Slashdot Mirror
How To Destroy a Black Hole
KentuckyFC writes "The critical concept that makes a black hole black is the event horizon: a theoretical boundary in space through which light and other objects can pass in one direction but not the other. Since light cannot escape the event horizon, it must be black. The event horizon is a nuisance to astrophysicists because it hides the interesting new physics that must go on inside a black hole. What they would like is a way to get rid of the event horizon so that they can see what goes on behind it. It turns out that just such a thing may be possible, say physicists. According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass. However the calculations are so fiendish (PDF) that nobody knows whether the black hole would shed this extra angular momentum and charge before it could settle into a stable 'naked' state. However, the possibility that the event horizon could be destroyed raises the question of what astrophysicists would see behind this veil. According to some, black holes are regions of spacetime with infinite curvature called singularities. Many believe that 'naked' singularities cannot exist in nature. And yet there are enough question marks to suggest that this mystery is far from settled."
What they would like is a way to get rid of the event horizon so that they can see what goes on behind it.
Am I understanding this? We don't really know how black holes work, but we know the event horizon is the point where light and other matter stop "coming out the other side", and in order to see what's on the other side, they want to dstroy a black hole?
two things...
Thing 1: head asplode
Thing 2: How is this a good thing to do? Aren't they basically stating that they don't understand how or why this is occurring, but they want to destroy something to figure out what goes on behind it? When are they planning to do this? December 21st, 2012?
Sent from your iPad.
Why am I getting a DEP when trying to open that PDF link?
did you forget to take your meds?
Someday, They'll find a way to actually go and feed a black hole all that charge and angular momentum. I'd like to be stored in a cryogenic storage till that day.
This is just damned neat. Destroy a black hole! Observe a singularity! Watch the cosmos bend into itself! Or...?
The best science is the stuff that ends in a big question mark. e.e. cummings nailed it on the head: "always the beautiful answer who asks a more beautiful question."
"People who do stupid things with hazardous materials often die." -- Jim Davidson on alt.folklore.urban
On a less serious note, does Rule 34 apply to naked singularities?
Remember to maintain your supply of
People thought communicators were way to far out too when TOS came out. Now we take
them for granted.
Now I don't think there are going to be any practical experiments around this theory /. but I'll go ahead and repeat it; a lot of scientists are heavily inspired by
anytime soon but "this shit" has to start somewhere. It's been said many times before
on
science fiction and, especially when they are young, love to see if their favorite
tech from their favorite shows are feasible.
Creationist Textbook Stickers Declared Unconstitutional by CowboyNeal
It makes sense, but seems overly impractical due to the sheer energy or mass involved with a black hole. It'd be fun to see what would happen if the static forces were able to push photons hard enough to kick them out of the gravity well. I don't buy the bit about angular momentum so readily, I think the mass would then need to be flying off the sides of the black hole ~ impractical to get that much kinetic energy when you're adding more mass.
Christ, you always make the most asinine comments. It's almost impressive.
I thought this was another story about somebody wanting to nuke the Gulf of Mexico.
"The average reporter we talk to is 27 years old......They literally know nothing." - Ben Rhodes
Rule 34 only applys if they exist... so if you can find port of a naked sigularity there's a good posability that they exist
All of my lost left sox.
Two bolts from my motorcycle.
The lost chord.
George Bush's dignity.
Several B-19s last seen headed towards Bermuda.
An iPhone 4G prototype.
Darl McBride's balls.
And I'm sure there's more.
---- Teach Peace. It's Cheaper Than War.
Isn't the event horizon the point at which the gravitational pull of a black hole becomes so powerful that not even light can escape? How on earth will feeding the black hole more mass make the event horizon go away? I thought more mass meant more gravity..
Yes, of course. Rule34 applies to everything (and if not, Rule35 comes into play).
In this case -- you've seen goatse, right?
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
I don't think that results in a Naked Singularity... it results in its annihilation.
So they can actually SEE how the earth was destroyed by the LHC. I mean, if you go to all that trouble to destroy our planet, don't you want everyone to SEE your handiwork?
I need trepanation like I need a hole in the head.
And the Australian Government will track every time you mention it in e-mail or surf the web to the site
Been there, done that, paid for the T-shirt
and didn't get it
See? The writers of StarGate SG-1 already knew this when they wrote the 200th episode, which had the line: "The singularity is about to explode!"
...I really need a life, don't I?
"I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
Since light cannot escape the event horizon, it must be black.
Right, because anyone imprisoned anywhere must be black, because only blacks break the law and get locked up.
Information theory is life. The rest is just the KL divergence.
I once read a bit about black holes, and one of the things I read was: a black hole doesn't necessarily have to be very dense. It can also be sparse (and the larger, the sparser it can be). For example, if you'd take a lot of stars and planets, and put them together (but not too close together), then at one point if you make this large enough, it'll also be a black hole: there appears an event horizon around all this matter. But inside of it are still stars with gaps between them, maybe some planets orbiting around them, ... So now I wonder, if the above is true: can someone live inside that? Would there be any noticeable difference between being inside of that, and the other side (the outside) of this event horizon?
