Black Hole Question

I've always been fascinated by black holes & while I was searching for whether science had discovered tachyons (FTL particles) yet, this question came up in my mind. (And I'm hoping someone here can answer.

Science says that nothing can escape a black hole, yet i recall reading that "they" discovered Cygnus X-1 by radio waves?

If nothing can escape, how are these radio signals getting to us? And, if they ARE escaping, then aren't they tachyons?

I'm sure there is something I am missing here, and I have done due diligence by trying to find this answer online. (Including watching many youtube vids with Kaku & Tyson.

Any geeks out there wanna help a fellow nerd out?

Thx in advance.

Originally posted by schadenfreude
I've always been fascinated by black holes & while I was searching for whether science had discovered tachyons (FTL particles) yet, this question came up in my mind. (And I'm hoping someone here can answer.

Science says that nothing can escape a black hole, yet i recall reading that "they" discovered Cygnus X-1 by radio waves?

If nothing can escape, how are these radio signals getting to us? And, if they ARE escaping, then aren't they tachyons?

I'm sure there is something I am missing here, and I have done due diligence by trying to find this answer online. (Including watching many youtube vids with Kaku & Tyson.

Any geeks out there wanna help a fellow nerd out?

Thx in advance.

I'm not sure about Cygnus X-1......But as for nothing escaping Black Holes, that may not be entirely true. Stephen Hawking has theorized that Black Holes slowly 'evaporate' due to what is now called 'Hawking Radiation' en.wikipedia.org...

reply to post by schadenfreude


I believe the simple/short answer to your question is the radiation being emitted by the black hole is coming from just outside the event horizon. As particles spiral around and are accelerated to near light-speed, they are ejected with massive amounts of energy (which is why we can detect them). However, anything that crosses the event horizon will NEVER return (even light). But, keep in mind their information cannot be lost, so it is (theoretically) stored on the event horizon as sort of a hologram-like surface.

ETA: Yes. Hawking Radiation is predicted to be how black holes die a slow death if not fed by incoming matter.

Originally posted by Krakatoa
reply to post by schadenfreude

 

I believe the simple/short answer to your question is the radiation being emitted by the black hole is coming from just outside the event horizon. As particles spiral around and are accelerated to near light-speed, they are ejected with massive amounts of energy (which is why we can detect them). However, anything that crosses the event horizon will NEVER return (even light). But, keep in mind their information cannot be lost, so it is (theoretically) stored on the event horizon as sort of a hologram-like surface.

ETA: Yes. Hawking Radiation is predicted to be how black holes die a slow death if not fed by incoming matter.

edit on 14-8-2013 by Krakatoa because: Added Hawking Radiation info

Is this your personal theory, or do you have sources explaining this is how they're found?

thx for the quick replies guys, this has been bugging me. Too used to instant knowledge, add water & stir, then something like this comes along...

Think it was any particle can't escape the event horizon thingie. Radio waves aren't particles and the black hole will emit waves. Gravity can only bend, and not contain, wave doohickies.

Saw it elsewhere on the internet, it must be true.

reply to post by ChuckNasty


Even radio waves, which are made of the same stuff as light, can't escape the event horizon.

What we detect is the emission of particles from the accretion disk outside the event horizon as stated by another poster.

Nature

Here is a lecture given by the theoretical physicist Leonard susskind that deals with the nature of black holes. It is actually quite easy to follow considering the complexity of the subject, and well worth watching if you have an hour to spare.

Originally posted by schadenfreude
Is this your personal theory, or do you have sources explaining this is how they're found?

No it's not his personal theory, and it's the right answer. If you want to find sources, I'm sure you can. I put "x-ray emissions black hole" in search and the very first result explains it along with other sources...you aren't too lazy to run a simple search, are you?

The Hawking radiation is hypothesized but I don't think it's experimentally confirmed. Part of the reason for this is it would be more intense on relatively low-mass black holes, and we've never found a "small" or low-mass black hole. we never found one smaller than 2 solar masses. Opinions vary but if the Hawking radiation idea is correct, all the low mass black holes, if there ever were any, have possibly already "evaporated", and the high mass black holes don't evaporate due to the cosmic microwave background radiation. Also not my personal theory and multiple sources explaining all this, probably in the black hole wiki for starters.

Originally posted by schadenfreude
I've always been fascinated by black holes & while I was searching for whether science had discovered tachyons (FTL particles) yet, this question came up in my mind. (And I'm hoping someone here can answer.

Science says that nothing can escape a black hole, yet i recall reading that "they" discovered Cygnus X-1 by radio waves?

If nothing can escape, how are these radio signals getting to us? And, if they ARE escaping, then aren't they tachyons?

