
Earth Might Have Hairy Dark Matter - kjstevo
http://www.nasa.gov/feature/jpl/earth-might-have-hairy-dark-matter
======
deanCommie
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 super-galactical? Could the rules at
such scales necessitate a new form of physics that we have yet to derive
because of the difficulty of observation?

I ask this because "dark matter" and "dark energy" always make me think of
past primitive attempts to align unexpected data to existing models of
understanding. Is it possible that they are just "echoes" or "shadows" of
concepts that exceed the very nature of "matter" and "energy"?

~~~
jahnu
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.

~~~
trhway
>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...](http://blogs.scientificamerican.com/running-ponies/catch-the-wave-
decoding-the-prairie-doge28099s-contagious-jump-yips/)

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".

The same is through the history of physics/mathematics. It takes a change in
fundamental point of view. The notion of derivative took decades of work to
develop by geniuses of that time. Imagine how physics/mathematics looked
without it.

When i look at strings theory of today i see epicycles, a very intricate and
complex system of epicycles in 11 dimensions :) We need a genius like Newton
or Einstein to again see and tell us what is behind that apparent complexity.

~~~
jstanley
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.

~~~
trhway
>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 know in
Chinese, and the task of learning a 1000 Chinese hieroglyphs scares the hell
out of me:

[https://www.thedodo.com/worlds-smartest-dog-
chaser-752002926...](https://www.thedodo.com/worlds-smartest-dog-
chaser-752002926.html)

>Maybe humans do not have the capacity to understand the complete workings of
physics.

why would it be so? So far the physics has been pretty simple (any abnormal
complexity has been usually an indication of our lack of understanding and has
been successfully cleared with time) , and even several orders of magnitude
complexity increase will fit into our brain.

Edit: to the comment below on 10% - there is a difference between 10% capacity
and 10% neurons. The fact that most of our brain is physiologically
participating while producing that little capacity most of the time in most of
the people is exactly the low efficiency i was talking about.

~~~
Ygg2
> As result we're using only like 10% of capacity of our brain.

This myth needs to die in a fire.
[https://en.wikipedia.org/wiki/Ten_percent_of_the_brain_myth](https://en.wikipedia.org/wiki/Ten_percent_of_the_brain_myth)

~~~
_kst_
It's been said (I don't know how accurately) that some people _do_ use 100% of
their brains. They just happen to be in the midst of a grand mal epileptic
seizure.

------
golergka
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.

~~~
hliyan
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.

~~~
ccozan
actually, there is something that it is not really understood: the 5.9 years
period of gravitational constant variation. [1]. Maybe the Earth is passing
through such a filament?

[1] [http://phys.org/news/2015-04-gravitational-constant-
vary.htm...](http://phys.org/news/2015-04-gravitational-constant-vary.html)

~~~
hliyan
Interesting! But... it's been 15 years since my last university level physics
course, but those error bars in the plot doesn't exactly lend lot of
confidence to the idea of a periodic pattern?

------
musgravepeter
The arxiv pre-print is
[http://arxiv.org/pdf/1507.07009.pdf](http://arxiv.org/pdf/1507.07009.pdf)

~~~
Steuard
Thanks! (I usually link to the arXiv abstract page rather than to the PDF:
[http://arxiv.org/abs/1507.07009](http://arxiv.org/abs/1507.07009) .)

------
hliyan
I find this fascinating, but still purely hypothetical, yes? Basically:

IF the observed expansion of the universe is indeed due to dark matter as we
think of it, and

IF such dark matter exist as streams, and

IF such streams mix with ordinary galaxies, and

IF the solar system is passing through such a stream

THEN Earth MAY have dark matter filaments in its vicinity.

IF we locate such a filament and send a probe, we might be able to learn about
dark matter directly.

Fingers crossed. That would be an amazing discovery.

~~~
poelzi
The universe does not expand: www.cosmology.info/newsletter/2014.05.pdf

I follow the BSM-SG model in which dark matter/dark energy is absolutely clear
what it is and how it functions. The illustration is even a bit similar to the
BSM-SG model, if you see it as the CL dimensions. Larger astronomical bodies
have their own CL space, which means they carry a bubble with them those
geometry is dependent on the body itself. This is why the photons get into a
gravitational pull on heavy bodies, time goes differently, ...

~~~
scentoni
In case this isn't immediately clear, BSM-SG is crackpottery akin to
[https://en.wikipedia.org/wiki/Time_Cube](https://en.wikipedia.org/wiki/Time_Cube)

~~~
poelzi
explain: I take logic errors or math errors seriously, everything else is just
crackpot talk.

~~~
kazinator
Do not forget errors of _fact_ (which are not logic errors).

A statement can be logically deductive, and contain no arithmetic errors; yet
be based on propositions which do not have true interpretations in this
universe.