I thought that the event horizon of a black hole was caused by the immense gravity of the main body. Just an area of space around the black hole where light would be unable to maintain enough momentum to escape the gravitational pull of the singularity. I don't even want to try understanding the calculations that this theory was derived from. If you were able to remove the event horizon, would that not mean that you would be destroying the singularity itself?
I sure am dumb
We always hear about singularities necessitating event horizons, but the converse is most certainly not true. An event horizon may exist without a singularity inside of it.
It depends on scale more than anything. Small black holes almost certainly require a singularity, but a black hole the mass of a galactic cluster actually has a very low average density. So while at the event horizon space-time is very much distorted, on the inside it may not be distorted enough to overcome common everyday forces (the trick of treating a collection of mass as a point source of force doesnt work from inside that collection of mass)
"His name was James Damore."
er... transporters maybe, but most people in 1966 were pretty familiar with radio... and funnily enough, even the idea of sending pictures over the air, since that's how they watched the show.
Isn't that brown hole?
I am very sucseptible to "let's have another drink"
Exactly. Same thing with light sabers, and now you can buy one online for $200, and go start carving people up (albeit a bit slowly with this generation ... the next generation should pretty much have nailed the tecnology though, just as cell phones are not quite communicators capable of reaching our orbital ships).
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
"Charge and angular momentum" aren't that hard to come by near supermassive black holes, after all - massive accretion disk certainly can add angular momentum; and with large part of it being ionized one way or another, we might have appropriate charge in some cases...
What if naked singularity would turn out to be behind quasars; generally some unusually active cores of galaxies or relativistic jets?
One that hath name thou can not otter
Hawking Radiation would cause the blackhole to get smaller and smaller, and with it the diameter of the event horizon, you wouldn't get a naked blackhole.
These comments are my personal opinions and do not necessarily reflect the opinions of the other voices in my head.
Photons cannot escape because they are red-shifted due to time dilation. This means that the horizon will vary depending on the level of energy trying to escape it. For example, an X-ray might escape where an infra-red photon wouldn't. All or part of a huge energy blast may or may not escape, depending on its frequency, level and position. Whether it would affect the hole itself seems problematic.
Let's get started and throw Alaska into the black hole that is New Jersey!
I tried to think of a good sig, and this wasn't it.
There are a number of factors to overcome when making singularity porn:
1. once you put it in, it's a real bitch to take it back out
2. nobody has ever successfully pulled out in time
3. they start at sucking and never manage to make it to the sex part
4. Ebony has a trademark on the term "black hole"
5. it's kind of a tease to watch because as much as they constantly approach the "event horizon", they never quite reach it
If you can't say something nice, make sure you have something heavy to throw.
If by next generation you mean the next generation of the human species... There is this annoying problem with lasers that they tend to not really stop until they hit something. Make them as powerful as you want, until we crack how to make light "expire" any time you fire up your human slicer/dicer it will also slice/dice whatever else is around you too. Perhaps one case where a glass house is a good idea. And then, we need it form a beam that behaves as a force field and/or solid object (to allow for dramatic duels.)
Crack those little catches, oh and increase the power by about ten thousand fold at least, and you might have something like a Light Saber.
LUDDITE!, LUDDITE! Someone get me the rope & torches!! :D
There is a war going on for your mind.
One of the problems with approaching a black hole (aside from massive amounts of radiation around ones actively eating matter) is the fact that the force of gravity increases as you approach the mass responsible for the gravity.
With small black holes, as you approach (feet first) the difference in gravitational pull at your feet would be many times larger than the gravitational pull at your head. You would be literally ripped apart, down to the molecular level. This is known as "Spaghettification".
http://en.wikipedia.org/wiki/Spaghettification
However, with a large enough black hole, you should be able to pass the event horizon before these tidal forces grow large enough to rip you apart. Of course, this does you no good, because once you are inside the event horizon you cannot exert a great enough force to prevent yourself from falling deeper until the forces ARE great enough to rip you apart.
But for a large black hole, in theory, you could cross the event horizon without being ripped apart.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
Although no one knows what happens at the end point of black hole evaporation it is unlikely it would leave a naked singularity since the mass of the singularity is what is being 'evaporated'. Besides, even if there was a naked singularity around just before the thing evaporates it would be kicking out so much energy you wouldn't be able to get anywhere near it. A 1kg black hole evaporating would release the equivalent energy to a large thermonuclear weapon in a fraction of a second.
Hello,
Suppose you were falling into a black hole, and you didn't get turned into spaghetti (as might be possible if you're approaching the event horizon of a supermassive black hole). Would the event horizon seem to retreat before you? I mean, light can't escape a black hole's event horizon as we see it, but if you're falling in, wouldn't you be able to see further into the black hole as you fall?
--PM
Just get BP to pump hydraulic fluid into it. That HAS to work!
Off the main deflector dish;
That's the way do things lad;
just makin' shit up as we wish.
The klingons and the romulans,
they pose no threat to us!
'Cause when we find, we're in a bind;
we just make some shit up
If telephones are outlawed, then only outlaws will have telephones.
Goatse is not a black hole but a brown dwarf.