I'm sure there is something I am missing here, and I have done due diligence by trying to find this answer online. (Including watching many youtube vids with Kaku & Tyson.

Any geeks out there wanna help a fellow nerd out?

Thx in advance.

What really gets me is the idea that what they pick up by radio waves is still not what is there now, it's what was there 26000 years ago. I believe in hawkings radiation (to at least some degree) and I do believe black holes emit something... it only makes sense that if something goes is, it is converted and something comes out.

If what we see in the middle of our galaxy was there 26000 years ago, then what is there now? Do they know? That is a question I'd like the answers to. Light, gamma rays, x-rays... all seem to travel the same speed, so what doesn't? If there is a more immediate gauge to judge then this is the connection we have currently, to the black hole. What if all that is gone... or drastically changed from what we see? The closest star is still over a light year, so that is still "last year" or more. When I look at the milky way... all I see is a big poof of the past... even though I know there must be something there, I can't escape the feeling when looking at the whole thing in the sky that it is just a distant past in so many ways.

Speed of light is something like 670 million mph in a vacuum. Space is not a perfect vacuum so refraction will slow down the speed of light... to varying degrees.

All this weirdness on top of the fact that the sun is moving over 50000 mph through the galaxy and we feel NONE of that because it is all relative and our relative little gravity protects us from feeling it... which gravity also happens to be the speed of light. That point by itself trips me out.

...but back to the speed of light, it has been demonstrated by different people through material and waveguide dispersion that the speed of light can be stopped altogether. Anyone who has ever blocked out a window trying to sleep during the day, to some degree knows this.

Now what do we know about black holes? They are dense... and the area around them is dense. So they are not black and they are certainly not empty... we just can't see them due to refraction of the immense density. This also trips me out.

I guess my point being that black holes emit something and it is no coincidence that there are stars packed around them... because they are not voids of any sort. They have immense gravity because they are supermassive, but they are not just sucking things in because something must be acting against that gravity.... perhaps like the sun but on a much larger scale. The sun has gravity and sometimes things fall into it but there is also things like solar winds and forces opposing that in different ways... or we'd all fall into the sun. We don't. We just keep spinning around it.

Thats what I think anyway... It emits and it is burning like a very dense star that you just can't see.

What if none of that is there now and it just exploded a very long time ago? Wouldn't that be interesting? What if parts of the galaxy are just the exploded remains of the inner core and we just won't know that for a very long time? And what if the explosion was so intense that it sent all kinds of stuff outward at the speed of light for quite some distance and that a lot of the galaxy that we DO see is really just parts of the black hole that we are not aware is really no longer there?

Ok, I'll stop with the what ifs. It's just so crazy to think about.

...but now I have to look up the speed of particles closer to the center of our galaxy because if they are moving really really fast... then that's weird and I'm going to be thinking about it a whole lot until I come up with a new weird theory.

what's beyond the event horizon?

Originally posted by spartacus699
what's beyond the event horizon?

The heaviest, most dense and most heat stable elements in our galaxy... and everything else that falls in is just...poof...gone, converted...hawkings radiation.

That's my guess... although I don't know what it would be called specifically.

Originally posted by Krakatoa
reply to post by schadenfreude

 

I believe the simple/short answer to your question is the radiation being emitted by the black hole is coming from just outside the event horizon. As particles spiral around and are accelerated to near light-speed, they are ejected with massive amounts of energy (which is why we can detect them). However, anything that crosses the event horizon will NEVER return (even light). But, keep in mind their information cannot be lost, so it is (theoretically) stored on the event horizon as sort of a hologram-like surface.

ETA: Yes. Hawking Radiation is predicted to be how black holes die a slow death if not fed by incoming matter.

edit on 14-8-2013 by Krakatoa because: Added Hawking Radiation info

No its due to heat being lost to space and as E=MC2 this means mass is being lost. Just keep in mind that this process would be incredibly slow. In fact no black hole of any mass larger then a soccer ball would have had time to evaporate yet. And also the entire subject of black hole evaporation is extremely speculative. It involves figuring out how to perform quantum-mechanical (or rather quantum-field-theoretic) calculations in curved spacetime, which is a very difficult and gives results that are essentially impossible to test with experiments. Physicists *think* that we have the correct theories to make predictions about black hole evaporation, but without experimental tests it's impossible to be sure.

Originally posted by spartacus699
what's beyond the event horizon?

Ironically you could pass through the event horizon and not notice, At least not at first anyway as you get closer to the singularity it gets really messy as the differences in gravity rip you apart. However this has to do with space time and being the observer. From outside the black hole an observer would literally see you come to a stop to them you would be frozen at the event horizon because time would almost come to a stop from there point of view.

