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/sci/ - Science & Math

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File: 31 KB, 400x267, black_hole_image.jpg [View same] [iqdb] [saucenao] [google]
2949541 No.2949541 [Reply] [Original]

Have black holes been observed or are they just theoretical?

>> No.2949583
File: 714 KB, 2670x4101, cutey_Emma_Shes.jpg [View same] [iqdb] [saucenao] [google]
2949583

There are observations of objects in space which are assumed to be what is predicted by general relativity, namely black holes.
So yes, in a sense they have been observed. (But it's not like bird in the forest where what you see is defined to be a bird.)

>> No.2949578

They have been shown to exist mathematically, and their gravitational influences have been observed.

>> No.2949584

the effects of them have been observed yes

>> No.2949603

iirc, they spotted the radiation it emits, better double check that though

>> No.2949605

the effects of them have been observed

>> No.2949618

Have you seen air or is it just theoretical?

>> No.2950766

>>2949603
This. Several different types of radiation in fact, as well as their gravitational influence. Basically a big area of nothing that has a strong gravitational pull and is emitting lots of energy of various types that coincides with our mathematical predictions of a black hole.

There is tons of evidence and they're treated as fact; but of course like the majority of things that cannot be directly observed they are regarded as theory (but then again so is evolution, general relativity, and many other things we base our understanding of the world on. Theory =/= made up crap, it's our current model of describing a phenomena.)

>> No.2950848
File: 633 KB, 256x256, Sagittarius-A*.gif [View same] [iqdb] [saucenao] [google]
2950848

The most eye-opening evidence of black holes I've ever seen. (Animated!)
Full reference here: http://apod.nasa.gov/apod/ap070114.html

>> No.2951777

Why does a star turn into a black hole?

What is the use of a black hole to the universe?

>> No.2951784

>>2951777
Wat?
You think everything has to have a purpose?
Hate to break it to you, but the universe doesn't work that way

>> No.2951800
File: 1.01 MB, 500x500, milky way nucleus.gif [View same] [iqdb] [saucenao] [google]
2951800

>>2950848

>> No.2951820

>>2950848
>>2951800

The magnitude of this really starts to sink in when you realize that a couple of these stars are moving at over 10% of light speed.

>> No.2951840
File: 51 KB, 987x274, CAT genome.jpg [View same] [iqdb] [saucenao] [google]
2951840

Don't we see light and other stuff being pulled towards a black hole? Granted we can't see shit beyond the event horizon, but but seeing a giant mass of gas swirling into a singular point should be a givaway of something exciting happening there.
Also, hasn't a black hole been observed at the center of our galaxy, and many others?
pic unrelated, it just makes me laugh

>> No.2951887

>>2951820
But I thought nothing moves faster than light?

>> No.2951905

>>2951887

10% of light speed. 1/10th the speed of light. And they're HUGE.

>> No.2951913

yeah i've seen one

>> No.2951937

>>2951800
lol, S0-17
"Like I give a fuck"

>> No.2951951

I dont think we've seen hawking radiation. Jets of material accelerated by a near pass to one, sure, but thats not a true emission from the black hole

>> No.2951962

>>2951800
>>2951937

SO-16
"WHEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE"

>> No.2951970

>>2951951
http://www.newscientist.com/article/dn19508-hawking-radiation-glimpsed-in-artificial-black-hole.html

>> No.2951971

>>2951937
SO-16
"Hey guys, what's going on he-NOPE"

>> No.2951974

>>2951962
S0-4
"Fuck you guys, Iam outa here."

>> No.2951981
File: 85 KB, 898x1042, 4char-forever-alone-guy-high-resolution.png [View same] [iqdb] [saucenao] [google]
2951981

S0-18

>> No.2952004

>>2951970
Eh, I guess thats close enough.

>> No.2952006

You can't really "see" a black hole...hawking radiation and all that, but it's all theoretical iirc. It's like finding the sign of an animal, it's scat, it's tracks it's kills, yet not being able to find the animal itself. You know it's there, and the general area of where it's at, but you haven't seen the actual animal.