Peel back an Event Horizon? Get blasted with Radiation/Exotic particles,etc... Um just think what happens to the axis area... They are evaporating just not in a observable curvature that we can understand or detect.
Hey Hawkins back me up on this...
<robotic voice> that's what she said. ha. ha. ha.
Didn't the last Star Trek movie already prove that you only need some bad writing to destroy one?
I don't think we're talking about black holes measured in solar masses. However, if it's possible for a naked black hole to exist, we might be able to feed and disrobe a small primordial black hole or micro black hole formed through high energy collisions.
I'd say that given they can burn flesh now, they are probably only 10x power from carving through it. Ending the beam seems like a job for a transparent length of carbon nanotube fibers ending in a dispersant point (or reflectors if you want to conserve power). Really, the engineering problems seem entirely solvable at this point (expensively), and the cost will be coming down fast.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
Hold it... Rule 34 states that "if it exists, there's porn of it." It says nothing about "if there's porn of it, then it exists." I'm willing to give you the benefit of the doubt since you said "there's a good possibility that they exist," but you shouldn't assume that the converse of an if-then statement has the same truth value as the original.
Exactly how you would make porn of something that doesn't exist is left as an exercise to the reader.
liberate tutamae ex inferis
I understand that this is important science, but what a weird gap in scientific knowledge when we are considering how to collapse a black hole when we can't stop the damn oil leak. Maybe we should get some of these guys involved.
Flexible bare-metal recovery for Linux/UNIX
Black holes that evaporate due to Hawking radiation don't leave behind a naked singularity. They're just gone.
Most of the calculations about black hole are based on steady state. However, the time it takes to reach this state is of order of event horizon size divided by speed of light. Larger the black hole, larger the time. Thus if you have a black hole of the size of our visible physical universe, it can take billions of years to reach steady state. During this billions of years, life can go on normally! In fact the equation of universe with omega greater than one (which means that the whole universe would eventually contract and collapse to singularity) are almost same as a black hole with event horizon of the size of the universe.
However, most black holes are much smaller in size and hence are much more exotic. From what I understand, it is impossible to see any events which happened inside the event horizon. Thus you may be able to supply enough charge and angular momentum to remove its event horizon and reveal the interior of the black hole, but that would only let you observe the events that happened after you pass the charge and angular momentum (there is nothing new here, it is known for a long time). Any event that happened inside event horizon is forever lost (from classical point of view). From QM perspective, those events carry signature in Hawking radiation but that has nothing to with changing event horizon by supplying charge and angular momentum.
Due to time dilation, it takes a seemingly infinite amount of time to reach an event horizon because your speed will approach the speed of light. So it is impossible for an observer to reach an event horizon without an infinite amount of time.
Did I miss a joke? Almost syntactically, if the conjectured black hole evaporates, there is not much interesting left. I bothered to look at the links too. Duh?
Cool, a way to power warp drive.
One that hath name thou can not otter
A significant number believe that singularities cannot exist in the first place, naked or otherwise.
Anyway, if a singularity could exist, it would be a point of infinite curvature in space-time, i.e. a point of infinite mass. As such I don’t see any way for it to not create an event horizon.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
however I will argue that to make it work it may end up being a matter of trying to collide two black holes into each other with great speed. Further that though I wouldn't be surprised if that speed ends up being c.
I'm guessing you'd cause the black hole to eject particles that hopefully would be structured enough to provide us with information about what's happening beyond the event horizon or they might be completely random and tell us nothing. The summary and the article itself seem very confused. They portray the event horizon like it's some kind of shell that surrounds the core of the black hole hiding it from view. The event horizon is more like an asymmetric field that you need to find the right frequency to pass back out of once reflected off the structure of the black hole. I seriously doubt the event horizon would be blown away revealing a naked singularity either. It would just become permeable to a certain stream of particles going out instead of being infinitely internally reflected.
Jeez, it's like these dudes have never watched Star Trek.
If you are inside an event horizon (you can't ever see anything outside of the event horizon),
then if something enters your event horizon you are now able to see it, thus
invalidating the premise of the event horizon.
That means either:
1) Event horizon's do not exist.
2) You can't *really* enter an event horizon from the outside.
Hello,
Suppose you were falling into a black hole, and you didn't get turned into spaghetti (as might be possible if you're approaching the event horizon of a supermassive black hole). Would the event horizon seem to retreat before you? I mean, light can't escape a black hole's event horizon as we see it, but if you're falling in, wouldn't you be able to see further into the black hole as you fall?
--PM
Well, since sight depends on light reflecting off of objects to work... No, as you approached the event horizon, you still wouldn't be able to see into the black hole, as no light would be escaping (hence no visual information conveyed).
As to other point, no, the event horizon would not appear to be receding. You would seem to be approaching it normally (from your perspective), however due to time dilation, the rest of the universe would seem to be aging quite rapidly compared to you.
More of a Giant than a Dwarf from what my scarred psyche remembers.
you guys are all token-ring, let the ethernet-heads take this one over. tickle it and record what happens.
if this is supposed to be a new economy, how come they still want my old fashioned money?
