| Topic: |
Science > Physics |
| User: |
"The Ghost In The Machine" |
| Date: |
24 Apr 2004 07:00:14 AM |
| Object: |
Dark Matter and an even darker sense of humor |
I have a dumb question.
My understanding of the Universe (such as it is) is that
it's 10% or so bright bits and 90% or so "dark matter",
which has been hypothesized to be anything from WIMPs to
MACHOs to other sorts of esoteric particles.
Suppose it's just rocks? What would be the dimming of the
starlight (on average) because of the rocks? (Would there
be a pellet size dependency?)
Would we be able to detect this, using good Earthly
telescopes? Or would we have to resort to Hubble's "big
brother", with far more light-gathering ability?
It's a thought that struck me during all this.
--
#191,
It's still legal to go .sigless.
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| User: "Old Man" |
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| Title: Re: Dark Matter and an even darker sense of humor |
24 Apr 2004 08:43:39 PM |
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"The Ghost In The Machine" <ewill@sirius.athghost7038suus.net> wrote in
message news:bimpl1-52j.ln1@lexi2.athghost7038suus.net...
I have a dumb question.
My understanding of the Universe (such as it is) is that
it's 10% or so bright bits and 90% or so "dark matter",
which has been hypothesized to be anything from WIMPs to
MACHOs to other sorts of esoteric particles.
Suppose it's just rocks? What would be the dimming of the
starlight (on average) because of the rocks? (Would there
be a pellet size dependency?)
Would we be able to detect this, using good Earthly
telescopes? Or would we have to resort to Hubble's "big
brother", with far more light-gathering ability?
It's a thought that struck me during all this.
--
#191,
OK, but then, shouldn't the solar system also consist of 90%
rock ? [Old Man]
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| User: "MorituriMax" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 12:33:28 AM |
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Old Man wrote:
OK, but then, shouldn't the solar system also consist of 90%
rock ? [Old Man]
Yeah Ghost, what about that? Good point Old Man.
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| User: "The Ghost In The Machine" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 11:00:15 AM |
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In sci.physics, MorituriMax
<newage@sendarico.net>
wrote
on Sun, 25 Apr 2004 05:33:28 GMT
<I4Iic.23246$hR1.6316@fe2.texas.rr.com>:
Old Man wrote:
OK, but then, shouldn't the solar system also consist of 90%
rock ? [Old Man]
Yeah Ghost, what about that? Good point Old Man.
Dunno. I'll admit at this point I'm simply wondering.
As it is, we're aware of the area swept out by the Sun's "solar wind",
which blew away everything to somewhere "out there" (we're starting
to discover objects like Sedna, for example). I don't know if we
have a lot of data regarding the Oort cloud. (I certainly don't. :-) )
--
#191,
It's still legal to go .sigless.
.
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| User: "MorituriMax" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 02:19:42 PM |
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The Ghost In The Machine wrote:
Dunno. I'll admit at this point I'm simply wondering.
As it is, we're aware of the area swept out by the Sun's "solar wind",
which blew away everything to somewhere "out there" (we're starting
to discover objects like Sedna, for example). I don't know if we
have a lot of data regarding the Oort cloud. (I certainly don't. :-) )
Just saw an article where they think the man made probe of ours that is close to
leaving the solar system may actually hit a much stronger "wind" once it leaves
the area of our solar system protected by the suns presence. So the
interstellar wind may be stronger than the solar wind. (may not even be a
wind-type effect at all but something different, been a few months since I saw
the article.)
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| User: "The Ghost In The Machine" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 07:00:15 PM |
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In sci.physics, MorituriMax
<newage@sendarico.net>
wrote
on Sun, 25 Apr 2004 19:19:42 GMT
<ibUic.25269$NR5.14467@fe1.texas.rr.com>:
The Ghost In The Machine wrote:
Dunno. I'll admit at this point I'm simply wondering.
As it is, we're aware of the area swept out by the Sun's "solar wind",
which blew away everything to somewhere "out there" (we're starting
to discover objects like Sedna, for example). I don't know if we
have a lot of data regarding the Oort cloud. (I certainly don't. :-) )
Just saw an article where they think the man made probe of ours
that is close to leaving the solar system may actually hit a
much stronger "wind" once it leaves the area of our solar system
protected by the suns presence. So the interstellar wind may be
stronger than the solar wind. (may not even be a wind-type effect
at all but something different, been a few months since I saw
the article.)
"Interstellar wind?" My head hurts. Then again, I don't know what's
out there, apart from nothing breathable. I'm not sure if there's
an elegant way of finding out, other than to throw a probe at
the problem -- which admittedly wasn't Pioneer 10's original
intent.
--
#191,
It's still legal to go .sigless.
.
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| User: "MorituriMax" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 10:34:34 PM |
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The Ghost In The Machine wrote:
"Interstellar wind?" My head hurts. Then again, I don't know what's
out there, apart from nothing breathable. I'm not sure if there's
an elegant way of finding out, other than to throw a probe at
the problem -- which admittedly wasn't Pioneer 10's original
intent.
