Large Hadron Colliders. Dangerous?

[dirty_g]

Pardon my ignorance , but I was wondering if any of you might be able to inform me as to any possible danger in the attempt to create nano-blackholes here on Earth.

I know that they are supposed to evaporate almost immediately via Hawking radiation, but what if this doesn't happen?

In the worst case scenario where the blackholes form together and fall into the center of the Earth where all that heavy uranium, lead and iron reside, what might be the result? How long would the Earth survive? Keep in mind that the the Earth's gravitational pressure could "force-feed" the blackholes.

Also, how do they intend to control them? It seems to me that a blackhole can't be susceptible to electromagnetic manipulation since any charge it has would be contained within the event horizon. Is this correct?

Lastly, if this works I presume they'll want to do it again, only bigger. Then again, only bigger. Then yet again, only bigger. When does someone start to draw lines here?

Wouldn't it be best to pursue these experiments off-world sometime in the future? Someplace far away?

I just finished watching the tape of "A Brief History of Time" wherein Stephen Hawking explains Hawking radiation. My opinion is that his conclusions are illogical.

As he stated the virtual pairs are broken apart by the event horizon, but it's a 50-50 chance whether the particle or anti-particle falls in. Therefore there can be no net change to the mass. Half of something minus half of something equals no change.

The radiation certainly should exist, but it should be the result of space itself radiating free particles and anti-particles, not a result of a loss of mass of the black hole itself.

Does this make sense?

[antoniseb]

1. In the worst case scenario where the blackholes form together and fall into the center of the Earth where all that heavy uranium, lead and iron reside, what might be the result? How long would the Earth survive? Keep in mind that the the Earth's gravitational pressure could "force-feed" the blackholes.
2. Wouldn't it be best to pursue these experiments off-world sometime in the future? Someplace far away?
3. As he stated the virtual pairs are broken apart by the event horizon, but it's a 50-50 chance whether the particle or anti-particle falls in. Therefore there can be no net change to the mass. Half of something minus half of something equals no change.
4. Does this make sense?

1. These black holes will be so small that even if we are completely wrong about them evaporating (very inlikely), no elementary particle is *likely* to get inside it, so they will orbit harmlessly inside the Earth.
2. By the time we're talking about experiments much larger than the LHC, we'll have to be off the planet, simply for the cost of real estate and availability of power.
3. Your question that I numbered 3 doesn't make sense to me. The electron and positron each have a mass of about 3x10^-26 grams. One escapes, and the other doesn't (though with black holes THAT small, I see no reason that they couldn't both escape).
4. It makes sense to ask.

[Eta C]

Actually, the LHC is probably not the accelerator you're thinking of here. Rather, the fears you're expressing (black holes, etc) were of concern to some with respect to the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab. For an overview here's the Wiki page. It discusses the black hole fears and how these were, and are, unfounded. For those who want a more technical side here is RHIC's website. There's a couple of links on it to black hole formation.

As to your concerns about Hawking radiation, might I respectfully suggest that it's a misunderstanding on your part rather than a mistake by Hawking. Without seeing the exact quote you're referring to I can't venture on a further explanation. Keep reading, and please ask again should questions come up.

[Ken G]

I echo antoniseb's important point that the gravitiy from a nanoblackhole is totally insignificant at any range of interest, and cannot "swallow" anything. Keep in mind that even if the Sun were turned into a black hole, its gravity would affect the Earth in the same way that it does now. What makes black holes special is that they are so small that you can get very close to them, and that is the only place where their gravity is strong. But a nanoblackhole is so small that to get that close would be an inconceivably rare event. The way to figure out the distance you need to get to a black hole to encounter super high gravity is to find the "Schwarzschild radius", which is GM/c^2, which is about 10 to the minus 28 times the mass in grams, and the answer comes out in cm. So if you put in, say, the mass of an electron, you get a distance of about 10 to the minus 55 cm! Even if you put in the mass of a proton, it's still about 10 to the minus 52 cm! Are you worried about something coming within 10 to the minus 52 cm? Our physics doesn't even have any way to measure or even conceive of such a small distance, the distance between nuclei in the Earth's core is more than 10 to the minus 8 cm. How is something going to come within 10 to the minus 52 cm of the nanoblackhole? Let's picture this by scaling up the proton-mass nanoblackhole until it is the size of a bead, say 1 cm. Then the distance between nuclei is 10 to the 44 cm, which is still 10 to the 16 times the size of the observable universe. I don't even know the name for 10 to the 16, but I know it's big, and I know the universe is big, and I know a bead is tiny. What is this bead going to be able to "swallow" if the next nucleus is that far away? Nanoblackholes were never even remotely a concern.

