Black Hole Question

reply to post by Atzil321


I actually fell asleep on it but did learn something, so thx.

I enjoyed how he had a laymen attitude though, very refreshing.

Originally posted by Arbitrageur

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.

Hi troll, how r u? Now wasn't that rude, or do you suffer from i'majerkitis?

The theory I asked him to define with sources WASN'T hawking radiation, but that the way they find black holes is by the energy ejected by these particles NEAR the event horizon, hence the question.

Why would I do a search on "X-ray emissions"? Why would I think that has anything to do as an answer UNTIL I can read a source for what he is saying and maybe THEN I'll do my google-fu instead of being called lazy.

I mean damn, I came here asking for answers, and barring that sources for answers given so i can LOOK THEM UP and I'm the lazy one?

DIAF.

reply to post by Krakatoa


thank you for your response. I don't understand how particles being emitted by random trajectories points to a specific point in space & identifies something specific like a black hole, (which is why I asked for sources) but thanks anyway.

Here is something that bugs me about black holes, the theory is that a star over 25 masses of Sol will collapse into a black hole, okay, so how does Sirius the dog star, biggest star in the galaxy, avoid collapsing?

Think of the "Event Horizon" as the ground on earth and everything above that the Atmosphere of the black hole. Well stuff on the ground stays there or below, and stuff can happen in the atmosphere like storms and such that produce energies enough to explode away from the black hole rather than get sucked onto the ground "Event Horizon".

The atmosphere of a black hole is so violent where gas or other atoms move at such high speeds that when they collide they produce energies that can still pull away from the black holes gravity and be detected in space.

Any atoms or matter that get to the ground of the black hole are stuck there for ever except maybe there is a tiny layer that can excrete energy.

Originally posted by schadenfreude
reply to post by Krakatoa

 

thank you for your response. I don't understand how particles being emitted by random trajectories points to a specific point in space & identifies something specific like a black hole, (which is why I asked for sources) but thanks anyway.

Your thinking to broadly x ray emissions created at the event horizon will have random trajectories but we will only see the ones heading for us. Its like looking at the sun we know photons are streaming out everywhere but when we see it we see only the ones that travel towards us. We dont see the ones on the opposite side for example unless we have something there to monitor it. As far as pointing to a particular place we need two coordinates line of sight and distance. So we can say hey here it is right there when we point the telescope at it. Distance is a bit trickier We use something called parallax.As we know the earth is moving so if we compare two pictures of stars will see they moved slightly. measure that difference and just like in geometry 2 points can give you a third.

The observed radio and x-ray emissions are not originating from the black hole itself, more over the effect the blackhole has on its surroundings.

The radio emission is called by Synchrotron radiation from highly relativistic charged particles bending and spiralling around magnetic fields, as they are 'accelerated' around the magnetic fields they emit radiation. A highly compact object such as a black hole, and one that can theoretically be highly magnetized too is a perfect environment for this. Black holes have been observed to have polar jets when they are 'feeding' or accreting material, these jets form streams of very hot and energetic particles which can emit synchrotron radiation.

The other source is accretion disks as material falls into a blackhole it never just goes straight in, but spirals down very slowly, in the reference frame of an object falling in, it would take only a matter of seconds, but to an external observer it would last for years, anyway the lowest energy configuration of a orbiting system is a disk, so when material falls into a blackhole it naturally forms a disk around the rotational axis. This material gains energy through loosing potential energy as it is accelerated around the blackhole. This too will emit synchrotron and bremstrallung (breaking) radiation which can reach the x-ray spectrum.

Im sure there are other effects but this is what is believed to occur for the most part

reply to post by schadenfreude


I tried to give you the simplest answer, and didn't provide "sources" since they are easily searched on the Internet...sorry.

Originally posted by dragonridr
Distance is a bit trickier We use something called parallax.As we know the earth is moving so if we compare two pictures of stars will see they moved slightly. measure that difference and just like in geometry 2 points can give you a third

This is only true for objects that are very close, our best parallax measurement is made by the Hipparcos satellite which (according to the wiki) goes out to 1600~ly

All is not lost however, there are variable stars and classes of stars regular stars that have been observed to always produce the same brightness or brightness oscillation. These are called standard candles and using a combination of this information and parallax we are able to calibrate distances to objects much much further away.

There are also certain types of supernova which produce very similar or identical flashes of light when they appear, these too are used as a calibration point, these measurements are what is used to calibrate distance/red-shift.

In all the question of distance measurement is a extremely complicated one and is one that is updated as measurements and methods improve.

reply to post by schadenfreude


Hi schadenfreude

As others have pointed out, black holes don't emit anything by themselves (ignoring possible Hawking radiation).

