Scientist: "Its almost impossible that this black hole will destroy the earth.."

[Zaknafien]

Lucky me, I'll be in iraq.. sucks for all you guys in Europe.

if you care to watch a movie about it:
http://www.moviesfoundonline.com/six...experiment.htm

Set to begin operation November 26th! let's have a party.

World’s Largest Supercollider Could Destroy the Universe


As the Cernier company prepares to test the world’s largest supercollider physicists express concern that too much is being left to chance.

The Cernier Company or CERN, the world’s largest physics research firm, is currently in the process of building what would be the world’s largest working supercollider. Known as “Large Hadron Collider,” or LHC, the device is 27 kilometers (16.7 miles) long and resides in a tunnel approximately 100 meters beneath the Franco-Swiss border, just outside of Geneva.

By accelerating protons toward each other at 99.999999% the speed of light the LHC can recreate conditions similar to those that resulted from the Big Bang, ultimately alighting a great deal about the particles and forces that comprise our Universe. A press release from CERN better illuminates their intent for the project:

…Our current understanding of the Universe is incomplete. We have seen that the theory we use, the Standard Model, leaves many unsolved questions. Among them, the reason why elementary particles have mass, and why are their masses different is the most perplexing one. It is remarkable that such a familiar concept is so poorly understood.

LHC functions by accelerating two counter-rotating beams of protons toward each other at high speeds. By cooling magnets to near absolute zero (-273 degrees celcius) with an enormous cryogenics system, the LHC can move particles toward each other at speeds only one millionth of a percent away from the speed of light.

And while Physicists have the logistics of the LHC well in hand ideas about its outcome are strictly theoretical. According to one scenario tiny black holes could be produced which hopefully would decay into what is known as Hawking radiation (the tinier the black hole, the faster it evaporates). If these black holes fail to decay, however, the consequences could be disasterous. CERN software developer Ran Livneh has expressed some concerns about the project:

This physical realm is unknown, and dangerous phenomena might arise…Any physicist will tell you that there is no way to prove that generated black holes will decay. The consequences of being mistaken are unfathomable. This subject deserves serious unbiased discussion.

Despite these theoretical discrepencies the LHC project will continue as scheduled toward its launch in 2007. Mankind has never progressed itself due to fear of the unknown. Although the results of the Large Hadron Collider could potentially be disasterous, the intellectual consequences of not conducting the experiment could be equally so.

[CrossLOPER]

Iraq? Unless you're planning to take a trip outside the Sun's solar system to a place named Iraq, things are not looking good for anyone.

Personally, I wish they would not go through with this.

[Sasaki Kojiro]

I find this amusing for some reason.

[CrossLOPER]

I find this amusing for some reason.

OK, most likely the thing will fall apart or fail to start, but still.

[Husar]

So here we have some guys with a physics degree who just tap around in the dark and accept that they might kill all of us?

[Uesugi Kenshin]

Sweet.

At least it's impartial. It's only racist against humans!!! (Or rather speciest)
And if there are Martians they'll probably die too.

[Xiahou]

"I said, super collider, I just met her! And then they made a super collider. Thank you, you've been a great audience."

"Humour Bot 5.0, ladies and gentlemen"

[Geoffrey S]

People have been fearful of the frontiers of science for a lot longer than just this case. Remember those perpetual energy things with manual brakes in case things got out of hand?

[Louis VI the Fat]

/ In before Time Paradox.

[Megalos]

Possibly unleashing the most powerful destructive force in the universe on earth sounds like a good idea to me! /sarcasm off


Doesn't the gravitational pull of a blackhole get stronger the more matter it pulls in?

Has a blackhole ever been proven to evaporate? I thought they went on and on infinetly?

[Megalos]

This might be of interest to some of you. I have however no idea as to it's accuracy, due to my infinite ignorance of quantem physics!

http://cosmology.berkeley.edu/Education/BHfaq.html#q7


Is there any evidence that black holes exist?
---------------------------------------------
Yes. You can't see a black hole directly, of course, since light can't get past the horizon. That means that we have to rely on indirect evidence that black holes exist.