And here's the final issue to keep in mind. Anything we can do in our experiments can happen naturally, and does. Nature has access to energetic reactions many times more powerful than anything we can even conceive of building the technology for, and those reactions are happening in our own atmosphere all the time in the form of cosmic ray interactions. We just can't control the inputs and measure the outputs, so we need our own accelerators. But we'll never accelerate anything that isn't already happening at much higher energies in the sky above you right now. Has a nanoblackhole dropped on you lately? Would you even know if it had?

[Kaptain K]

Also, how do they intend to control them? It seems to me that a blackhole can't be susceptible to electromagnetic manipulation since any charge it has would be contained within the event horizon. Is this correct?

No! A black hole has three measurable properties. Mass, spin and charge.

As he stated the virtual pairs are broken apart by the event horizon, but it's a 50-50 chance whether the particle or anti-particle falls in. Therefore there can be no net change to the mass. Half of something minus half of something equals no change.

Antimatter has positive mass.

The radiation certainly should exist, but it should be the result of space itself radiating free particles and anti-particles, not a result of a loss of mass of the black hole itself.

The energy to create the virtual pair comes from the gravity of the black hole.

Stephen Hawking explains Hawking radiation. My opinion is that his conclusions are illogical.

The finest minds in theoretical physics disagree with you.

[dirty_g]

I'm no scientist at all but I know some basic sciences. I'm allowed an opinion though arnt I? Plus science is changing all the time. If we all thought the same and never challenged ideas we would never of progressed. Anyway The CERN study indicates that Micro Black Holes present no danger because they will evaporate with Hawking evaporation. However, Hawking evaporation has never been tested. If it's not been tested why are we putting trust in it

[antoniseb]

I'm no scientist at all but I know some basic sciences. I'm allowed an opinion though arnt I?

You are allowed an opinion, though you seemed to be saying that your non-expert opinion should have sufficient weight to stop a major project that has been reviewed by a lot of very careful thinkers with great knowledge and experience. That's a little different than simply being allowed to have it.

Looking at the other side, would you agree that we should be able to provide rebuttle to your statements?

[dirty_g]

oh sure have your opinions. just allow me to express mine. anyway maybe I got ahead of myself. Still like I said Hawking radiation has never been tested. Nobody think it should be tested in a safer way first?

[antoniseb]

Still like I said Hawking radiation has never been tested. Nobody think it should be tested in a safer way first?

How do you suppose it should be tested? Perhaps we should wait until we have the instruments required to view the spectrum at the surface of Sgr A*?

[tdvance]

The best reason I've heard that the LHC does not create a hazzard by producing mini black holes is that the same theories that say LHC would produce black holes also says cosmic rays produce far more black holes in our atmosphere. If there were a danger, we'd be dead already.

Todd

[snarkophilus]

I recall a Larry Niven story in this vein... scientists on a newly colonized Mars created a quantum black hole (and then there was a murder mystery surrounding it). The thing escaped, and the main character remarked that no one would notice for a while, as only a couple of atoms per year would be absorbed, but eventually the thing would grow, and one day about twenty years later Mars would just be gone.

A good story, anyway.

[dirty_g]

Well my point is that Hawking radiation has not at all been tested and to assume it will work is rather reckless. The repercussions for this could be rather dire if it does not work. Anyway thanks for reading people!

[Kaptain K]

It depends on your definition of "tested"! While Hawking radiation has not been directly detected;
1) As has been said before, cosmic rays have energies that exceed anything the LHC can do by orders of magnitude. If the LHC can produce micro-black holes, then cosmic rays have been doing so for billions of years and we're still here!
2) The theoretical underpinnings of Hawking radiation are solid. If it did not happen, there would be other evidence to show that the physics behind it is wrong.

[dirty_g]

are cosmic rays passing through the Earths atmosphere on a regular basis?

[Kaptain K]

Constantly.

Actually, that's not quite correct.

Cosmic rays are constantly entering the atmosphere.

[cjl]

Absolutely. This can be shown relatively easily with a cloud chamber - it allows you to detect cosmic rays. You could even build one yourself if you wanted to (really interesting).

[dirty_g]

ahh...... cool thanks for sharing. I read the magnitude of ones created here could be greater. Still I see reasons for doing the experiments. Maybe a source of unlimited energy for one? Anyway my concen is that physics cannot provide a 100% safe paper for the defence of these projects and when you are dealing with the planet I think you need to be a tad careful.

[Kaptain K]

I read the magnitude of ones created here could be greater.

