A real whirlpool in space
Click for original image.
Cool image time! The picture above, cropped to post here, was taken by the Hubble Space Telescope as part of a survey of nearby galaxies that have what astronomers call an Active Galactic Nuclei (AGN), because the supermassive black hole at the center is devouring nearby material at a great rate and thus producing high energy emissions as it does so.
Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.
The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center. One cannot help wondering why such galaxies don’t end up eventually getting completely swallowed by that black hole.
Or maybe they do, and we don’t see such things because all that is left is a supermassive black hole that emits no light or energy at all, a dark silent ghost traveling between the galaxies unseen and undetectable.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for original image.
Cool image time! The picture above, cropped to post here, was taken by the Hubble Space Telescope as part of a survey of nearby galaxies that have what astronomers call an Active Galactic Nuclei (AGN), because the supermassive black hole at the center is devouring nearby material at a great rate and thus producing high energy emissions as it does so.
Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.
The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center. One cannot help wondering why such galaxies don’t end up eventually getting completely swallowed by that black hole.
Or maybe they do, and we don’t see such things because all that is left is a supermassive black hole that emits no light or energy at all, a dark silent ghost traveling between the galaxies unseen and undetectable.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Mr. Z.,
Great picture.
I’ll just drop these in–
Idealized Circular orbits near Schwarzschild black hole
Pavel Rozhkov
https://youtu.be/l3hmtbnYK_0
(2:01)
Do Black Holes Have a Size Limit?
https://youtu.be/EGzvGgNmaiY
(10:20)
“The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center.”
This really isn’t true. At distances well beyond their event horizons, black hole gravity fields are no different than any others. The whole galaxy is no closer to being sucked into the black hole at its center than Jupiter (and Earth) are to being sucked into the Sun.
But wouldn’t there be a cascade effect? As the nearer things get sucked in, there is more gravity pulling on what’s left. Or not? If Mercury, Venus, Earth, and Mars fell into the sun, the amount of mass inside the orbit of Mars (or where Mars used to orbit) would not change. However, it would all be in one place, rather than spinning about, tugging this way and that.
Either way, one either ends up with a giant black hole that sucked up the entire galaxy or a donut shaped galaxy where the black hole got all it could and everything else is left spinning around it.
There’s also a time aspect involved. It could be that there simply hasn’t been time for either one to occur. A galaxy is a big place and black holes are not ShopVacs. It takes a while for stuff to fall in because it spins around so much, first.
Some of the very far away galaxies that we see now might have already been completely sucked in, we just can’t see it, yet. (Yes, that is a classical definition of “now”, but I insist, despite all evidence, that there is such a thing as a universe-wide, simultaneous “now”. I understand General Relativity’s “now”, but I don’t think it removes the normal one.)
Related:
NO, I AM NOT MAKING THIS UP
“How much free money as an American citizen to buy a house where you offered by your government? Please let me know.”
https://www.sigma3ioc.com/post/the-enemy-of-every-american-democrat
Somewhat related to Mark Sizer’s comment; I also wondered if a galaxy could be completely ‘swallowed’, leaving a wandering, giant black hole. I surmise it could be detected by the gravity lens effect. The other suggested result of a donut-shaped galaxy makes sense if there is a limit to how much the black hole could ingest.
“… the amount of mass inside the orbit of Mars (or where Mars used to orbit) would not change.”
It can be mathematically proven (although not by me) that this really is all that matters. If everything inside the orbit of Mars somehow got sucked into the Sun, Mars wouldn’t even twitch. If the Sun were somehow replaced by a one-solar-mass black hole, the orbits of everything outside of the Sun’s current “surface” radius from the black hole would be entirely unaffected.
Not a physicist nor an orbital-mechanic, but I do know there is no “sucking'” when it comes to gravity.
I’m taking Mr. Z’s language as being Poetic, rather than literal, and this picture does evoke a sense of motion, and I did a cursory look-up as to Why everything doesn’t spiral in.
Apparently this all has to do with the size of the black hole, the innermost stable circular orbit, and the Schwarzschild radius.
General Relativity says black holes have no upper size limit, but we know GR falls apart inside the event horizon. Recent calculations put the upper limit at 50-65 billion solar-masses, depending on spin. At that point matter in a galaxy is either inside the innermost stable circular orbit and lost, or it’s outside the orbit and feels more gravity between itself, than from the black hole.
(so sayeth the internet…)
see this segment:
https://youtu.be/EGzvGgNmaiY?t=355