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420chan is Getting Overhauled - Changelog/Bug Report/Request Thread (Updated July 10)
The shape of Galaxies. Ignore Report Reply
Nicolaus Copernicus - Sun, 14 Jun 2015 00:27:54 EST ID:kfQx+w9j No.55402
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So if I'm correct, every galaxy has a supermassive black hole at the center of it. Every galaxy was once an active Quasar and then cooled after the black hole at the center of the galaxy spewed and consumed all the matter around it. So if a black hole has angular momentum at the center of a galaxy, does that mean the galaxy would result in a spiral shape? And would non rotating black holes instead form more of an irregular galaxy shape? I'm thinking in terms of galaxy evolution and the various shapes different galaxies take. Cheers.
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Arno Penzias - Sun, 14 Jun 2015 01:01:51 EST ID:415JX8nG No.55403 Ignore Report Reply
I'm sure it is a contributing factor.

A stupid question I have that I can't of an answer to is,
Are all of our views of galaxies fundamentally distorted from their real shape because of the shear size?
What I'm referring to is a galaxy has a real size, x light years, all of them have some sort of angle to them; there's a point of that galaxy that is closer to us, and a point farthest away. Forgive my math, I'm just thinking this out, but if you had a galaxy 100,000 years across, angled at 45° from our perspective there would be a time difference of 50,000 years.
Throughout those 50,000 years, all the stars have been in constant orbit, so the further away a star is from us in its hosts galaxy, wouldn't the real location of the far star be further along its orbit when you consider the location of the closest star to you in a galaxy?
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Cecelia Payne-Gaposchkin - Sun, 14 Jun 2015 03:53:16 EST ID:owUNJHWO No.55404 Ignore Report Reply
>>55403
A galactic year (Earth's oribtal period around the Milky Way) is around 225 to 250 million terrestrial years. If my plebian calculations are correct, stars traverse around 1.5% of their orbit in the time difference between the near and far edges. Thus, there is distortion, but not so much.
Thus, stars don't move a significant the time difference between the near and far edges
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Joseph Taylor Jr. - Sun, 14 Jun 2015 15:30:50 EST ID:TBQu5K6m No.55406 Ignore Report Reply
1434310250877.gif -(64268B / 62.76KB, 250x141) Thumbnail displayed, click image for full size.
The shape of a galaxy is not generally due to the nature of black hole in the middle of it but due to the nature of gravity. A lot like all the planets around our sun all move in the same direction since there is no more unbalanced force acting on them, the stars in a galaxy have been set in motion around the center of a galaxy and keep moving that way since there's nothing to stop them from acting otherwise (anymore).

The planets around the sun aren't moving at the certain way because of the sun spins that way but because of gravity and Newton's first law of motion.
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James Elliott - Sun, 14 Jun 2015 16:18:15 EST ID:FyXGVhqE No.55408 Ignore Report Reply
Super massive black holes are tiny compared to thhe cores of most galaxies, they simply don't have the influence to cause spiral arms. Simply spinning wouldn't cause them anyway. Some spirals like M33 simply don't have supermassive black holes.
Spiral arms are complex phenomena but the explanation now is quite clear and is backed by observation, that model being spiral density waves.
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Heinrich Olbers - Sun, 14 Jun 2015 23:46:03 EST ID:kfQx+w9j No.55409 Ignore Report Reply
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I love talking to you djents about this stuff. Our Universe is such a crazy fascinating place...
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Clyde Tombaugh - Sat, 20 Jun 2015 18:11:14 EST ID:YHjXylC8 No.55430 Ignore Report Reply
1434838274891.gif -(1365569B / 1.30MB, 500x281) Thumbnail displayed, click image for full size.
>>55408
This, also spiral are a temporary thing; older galaxies tend to be elliptical.
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Johannes Kepler - Sun, 21 Jun 2015 16:17:15 EST ID:XJHlYsmW No.55431 Ignore Report Reply
>>55406

You forgot frame dragging.
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Edmond Halley - Tue, 23 Jun 2015 10:35:57 EST ID:2uBuMclp No.55441 Ignore Report Reply
arent they thinking that all galaxies might be spiral and all these different shapes that we see could be just the remnants of collisions between two or more galaxies that haven't normalized yet?
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Fred Hoyle - Wed, 24 Jun 2015 08:28:23 EST ID:YHjXylC8 No.55446 Ignore Report Reply
1435148903466.jpg -(149943B / 146.43KB, 1024x576) Thumbnail displayed, click image for full size.
>>55441
Elliptical galaxies tend to have far older stars than spirals. It's likely that the spirals are the ones that haven't quite normalized.
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William Huggins - Fri, 26 Jun 2015 22:06:49 EST ID:LmQ6qdUZ No.55458 Ignore Report Reply
All about spirals:
https://en.wikipedia.org/wiki/Gravitationally_aligned_orbits
https://www.youtube.com/watch?v=-ii0nksV2lY
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Charles Bolton - Sun, 28 Jun 2015 01:39:16 EST ID:P+fSJ1RL No.55460 Ignore Report Reply
>>55446
That fucking pic. I always knew the galaxyy was huge. Had no real concept until I started playing elite dangerous, the playable world contains the estimated 400 billion stars of the milky way. Viewing the map is an awe inspiring and simultaniously crushing experience. Now I see this fuckin pic.

Why do we still live on one planet?
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Roger Penrose - Sun, 28 Jun 2015 09:38:23 EST ID:IQY0YtFB No.55461 Ignore Report Reply
Eventually the spiral forms take shape of malicious code and Avira antivirus will detect them as false positives, You should try a Linux Distro, OP.
Just sayin'
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Henry Draper - Sun, 28 Jun 2015 13:23:21 EST ID:XJHlYsmW No.55462 Ignore Report Reply
>>55460

Space is big and also hard.
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Kiyotsugu Hirayama - Sun, 28 Jun 2015 14:38:04 EST ID:L3OB90Tk No.55463 Ignore Report Reply
>>55441
>>55446

You're both sort of right. Before major mergers when galaxies shave a lot of gas and are actively forming stars most of the big ones are spirals, some of the small ones can be irregular bit that's a different story. Left to it's on devices a spiral will not evolve or normalise into an elliptical.

A major merger is when two roughly equally sized galaxies collide and merger. It is believed elliptical form major mergers of spirals. As part of this merger the gas is usually stripped out and star formation shuts down with nothing to make stars out of (After the merger is finished). When it reaches a steady state it will be an elliptical, it will not evolve back into a spiral. The reason ellipticals have older stars is because they don't form any new ones, the oldest stars in each galaxy will not be significantly older or younger than the other.

>>55431

Frame dragging is a tiny effect, it doesn't affect things like that.


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