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Massive black hole discovered near heart of the Milky Way (NOT Sagitarius A*)

F

Fenderputty

Banned
All Possible Ways said:
You know, this is a very important problem. In physics information cannot be destroyed, but it appears that if something falls into a black hole, its identity is completely erased. This is called the information paradox.

Since Hawking predicted that black holes slowly evaporate by emitting a faint radiation, it is conjectured that the information of what fell in is stored in the particles that come out and so is preserved overall. In some idealised cases, where people can do the calculation, it seems to be true, but it remains an open problem in general.
Click to expand...

Holographic Principal addressed this too, no?
 
F

Fenderputty

Banned
Cewyn said:
Can you explain more on this?

Edit: Yes, I'm serious. I'm a bit confused especially per the previous post
Click to expand...

If you were to observe a black hole from the outside, the event horizon is the line in which light cannot escape. So the closer an object gets to the even horizon the harder it is for the light to escape gravity. Since we require light to see visually, our perception of what is happening is different than what is actually happening because of this.
 
S

Simon Belmont

Banned
Fenderputty said:
If you were to observe a black hole from the outside, the event horizon is the line in which light cannot escape. So the closer an object gets to the even horizon the harder it is for the light to escape gravity. Since we require light to see visually, our perception of what is happening is different than what is actually happening because of this.
Click to expand...

It's not just light though, gravitational time dilation "freezes" the in falling ovserver in time from the perspective of the outside observers if that makes sense.
 
F

Fenderputty

Banned
Simon Belmont said:
It's not just light though, gravitational time dilation "freezes" the in falling ovserver in time from the perspective of the outside observers if that makes sense.
Click to expand...

I do understand time dilation, maybe I just had things explained to me incorrectly regarding the event horizon. Maybe they're similar concepts? The same mechanisms causing time dilation are trapping the light as well and I know we need light to see.
 
K

kmax

Member
Fascinating find. Good thing that it's smaller than the Sagittarius A* which is a supermassive black hole.

To class as a supermassive black hole, it needs to have 1 million times the mass of the sun. Sagittarius A* is around 4 million while this one is at, going by the article, 100.000 times the sun. A fun fact is that a black hole can be as small as an atom, yet have the mass of a mountain. (according to NASA)

That's scary.

Black holes sure are fascinating and frightening.
 
S

Simon Belmont

Banned
Fenderputty said:
I do understand time dilation, maybe I just had things explained to me incorrectly regarding the event horizon. Maybe they're similar concepts? The same mechanisms causing time dilation are trapping the light as well and I know we need light to see.
Click to expand...

I believe that's more or less true. The curvature of space stretches the last emitted photons from right before the event horizon to invisibility on any spectrum. Space is so cool.
 
Z

Z3M0G

Member
The very center of our galaxy is a black hole? I never knew this...

I miss space science... I miss being interested in stuff like that...
 
Alebrije

Alebrije

Member
Z3M0G said:
The very center of our galaxy is a black hole? I never knew this...

I miss space science... I miss being interested in stuff like that...
Click to expand...

So , No Mans Sky ending is accurate.

OSP5pQJIkxpClEtxIuJ-_hPonYMWxWwP07vh1m4XOGkjaStA3ZQMfWNxTOhIvCob_duUT_Ach3EGMekBfWW5NywprMwDYJ_ifNfVMA2r22HFu4Bl_PCNhjUb0V3x0eV5dmJondqQt1M=w480-h240-nc
 
S

Simon Belmont

Banned
G

gun_haver

Member
i agree with the early poster who said he's basically a casual space fan

that's me. love to hear about it, don't understand it.
 
A

All Possible Ways

Member
Cewyn said:
Can you explain more on this?

Edit: Yes, I'm serious. I'm a bit confused especially per the previous post
Click to expand...
Sure.

In general relativity time intervals depend on the observer.
The important effect here is the gravitational time dilation. Basically, the stronger the gravitational field you're in, the slower time passes for you compared to a distant observer.

If you remember, the gravitational potential of a spherical body is given by V=-GM/r, where G is Newton's constant M is the mass and r is the distance from the center.

The time interval "T" measured by a distant observer is related to the free falling time "t" by
T=t/Sqrt (1+2V/c^2),

where V is the potential above, c is the speed of light and sqrt means square root. If the person is right at the horizon, r=2GM/c^2 (the black hole radius) and the denominator goes to zero, so the time T goes to infinity. This means that the time a distant stationary observer measures is infinitely dilated with respect to the time of the freefalling person at the horizon.