Suppose you have found a region of space where you think there might be a black hole. How can you check whether there is one or not? The first thing you'd like to do is measure how much mass there is in that region. If you've found a large mass concentrated in a small volume, and if the mass is dark, then it's a good guess that there's a black hole there. There are two kinds of systems in which astronomers have found such compact, massive, dark objects: the centers of galaxies (including perhaps our own Milky Way Galaxy), and X-ray-emitting binary systems in our own Galaxy.

According to a recent review by Kormendy and Richstone (to appear in the 1995 edition of "Annual Reviews of Astronomy and Astrophysics"), eight galaxies have been observed to contain such massive dark objects in their centers. The masses of the cores of these galaxies range from one million to several billion times the mass of the Sun. The mass is measured by observing the speed with which stars and gas orbit around the center of the galaxy: the faster the orbital speeds, the stronger the gravitational force required to hold the stars and gas in their orbits. (This is the most common way to measure masses in astronomy. For example, we measure the mass of the Sun by observing how fast the planets orbit it, and we measure the amount of dark matter in galaxies by measuring how fast things orbit at the edge of the galaxy.)

These massive dark objects in galactic centers are thought to be black holes for at least two reasons. First, it is hard to think of anything else they could be: they are too dense and dark to be stars or clusters of stars. Second, the only promising theory to explain the enigmatic objects known as quasars and active galaxies postulates that such galaxies have supermassive black holes at their cores. If this theory is correct, then a large fraction of galaxies -- all the ones that are now or used to be active galaxies -- must have supermassive black holes at the center. Taken together, these arguments strongly suggest that the cores of these galaxies contain black holes, but they do not constitute absolute proof.

Two very recent discovery has been made that strongly support the hypothesis that these systems do indeed contain black holes. First, a nearby active galaxy was found to have a "water maser" system (a very powerful source of microwave radiation) near its nucleus. Using the technique of very-long-baseline interferometry, a group of researchers was able to map the velocity distribution of the gas with very fine resolution. In fact, they were able to measure the velocity within less than half a light-year of the center of the galaxy. From this measurement they can conclude that the massive object at the center of this galaxy is less than half a light-year in radius. It is hard to imagine anything other than a black hole that could have so much mass concentrated in such a small volume. (This result was reported by Miyoshi et al. in the 12 January 1995 issue of Nature, vol. 373, p. 127.)

A second discovery provides even more compelling evidence. X-ray astronomers have detected a spectral line from one galactic nucleus that indicates the presence of atoms near the nucleus that are moving extremely fast (about 1/3 the speed of light). Furthermore, the radiation from these atoms has been redshifted in just the manner one would expect for radiation coming from near the horizon of a black hole. These observations would be very difficult to explain in any other way besides a black hole, and if they are verified, then the hypothesis that some galaxies contain supermassive black holes at their centers would be fairly secure. (This result was reported in the 22 June 1995 issue of Nature, vol. 375, p. 659, by Tanaka et al.)

A completely different class of black-hole candidates may be found in our own Galaxy. These are much lighter, stellar-mass black holes, which are thought to form when a massive star ends its life in a supernova explosion. If such a stellar black hole were to be off somewhere by itself, we wouldn't have much hope of finding it. However, many stars come in binary systems -- pairs of stars in orbit around each other. If one of the stars in such a binary system becomes a black hole, we might be able to detect it. In particular, in some binary systems containing a compact object such as a black hole, matter is sucked off of the other object and forms an "accretion disk" of stuff swirling into the black hole. The matter in the accretion disk gets very hot as it falls closer and closer to the black hole, and it emits copious amounts of radiation, mostly in the X-ray part of the spectrum. Many such "X-ray binary systems" are known, and some of them are thought to be likely black-hole candidates.

Suppose you've found an X-ray binary system. How can you tell whether the unseen compact object is a black hole? Well, one thing you'd certainly like to do is to estimate its mass. By measuring the orbital speed of visible star (together with a few other things), you can figure out the mass of the invisible companion. (The technique is quite similar to the one we described above for supermassive black holes in galactic centers: the faster the star is moving, the stronger the gravitational force required to keep it in place, and so the more massive the invisible companion.) If the mass of the compact object is found to be very large very large, then there is no kind of object we know about that it could be other than a black hole. (An ordinary star of that mass would be visible. A stellar remnant such as a neutron star would be unable to support itself against gravity, and would collapse to a black hole.) The combination of such mass estimates and detailed studies of the radiation from the accretion disk can supply powerful circumstantial evidence that the object in question is indeed a black hole.

