kind of aether 2.0 with a mass that causes the gravitational lensing effect.

Personally I think this is the wrong approach to work with this. We know that a cause c1, was the result of phenomenon p1. We are assuming another cause c2, which is very similar to c1 MUST also be happening due to p1.

It might very well be there is a phenomenon p2 responsible for c2.

We seem to be trying to state cause(dark matter) in terms of its side effect(phenomenon similar to gravitational lensing) without understanding what it actually is.

Re: Earth Might Have Hairy Dark Matter

#108

Post by darkmighty »

yxhuvud wrote: post #77
daveguy wrote: post #58

Earlier quoted context omitted.

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.

He means the most common definition of truth is 'The best predictive model' (in the scope of the problem). I would add the principle of parsimony, truth is 'The simplest available formulation of the best predictive model'.

In both cases you cannot know that no better predictive models exists (and hence if your truth is absolute), even if you experimental error is zero (which is essentially impossible in most sciences unless you grossly overfit), since there may be unobserved phenomena as well.

Re: Earth Might Have Hairy Dark Matter

#109

Post by rthomas6 »

jacquesm wrote: post #96
rthomas6 wrote: post #74

Earlier quoted context omitted.

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

I don't think mice live for 1,000 years so there is a slight problem with your theory.

My point was that humans can pass acquired knowledge to future generations. Given enough time, we can figure out things that would take too long for any one generation to understand on their own.

Re: Earth Might Have Hairy Dark Matter

#110

Post by jacquesm »

rthomas6 wrote: post #109
jacquesm wrote: post #96

Earlier quoted context omitted.

I don't think mice live for 1,000 years so there is a slight problem with your theory.

My point was that humans can pass acquired knowledge to future generations. Given enough time, we can figure out things that would take too long for any one generation to understand on their own.

Yes, but your example is both irrational, poorly chosen and simply will not work, no matter how much time we have since it requires the co-operation of the subject which simply does not have the neural apparatus to comprehend speech as we generally understand it. So no, given 1,000 years we will not be able to teach mice French, nor Russian, Chinese, English or any other human language.

There's more to that than simply wanting it to be so, no matter how much information we can pass on to future generations.

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