Not true. we might be able to create a microscopic black hole that is massive enough to exist long enough that we could attempt this and observe the result. But you are right that attempting it on a natural black hole is pretty much impossible.
I have a pair of highly reflective scissors that say your idea won't hold up well in a duel... And for what it's worth handheld lasers (in the 500mw range) than can 'burn' flesh for the most part just blacken it, and have a relatively short duty cycle (10s/min for example) and lasers with enough power to reliably cut through things (such as those used in surgery, research, or manufacturing) are 100 or 2000 times as powerful (in the 50w to 1000w range) and also use an entirely different process (chemical) versus handheld lasers.
We might get there, but I would put money on clean fusion power before lightsabers or a lightsaber-equivalent portable device.
That allows information from inside the event horizon to leak outside (which is all the astrophysicists really need) and allows the evaporation of black holes, but the event horizon would remain intact. However, we have never seen Hawking Radiation (yet) and it depends some on certain assumptions being valid. One of these assumptions is that the singularity is something "physical".
A lot of cosmologists don't like infinities, so don't like singularities, but let us consider what "infinite gravity" would actually mean. It would mean you have a vertical gravitational well, with the universe being the "walls" of this well. As far as the universe is concerned. the actual hole that makes up the interesting part of the well is on the outside, just as the air in a physical well is outside the brick lining that comprise the walls. Since what we call "physical" are the objects inside the universe, it makes no logical or rational sense to talk of something that is on the outside as being "physical". You can detect it using the usual rules of topology and geometry (you can't apply any topological transformation to a torus to produce a sphere), but if you picture yourself as a Flatlander on the surface of said torus, you could NEVER observe the region on the outside that distinguishes the torus from a sphere. You could infer it existed, you could even prove that it has certain properties, but that's it.
Cosmologists and topologists don't get along, which is why space/time existed as fact in geometry long, long before any physicist accepted it was real. Einstein is said to have loathed and despised the concept, and only grudgingly accepted it had to be true after being dragged, kicking and screaming, by his theories into reaching no other answer. (You might gather from this I have a low opinion of certain branches of physics.)
But precisely because the rules of topology FORBID a torus to become a sphere, it would be impossible for a genuinely infinite-gravity singularity to evaporate completely. Instead of their evaporation speeding up as they shrank, it would have to slow down -- if they evaporated at all. Entirely the opposite of what physics expects. There's no reason for them TO evaporate, however. It is only required in cosmology to meet the requirements of the 2nd Law of Thermodynamics, but thermodynamics only applies to what exists. A hole is a region where the walls do NOT exist.
There is a third possibility. Under the standard model for space/time, time is orthogonal to space. If space is bent at 90' to all other spacial dimensions, then it is no longer space. It is time. This means that not only is there a singularity at the heart of every black hole, it would be the SAME singularity. There would have only ever been one singularity, right at T=0, and the throats of all black holes would be directly and permanently hard-linked to this. There would still be no evaporation at this end of time (it has already happened).
A fourth (and fifth) possibility is that black holes never actually form at all. There's an entire alternative model in cosmology which prohibits them outright, giving you that fourth option. Then, Professor Hawking's work on imaginary time and the curvature of time around singularities would eliminate the need for a singularity outright. If you factor time curving as well as space, then space/time never vanishes to a point. Space/time would become parabolic, giving it a minimal state, but there is no moment in which any variable hits zero or any infinite states are achieved.
There's probably others I've either not heard of, or have heard of and forgotten. But at least five different ways DO exist and are recognized in modern physics as possible in which no black hole singularity of the kind imagined would arise. That means there is simply no theoretical ground (right now) to assume that this new theory has any meaning or would make any sense.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
So would a naked black hole be known to have a "Non-Event Horizon?" Sounds like a suitable term for new title launches from 3-D Realms ...
The title of the paper is "Destroying black holes with test bodies," and the language about "destroying" black holes is echoed in both the arxiv blog summary and the /. summary. This may be somewhat misleading. They're actually talking about processes that would strip away the event horizon, leaving behind a naked singularity. The black hole wouldn't have been "destroyed," but just changed into a different form. The authors themselves put the word "destroying" in quotes in the paper.
The paper doesn't settle this one way or the other. It says shows that if you use a certain set of approximations, the result is that the event horizon can go away. However, there is no particular reason to believe that the approximation is correct.
The real issue here isn't whether a black hole can actually be transformed this way, it's the question of whether cosmic censorship holds. If cosmic censorship fails, then general relativity is fundamentally flawed as a classical field theory, because it fails to make predictions. John Earman's famous way of expressing this is that anything could come out of a naked singularity: lost socks, green slime, even horrible things like Nixon's "Checkers" speech or Japanese monster-movie creatures.
Find free books.
The event horizon is like where reality has hit a divide by zero error.
Hey! Who are you calling an error?
Event horizons only refer to light (or rather events or information that could be conveyed by light). Event horizons have nothing to do with other objects (with mass).
Other objects will have their own horizons, at greater distances from the black hole. These horizons are a function of the mass of the object. In scifi stories and thought experiments they like to talk about how some guy gets stretched thin like a noodle as he crosses the even horizon... Well, I have some bad news. You would get noodle-fied long before you crossed the event horizon.