Originally posted by NotAnAspie

Originally posted by spartacus699
what's beyond the event horizon?

The heaviest, most dense and most heat stable elements in our galaxy... and everything else that falls in is just...poof...gone, converted...hawkings radiation.

That's my guess... although I don't know what it would be called specifically.

thats' thinking on such a physical level. ... Hawkings it figures. What it might actually be is some kind of spiritual portal where the 3rd dimention intersects with the 4th

reply to post by NotAnAspie

If what we see in the middle of our galaxy was there 26000 years ago, then what is there now? Do they know? That is a question I'd like the answers to.

To answer the question, we would have to map the position and velocity of every object now visible within 26,000 light-years of the galactic centre. Then we'd have to extrapolate forward 26,000 years to see where they are now. We would, of course, have to take into account the effects of gravity and of collisions between bodies when making the calculation...

...nope. I don't think even the world's greatest supercomputer has the processing capacity to do that.

Light, gamma rays, x-rays... all seem to travel the same speed, so what doesn't?

All of the above are forms of electromagnetic radiation – forms of light, along with microwaves, radio waves, infrared and ultraviolet radiation. All travel at the speed of light. Everything else travels more slowly.

I can't escape the feeling when looking at the whole thing in the sky that it is just a distant past in so many ways.

That is absolutely correct. Astrologers believe the future is in the stars; astronomers know that it isn't the future, but the past that we see up there.

space is not a perfect vacuum so refraction will slow down the speed of light.

The vacuum of space is pretty good. The speed of light is not reduced from c.

it has been demonstrated by different people through material and waveguide dispersion that the speed of light can be stopped altogether. Anyone who has ever blocked out a window trying to sleep during the day, to some degree knows this.

These tricks don't actually slow light down; what's happening is a bit more subtle than that. A subject for another day, perhaps. Actually, there are plenty of threads on ATS about it.

Now what do we know about black holes? They are dense... and the area around them is dense. So they are not black and they are certainly not empty... we just can't see them due to refraction of the immense density.

The area around a black hole doesn't have to be dense. If a very small black hole is floating in intergalactic space, there may be nothing but vacuum around it. It isn't refraction but absorption that makes black holes invisible. And it's the destruction of matter around large black holes that makes them detectable.

I guess my point being that black holes emit something and it is no coincidence that there are stars packed around them... because they are not voids of any sort. They have immense gravity because they are supermassive, but they are not just sucking things in because something must be acting against that gravity.... perhaps like the sun but on a much larger scale. The sun has gravity and sometimes things fall into it but there is also things like solar winds and forces opposing that in different ways... or we'd all fall into the sun. We don't. We just keep spinning around it.

Hawking radiation is just a tiny trickle. It is not the way we spot black holes. We spot them, as I said above, by the energy emitted from matter circling the hole (like water round a plughole) and being torn to pieces by tidal (ie gravitational) forces.

What keeps us from falling into the Sun is the speed of Earth's orbit. The solar wind has no effect on this.

(A black hole) emits and it is burning like a very dense star that you just can't see.

We have no idea what conditions are like inside a black hole, nor could we ever, because the laws that govern matter and energy break down inside them.

reply to post by ChuckNasty


I believe you do not understand what event horizon means... its the border between the even activity and "normal" space...

Originally posted by Astyanax
reply to post by NotAnAspie

 

To answer the question, we would have to map the position and velocity of every object now visible close to the galactic centre. Then we'd have to extrapolate forward 26,000 years to see where they are now. We would, of course, have to take into account the effects of gravity and of collisions between bodies when making the calculation...

That is absolutely correct. Astrologers believe the future is in the stars; astronomers know that it isn't the future, but the past that we see up there.

Now what do we know about black holes? They are dense... and the area around them is dense. So they are not black and they are certainly not empty... we just can't see them due to refraction of the immense density.

The area around a black hole doesn't have to be dense. If a very small black hole is floating in intergalactic space, there may be nothing but vacuum around it. It isn't refraction but absorption that makes black holes invisible. And it's the destruction of matter around large black holes that makes them detectable.

What keeps us from falling into the Sun is the speed of Earth's orbit. The solar wind has no effect on this.


We have no idea what conditions are like inside a black hole, nor could we ever, because the laws that govern matter and energy break down inside them.

What I meant was "what travels *faster* than the speed of light", because that is the only way to detect what is there & that is what I meant by gauging it. How else could we gauge it but with an information medium that arrives much sooner than 26000 years... so instead of "everything else" it seems more like "nothing else" is the correct answer... but I understand what you are saying. Most things travel much slower. I certainly wasn't under the impression that everything travels at the speed of light.

