Information Paradox

[mrcurious]

I've read on wiki about the information paradox, but I don't really understand what its trying to say. What type "information" can't be destroyed? Everything is destroyed by a black hole, so what makes information so special?

 

[kelvinzero]

As I understand it, black holes are predicted by general relativity while the notion that information cannot be destroyed is a result of quantum mechanics.<br /><br />This conflict is a barrier to unifying the two theories.<br /><br />Remember that we have no experimental evidence that black holes destroy information, only the predictions of one theory that seems to conflict with another theory.

 

[heyscottie]

Steven Hawking recently came up with a method that he believes allows information to be preserved in a black hole, where it can be released to the universe at large through Hawking radiation...

 

[mrcurious]

I understand that, but I'm more concerned about the type "information." Are we talking about particles, atoms, all forms of matter that enter the black hole? I guess I don't understand what kind of information and why can't it be destroyed.

 

[alokmohan]

You can know only mass,charge and spin of black hole.Never what aws there before it becme black hole.Information barred.

 

[vogon13]

I think we need to exam a possible conservation law here, information can neither be created nor destroyed.<br /><br />So if we accept black holes as unable to erase information, then, logically, what creates information in the first place?<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[spacester]

<font color="yellow">what creates information in the first place? </font><br /><br />My understanding is the answer to that question is "The Big Bang"<br /><br />http://en.wikipedia.org/wiki/Information_entropy <br /><br />rogers_buck would be all over this. When he returns, we'll get a better answer. <div class="Discussion_UserSignature"> </div>

 

[kyle_baron]

<font color="yellow"><br />I'm more concerned about the type "information." Are we talking about particles, atoms, all forms of matter that enter the black hole? I guess I don't understand what kind of information and why can't it be destroyed. </font><br /><br />The 3 dimensional "stuff" that falls into a blackhole is destroyed. However, it is preserved on the surface area (not within the volume!) of the blackhole, as a 2 dimensional screen. The analogy is similar to a Cat Scan of any part of your 3 dimensional body. It would show a 2 dimensional picture (the information) of that part of the body. Keep in mind that this is a highly abstract concept that was proven mathematically. In reality, you're never going to be able to actually look at the surface area of a black hole. <img src="/images/icons/wink.gif" /><br /><br />Hawking's Radiation carries energy away from the blackhole. The black hole slowly loses mass, and slowly evaporates. At this point, the surface area decreases, and space re-emerges. The bet between Hawking and John Preskill is whether the information also re-emerges. Hawking said No, and Preskill says Yes. Apparently, Hawking paid off the bet, admitting that the 2 dimensional information re-emerges. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[weeman]

This is what some physicists are arguing in favor of: Information cannot be destroyed, so when a black hole evaporates, it has to release this information back into the universe.<br /><br />All particles that make up all matter in the universe consist of information, sort of like the code that makes up a computer program. Only we are talking about the code that makes up the entire universe.<br /><br />Some physicists argue that this is one of Hawking's blunders when it comes to the fundamentals of black holes. Physicists say that this information cannot be destroyed. So, when a black hole eventually evaporates, what happens to this information?<br /><br />Information exists in a way so that you could seemingly be able to destroy it, but if you had all the bits and pieces together in the right place, you could hypothetically bring it back to its original state, almost as if it were out of magic. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[alokmohan]

A black hole is end result of death of massive stars. BeFore demise there may be features of that STAR .For instance it may have mountain.Another star may not have mountain.But they becomr black hole there surface is all the same somooth in either case.It is said black hole has no hair.

 

[enigma10]

Mountains and hairs. Sounds kind of , erm, kinky for a black hole. <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[alokmohan]

John Wheeler is leading scientist of black hole.He holds this view.The "No hair" theorem states that black holes have only 3 independent internal properties: mass, angular momentum and electric charge. It is impossible to tell the difference between a black hole formed from a highly compressed mass of normal matter and one formed from, say, a highly compressed mass of anti-matter, in other words, any information about infalling matter or energy is http://en.wikipedia.org/wiki/Black_hole#Do_black__holes_have_.22no_hair.22.3F

 

[kyle_baron]

<font color="yellow"><br />Some physicists argue that this is one of Hawking's blunders when it comes to the fundamentals of black holes. Physicists say that this information cannot be destroyed. So, when a black hole eventually evaporates, what happens to this information? </font><br /><br />IMO, when a black hole evaporates completely, the information is gone. However, while it is evaporating, it acts as a 2 dimensional screen. The question is, how does this screen work? I believe it has to do with the infinite redshift and time dialation that occurs when something falls into a black hole. In other words, it would <i>appear</i> (from outside the black hole) that an object would take <i>forever</i> to fall in.<br /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[weeman]

Correct. <br /><br />Visualize that you are in a ship with your friend, sitting a ways away from the event horizon. Your friend decides he is going to travel into the black hole to see what it is all about. As he makes his way towards the event horizon you watch him move farther and farther away. However, there is a point where you will see him as if he is frozen in place, even though he crossed the event horizon a long time ago. To you, he will never appear to cross the horizon, it will seem to take an infinite amount of time for him to cross over. <br /><br /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[alokmohan]

Frozen star as they say.

 

[alokmohan]

Frozen star.

 

[ajna]

Weeman: "To you, he will never appear to cross the horizon, it will seem to take an infinite amount of time for him to cross over."<br /><br />Is this the same as preservation of information at the horizon then? If you can still see him, his information is still there. Is that the 2D screen?<br /><br />Also, what would happen to this man as the BH evaporated? Would he come back out through that 2D image, or is it that the image will disappear and be converted to a higher entropic state as random radiation/gravity waves etc? Thanks

 

[docm]

The latter plus particles since he would have long since been spaghettified.. <div class="Discussion_UserSignature"> </div>

 

[alokmohan]

Information paradox means you never know what happened earlier,at the beginning.

 

[mrcurious]

<font color="yellow">"To you, he will never appear to cross the horizon, it will seem to take an infinite amount of time for him to cross overIs this the same as preservation of information at the horizon then? If you can still see him, his information is still there. Is that the 2D screen?</font><br /><br />Thats how I understood the description.....if thats not it, then someone please provide a better description.<br />

 

[ajna]

"Information paradox means you never know what happened earlier,at the beginning."<br /><br />This is just the nature of the quantum realm then, as nothing can be discerened with certainty before or after a quantum event. So this is where quantum mechanics meets general realivity. I wonder, is gravity subject to quantum effects at planck scales? Have we assumed gravity is continuous when it is not? <br /><br />The event horizon must be where the fabric of spacetime curves to such an extent it prohibits the internal dimensions to exist as we know them, thereby releasing that energy to the quantum soup within, only to be released via quantum evaporation into our dimensional configuration as randomised information. In other words, a cosmic mincer.<br /><br />So the information is both lost and not lost. One the one hand it is transformed beyond predictable recognition (even though its image immediately prior to the event horizon lies in-state), on the other it exists but in another form.

 

[alokmohan]

Possibly it means blackhole has no hair.See Wheeler .Read Wheeler.

 

[kyle_baron]

<font color="yellow"><br />"To you, he will never appear to cross the horizon, it will seem to take an infinite amount of time for him to cross overIs this the same as preservation of information at the horizon then? If you can still see him, his information is still there. Is that the 2D screen? </font><br /><br />Yes, the 2D screen is the gravity well at the Event Horizon. When the Blackhole evaporates completely, the gravity is gone, and so is the 2D screen.<br /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[alokmohan]

It never evaporates.Does Hawing think so now?I doubt.