Please!!! When i said "orders of magnitude", I meant large orders of magnitude!
Google for "The Oh-My-God Particle"!
Cosmic rays have been detected with energies 10 million times as much as could have been reached by the (cancelled) SuperConducting Super Collider! Single protons with the energy of a 55mph fastball - the equivelent of dropping a brick on your foot! No collider we have built, are contemplating building, or can even conceive of building can even come close to the energies of cosmic rays that nature has been throwing at us since the Earth formed.

[Nereid]

It's an interesting story, how cosmic rays were discovered.

Imagine the astonishment at finding that the electroscope discharged more rapidly as the balloon ascended, rather than less!

On the flip side, it takes several km of rock to stop (most) cosmic rays, so SuperK was built 2.7 km deep (and still it detects cosmic ray muons!).

[antoniseb]

it takes several km of rock to stop (most) cosmic rays

Just as an augmentation of what Nereid is saying here, pretty much all cosmic rays (not counting neutrinos) only penetrate a short way into our atmosphere before turning into a cascade of lower energy particles. Some of these daughter products of the original Cosmic Ray (especially muons) are able to penetrate through hundreds of meters of Earth.

[Ken G]

Well my point is that Hawking radiation has not at all been tested and to assume it will work is rather reckless.

The very first three answers to your question quite clearly pointed out that there is no need to assume that nanoblackholes will degrade via Hawking radiation. Did you just not read that? Why do we have to cover the same ground over and over? You may have an opinion, but it is up to you if it will be an informed opinion or not.

[dirty_g]

calm down Kenny boy dont get out of your Pram. I simply missed the part you wrote. yes but if a nano blackhole does not degrade via hawking radiation would one at the centre of the earth for example not be considered a bad thing in your books? At the end of the day it could as I said above be "force fed" via gravitational preassure. I said it in a previous post. Physics cannot guarantee 100% safety for these experiments and in this case I beleive you need 100% safety. Say what you want but experiments with "potential" to go wrong even though that potential maybe be 0.000001% still scare me. As if it did go wrong then it would be soemthing to worry about

[Ken G]

No, it would not be a bad thing at all. The mathematics of quantum mechanics already includes nanoblackholes, in effect, in the center of all atoms, when we include gravity in the wave mechanics of an atom. The effect is absolutely minimal, for the reasons I explained. The size of a nanoblackhole fits into such a vanishingly small fraction of the size of an atom, it would have no effect whatever, with or without Hawking radiation. Furthermore, what part of "these reactions are already occuring naturally with far greater frequency and at far greater energies" didn't you get? As for 100% safety, I think you better not sneeze-- can we guarantee that your sneezing won't initiate a chain reaction that will destroy the world? With 100% safety, I mean. Here's the bottom line, if you are ready to know the truth: worrying about nanoblackholes destroying the world is absolutely preposterous, ludicrous, laughable, and annoying to anyone with a whit of physics knowledge or even downright common sense. Now you know.

[antoniseb]

calm down Kenny boy dont get out of your Pram.

dirty_g, this is not acceptable writing style around here. You must be more polite to the people on the forum.

[dirty_g]

I am pretty sure modern science could (if anybody could be actually bothered to put the funding into it and investigate it) very much show that my sneezing would not warrant the destruction of the Earth.

[Ken G]

No better than it can show that nanoblackholes can't either. Accept one, you accept the other, or you are just picking and choosing your science. (And thanks antoniseb, but I took dirty_g's tone as humorous rather than offensive. I give people the benefit of the doubt because it's hard to read "intonation" in posts!)

[Kaptain K]

Pardon my ignorance , but I was wondering if any of you might be able to inform me as to any possible danger in the attempt to create nano-blackholes here on Earth.

My bold.

From the tone of your reaction to our responses, it might have helped if you had added "unless there isn't any, because I'm not interested in that."

[antoniseb]

I am pretty sure modern science could (if anybody could be actually bothered to put the funding into it and investigate it) very much show that my sneezing would not warrant the destruction of the Earth.

Just looking at it from the point of view of weather, this is called the Butterfly effect. It is certainly *possible* that you sneezing could start a chain of events that ultimately eradicates mankind.

[Ken G]

Just looking at it from the point of view of weather, this is called the Butterfly effect.

Good point, since we are talking about 100% after all.

[Ken G]

From the tone of your reaction to our responses, it might have helped if you had added "unless there isn't any, because I'm not interested in that.

LOL, well put. It's OK dirty_g, we know your concerns are genuine, we are just trying to educate them away. They are at the level of the concerns people used to have whenever a comet appeared in the sky. Science knowledge can sometimes present a threat, it's true, but more often it may be used to allay fears rather than create them.