Cygnus X-1 belongs to a binary system consisting of a star and a black hole. The hole is fed by the star with matter. The accretion disc around the hole, solar gases superheated to several million degrees, is generating the x-rays.

black holes eat everything up,thats the theory to scientists,now they say everything goes some where so where does it go once its entered the black hole?every1 says everythings ripped apart but do we know that as fact?we don,t so it makes u wonder where 1 would take u if it was entered.

Originally posted by sparky31
black holes eat everything up,thats the theory to scientists,now they say everything goes some where so where does it go once its entered the black hole?every1 says everythings ripped apart but do we know that as fact?we don,t so it makes u wonder where 1 would take u if it was entered.

Due to the information paradox, it is theorized that at the quantum level, as a particle crosses the event horizon, it could result in one (or none) of the following theories,depending upon your personal beliefs:

Stephen Hawking posits that, "...it was possible that, as an object fell into a black hole, it would disturb the black hole’s radiation field. The information about the object could seep out, though probably in mangled form, through the fluctuations in this field.

Leonard Susskind and Gerard ’t Hooft posit that, "another way to approach the problem of black hole information loss is through the holographic principle of, or the related AdS/CFT correspondence developed by Juan Maldacena. If these principles hold for black holes, it may be possible that all the information within the black hole is also encoded in some form on the surface area of the black hole."

String Theory and the Information Paradox
NOTE: Please do not take offense at the source being a "for Dummies" reference....it is just a simpler explanation for the lay person, avoiding all the complicated and mind altering mathematics under-the-covers.

reply to post by schadenfreude


You can Google: Black Hole Polar Jets

The polar jet/jets that are sometimes spewing from active black holes, are exiting near the speed of light. It is probably the same kind of gravitational magnetic field process for a flying saucer, that uses a black hole core engine --- only the saucer uses one jet for propulsion --- due to the "one-sided gravitational dragging of space time near it's core." Quote: Dr. Revak Williams.

Since the saucer is a free bird...by not having it stuck in it's own space time --- it can use a polar jet from a thruster that would increase speed --- exponentially squared --- into the superluminal [beyond the speed of light] realm.

"As the particle spiral into the black hole that drags the magnetic fields causing them to twist. Eventually the magnetic fields will become so strong that instead of the particles dragging the magnetic field accelerates the particles toward the poles; then go flying out in the form of jets."

The photons are heated into a plasma and converted "from rest mass into energy."

Quotes: Black Hole Polar Jets

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

Nothing can escape a black hole, but plenty can escape before it's swallowed up. What astronomers are seeing is energy escaping as it's being pulled near the speed of light toward the hole. It speeds up, emits radiation, which in turn blocks itself from going faster and into the hole. A little like having too much water trying to go down a small drain. It backs up. And in the case of a black hole, some of it has enough momentum to get blasted all the way away from the hole in the form of radiation that we can hear as a radio signal.

That's kind of the way I understand it, anyway. Stephen Hawking could probably explain it better. He's the dude with the Nobel Prize.

Originally posted by sparky31
black holes eat everything up,thats the theory to scientists,now they say everything goes some where so where does it go once its entered the black hole?every1 says everythings ripped apart but do we know that as fact?we don,t so it makes u wonder where 1 would take u if it was entered.

Well the problem has all was been 1 thing the singularity itself math breaks down completely at the singularity. This has all ways been the stopping point of physicists. Though i remeber reading a paper that said in certain circumstances we could pass through the singularity and would pop up in another universe. There is also a theory that are universe exists in a black hole. This is used to explain a couple of things we dont have the answer to like how was the singularity created in the big bang. How did inflation start why did it end and what is dark energy.

It has to do with something called space time torsion. Ill try to explain this Einstein-Cartan-Sciama-Kibble theory of gravity, takes into account effects from quantum mechanics. In quantum mechanics spin is very important well this spin can create twists in space time. We need to define space time here everyones seen the rubber stretched with a bowling ball on it. Forget that think of space time as more like a net made of steel threads all interlacing much like a net. Now if we bend those threads act much like what we see as gravity but there is another option that would only occur in the early universe and of course black holes where things are so extreme.

Instead of our steel threads bending they twist like a spring this is called torsion. Now under normal conditions these twists are not enough to overcome gravity but in the black hole these twists in space time can build up to the point where they overpower gravity.And just like a spring that energy expands outward causing inflation. The increasing numbers of particles with spin would result in higher levels of spacetime torsion. The repulsive torsion would stop the collapse and would create a "big bounce". It even explains why time only moves in one direction as matter passes through the event horizon it can only move in one direction thus we get time only able to move in one direction as well.not to mention explains matter anti matter imbalance. so imagine in every black hole could be an entire universe!

reply to post by NotAnAspie

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.

