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Marchimedes #36198 09/18/10 06:02 PM
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I was wondering...

Dark matter is uncounted for mass in the universe. We are pretty sure it's there because of gravitational lensing. That is, look at a distant galaxy and the light from stuff behind said galaxy gets bent around it by the gravitational mass of the galaxy and the amount estimated mass in the galaxy is insufficient to account for the stuff that we see. There should be more mass. We call this dark matter, not to be confused with dark energy, which I am not fond of as shown in my space theories. Now, I've read that even in the deep vacuum of space there is on average 1 atom per cubic centimeter. Add up all the space between stars in said galaxy and you've got a good bit of mass. Knowing scientist as I seem do and their propensity to overlook the obvious I wonder if all these little atoms in the vacuum of space could be the mysterious dark matter.


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Marchimedes #36203 09/18/10 11:03 PM
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Marchi, it's been found that the distribution of galaxies coincides with the distribution of Dark Matter, according to a study published in Nature journal a few years ago. The supposed reason is the gravitational attraction of 'ordinary' matter toward dark matter. That doesn't mean there's no Dark Matter in the cosmic cavities that you mention. I imagine there is. But the view at the moment is that most of it's in the same regions as most of the ordinary matter.


"Time is what prevents everything from happening at once" - John Wheeler
redewenur #36388 10/02/10 03:15 PM
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Originally Posted By: redewenur
Marchi, it's been found that the distribution of galaxies coincides with the distribution of Dark Matter, according to a study published in Nature journal a few years ago. The supposed reason is the gravitational attraction of 'ordinary' matter toward dark matter.


Stands to reason.

Quote:
That doesn't mean there's no Dark Matter in the cosmic cavities that you mention. I imagine there is. But the view at the moment is that most of it's in the same regions as most of the ordinary matter.


Also stands to reason.

But what I was looking for is has the so-called scientists accounted for the normal interstellar matter I referred to as normal mass of galaxies?


And another question...

I'm looking for information of how long it would take to get to light speed from a dead stop at various accelerations. For instance, at 2 G's how long would it take to get to c?


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Marchimedes #36389 10/02/10 06:02 PM
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Originally Posted By: Marchimedes
But what I was looking for is has the so-called scientists accounted for the normal interstellar matter I referred to as normal mass of galaxies?

Regarding interstellar - as opposed to intergalactic - distribution of Dark Matter, I don't know what the current data is purported to suggest. A few years ago, I asked an astronomer if dark matter might affect the orbits of planets in our Solar System. His answer was no, because the Dark Matter seems to occupy the space around the Milky Way, and if there is some local interstellar Dark Matter, it's an insufficient amount to have a measurable effect. So, in other words, all (as far as anyone can tell) of the stuff within the visible galaxy is reckoned to be normal matter, with Dark Matter surrounding it and affecting the characteristics of its rotation. Since no one yet knows what DM is, it's not a good time in history to be making bold assertions about it. The research is ongoing.

http://www.solstation.com/x-objects/darkhalo.htm

Originally Posted By: Marchimedes
And another question...

I'm looking for information of how long it would take to get to light speed from a dead stop at various accelerations. For instance, at 2 G's how long would it take to get to c?

Thanks to RickB, who did the work for us...

At 1g:

99%............6.8 years
99.9%..........21.66 years
99.99%.........68.5 years
99.999%........216.76 years

You can cut those times in half by going at "2g" instead of "1g"...but you still have the same problem of the times stretching out to infinity.


http://answers.yahoo.com/question/index?qid=20090425080114AAIsYZx

I find it difficult to grasp, Marchi, since it's all about frames of reference (with more than a bit of maths to understand). For example:

"So in theory you can travel across the galaxy in just 12 years of your own time"

So the times above are as witnessed by the guys at mission control, not to anyone aboard the spacecraft.

http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html




"Time is what prevents everything from happening at once" - John Wheeler
redewenur #36390 10/02/10 06:16 PM
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Originally Posted By: redewenur
His answer was no, because the Dark Matter seems to occupy the space around the Milky Way, and if there is some local interstellar Dark Matter, it's an insufficient amount to have a measurable effect.


Go out into an open space on a slightly misty day, you will observe little or no mist close to you. In the distance, however, you will see a lot more mist, even though the mist might be evenly and widely distributed. Could it be the same with dark matter? Could it be evenly distributed throughout the galaxy, but detectable only with distance.


There never was nothing.
Bill S. #36392 10/02/10 08:21 PM
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Nice analogy, Bill, but unsupported by the data, which continues to be consistent with a halo configuration, as supported by this recent research:

http://www.solstation.com/x-objects/darkhalo.htm


"Time is what prevents everything from happening at once" - John Wheeler
redewenur #36414 10/04/10 04:26 PM
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Originally Posted By: redewenur
Since no one yet knows what DM is, it's not a good time in history to be making bold assertions about it.


Nuttin but net.