Because of this, from the outside viewpoint, the person is never able to cross the horizon and enter the black hole, but instead freezes right at the horizon.

The situation is quite different from the point of view of the person that is falling into the BH though. Since he falls freely, he doesn't experience a gravitational force, so from his point of view, time flows normally. All you have to do, roughly, is calculate the length he travels divided by his speed. The length is not the black hole radius because its actually bigger on the inside (seriously) and the speed is not constant, but complications aside, in the end you get that a finite time passes equal to t=pi GM/c^3 before you reach the center.

This is all for nonspinning BHs and radial trajectories, but qualitatively it is correct. Hopefully I didn't confuse you further!
 
A

All Possible Ways

Member
Fenderputty said:
Holographic Principal addressed this too, no?
Click to expand...
Yes but the only calculable model is based on AdS/CFT correspondence, in which you relate calculations in a 5d negative curvature space (AdS) with a black hole in it to a 4d conformal field theory at finite temperature (CFT). Since the CFT preserves information, the space with a black hole should as well.

The problem is that our universe is quite different from that, but the hope is that an analogous statement holds. No rigorous calculation for a realistic situation exists yet to my knowledge.
 
I

Iceman

Member
All Possible Ways said:
I'm well aware. You can include me in the satisfied camp.

Btw, love your short film. Keep up the good work!
Click to expand...

Thanks tons. I wonder if you've seen our little follow-up, Quantum is Calling, with Zoe Saldana?

I'm assuming from your username that your familiar with the Feynman path integral. I'm struggling to grasp that right now by digesting his book, QED. Also, I've been working with his daughter on a presentation she wants to give that will explore her unique, most intimate point of view of Feynman. I'd appreciate it if you could shoot me any questions or curiosities you had about Feynman that we should/might address in her talk.

We also got some big, super secret stuff in the works related to Feynman early next year, for his 100th birthday.
 
D

Deleted member 80556

Unconfirmed Member
was a black hole no more than 1.4 trillion km across.
Click to expand...

Jesus fucking Christ. My mind cannot grasp this. I cannot grasp the fact that the distance from here to the moon, all the solar system planets can fit. This is just fucking ridiculous.
 
P

Polioliolio

Member
People seem to have a misconception about black holes.. That they're like sharks cruising around space for a kill and can strike at any moment.

Even if we were on a collision course with a black hole, which I don't know, we probably are given enough time, we would live out our insignificant lives utterly oblivious to it even as our solar system is on the brink of getting destroyed. You see, we are so damned small and unimportant, we're likely to be dead and gone a million times over and even if we were still here as the earth and the solar system flew into a black hole, would we ever know or realize it? Even if we were about to enter the event horizon, your pathetic lives would be here and gone before the solar system would be destroyed. You fucking pathetic ant.
 
S

sturgboski

Member
Polioliolio said:
People seem to have a misconception about black holes.. That they're like sharks cruising around space for a kill and can strike at any moment.

Even if we were on a collision course with a black hole, which I don't know, we probably are given enough time, we would live out our insignificant lives utterly oblivious to it even as our solar system is on the brink of getting destroyed. You see, we are so damned small and unimportant, we're likely to be dead and gone a million times over and even if we were still here as the earth and the solar system flew into a black hole, would we ever know or realize it? Even if we were about to enter the event horizon, your pathetic lives would be here and gone before the solar system would be destroyed. You fucking pathetic ant.
Click to expand...

Look Gary, just because the Traveller blessed us with the light doesn't mean you need to be so salty.

Actually I think time horizon Wise it's either we are swallowed by our sun as it dies or we are jettisoned when the MG collides with another galaxy (forget the name but I believe we are on a collision course with one). Then again based on how things are going, life on Earth would have been long extinct by then.
 
U

Unknown One

Member
Space is so damn cool, I wish I can travel space as an immortal. Just floating around looking at stuff would be cool. Too bad I won't be able to hear anything.
 
U

UpDownLeftRight

Banned
sturgboski said:
Look Gary, just because the Traveller blessed us with the light doesn't mean you need to be so salty.

