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420chan is Getting Overhauled - Changelog/Bug Report/Request Thread (Updated July 26)

WTF is up with barred spirals?

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- Sat, 23 Mar 2019 22:16:58 EST aGo2dCNY No.57596
File: 1553393818527.jpg -(6845831B / 6.53MB, 6637x3787) Thumbnail displayed, click image for full size. WTF is up with barred spirals?
Why did all of the material in those two spiral arms lose all of their angular momentum and head for the core at the same time? I bet those two hard right turns those arms tax are separated by 15-20kpc. Since so many galaxies do this, whatever is happening to this one must be pretty common.
Also check out all those galaxies buried in the background, there must be some kinda awesome galaxy cluster back there.
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George Airy - Sun, 24 Mar 2019 00:53:43 EST 457vC2+I No.57597 Reply
Man if we had a dime for every time we didn't know why a galaxy was shaped the way it was we would be sitting on a dark matter theory that actually made sense. wait what?

Seriously though I've heard its that the bar formation is a temporary phase, that essentially over time the bar shrinks as the inner arms are drawn in, but then they get drawn in so far they disconnect from the rest of the arm, forming a bar, resetting the processes.
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Viktor Ambartsumian - Sun, 24 Mar 2019 13:36:41 EST atel6lDt No.57598 Reply
>>57597
fucking galaxies man. how do they work?

how is it that we live on a tiny rock in a swirl of stars in a big vast nothingness?
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George Airy - Sun, 24 Mar 2019 18:28:27 EST 457vC2+I No.57600 Reply
>>57598
>>fucking galaxies man.
Yeah man they're some fucky shit. Did you see the thing last year about the 'dark matter galaxy' with almost no stars? Pretty creepy.

>>how is it that we live on a tiny rock in a swirl of stars in a big vast nothingness?
Because the nothingness is so vast that it contains every possible thing, including lil' ol' you & me.
>>
Margaret Burbidge - Tue, 26 Mar 2019 00:41:47 EST aGo2dCNY No.57613 Reply
1553575307033.jpg -(1737334B / 1.66MB, 1700x1167) Thumbnail displayed, click image for full size.
>>57597
if you had that many dimes together in a one space they'd explode and turn into a stack of c-notes according subrahmanyan chandrasekhar's pocket change hypothesis. heres a good way to make another 10ยข, because to me it seems that large scale gravity is a force which has to balance against cosmological expansion. at the edge of a galaxy's well there should be a position at which the infall force into the well is exactly balanced against cosmological expansion in the same way that a surfer can ride downhill on a rising wave an maintain height. beyond that radius matter is drawn away from the galaxy and becomes part of cosmic space. matter exiting the system into cosmic expanding space would be effectively tightening the balancing radius and steepening the galaxy's gravity well causing the spin up towards the outside and dark matter doesn't even need to exist.
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George Herbig - Tue, 26 Mar 2019 19:24:04 EST JdYAGiGD No.57615 Reply
>>57598

Yeah, dude. Reality is ducking gnarly, isn't it? Truth is stranger than fiction. This universe is just so utterly magnificent and complex, it boggles me endlessly.

I love staring at the nigh sky, trying to imagine the incomprehensibly large distances between objects in space, and wondering who else is out there, not on this Earth, wondering as I wonder.
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Christiaan Huygens - Wed, 27 Mar 2019 01:04:51 EST aGo2dCNY No.57618 Reply
1553663091052.jpg -(1015305B / 991.51KB, 1920x1080) Thumbnail displayed, click image for full size.
heres an image i found which completely explains galactic rotation curves in terms of an expanding rather than a static universe. given that the hubble constant is 68 meters per second per kiloparsec and galaxy is several kpc wide, the velocity necessary to maintain a circular orbit increases substantially with radius rather than falling off without any necessary dark matter present. the imaginary shell of dark matter causing apparent negative graviton doesn't exist, the apparent negative gravitation is probably the momentum left over from the pre-decoupling era or som shit like that.
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Johannes Kepler - Mon, 20 May 2019 15:46:19 EST 457vC2+I No.57713 Reply
1558381579047.png -(10359B / 10.12KB, 265x430) Thumbnail displayed, click image for full size.
>>57618
We don't know that the hubble constant is 68 mps/kpc. It could be any of the values in this image. Recent, more accurate surveys have removed the shared margin of error space between the cepheid method and the redshift method, which seems to be the main force pushing astrophysics in a direction more critical of LCDM recently. But, nothing about it has been resolved, most especially the value of the hubble constant. The most important question now is why there are apparently different values of the constant at different points in the past, or to explain some other mechanism for these data.
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Friedrich von Struve - Tue, 21 May 2019 01:55:12 EST qv1adCLC No.57716 Reply
>>57713
Why are you so positive that the Hubble constant isn't just an observational effect? maybe its all just in your imagination. Why is it a constant anyway? Shouldn't it be variable over time? Maybe the universe is static, but there are expanding and contacting parts and we happen to be in an expanding part at the moment, but in 3 billion years maybe the sky will look different?
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John Bahcall - Tue, 21 May 2019 17:02:19 EST 457vC2+I No.57724 Reply
>>57716
>>Why are you so positive that the Hubble constant isn't just an observational effect?
I'm not positive, except about the fact that I nor anyone else really knows. I'm positive I don't know that whether or not it's an observational effect, just like I'm positive no one else knows either.
>>maybe its all just in your imagination.
Well, no, because it's an empirically measurable effect. There must be some physical explanation for that phenomena. Also, the WMAP doesn't exist in my imagination, so there must be some explanation for its data, even if it turns out not to be LCDM.
>>Why is it a constant anyway?
Cause that's what we call a figure in an equation that apparently has a 'constant' value. If hubble's constant truly has a fluctuating value, it would require major refinements to hubble's law and the rest of physics.
>>Shouldn't it be variable over time?
Well, maybe. That's certainly what the present data suggest, but since we don't understand the mechanism of that change, we don't know if it's a real phenomena or, like you suggest, an observational effect. So we simply can't know with the data we have.
>>Maybe the universe is static, but there are expanding and contacting parts and we happen to be in an expanding part at the moment, but in 3 billion years maybe the sky will look different?
Yeah, maybe, man. But how are we gonna test that idea? You see how that is the real root of the problem?
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Henrietta Levitt - Sun, 26 May 2019 09:09:02 EST HUBAqrsF No.57729 Reply
on one hand it follows pretty commonly observed magnetic field line patterns, on the other isnt there a supermassive black hole at the center of most galaxies?
>>
A_Wizard !cMZsY.BCnU!!vVWR8L52 - Sun, 16 Jun 2019 15:28:59 EST 9YXtXzja No.57746 Reply
>>57724
>because I don't know, nobody does!
You've clearly fallen for the same logical fallacy of the agnostics.
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