>> No.2952011

>>2952006

Well, think of the same thing except THE ANIMAL IS INVISIBLE!

>> No.2952024

>>2952011
well if you want to take it to that level...make the animal Predator

>> No.2952027

>>2950848
>>2951800
Wait, is this real time? Not a compilation of months of observation?

>> No.2952040

>>2952027
Click the link you lazy prick
Its over 8 years

>> No.2952055

>>2949541
Why is a black hole flat instead of being spherical?

>> No.2952060

>>2952055
vanishing dimensions.

>> No.2952104

>>2952060
Please expand further

>> No.2952153

>>2952055
is is spherical

>> No.2952159
File: 102 KB, 320x320, 1256912083561.png [View same] [iqdb] [saucenao] [google]
2952159

>>2952055
>>2952060
> blackholes are flat
> my face when I learned something today

>> No.2952160

>>2952104
He probably meant that you can't see shit from your point of view.
If you looked at it from few different points, you'd notice it is spherical.
From one you only see a 2D shadow - just like with any uniform sphere devoid of light.

>> No.2952171

>>2952160
Why is it represented as a 2d object in science then, there must be some maths behind its justification of being flat, innately it should be reasonable to assume it would be spherical:

Uber dense object, point of highest gravity = in middle, in middle from all sides would be stable = it would be spherical

>> No.2952183

>>2952171
We define a space by how the objects in space can move. We can move in roughly 3 dimensions. Not quite 3 because it takes more energy to move away from massive objects like the earth. Beyond the event horizon of a black hole, an object must approach the singularity, as it has lost a degree of freedom, space inside has lost a dimension.

>> No.2952186

>>2952183

What? I'm a person on an escalator that cannot go fast enough to travel towards the opposite direction of it's movement. Just because I can't go one direction due to my inability to exceed a speed does not mean that direction no longer exists.

>> No.2952187
File: 8 KB, 259x194, 1302154112781.jpg [View same] [iqdb] [saucenao] [google]
2952187

>>2951777
>looking for purpose in the Universe

>> No.2952192

>>2952183
so it's 1D

>> No.2952206

>>2952186
Sure you can, just use a rocket. Nothing will move you away from the singularity when you are inside an event horizon.

>>2952192
Closer to the singularity, yes.

>> No.2952208

>>2952183
The singularity would be the middle if the black hole is equally distributed


>Not quite 3 because it takes more energy to move away from massive objects like the earth.

I don't think this makes sense

>>2952186
good example

>> No.2952236

>>2952208
Yes, the singularity is still in the center, it's just that time no longer takes place in a volume, it takes place in 2d shells around the singularity. Inside a the event horizon, an object closer to the singularity cannot communicate information about itself to a more distant object. The closer object is in the future of the more distant object.

>> No.2952253

>>2952236
But wouldn't it be just the object that cannot escape a black hole that loses its dimensions, not the black hole itself?

This is interesting, are your comments your own or are they backed by scientific research/publishings? Post articles if they are!

>> No.2952263

>>2952192
Nope.
You can still move like on a surface of a sphere, which is 2D.
>>2952171
>Why is it represented as a 2d object in science then
Because we only consider the outermost "layer" - the even horizon, which is spherical and surface of a sphere is 2D.
The black hole is a ball (from the outside), not a disc.

>> No.2952264

They are shown to exist both theoretically (with mathematics) and because of gravitational tugs on certain stars and otherwise. (Sort of like dark matter; there's gravity there, but we can't see it!)

As Carl Sagan said, black holes are like footprints in snow of an invisible man walking.

>> No.2952265

>>2952253
http://arxiv.org/PS_cache/arxiv/pdf/1102/1102.3434v2.pdf

>> No.2952299

>>2952171
In sci fi movies/tv shows and such, things need to be visual, and an accurate representation of a black hole wouldn't look as impressive as a blue spiralling wirlhole type object in space.

