Why Are Most Galaxies Spiral-Shaped?
148,763
Published 2016-08-26
Everything We Know About The Andromeda Galaxy - bit.ly/2blkOkG
Sign Up For The Seeker Newsletter Here - bit.ly/1UO1PxI
Read More:
What Process Creates And Maintains The Beautiful Spiral Arms Around Spiral Galaxies? I've Been Told That Density Waves Are Responsible -- So Where Do The Density Waves Come From?
www.scientificamerican.com/article/what-process-cr…
""The basic physics of why galaxies have spirals is known, but the details remain controversial, sometimes intensely so. Spirals exist only among flattened or 'disk' galaxies. These galaxies are differentially rotating--that is, the time to complete a full rotation increases with distance from the center. Differential rotation causes any disturbance in the disk to wind up into a spiral form. The trouble with this simple explanation is that the differential rotation would cause spiral features to wind up too quickly, so galaxies would not look like spirals for any appreciable length of time."
How Do Spiral Galaxies Keep Their Shape?
earthsky.org/space/how-do-spiral-galaxies-keep-the…
"Astronomers sometimes call this the "wind-up problem" of the spiral arms. It has been observed that the inner parts of galaxies rotate faster than the outer parts. If so, are the inner parts of the spiral arms moving faster than the other parts? If that is happening, then the galaxy would have no choice but to wind up so much that the spiral structure would be thinned out and ultimately destroyed.
But we can see galaxies billions of light-years away - as well as those relatively nearby - that have maintained their spiral structure. How?"
Astrophysicists Discover Mechanism For Spiral-Arm Formation In Disk Galaxies
phys.org/news/2016-08-astrophysicists-mechanism-sp…
"Astrophysicists at the University of Arkansas have discovered a mechanism for the formation of the spiral arms in disk galaxies. The finding was published in the Astrophysical Journal Letters, the journal of the American Astronomical Society. The discovery provides a better understanding for the formation of spiral arms in a kind of disk galaxy known as a spiral galaxy, said Hamed Pour-Imani, a physics doctoral student at the U of A and lead author of the study."
____________________
DNews is dedicated to satisfying your curiosity and to bringing you mind-bending stories & perspectives you won't find anywhere else! New videos daily.
Watch More DNews on Seeker www.seeker.com/show/dnews/
Subscribe now! youtube.com/subscription_center?add_user=dnewschan…
DNews on Twitter twitter.com/dnews
Trace Dominguez on Twitter twitter.com/tracedominguez
DNews on Facebook facebook.com/DiscoveryNews
DNews on Google+ gplus.to/dnews
Discovery News discoverynews.com/
Sign Up For The Seeker Newsletter Here: bit.ly/1UO1PxI
All Comments (21)
-
I think of Gurren Lagann when I hear the word spiral.
-
To make it easier for Gurren Lagann to throw them of course.
-
I learned something little different in astronomy. As galaxies were forming, they were flung out of the cloud of gas and as they were thrown out, they continued their rotating motion. This led to galaxies have spiral shapes over time.
-
It's because the Flying Spaghetti Monster created them to ressemble Him, in order for us to admire His glory. R'amen !
-
Probably something to do with gravitational waves and rotational spacetime momentum from rapidly rotating black holes at the center of galaxies
-
"to hug us"- the cutest thing I've ever heard in my life
-
That intro was adorable
-
hey trace...fab video.can you plz do a video on..information about list of all theories and information on black holes at single place...will be easy to collect...thanks
-
What if there are spiraling outward black holes which are devouring the stars in between the arms? No, we probably would have noticed that. Okay, what if the stars are just brighter in the arms, because there's more fuel to burn from a spiral shape in the gases that formed the galaxy in the first place? No, then the older galaxies would have more spirals than the younger ones, instead of the other way around. Okay, how about there's some kind of opaque material spread out in a spiral, blocking our view of the stars in between the "arms?" No, that can't be it either, because then we wouldn't be able to see the rest of our own galaxy. Okay, what if the dark matter is in a naturally spiral shape, and its gravity is pulling the stars into the arm positions? But then we'd have to explain why the dark matter is in a spiral, and we're back to where we started. Damn, astronomy is hard!
-
Hi! I'm a big fan and I'm wondering if Dnews can please make an episode or a lot :-) about how the universe its looking right now? since what we are seeing is from the past. Thanks! :-)
-
Very cool information.
-
Hey DNews Team! love your videos :3 i wanted to ask wether you would make a video on how space travel is likely tp change within the next century or so. for example when will it be a fully reusable method of transport (same way airplanes are now) [SpaceX?] i hope you get the idea :D thanks to everyone at DNews!
-
2:03 that blue minivan really wanted to change into that lane
-
What space topic should we answer next?!
-
Fun fact: The most abundant type of galaxies in the universe are DWARF galaxies ( The one containg 1000 up to several billion stars,)
-
Ok, your graphic shows the galaxy rotating towards the ends of the arms. On Earth, to get a spiral, the core would have to rotate away from the tips, due to atmospheric friction slowing the extremities. Do all galaxies rotate towards the tips, or is it a random mixture of both directions?
-
I do have a "space-question". It is if you could balance a Planet between two stars of a binary star system or have a planet, switching orbits between stars regularly... Basically a lot of theories about binary systems and weird planetary orbits would be nice.
-
Could be linked to the Fibonacci Spiral!
-
We orbit around the sun. The Sun orbits around the milky way's black hole. Imagine what the milky way orbits around... Woah...
-
Are their near by galaxies to ours or any that are spiraling an opposite direction if so have telescopes captured a picture of them spiraling in a different direction that we can have a view of?