I can't quite wrap my head around a black hole surrounded by a vacuum, but I will certainly look into it. The reason I can't is because if it is surrounded by a vacuum, there's nothing stopping us from seeing photons emitted from it or anything else that could be visually detectable.

The solar winds absolutely have to exert some type of force on earth, even if it is the orbit that mainly holds it in place. We are not close enough to the sun for it's gravity to effect us in a large way, yes, most of our gravity is diamagnetic... but the sun's solar winds create a bow shock between it and the earth. That is definitely force to some degree. The sun also has strong gravity, which to us... may be slight, but it's still there and over time could draw us closer. Gases and electricity are something that I see as differing forms of energy potential, but they are related in the cosmos. Without one, you wouldn't have the other... vice versa. We see matter and gases when we look at stars and planets, but they are also electric. Material and electric potential are two side of the energy potential coin. We lose or magnetosphere, we lose our atmosphere. They are related in ways. When the sun loses one form of energy, it will have also lost the other. But both have at least some small effect on Earth.

As for the inside of a black hole, well I do not agree with that video that it shows how the world is a hologram... although he did raise interesting points. Such as the information only being able to exist on the surface. The reason is obvious... it's full. There is no more room inside of it because it is super dense & nothing else can fit into it. It is hotter than imaginably hot and simply disintegrates anything that falls into it and turns it into radiation. In our world we have things inside of all other things, because there is simply room for those things... it's not a hologram. A black hole is not 2 dimensional... it's simply *full*. The laws of matter and energy do not break down.

Hawkings radiation is of course not the way it is detected, but it's ever present if anything falls into it that cannot remain stable for at least some period of time, imo...it must. It will be incinerated. It's probably a combination of elements we could never combine. Most things would not survive those temperatures in any form but clearly something very dense *does* or it would have no mass and no density at all.

gravity is strong so it would naturally collect heavy dense matter & burn the rest off and the reason the gravity is so strong is because it is the core of our galaxy. It would have the strongest gravity of anything in the galaxy... There are things that can escape gravity to a degree, like gases... so it wouldn't be attracting those things near as much as more dense heavier elements... so it's certainly not gases it is attracting most.

As for a black hole surrounded by a vacuum... I'd like to see this if you know of a particular example.

Originally posted by dragonridr
In fact no black hole of any mass larger then a soccer ball would have had time to evaporate yet.

Something is wrong with either the math of Professor Baez, or your math...I'm guessing yours.

Hawking Radiation

the total lifetime of a black hole of M solar masses works out to be

10^71 M^3 seconds

I used a mass of a million kilograms for the black hole, which I'm pretty sure is more massive than a soccer ball, and got around 10^-72 for M^3 (assuming solar mass of 1.9891×10^30 kg), which when multiplied by 10^71 is just a fraction of a second. So even a million kilogram black hole would evaporate very quickly if the equation is right.

Thus a black hole with the mass of a soccer ball would easily evaporate in less than a millionth of a second, according to Baez's equation. If you know the mass for the soccer ball, you can plug it into the equation and find out how much less than a millionth of a second it would last.

Originally posted by Arbitrageur

Originally posted by dragonridr
In fact no black hole of any mass larger then a soccer ball would have had time to evaporate yet.

Something is wrong with either the math of Professor Baez, or your math...I'm guessing yours.

Hawking Radiation

the total lifetime of a black hole of M solar masses works out to be

10^71 M^3 seconds

I used a mass of a million kilograms for the black hole, which I'm pretty sure is more massive than a soccer ball, and got around 10^-72 for M^3 (assuming solar mass of 1.9891×10^30 kg), which when multiplied by 10^71 is just a fraction of a second. So even a million kilogram black hole would evaporate very quickly if the equation is right.

Thus a black hole with the mass of a soccer ball would easily evaporate in less than a millionth of a second, according to Baez's equation. If you know the mass for the soccer ball, you can plug it into the equation and find out how much less than a millionth of a second it would last.

edit on 14-8-2013 by Arbitrageur because: clarification

1 miillion kg wouldnt even be the size of a soccer ball. Just so you know our sun wouldnt even form a black hole but its solar mass is 1.98 nonillion kilograms. And alsi 1 million years = 31 557 600 000 000 seconds. So look again at your math.

Originally posted by dragonridr
! illion kg wouldnt even be the size of a soccer ball. Just so you know our son wouldnt even form a black hole but its solar mass is 1.98 nonillion kilograms.

Originally posted by dragonridr
In fact no black hole of any mass larger then a soccer ball would have had time to evaporate yet.

You may have meant size, but you said mass, the first time. Now you mention size. There is a difference.