Of course, the good news is that since this happens before you reach the event horizon, the rest of us get to see it!
dumb.
I did Ph.D. research on this exact subject a decade ago, and at a quick glance I didn't see anything new in this paper. A spinning and/or charged black hole in theory can be spun or charged to the point where a naked singularity would appear. But, the harder you spin/charge the black hole, the harder it tries to neutralize itself by preferentially emitting particles of a given angular momentum or charge. So the equality probably is a physical limit. I thought someone had proven that years ago, but I've been out of the field for a while.
This looks kind of like someone wrote a paper so they could go to a conference or something. There doesn't appear to be anything earth-shattering (or black hole-shattering) here.
Adding lots of angular momentum means the object has substantial velocity relative to the observer. If the observer is moving along with the black hole, then it doesn't have angular momentum, relative to whatever tools you are using to observe it, so that observer will still see an event horizon. If the observer isn't moving along then the black hole will move out of range for a lot of observations pretty swiftly. Note that a black hole can gain momentum relative to an observer just as well if the observer is the thing accelerated instead of the hole.
Probably the only even slightly practical way to add angular momentum to a black hole would be to get a serious electric charge on it first, so it could be accelerated magnetically. That's still far fetched engineering, but isn't theoretically banned. So the device that could do the preliminary job of making adding momentum possible, most likely could simply do the whole job by pumping more electrons in. Ergo, any species wishing to conduct the experiment will only build the gigantic electron gun, not the space magnets.
Who is John Cabal?
Does this make sense to anybody else, or I am just getting it wrong? From what I understand the event horizon is just a boundary signaling a point of absolutely no return due to the intense gravity pulling anything and everything into it. Neutralize the event horizon and you neutralize the gravity, which is proposed to be the element of the blackhole. Without gravity, no blackhole, or at least its a blackhole in stasis. Is the article meaning to neutralize gravity in the area around the blackhole, while leaving said hole itself intact?
They still had pack radios. It's not like it was a new impossible technology. It just took them about 30 years worth of miniaturization to get them down to the size as was in Star Trek.
That's what Japan is for.
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
That's not really correct. You don't directly perceive the time dilation, in that time seems to be passing the same to you. Only compared to an outside observer do you experience time dilation effects. Assuming that tidal forces/radiation/etc. weren't an issue, you wouldn't really notice much of anything different as you actually crossed the event horizon.
One time I threw a brick at a duck.
what I suggest is sending all those used tissue papers and playboy mags laying around young mens rooms! should be enough mass to plug that hole!
Since light cannot escape the event horizon, it must be black
That's racist!
Where some see a problem, other see an opportunity. Seems that the market niche for black hole haute couture has just opened.
Unless we are talking about microscopic black holes (lhc could be useful there) the typical scale of the maybe only useful for this black holes could imply throwing in things of the size of big suns or small galaxies. Probably by the time we could do that we already know what happens inside black holes (almighty usually implies allknowing too),
Not to mention the Dick Tracy comic strip, which featured futuristic gadgets like a two-way wrist radio. It was, as I remember, fairly popular before Star Trek.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
You can't destroy a black hole. Don't bee silly.
But you could block it with several parsecs of duct tape.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Looks like nobody took you seriously ;-)
http://en.wikipedia.org/wiki/Event_Horizon_(film)
You can't take the sky from me
According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass.
Who's gonna go spin the black hole and zap it with a few billion tazers?
Anybody?
Come on, it's for science!
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Maybe by the time anything reaches the singularity, the universe would've ended and time would cease to exist. That is, you can never reach a singularity, you (or what's left of you) can only ever continue to spiral around it until literally the end of time.
"If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
+3 Insightful
What are you trying to imply with a "white hole"? It would sound like you are suggesting that an antimatter variation of a black hole would have strong anti-gravity... That it would be so strong that even light could not reach it. Would that make the antimatter version of an event horizon to be... a U-Turn?
Though that is a funny though, I have serious doubts about such an idea.
'tis the wrath of our lord, the fly spaghetti monster as he takes his vengeance on those who disturb his home.
Read what I mean, not what I wrote.
The biggest problem is efficiency. Even if you had a battery with enough energy and power for a workable lightsabre, at even 99.9% efficiency the handle would probably melt in less than a second of use.
Emergency protocol at the LHC: blast it with charge and angular momentum.
I am not a theoretical astrophysicist, but I pretend to be one on Slashdot...
One thing that bothers me about this paper is that it suggest that by increasing the angular momentum (and/or the charge) to a great degree relative to the mass will cause the singularity to be exposed.
The problem I see is that as you add angular momentum or charge to a black hole, (even if you do it without directly dumping mass in), you are still adding mass. (E=mc^2, remember energy is mass). Without breaking out the old pencil and paper to check the numbers, I would suspect that by adding enough energy to the system to get it into an 'extreme' state with respect respect to the initial mass, you will have increased the mass to the point that you wont have enough charge or momentum to expose the singularity.