It's a bit like wormholes in sci fi should be spheres you can walk into from any side and then directly behind you would be a sphere you could also enter from any direction to get back. But in sci fi they always use star gates or dr who like tunnel nonsense.

(video>my description of a wormhole http://www.youtube.com/watch?v=Dz-PDxb5qVQ))

>> No.2952308

>>2952265
I will look over it in depth and around this thanx.

>>2952263
>Because we only consider the outermost "layer" - the even horizon, which is spherical and surface of a sphere is 2D.
>The black hole is a ball (from the outside), not a disc.

Where is this being said? Who is saying this? Whenever I have talked with teachers or watched documentary's on black holes it is always taught as a disk, and never mentions it as being spherical.

>> No.2952322

>>2952299
I have watched a bbc documentary and I explicitly remember them showing a black hole from the side and that you cant see it unless its facing away/toward you, they mentioned this in justification that there maybe many more black holes out there that we cant see form our perspective - because it is a 2d object.

Black holes are like magnets. How the fuck do they work.

>> No.2952329

>>2952308
You are probably thinking of the stuff orbiting the black hole, which will always be in a disk for the same reasons galaxies and solar systems are disks.

You know a black hole is a very large amount of mass in one point, you know that gravity works in three dimensions, so you know that the event horizon is a sphere, as this is the area of space where the strength of gravity is equal or greater than the speed of light.

>> No.2952331

>>2952299
Also, that video does describe very well the concept of what were talking about.

>> No.2952368

>>2952322
The reason for this isn't that the black hole itself is flat, it is the stars orbiting the black hole are in a disk, take a look at OP's image, the large black circle would be a sphere, from a side angle you would just see a large cluster of stars and no signs of a region of empty space.

Were looking for the khanacadamy video I watched a year ago that explains why solar systems/galaxies/black hole excretion disks are flat... but couldn't find it... and my explanations are long and terrible.

Although did find a simple one on black holes
http://www.youtube.com/watch?v=JoL2pO3O0rg

>> No.2952430
File: 127 KB, 1533x798, ms paint black holes.jpg [View same] [iqdb] [saucenao] [google]
2952430

>>2952322
Here's a terrible ms paint of what the bbc were probably talking about when it comes to not being able to see black holes from other angles, they certainly wouldn't have said that a black hole is 2d..

>> No.2952451

>>2952430
I understand this and this is reasonable to assume, but people when they have explained it talk about the fabric of space/time and talk about it being flat. Space/time shouldn't be represented as a flat fabric with indentations, but a mesh net.

>>2952368
I'l check that out in a bit

>> No.2952467

>>2952368
>Were looking for the khanacadamy video I watched a year ago that explains why solar systems/galaxies/black hole excretion disks are flat

I would be very interested in this if anyone has it. It's always struck me as odd, given that gravity is a '3d' force, that solar systems and galaxies and such are all 'flat'.

>> No.2952488

So in conclusion the answer to op's question is, "Black holes have not been observed, but we think they exist because if they don't, our current theories of existence are wrong, and we don't want to admit that."

>> No.2952673

>>2952368
Thanx for posting the vid on black holes, my understanding of what exactly the event horizon is and what it means by singularity have been increased.
+1 internets

>> No.2952836

>>2952673
no problem ^^, you should check out his other videos, he has a Cosmology and astronomy playlist with 55 videos http://www.youtube.com/watch?v=GZx3U0dbASg&feature=BFa&list=SP2186CFB2CE12A8B5&index=1

^^, all pretty informative and easy to listen to.

>> No.2952923
File: 228 KB, 521x281, hs-1999-43-c-full_jpg[1].jpg [View same] [iqdb] [saucenao] [google]
2952923

couple of electron jets from hubble

m87 galaxy

>> No.2952927
File: 1.71 MB, 1222x1276, hs-2000-20-a-full_jpg[1].jpg [View same] [iqdb] [saucenao] [google]
2952927