Actually I think time horizon Wise it's either we are swallowed by our sun as it dies or we are jettisoned when the MG collides with another galaxy (forget the name but I believe we are on a collision course with one). Then again based on how things are going, life on Earth would have been long extinct by then.
Click to expand...

Second part is kind true and false at the same time. The Milky Way and Andromeda are on a 'collision path but that's an extremely dramatic way of putting I versus the reality. Space is just too damn big, The galaxies will cross each other but the latest simulations put the chances of being flung from the solar system as infinitesimal.

There's just so much distance between everything that it's going to be less eventful than you'd think. However the sky will become beautiful and eventually as it gets close enough night will cease all together for thousand and thousand of years as the galaxies approach each other.
 
A

All Possible Ways

Member
Iceman said:
Thanks tons. I wonder if you've seen our little follow-up, Quantum is Calling, with Zoe Saldana?
Click to expand...
I did! Its cute and creative. Congrats, love her lots!

I'm assuming from your username that your familiar with the Feynman path integral. I'm struggling to grasp that right now by digesting his book, QED.
Click to expand...
Indeed. I think its a good book, he really had a knack for presenting technical stuff in an accessible language. Good luck and please let me know if I can help with that.
Also, I've been working with his daughter on a presentation she wants to give that will explore her unique, most intimate point of view of Feynman. I'd appreciate it if you could shoot me any questions or curiosities you had about Feynman that we should/might address in her talk.

We also got some big, super secret stuff in the works related to Feynman early next year, for his 100th birthday.
Click to expand...
Wow, great! To be honest I'm at a loss right now about what I should ask, but I will shoot you a pm if I can think of something interesting!
 
F

FyreWulff

Member
Simon Belmont said:
It's not just light though, gravitational time dilation "freezes" the in falling ovserver in time from the perspective of the outside observers if that makes sense.
Click to expand...

Also if you were able to look back outside the black hole as you are falling in, you'd see the universe go in fast forward.

The larger the black hole, the more future you will see before you hit the singularity.

Of course tidal forces would rip you apart pretty fast, so this is only theoretical. You can hover just outside of an event horizon and watch the universe go faster, though.
 
BizzyBum

BizzyBum

Member
Unknown One said:
Space is so damn cool, I wish I can travel space as an immortal. Just floating around looking at stuff would be cool. Too bad I won't be able to hear anything.
Click to expand...

Would be pretty cool to become a ghost when you die and then just travel the cosmos checking out cool shit. lol

edit: What if ghosts and other paranormal stuff are just dead aliens that traveled space for who knows how long, came to our planet, and now just fuck with us.
thinking-face_1f914.png
 
I

I H8 Memes

Member
Dont most healthy disc shaped galaxies have many massive black holes at the center of the galaxies? What would be the purpose of that?
 
V

Volimar

Member
I H8 Memes said:
Dont most healthy disc shaped galaxies have many massive black holes at the center of the galaxies? What would be the purpose of that?
Click to expand...


There are so many stars at the center of galaxies that it would be more odd if there didn't end up being massive black holes at the center.
 
K

KarmaCow

Member
Volimar said:
There are so many stars at the center of galaxies that it would be more odd if there didn't end up being massive black holes at the center.
Click to expand...

Yea blackholes definitely have unintuitive or weird properties but they are still basically just a fuckton of mass. It's not any different than anywhere else in the universe: a bunch of objects tend to collapse toward the center of their combined mass. The reason the galaxy (or even universe) isn't just a ultra super arcade edition massive blackhole is that there are other forces at play and gravity rapidly gets weaker as distance increases between objects.
 
F

Fenderputty

Banned
All Possible Ways said:
Sure.

In general relativity time intervals depend on the observer.
The important effect here is the gravitational time dilation. Basically, the stronger the gravitational field you're in, the slower time passes for you compared to a distant observer.

If you remember, the gravitational potential of a spherical body is given by V=-GM/r, where G is Newton's constant M is the mass and r is the distance from the center.

The time interval "T" measured by a distant observer is related to the free falling time "t" by
T=t/Sqrt (1+2V/c^2),

where V is the potential above, c is the speed of light and sqrt means square root. If the person is right at the horizon, r=2GM/c^2 (the black hole radius) and the denominator goes to zero, so the time T goes to infinity. This means that the time a distant stationary observer measures is infinitely dilated with respect to the time of the freefalling person at the horizon.