HA! I just wasted some of your bandwidth with a frivolous sig!
You were talking to an astronaut on the shuttle? Cool, the secret missions continue!
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
On a completely unrelated note, I listened to a BBC radio 4 report this morning all about the "Goatse hackers". I was sniggering all throughout the report, wondering how many of the unitiated googled goatse. I'm suprised this story hasn't hit /. yet, to be honest.
Show your work.
Admit nothing. Deny Everything. Make Counter-accusations.
What they would like is a way to get rid of the event horizon so that they can see what goes on behind it
I'll save you the trouble and expense.. The answer is Cthulhu and creeping madness... That's what's behind the event horizon and that's what goes on there...
You've been warned.
Save the Black Holes!
It is assumed that you are falling into the black hole accelerating according to the force of the gravitational pull of the black hole. So you WILL pass through the event horizon in a heartbeat.
Think of it this way:
Even if you had a magical platform that you could stand on just /outside/ the event horizon, you'd still be dead. The amount of gravity pulling down on your would not just stop your blood from flowing upwards, it would crush you into a puddle of goo on the platform.
The ONLY way you could survive the fall into the black hole would be under freefall. Any attempt to appreciably slow down your fall would result in you getting crushed. So any trip through the even horizon will be very, very fast. Probably an an appreciable fraction of the speed of light.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
So, if you cross the event horizon, time doesn't exist or is infinitely fast - which means you live forever. Then, as you hit the singularity, you are transported back to the begin of the (some?) universe. Fascinating.
1 - Is this literally true?
2 - What does it mean?
I've always wondered about this.
We got space, which is a vacuum, from what i understand.
We got black holes, that apparently light and nothing else can escape from.
We also have massive blackholes that are the center of galaxies that seem to be seeding the galaxies.
Here's my theory (construction zone ahead, ie, work in progress)
Our "big bang" started from a black hole being started in another universe. My thoughts are: A black hole starts, it's like pimple or something. A weakening in the structure of time & space that's able to hold stuff in it, but not spit it back out the way it came. When it gets full enough, it causes a "big bang" in a new universe.
Being as space is a vacuum, that the pressure created from one universe to the other is enough to push the galaxies like they are going.
Of course, there's a lot of work to go in this theory, and it's not based of math or physics, or anything, other then my own understanding or trying to understand.
Be seeing you...
I'm going to go outside and stare up at the sky for a while now... and maybe eat a doughnut.
Here's to hot beer, cold women, and Glaswegian kisses for all.
Singularities in your model are always places where your model stops working - you have to be pretty silly to think what you're modeling has a singularity.
A black hole, per general relativity, is just a place where (from the perspective of an outside observer) the space and time axes are titled significantly, so that the time "direction" looks like a spatial direction. Of course, that's how all of gravity works, just not ususally to such an extent.
While Hawking's imaginary time is a good and clever way to make a model that doesn't have a sigularity, I rather suspect that the model we have based on the observable universe is just flat out wrong past the event horizon - but's it's boring to say "you can't do science there" and entertaining to read Hawking, so I'm not complaining!
Socialism: a lie told by totalitarians and believed by fools.
For a more entertaining look at a naked black hole see http://www.amazon.com/Compleat-McAndrew-Charles-Sheffield/dp/067157857X "The Compleat McAndrew" by Charles Sheffield Good read on how to use and abuse a black hole for fun and profit.
Black hole evaporation converts the mass of the black hole into energy. 1 kg per the Google calculator is 8e+16 joules, or about a 20 megaton explosion.
Socialism: a lie told by totalitarians and believed by fools.
No, but North Korea is better known for making things that don't really exist. I'm not sure that Japan has yet proven successful at making things out of nothing, as of yet. But if anyone can do it, I bet it's North Korea's Kim Jong Il.
Not quite.
Time stops... and you are moving infinitely fast... the two of which, together, mean you get ripped apart. On a sub-atomic level. Sorry about your luck.
What happens to the particles that formerly composed you when they hit the singularity... well, that’s anyone’s guess. Personally, I’m inclined to believe that the universe is a continuous medium and singularities are impossible, but it’s all theoretical no matter what theory you believe.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
http://www.youtube.com/watch?v=eI9CvipHl_c
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
flashlight and an energizer bunny battery?
If one can assume that there is a reason for an event horizon to be missing from a Black Hole, why don't we just look for one that has? And while I'm depositing my 2 cents in a bank account so that I can get a table at the End of the Universe, what would a Black Hole look like without an event horizon?
Always remember that, in Russian, 'black hole' does not refer to a collapsed star.
It means exactly the same in Russian that it does in English (what formally is not a "collapsed star" but "an object capable of capturing light by its gravity").
(In Soviet Russia humor fails you).
Contrary to the popular belief, there indeed is no God.
The existence of an event horizon does NOT require the existence of a singularity. It only requires a certain amount of mass within a given volume (defined by the equation for the Schwartzchild radius http://en.wikipedia.org/wiki/Schwarzschild_radius. For the size of black holes we usually think about (up to the size of the black holes assumed to be at the center of most galaxies), the gravitational forces are so large that nothing we know of will stop complete collapse into a singularity. For extremely large black holes, however, the gravitational forces would be so small that ordinary matter exists inside the event horizon. In addition, there may be repulsive forces at very short distances that we don't yet know of that prevent singularities in smaller (e.g. stellar mass) black holes.