------
geuis
First thing that occurred to me: could/would this look something like iron
filings around a magnet if the dark matter stuff could be seen? Something like
this. [http://www.google.com/imgres?imgurl=https://apex-
emovendollc...](http://www.google.com/imgres?imgurl=https://apex-
emovendollc.netdna-
ssl.com/media/catalog/product/cache/1/image/800x800/9df78eab33525d08d6e5fb8d27136e95/d/-/d-16191-14.jpeg&imgrefurl=https://www.apexmagnets.com/iron-
filings-12-ozs&h=800&w=800&tbnid=EswZ7wNlrPyluM:&docid=CyE5SHWaTnAIgM&hl=en-
us&ei=Mu9VVoC3OsivogSZwaP4BA&tbm=isch&client=safari&ved=0ahUKEwiAmI2JjKzJAhXIl4gKHZngCE8QMwh3KFEwUQ)

------
idlewords
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?

~~~
danbruc
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)](https://en.wikipedia.org/wiki/Caustic_\(optics\))

------
jussij
The good news is the idea has been put forward now.

That means, through the wonders of experimental physics, sometime in the next
10, 20, 50 years we will find out if the idea sinks or swims.

I wish the idea the best of luck, as we do need to figure out this issue once
and for all.

------
CBABIES
Dark matter seems like a misunderstood component of gravity.

The current explanations just seem ridiculous.

~~~
idlewords
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](https://en.wikipedia.org/wiki/Bullet_Cluster)
for a textbook example.

~~~
nikhilgk
Also, look at the Bolshoi Cosmological Simulation
([https://en.wikipedia.org/wiki/Bolshoi_Cosmological_Simulatio...](https://en.wikipedia.org/wiki/Bolshoi_Cosmological_Simulation)).
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.

------
anon6_
I love theoretical physics - I do get tired of all the fluff articles churned
out. It's like medical research. You'd think they've cured cancer by now.

If you google around for dark matter, you'll find sources, including nasa.gov
saying "direct proof" of dark matter has been found already. This was back in
2006.

Theoretical physicists: disprove MOND, TeVeS, Mass in other dimensions, Scale
relativity, or better yet, get better data before throwing around theoretical
speculation with such confidence?

~~~
qrendel
These types of questions seem to come up a lot, and while I'm not an expert,
here are some typical responses, from one of the last dark matter threads (in
particular, the two top replies):
[https://news.ycombinator.com/item?id=10550732](https://news.ycombinator.com/item?id=10550732)

I assume the tendency for the general public to give higher consideration to
"other explanations," relative to professional physicists who seem to lean
heavily towards the "matter" hypothesis, is lack of expertise in the current
state of research. If you don't have a lot of good evidence one way or the
other, all options seem about equally likely, so why take WIMPs more seriously
than MOND or other hypotheses? Not that considering those alternatives is
silly, but I think this might explain why this question keeps coming up even
though the physics community seems pretty focused on the dark-matter-as-matter
hypothesis.

Though whatever the answer should turn out to be, it will certainly be an
interesting development.

------
k8tte
All this "dark matter might be here and there" articles makes me feel they are
missing the point.

The article even fails to mention electromagnetism, which together with
gravity causes matter to collapse on itself, causing black holes, which is the
gravitational core of every galaxy.

Electromaginetic fields has also been dictating the galaxy cluster structures
(aka "mega structures" that has emerged since the hypothesed event we commonly
refer to as the big bang).

[http://www.sciencechannel.com/tv-shows/how-the-universe-
work...](http://www.sciencechannel.com/tv-shows/how-the-universe-
works/basically-electromagnetism-rules/)

[http://www.setterfield.org/Astronomy/Galaxy_Cores.html#elect...](http://www.setterfield.org/Astronomy/Galaxy_Cores.html#electomagnetic)

~~~
danbruc
Essentially the defining property of dark matter is that it does not interact
electromagnetically, so there is no point to consider it.

~~~
k8tte
I think you misunderstood me. I am saying the electromagnetic force can be fit
the bill where we currently are trying to squeeze in "dark matter". Please be
aware that we have not discovered dark matter, we don't know what its made of,
its properties, or really, if it even exists.

But i get it. Thinking outside of the box is frowned upon around here. Lets
all be fanboys, and fuck yea downvote me some more.

~~~
danbruc
I never vote someone down, maybe three or so exception - can I look that up
somewhere? That aside the page you linked to contains unscientific and plainly
wrong nonsense and clearly shows no understanding of physics. I totally
understand that you get downvoted for that content because it does almost the
equivalent of saying that air doesn't exist because I can't see it.

 _That being said, it must be stated first, and bluntly, that we don 't think
black holes exist. If not even light can get out, how is it the cores of
galaxies are shooting out massive amounts of x-rays and material?_