Because of this, from the outside viewpoint, the person is never able to cross the horizon and enter the black hole, but instead freezes right at the horizon.

The situation is quite different from the point of view of the person that is falling into the BH though. Since he falls freely, he doesn't experience a gravitational force, so from his point of view, time flows normally. All you have to do, roughly, is calculate the length he travels divided by his speed. The length is not the black hole radius because its actually bigger on the inside (seriously) and the speed is not constant, but complications aside, in the end you get that a finite time passes equal to t=pi GM/c^3 before you reach the center.

This is all for nonspinning BHs and radial trajectories, but qualitatively it is correct. Hopefully I didn't confuse you further!
Click to expand...

So where I'm confused is how this relates to visible light and our ability to see. How do we see something stuck event horizon if visible light has to bounce off an object and that light would get stuck too at this point? I get how we see something slow and maybe stretch as it approaches, but how do we see something stuck for an eternity?
 
U

UpDownLeftRight

Banned
All Possible Ways said:
Sure.

In general relativity time intervals depend on the observer.
The important effect here is the gravitational time dilation. Basically, the stronger the gravitational field you're in, the slower time passes for you compared to a distant observer.

If you remember, the gravitational potential of a spherical body is given by V=-GM/r, where G is Newton's constant M is the mass and r is the distance from the center.

The time interval "T" measured by a distant observer is related to the free falling time "t" by
T=t/Sqrt (1+2V/c^2),

where V is the potential above, c is the speed of light and sqrt means square root. If the person is right at the horizon, r=2GM/c^2 (the black hole radius) and the denominator goes to zero, so the time T goes to infinity. This means that the time a distant stationary observer measures is infinitely dilated with respect to the time of the freefalling person at the horizon.

Because of this, from the outside viewpoint, the person is never able to cross the horizon and enter the black hole, but instead freezes right at the horizon.

The situation is quite different from the point of view of the person that is falling into the BH though. Since he falls freely, he doesn't experience a gravitational force, so from his point of view, time flows normally. All you have to do, roughly, is calculate the length he travels divided by his speed. The length is not the black hole radius because its actually bigger on the inside (seriously) and the speed is not constant, but complications aside, in the end you get that a finite time passes equal to t=pi GM/c^3 before you reach the center.

This is all for nonspinning BHs and radial trajectories, but qualitatively it is correct. Hopefully I didn't confuse you further!
Click to expand...

Well now I'm curious.
 
A

All Possible Ways

Member
Fenderputty said:
So where I'm confused is how this relates to visible light and our ability to see. How do we see something stuck event horizon if visible light has to bounce off an object and that light would get stuck too at this point? I get how we see something slow and maybe stretch as it approaches, but how do we see something stuck for an eternity?
Click to expand...
Well, the time slows down for light as well, and since frequency is the inverse of the period, the frequency of the light emmited near the horizon as measured by the distant observer decreases. This is the gravitational redshift.

Since the frequency is proportional to photon energy, the energy decreases as well. You may imagine the photon loses energy climbing out of the gravitational well of the BH.

Eventually, the light is so stretched and low energy that you can't detect it anymore, so not only you see the person slow down, but his image gets fainter and redder until its below the sensitivity of your detector, and then you don't see the guy anymore.
UpDownLeftRight said:
Well now I'm curious.
Click to expand...
Because space is curved, the usual relation between a sphere's radius and its surface area (A=4pi r^2) no longer holds.

The radius people quote is the one you would see from the outside (the root of the area over 4pi) but if you fell in the bh and actually measured the distance to the center, it would be larger than that.

One way to visualize that is those "funnel" pictures, like so:
karadelik_embedding.gif


The "normal" radius would be the distance straight across the hole, while the actual distance to the center would be along the funnel. Keep in mind that this is only a way to represent in 2d a curved 3d space, so don't take the picture too literally.
 
M

MogCakes

Member
I want to know what happens inside the event horizon once something passes through. If the hole is large enough that objects will enter undilated, what happens to them? Since from the outside they appear to freeze.
 
F

FyreWulff

Member
MogCakes said:
I want to know what happens inside the event horizon once something passes through. If the hole is large enough that objects will enter undilated, what happens to them? Since from the outside they appear to freeze.
Click to expand...

the only way forward is towards the singularity. Eventually they'll reach it and we have no idea what happens then.
 
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