Thanks to RickB, who did the work for us...
Quote:

At 1g:

99%............6.8 years
99.9%..........21.66 years
99.99%.........68.5 years
99.999%........216.76 years

You can cut those times in half by going at "2g" instead of "1g"...but you still have the same problem of the times stretching out to infinity.

http://answers.yahoo.com/question/index?qid=20090425080114AAIsYZx


Ah, thank you. Not that long actually.

Quote:
I find it difficult to grasp, Marchi, since it's all about frames of reference (with more than a bit of maths to understand). For example:

"So in theory you can travel across the galaxy in just 12 years of your own time"

So the times above are as witnessed by the guys at mission control, not to anyone aboard the spacecraft.

http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html


Yea, I get the observer point of view deal.

Ties in with my speed of light limit too.

Thanks, now I've got yet more pondering to do...


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Okay kids, it's election time and I'm terribly busy at my political forum, where I am, by the way, a lead moderator, go figure huh? Especially at a place that is named liberalforum. See, the joke is I'm not very liberal.

Anyway, it's time to pimp that site, or my thread there actually...

http://liberalforum.org/liberalforum/index.php?/topic/22244-and-the-horse-you-rode-in-on/

It's a 120k+ view thread, lagging just a little behind this thread, which is odd, but there ya go.

And don't worry, I pimp this thread/site over there...

[quote name='teacher' timestamp='1286209627' post='1832441']
And some speed of light stuff...

http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=36414&#Post36414
[/quote]

See? All's fair.

Anyway, it's election time and if you are a liberal you need to be abused and that is just the thread for that to get done at.

It's a public service/humanitarian kind of thing.


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Now the so-called scientists are saying that there are triple the stars that they thought there was.

So much for dark matter.


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There is no acceleration, the only acceleration was the initial big bang blast.

#36812 12/10/10 07:33 PM
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Originally Posted By: stela
There is no acceleration, the only acceleration was the initial big bang blast.


Classic case.

The so-called scientists tell us that using the light from distant super novas in other galaxies being red Doppler shifted that the universe, hang on, as I say it, appears to be accelerating away from us.

New here?

Originally Posted By: Marchimedes
Now the so-called scientists are saying that there are triple the stars that they thought there was.

So much for dark matter.


I guess I should, expand (hehe) on that.

But first, I would like to say I had beer for lunch.

Anyway, again, the so-called scientists have been telling us that by using gravitational lensing that there is a large amount of mass missing from the universe.

These gents, in their genius, and in their propensity to telling us a bunch of crap to explain the half of crap that they don't know, as opposed to the other half that they make up, to get grants, you know, have accounted for the missing matter by making up "dark matter", that is, a mysterious, apparently invisible, bunch of matter we can't see.

Well, now that they have come out and said that there are, apparently, triple the amount of stars than they first thought, then that would account for all the missing mass now, wouldn't it?

See?

Like I been saying all along, these guys are making it up as they go along.

Like the "dark energy".

But then I gots that one covered.

Giddyup.

Really, stela, you should read.

-

I see you folks are ready to give me the 150k view mark.

I am well pleased with this.


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Originally Posted By: Marchimedes
I usually go by the screen name teacher.


Would that be physics or astronomy that you teach?


There never was nothing.
Bill S. #36828 12/13/10 04:46 PM
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Originally Posted By: Bill S.
Originally Posted By: Marchimedes
I usually go by the screen name teacher.


Would that be physics or astronomy that you teach?


Ha, good one.

Nah, I don't teach Jack. If fix, install and destroy stuff for a living.

I sure wing this science gig pretty well though, eh?


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Quote:
I sure wing this science gig pretty well though, eh?


Especially after a few beers. smile


There never was nothing.
Bill S. #36846 12/15/10 07:01 PM
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Originally Posted By: Bill S.
Quote:
I sure wing this science gig pretty well though, eh?


Especially after a few beers.


Nuttin like knocking back a dozen or two cold ones to help one think out of the box.


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can't have my thread here going second page.

I'm a busy and impotent man in the world of internet political debate and while I have an image or two to make about pyramid leveling and a nice rant about astro physicists lemme, for now, leave you with a joke I wrote that I so very much enjoy...


The protesters. Cairo, Egypt.

What's wrong with this picture?



Where the women at?

At home, furiously sewing emergency burkas.


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There must be some way in which emergency burkas contribute to the expansion of the Universe. smile


There never was nothing.
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Expansion/Contraction is a viable choice against the big bang. It does seems to explain the small cosmological constant. Is receiving second look due to our 25% dark mass maybe in Feynmann's 'ghost of a vortex.' And appears the 70% dark energy is the ether.

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Originally Posted By: Bill S.
There must be some way in which emergency burkas contribute to the expansion of the Universe. smile


It's posts like that that make this train wreck late.

Originally Posted By: katesisco
Expansion/Contraction is a viable choice against the big bang.


Why does it have to be against? Couldn't the contraction end up with a black hole like something that does a big bang kinda deal?

Quote:
It does seems to explain the small cosmological constant. Is receiving second look due to our 25% dark mass maybe in Feynmann's 'ghost of a vortex.' And appears the 70% dark energy is the ether.


I'm gonna need that in English please.

Maybe some pictures, that always helps.


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