Many of these "X-ray binary" systems are known, and in some cases the evidence in support of the black-hole hypothesis is quite strong. In a review article in the 1992 issue of Annual Reviews of Astronomy and Astrophysics, Anne Cowley summarized the situation by saying that there were three such systems known (two in our galaxy and one in the nearby Large Magellanic Cloud) for which very strong evidence exists that the mass of the invisible object is too large to be anything but a black hole. There are many more such objects that are thought to be likely black holes on the basis of slightly less evidence. Furthermore, this field of research has been very active since 1992, and the number of strong candidates by now is larger than three.



How do black holes evaporate?
-----------------------------
This is a tough one. Back in the 1970's, Stephen Hawking came up with theoretical arguments showing that black holes are not really entirely black: due to quantum-mechanical effects, they emit radiation. The energy that produces the radiation comes from the mass of the black hole. Consequently, the black hole gradually shrinks. It turns out that the rate of radiation increases as the mass decreases, so the black hole continues to radiate more and more intensely and to shrink more and more rapidly until it presumably vanishes entirely.

Actually, nobody is really sure what happens at the last stages of black hole evaporation: some researchers think that a tiny, stable remnant is left behind. Our current theories simply aren't good enough to let us tell for sure one way or the other. As long as I'm disclaiming, let me add that 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 task, and which 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.

Now why do black holes evaporate? Here's one way to look at it, which is only moderately inaccurate. (I don't think it's possible to do much better than this, unless you want to spend a few years learning about quantum field theory in curved space.) One of the consequences of the uncertainty principle of quantum mechanics is that it's possible for the law of energy conservation to be violated, but only for very short durations. The Universe is able to produce mass and energy out of nowhere, but only if that mass and energy disappear again very quickly. One particular way in which this strange phenomenon manifests itself goes by the name of vacuum fluctuations. Pairs consisting of a particle and antiparticle can appear out of nowhere, exist for a very short time, and then annihilate each other. Energy conservation is violated when the particles are created, but all of that energy is restored when they annihilate again. As weird as all of this sounds, we have actually confirmed experimentally that these vacuum fluctuations are real.

Now, suppose one of these vacuum fluctuations happens near the horizon of a black hole. It may happen that one of the two particles falls across the horizon, while the other one escapes. The one that escapes carries energy away from the black hole and may be detected by some observer far away. To that observer, it will look like the black hole has just emitted a particle. This process happens repeatedly, and the observer sees a continuous stream of radiation from the black hole.



Won't the black hole have evaporated out from under me before I reach it?
---------------------------------------------------------------------
We've observed that, from the point of view of your friend Penelope who remains safely outside of the black hole, it takes you an infinite amount of time to cross the horizon. We've also observed that black holes evaporate via Hawking radiation in a finite amount of time. So by the time you reach the horizon, the black hole will be gone, right?

Wrong. When we said that Penelope would see it take forever for you to cross the horizon, we were imagining a non-evaporating black hole. If the black hole is evaporating, that changes things. Your friend will see you cross the horizon at the exact same moment she sees the black hole evaporate. Let me try to describe why this is true.

Remember what we said before: Penelope is the victim of an optical illusion. The light that you emit when you're very near the horizon (but still on the outside) takes a very long time to climb out and reach her. If the black hole lasts forever, then the light may take arbitrarily long to get out, and that's why she doesn't see you cross the horizon for a very long (even an infinite) time. But once the black hole has evaporated, there's nothing to stop the light that carries the news that you're about to cross the horizon from reaching her. In fact, it reaches her at the same moment as that last burst of Hawking radiation. Of course, none of that will matter to you: you've long since crossed the horizon and been crushed at the singularity. Sorry about that, but you should have thought about it before you jumped in.



What is a white hole?
---------------------
The equations of general relativity have an interesting mathematical property: they are symmetric in time. That means that you can take any solution to the equations and imagine that time flows backwards rather than forwards, and you'll get another valid solution to the equations. If you apply this rule to the solution that describes black holes, you get an object known as a white hole. Since a black hole is a region of space from which nothing can escape, the time-reversed version of a black hole is a region of space into which nothing can fall. In fact, just as a black hole can only suck things in, a white hole can only spit things out.