My SIG is a P226
I always wondered - if you had a body that was just under the mass of a black hole, and then put another star nearby such that it was a binary star, could the resulting gravitational effect be a partial black hole? From all angles except opposite the smaller star, it would appear to be a black hole.
"According to the mathematics of general relativity, the event horizon should disappear if a black hole were fed enough charge and angular momentum relative to its mass. "
You mean... all we have to do to escape the event horizon is... reverse the polarity?
Some people have brainfarts... my brain just shat itself.
So is that why we can't see outside the "universe"? Because it's a giant "black hole" the event horizon of which we can't escape because all paths lead back to within?
There is a 50/50 chance that would destroy the world!
I want credit for the name if the maths work out.
Consider the Kerr solution, a rotating, non-charged body approaching the Schwarzchild limit. As it shrinks the spin increases. As this happens the matter near the edge of the now disk-like body gains mass via increased speed a la relativity. The amount gained may not be significant in normal space, but near the Schwarzchild limit it might prove enough to alter the development of the hole. (This mass gain may or may not serve to increase rotational speed more. If it does the following becomes more likely. We'll take the conservative view and ignore this possibility.)
As the body as a whole nears the limit, any portion of the body with greater mass will cross the limit first. This is generally taken as the center. However, the additional mass of the material near the edge of the disk causes it to cross over first and development of the hole begins around this material rather than the center. The hole begins to develop as a toroid. The matter that crosses over first becomes a singularity in terms of its effects, but takes the shape of a ring. The resulting toroidal black hole finishes its parent body off as the outer portion having turned into a black hole pulls in the remaining matter nearer the center, feeding the toroid formation process. The result is a black 'donut' hole, with a path through the axis that does not cross the event horizon. The center is empty (ie. non-horizon involved) because of the balance of gravity in the region neat the 'center' where the gravity from the opposite side of the ring balance out. The size of the hole remains to be calculated. From macro to quantum sized as long it stays non- zero, the donut remains. Even zero may work out as a toroid with a zero diameter center is possible. Perhaps only a negative result (indicating a merger of the opposing event horizons) ruins this postulation.
The singularity ring itself is presaged in description by Mbrane theory. It is simply a circular macro-string of the sort postulated as having been created with the Big Bang. One could approach this from the other direction and starting with that description increase the mass until an external event horizon forms.
The above approaches the Kerr solution in tiny steps very near the time of formation and the logic as well as the physics and associated maths well known. It shouldn't be too difficult to test. If it is borne out, the paper referred to in the article, regarding 'destroying' a black hole, may have other solutions to consider. While an increase in angular momentum may 'destroy' a particular conformation, rather than shedding the event horizon, the singularity/hole may simply take up another form such a what is described here. If a rapidly spinning object can form a toroidal black hole, perhaps a rapidly spun black hole can also.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
This is true, it however, does not offer any evidence that a black hole will instantly evaporate if the event horizon is removed.
Admit nothing. Deny Everything. Make Counter-accusations.
At no point did I claim that a black hole will instantly evaporate if the event horizon is removed. What I claimed is that if through some fluke of physics there was a naked singularity exposed during the end of the lifetime of a black hole like the OP suggests (perhaps a result of quantum gravity although I doubt it) then we would have a very hard time seeing it through the multimegaton TNT equivalent outpouring of radiation.
A lazer is simply not the correct type of technology for that type of weapon. A lazer will be great for guns which fire a direct beam at a target. To contain a laser into the shape and functionality of of a sword will be more work than it would be practical.
A sword has a set blade length, while lazer beams have an infinite length and would need to be contained somehow. A sword has a strong solid blade which can parry blows, a lazer is not solid at all. A sword has a sharp blade edge for cutting cleanly through opponents without getting stuck. A lazer would have to have enough heat to vaporize whatever it contacts or else it won't cut through opponents at all. A sword doesn't need a power source, lazers do.
The lightsaber itself only has a few advantages over a regular sword anyway: Carry space (lightsaber handle that blade expands from vs. whole sword & scabbard), blade maintainence (sword blades need to be kept sharp and free of oxidization), blade durability (sword blades can break, lightsabers shouldn't), blade strength/sharpness (sword blades cannot cut through all materials, lightsaber might be able to).
So a lightsaber would need to be constructed using a more suitable technology. It also would have to provide a significant enough advantage over a sword in the first place.
The clash of honour calls, to stand when others fall.
Oh, no. Gravity's caused by heat!
But, ok, if it is caused by heat, it may be due to eletricity, you have a point... Or entropy, of all weard things, entropy is the worst ofender, so it MUST be entropy.