Grin, that was sort of tongue in cheek there... hopefully it will survive for a
while longer, we might actually get some interesting data.. maybe it will come
back in a couple centuries looking for its creator (heh)
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| User: "The Ghost In The Machine" |
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| Title: Re: Dark Matter and an even darker sense of humor |
27 Apr 2004 01:20:16 AM |
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In sci.physics, MorituriMax
<newage@sendarico.net>
wrote
on Mon, 26 Apr 2004 03:34:34 GMT
<er%ic.24591$hR1.15405@fe2.texas.rr.com>:
The Ghost In The Machine wrote:
"Interstellar wind?" My head hurts. Then again, I don't know what's
out there, apart from nothing breathable. I'm not sure if there's
an elegant way of finding out, other than to throw a probe at
the problem -- which admittedly wasn't Pioneer 10's original
intent.
Grin, that was sort of tongue in cheek there... hopefully it will survive for a
while longer, we might actually get some interesting data.. maybe it will come
back in a couple centuries looking for its creator (heh)
One hopes it doesn't shoot at us while doing so. :-)
--
#191, -- insert random creation here
It's still legal to go .sigless.
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| User: "MorituriMax" |
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| Title: Re: Dark Matter and an even darker sense of humor |
24 Apr 2004 09:13:02 AM |
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The Ghost In The Machine wrote:
Suppose it's just rocks? What would be the dimming of the
If it was just rocks, we'd be able to see them... dark matter isn't called dark
matter because of how much light is hitting them, they are called this because
they are invisible to all methods of detection so far devised. We infer their
presence by their indirect effect on the universe "around" them..
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| User: "The Ghost In The Machine" |
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| Title: Re: Dark Matter and an even darker sense of humor |
24 Apr 2004 11:00:15 PM |
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In sci.physics, MorituriMax
<newage@sendarico.net>
wrote
on Sat, 24 Apr 2004 14:13:02 GMT
<OBuic.18783$hR1.9197@fe2.texas.rr.com>:
The Ghost In The Machine wrote:
Suppose it's just rocks? What would be the dimming of the
If it was just rocks, we'd be able to see them...
OK, another dumb question. How?
If they're not radiating energy they'd be hard to see. Of course
things the size of Jupiter would probably be radiating radio
waves, which could be picked up by such as Arecibo, if sensitive
enough. But I'm not sure if this "dark matter" is that big.
I'm thinking more along the size of granules of ice or maybe
frozen methane. (I pick methane because it's got carbon, and
carbon is probably one of the more prevalent elements generated
in stars, after helium and maybe beryllium. At least, such
is my understanding.)
dark matter isn't called dark matter because of how much light
is hitting them, they are called this because they are invisible
to all methods of detection so far devised. We infer their
presence by their indirect effect on the universe "around" them..
Yes, that I can understand. I'm just not sure why one has to go
to all this trouble to hypothesize exotic particles and strange
beasties when one could simply throw lots of grit into the works
and achieve a similar effect, barring additional research/information
on my part.
Admittedly, there is a problem, though, with my theory (such as it is);
the grit will tend to clump together into planetesimals, and the
planetesimals into planets, so now we'd have wandering planets
running around the Universe. If they get big enough they start
emitting radio waves.
My brain hurts. :-) And then there's "dark energy". Dark matter
is weird enough, but dark energy is extremely peculiar, and makes
me wonder what the Universe is doing.
(Perhaps we won't know until we go out and look? :-) A multigenerational
interstellar drive [a la Arthur C. Clarke's _Rama_ series, though
without the pyrotechnics, just lots of rocket fuel) might be the only
way to be sure.)
--
#191,
It's still legal to go .sigless.
.
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| User: "MorituriMax" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 12:33:05 AM |
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The Ghost In The Machine wrote:
OK, another dumb question. How?
The same way we "see" planets around other stars.
If 90% of the missing mass of the universe was rocks, we could walk to the
nearest star.
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| User: "The Ghost In The Machine" |
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| Title: Re: Dark Matter and an even darker sense of humor |
25 Apr 2004 11:00:13 AM |
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In sci.physics, MorituriMax
<newage@sendarico.net>
wrote
on Sun, 25 Apr 2004 05:33:05 GMT
<l4Iic.23245$hR1.2203@fe2.texas.rr.com>:
The Ghost In The Machine wrote:
OK, another dumb question. How?
The same way we "see" planets around other stars.
If 90% of the missing mass of the universe was rocks, we could walk to the
nearest star.
Well, AIUI the method by which we "see" planets is by
stellar wobble, though we're developing new techniques,
and there is one case where we're lucky and saw a star
dimming because a huge planet passed in front of it (from
our vantagepoint).
I would hope that the scientist-types have crosscorrelated:
[1] nearby star observations, to get an average momentum of matter
from maybe 100 lightyears out. (It doesn't need to be ultra
precise.)
[2] galactic observations and red shift comparisons between the
edges of the galaxy, if such are possible (as opposed to just
the entire galaxy). That way, rotation data might be obtainable
although local motions make things interesting, not unlike [1].
[3] various theoretical computations based on Earthly observations,
e.g., we know how big a carbon atom is. The only work I'm
personally aware of here is various "tweaking" of physical
constants based on observations of the average distribution of
said elements in the Universe -- and I'll admit I'm not entirely
sure how we've determined that distribution. (We know what
it is on Earth, of course, and can add in the mass of the Sun
and maybe Jupiter. Problem is: do we know what's inside Jupiter?)
--
#191,
It's still legal to go .sigless.
.
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