White holes are a perfectly valid mathematical solution to the equations of general relativity, but that doesn't mean that they actually exist in nature. In fact, they almost certainly do not exist, since there's no way to produce one. (Producing a white hole is just as impossible as destroying a black hole, since the two processes are time-reversals of each other.)



What is a wormhole?
-------------------
So far, we have only considered ordinary "vanilla" black holes. Specifically, we have been talking all along about black holes that are not rotating and have no electric charge. If we consider black holes that rotate and/or have charge, things get more complicated. In particular, it is possible to fall into such a black hole and not hit the singularity. In effect, the interior of a charged or rotating black hole can "join up" with a corresponding white hole in such a way that you can fall into the black hole and pop out of the white hole. This combination of black and white holes is called a wormhole.

The white hole may be somewhere very far away from the black hole; indeed, it may even be in a "different Universe" -- that is, a region of spacetime that, aside from the wormhole itself, is completely disconnected from our own region. A conveniently-located wormhole would therefore provide a convenient and rapid way to travel very large distances, or even to travel to another Universe. Maybe the exit to the wormhole would lie in the past, so that you could travel back in time by going through. All in all, they sound pretty cool.

But before you apply for that research grant to go search for them, there are a couple of things you should know. First of all, wormholes almost certainly do not exist. As we said above in the section on white holes, just because something is a valid mathematical solution to the equations doesn't mean that it actually exists in nature. In particular, black holes that form from the collapse of ordinary matter (which includes all of the black holes that we think exist) do not form wormholes. If you fall into one of those, you're not going to pop out anywhere. You're going to hit a singularity, and that's all there is to it.

Furthermore, even if a wormhole were formed, it is thought that it would not be stable. Even the slightest perturbation (including the perturbation caused by your attempt to travel through it) would cause it to collapse.

Finally, even if wormholes exist and are stable, they are quite unpleasant to travel through. Radiation that pours into the wormhole (from nearby stars, the cosmic microwave background, etc.) gets blueshifted to very high frequencies. As you try to pass through the wormhole, you will get fried by these X-rays and gamma rays.


Where can I go to learn more about black holes?
-----------------------------------------------
Let me begin by acknowledging that I cribbed some of the above material from the article about black holes in the Frequently Asked Questions list for the Usenet newsgroup sci.physics. The sci.physics FAQ is posted monthly to sci.physics and is also available by anonymous ftp from rtfm.mit.edu (and probably other places). The article about black holes, which is excellent, was written by Matt McIrvin. The FAQ contains other neat things too.

There are lots of books out there about black holes and related matters. Kip Thorne's "Black Holes and Time Warps: Einstein's Outrageous Legacy" is a good one. William Kaufmann's "Black Holes and Warped Spacetime" is also worth reading. R. Wald's "Space, Time, and Gravity" is an exposition of general relativity for non-scientists. I haven't read it myself, but I've heard good things about it.

Both of these books are aimed at readers without much background in physics. If you want more "meat" (i.e., more mathematics), then you probably start with a book on the basics of relativity theory. The best introduction to the subject is "Spacetime Physics" by E.F. Taylor and J.A. Wheeler. (This book is mostly about special relativity, but the last chapter discusses the general theory.) Taylor and Wheeler have been threatening for about two years now to publish a sequel entitled "Scouting Black Holes," which should be quite good if it ever comes out. "Spacetime Physics" does not assume that you know vast amounts of physics, but it does assume that you're willing to work hard at understanding this stuff. It is not light reading, although it is more playful and less intimidating than most physics books.

Finally, if "Spacetime Physics" isn't enough for you, you could try any of several introductions to general relativity. B. Schutz's "A First Course in General Relativity" and W. Rindler's "Essential Relativity" are a couple of possibilities. And for the extremely valiant reader with an excellent background in physics, there's the granddaddy of all books on general relativity, Misner, Thorne, and Wheeler's "Gravitation." R. Wald's book "General Relativity" is at a comparable level to "Gravitation," although the styles of the two books are enormously different. What little I know about black-hole evaporation comes from Wald's book. Let me emphasize that all of these books, and especially the last two, assume that you know quite a lot of physics. They are not for the faint of heart.