I see. Well, nothing travels faster than the speed of light as far as we know. Tachyons have never been detected and there is no theoretical necessity for them to exist, either.

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.

Hawking radiation is just a trickle of infrared photons, emitted in all directions. Unless quite a few of those photons happened to strike your detector you wouldn't know a hole was there.

Just how small is this trickle? Well, the temperature of a black hole of M solar masses is only .0000006/M degrees Centigrade above absolute zero. Unless the hole is tiny – like virus-sized – you wouldn't be able to detect its Hawking-radiation emissions. And black holes that put out a lot of Hawking radiation are very short-lived, so the chances of some telescope being pointed in the right direction at the right moment to detect one are miniscule.

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

The above explains why it is very unlikely that any will be detected. We'll have to create one ourselves!

More about Hawking radiation.

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... the sun's solar winds create a bow shock between it and the earth. That is definitely force to some degree.

As I type this, the solar wind density (updated every ten minutes here) is five protons per cubic centimetre, which is about average. The solar wind is really a pretty high-grade vacuum, and presents absolutely no obstacle to the motion of Earth (or anything else) round the Sun.

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...

Gravity works at all distances, though its force decreases in an inverse-square ratio with distance. The Sun's gravity works on Mercury and it works on Pluto just as it works on Earth, but none of them fall into the Sun because they are moving too fast for that – Earth much faster than Pluto, and Mercury much faster still.

Diamagnetism has nothing to do with gravity.

Information (is) only able to exist on the surface (of a black hole because)... it's full. There is no more room inside of it (for information) 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.

A black hole is never full. That's why it keeps swallowing things up. Black holes are insatiable.

A black hole is never hot. Black hole temperatures (again, except for very tiny ones) are just a few billionths of a degree above absolute zero.

reply to post by pikestaff

How does Sirius the dog star, biggest star in the galaxy, avoid collapsing?

The size of a star is determined by two forces: the explosive force of nuclear fusion which pushes matter outward from the core, and the force of gravity that attracts matter inward, toward the centre of the star. These two forces, opposing each other, reach equilibrium at some distance from the centre. This distance is the radius of the star.

As a star ages, it uses up more and more of its fusion potential, turning lighter elements into heavier ones and growing cooler. Eventually, the fusion process runs out of fuel and the star begins to collapse in on itself.

What happens thereafter depends on how massive the star is. If it's massive enough (about four or more times the mass of the Sun), it will end up as a black hole.

Sirius, by the way, is only about two solar masses. It won't collapse into a black hole, ever. The most massive star in the Galaxy is about 80 times as massive as Sirius.

Sirius is an interesting system, in that Sirius A is a hot white/blue star (pretty unusual around these parts much like the sun (which is yellow) ) with mass around 2 solar. Its companion is a 1 ish solar mass white dwarf which is unusual in that most white dwarfs are about half that.

It is possible during the evolution of this system that during the red giant stage of Sirius A, Sirius B might be able to accrete enough material to pass the Chandrasekhar limit and collapse to form a neutron star. This would be an extremely energetic event and probably one that would cause significant disruption to Sirius A, if not our own solar system in terms of a nice radiation bake.

Though Sirius A is over the Tolman–Oppenheimer–Volkoff limit currently, because during the later stages of a stars life, it will loose a good deal of its mass before dying and likely end up as a heavy white dwarf. To end up with a Neutron star the original must be something like 10-20 solar masses.

Still extremely interesting that all this will occur so close to us... though not for billions of years.

My deduction: Since alien starships have peaceably invaded our planet --- since at least the 1940's --- they would have to have the technological wherewithal to build and pilot a starship that is capable of superluminal speeds. With my speculation: That the stardrive of said alien starship...would have the properties and substance of a black hole which is needed to attract photons, in order to propel the starship into the superluminal realm.


Cheers,

Erno

Originally posted by Erno86
My deduction: Since alien starships have peaceably invaded our planet --- since at least the 1940's --- they would have to have the technological wherewithal to build and pilot a starship that is capable of superluminal speeds. With my speculation: That the stardrive of said alien starship...would have the properties and substance of a black hole which is needed to attract photons, in order to propel the starship into the superluminal realm.


Cheers,

Erno

There is no drive that can be created to go faster then light the universe wont allow it. the only hope would be to warp space lessening the distance you need to travel.Now there may be aliens that learned how but we would see them coming. We would have detected the warping of space time much as we have to see black holes.So more then likely they arent here sorry,