Rethinking email
shit i feed on, but like most of those it will ofcourse not be happening anytime soon. Still, i prefer people doing this with the freedom of choice they got ever since lightbringer freed them from the prison of Eden ;-) maybe inthere they will find the stuff dreams are made of ?
beware he who denies you access to information for in his mind, he already deems himself to be your master (SMAC-ish)
D'oh! This is further proof Homer Simpson is the greatest mind of our time.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It's pretty much accepted these days that time and space are indistinguishable other than that the 2nd Law of Thermodynamics creates a time arrow that no spacial dimension possesses. The notion that time is different from space was rejected in the late 1800s by mathematicians, early 20th century by physicists. In relativistic physics, the equations for modeling relative time, relative space and relative mass are merely Pythagoras' equations where the hypotenuse is fixed at C for all objects. (For reasons that escape me, I won an award from Warwick University for the proof of this. It's so bleedin' obvious.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Yawn. As I said, there are competing theories. Your absolutism, though, tires me. Have you tried founding a major religion? I hear it's quite profitable. It's certainly going to be more entertaining for the rest of us to watch than your posts. Your claim that singularities aren't required by an event horizon ignores not only all of the alternative theories put forward in physics (pretending a theory does not exist is NOT a way to win friends and influence people, your "proof" is utter drivel. You start by assuming that the radius of the singularity is equal to the radius of the event horizon, then "prove" singularities aren't present by showing this can't be true. Blah blah puke. Get over your ego.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
You are arguing with nature, not me. A large enough mass in a small enough space will have an event horizon, but will never form a singularity because nuclear repulsion is enough to prevent complete collapse. No alternative theories required. Now whether such a large black hole actually exists is another question, but the laws of physics don't prevent it. BTW, you seem to not know, but a singularity has a zero radius by definition. You completely missed my argument.
My SIG is a P226
Of course, the same rules would make it impossible for a genuinely infinite-gravity singularity to form where there wasn't one previously. Which leads into your later points of black holes never forming at all...
Kerr ring singularities are interested in your theory and wish to subscribe to your newsletter. (Translation: I'd forgotten more about singularities by the 1987 Tercentenary lectures at Cambridge than you've ever learned.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
OK, I'll try to say this slowly. The radius of the event horizon is linearly proportional to the mass. The radius of a spherical mass at constant density is proportional to the cube root of the mass. This means the average density required to create an event horizon is inversely proportional to the square root of the mass, Therefore, as the mass gets bigger, the average density to create an event horizon goes down. At a mass of 270 million solar masses, the density required to form an event horizon is the same as ordinary water. It is possible for enough ordinary matter to form an event horizon. As I originally said, no singularity is required. Of course, most black holes we imagine are much smaller, and require huge densities. A solar mass black hole requires an average density almost 400 times nuclear density. At these densities, we know of no force that can prevent complete collapse so we assume a singularity forms. Certainly there are alternate theories that apply in this case. I'm know stepping off your lawn, old man.
My SIG is a P226
Divide by zero???
Defender of Microsoft and Communism!!!
is insignificant compared to the power of the force...
I think they might, for a few femptoseconds see a formation of particles that could, from the right angle, be mistaken for the words, "We're sorry but the universe does not have imagery at that zoom level." Or, just possibly, "We apologize for the inconvenience."
What do you think all the detectors are for in the LHC? Trying to catch them in the act.
The lightsaber itself only has a few advantages over a regular sword anyway
Don’t be ridiculous...
Pit an expert swordsman against a Jedi knight and if the swordsman’s blade is in any fewer than eight pieces when he hits the ground then the Jedi knight obviously wasn’t trying very hard.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
And I will say this slower, as your brains make several weeks to percolate through each fact:
OK, I'll try to say this slowly. The radius of the event horizon is linearly proportional to the mass.
No. The radius of the event horizon fomr abssolut mean position to absolutute is directly proprtional to the total informatiomn present. If you want to offer a rebutall do so, but repeating yourself only makes you look the more moronic. Try to understand the basics of Hamiltonian Tensors and Minkowski spacetime. Try, however, may well be as far as your limited brains can go.
The radius of a spherical mass at constant density is proportional to the cube root of the mass.
Only useful for those cases where there is (a) a single, point-sized singularity.
You have IGNORED the fact that:
a) You don't need a sungularity
b) The fact that singularities need not be points but may be any shape that cannot be reduced further (a torus is an example).
c) The singularity, if it even exists and is the shape you imagine it to exist, need not behave as you think. Nothing else in the physical world ever has. Anything the size of a particle exists in all space and at all times, can simultaneously change position and velocity.
d) One of the alternative theories listed had no black holes in them AT ALL!
e) Another had one singularity, but not the one you are predisposed to believe at all costs.
> This means (blah blah blah)
"The world is full of obvious things which nobody by any chance ever observes."* You can say nothing about what "it" means until you have an accepted idea of what "it" is!
"No, no: I never guess. It is a shocking habit, -- destructive to the logical faculty."
Enough said, if you are incapable of reading the posts of others of reading even the most basic of replies you are not worthy of my attention.
> I'm know stepping off your lawn, old man.
Too late. I mowed your post into fertilizer. I'm sure there are some deadly parasitic species that could benefit from your gall-loaded remarks, but nothing beneficial, s gerroff my lawn and take your damn poster-made-fertilizer with you!
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)