[KukriKhan]

CERN has had to postpone operation until May of next year... so at least we get one more christmas-new year's holiday before earth's being sucked into an accidentally-created black hole, starting in France.

:)

[Viking]

I dont's see how colliding atom nucleuses can cause the creation of a black hole when you usually need a star with 10 solar masses or more for it.

Found this on wikipedia:

[...] CERN has pointed out that the probability of such events is extremely small. One argument for the safety of colliders such as the LHC states that if the Earth were in danger of any such fate, the Earth and Moon would have met that fate billions of years ago due to their constant bombardment from space by protons, other particles, and cosmic rays, which are millions of times more energetic than anything that could be produced by the LHC. [...]

http://en.wikipedia.org/wiki/Large_H...and_assurances

[Myrddraal]

Btw, ignore what that man had to say about wormholes. It's fundamentally impossible.
EDIT: Just read a bit more and even he agrees

I've been to CERN, a fascinating place. I was fortunate enough to see components of the LHC. When the construction is finished those components will be encased underground but when I went they were still in big warehouses. Very very impressive technology.

My understanding of particle physics isn't nearly complete enough to know about the Hawking Radiation, but I can say that I think the people at CERN are a little short sighted. They are persuing knowledge for it's own sake, which might be a good thing, or might not. I can't help but think how much this project costs.

Having said that, spin off's from CERN include the world wide internet, and various medical applications.

[Marshal Murat]

It is kind of like the scientist afraid that going to fast on a train would asphyxiate you, or that exploding a nuclear device under the ocean would cause a train-reaction that would evaporate the ocean.

The worst is that if you explode a hydrogen bomb underwater, I think it will destroy the ocean in a massive chain reaction.

[Zaknafien]

cost is six billion dollars--hence the name of the movie I posted in the OP :)

[Marshal Murat]

At least it will be quick.

[woad&fangs]

At least the end of the world sex will be good. And if you get end of the world sex and the world doesn't end than that's just a bonus.

[Banquo's Ghost]

And if you get end of the world sex and the world doesn't end than that's just a bonus.

That very much depends on who you had sex with and whether you own a bunny rabbit and a saucepan.

[Redleg]

That very much depends on who you had sex with and whether you own a bunny rabbit and a saucepan.

Now why would you want to hae sex with a bunny in a saucepan?

[Evil_Maniac From Mars]

Now why would you want to hae sex with a bunny in a saucepan?

Maybe he was planning to cook the bunny for nourishment before the sex. If not, who am I to question the sexual perversions of others?

[Watchman]

I'm pretty sure bestiality involving small rodents goes under "nonconsensual" by default, so there would be that.

[Mikeus Caesar]

Well, they do say that on an infinite timescale, anything is possible, including the world being destroyed by blackholes from France.

EDIT: And remember, if anything does go wrong, such as inter-dimensional aliens coming through the walls, and a mysterious man with a briefcase popping up in unlikely places, a physicist in an orange and black hazard suit will save us!

[The Wizard]

Just in time for the end of the Mayan calendar, guys. Happy Apocalypse!

[Viking]

Now why would you want to hae sex with a bunny in a saucepan?

Now why would you even ask about that?

[CrossLOPER]

Just in time for the end of the Mayan calendar, guys. Happy Apocalypse!

Four years off.

[Uesugi Kenshin]

Well, they do say that on an infinite timescale, anything is possible, including the world being destroyed by blackholes from France.

EDIT: And remember, if anything does go wrong, such as inter-dimensional aliens coming through the walls, and a mysterious man with a briefcase popping up in unlikely places, a physicist in an orange and black hazard suit will save us!

Gordon never really saved anyone...

[The Wizard]

Four years off.

No, no, no... you're getting me all wrong. In 2012 at the exacty moment the Mayan calendar ends, the hadron collider will produce an all-consuming black hole and kill us all

[Whacker]

Last one across the event horizon has to buy anti-matter beer for everyone!

[Mikeus Caesar]

Gordon never really saved anyone...

He kind of has...i mean, come on, you know it's all going to end with him saving the world.