Exploring the Risks of the Large Hadron Collider

[Max85]

Hi,
I have no academic grounding in advanced physics, but I have read a lot of the popular books on physics, and am generally interested in it. (In a couple of years that's probably what I'll learn in college).
Anyway, there are people who are afraid that when the LHC goes on this summer we might accidentally create a black hole and destroy the planet.
I don't have the mathematics to back this up, but:
If we do create a singularity in CERN we will be inside the event horizon, and so close to the singularity itself that we will feel the effects of infinite time dilation. So if we did create a black hole, we won't know about it because time has ceased to have a meaning for us.
Does that make any sense?

 

[humanino]

Anyway, there are people who are afraid that when the LHC goes on this summer we might accidentally create a black hole and destroy the planet.

We have been discussing this many times, and you can find many such discussions. [thread=236225]This one for instance[/thread]...

Physicists know what they are doing, and the LHC will not destroy the Earth.
Otherwise claims are simple displays of scientific misunderstandings. Those claims simply do not hold water under inspection.

Most important for us physicists, is that this is a communication problem. We have interesting things to do in LHC. Public interest in this fake problem is very disappointing, since it distracts attention from the real points of LHC.

If we do create a singularity in CERN we will be inside the event horizon, and so close to the singularity itself that we will feel the effects of infinite time dilation. So if we did create a black hole, we won't know about it because time has ceased to have a meaning for us.
Does that make any sense?

No it does not. Sorry. This is qualitatively wrong, not even to mention quantitative thinking.

If you want to study physics, may I advise you to quit reading popular books, and start reading the real stuff ?
I mean, at your level, start building a concrete knowledge of physics instead of reading about physics.

 

[Max85]

I for one am not worried about the black hole, I think it would be pretty cool. It would be even more cool if the time dilation thing made sense.
Could you please explain (without being condescending) why this is qualitatively and quantitatively wrong.
What do you mean "the real stuff"?
I've read two of Stephen Hawkings' books, (didn't like them much), Brian Greene's "The elegant univers" (3 times), George Gamow's "Mister Thompson" (the original and the newer one with the right physics), "Big Bang" by Simon Singh and a few others I've forgotten.

 

[humanino]

Could you please explain (without being condescending) why this is qualitatively and quantitatively wrong.

Sorry if I appear condescending to you. I am just really tired of discussing about BH in LHC. As I mentionned to you, the BH stuff is anecdotal compared to what LHC is really about.

It should not be my task to show to you why "If we do create a singularity in CERN we will be inside the event horizon..." is just wrong. I can not guess where your calculation went wrong if you do not let us know any element of this calculation. For one thing, what is the BH mass that you use ? The BH mass will allow us to estimate the horizon radius. You should find something insanely tiny, much smaller than typical atomic sizes.

 

[Max85]

I am just really tired of discussing about BH in LHC

Sorry about that. I'm interested in the LHC not because of th BHs but for the REAL experiments going on there. I thought that it would also be cool if we got a BH and didn't know about it.

I can not guess where your calculation went wrong if you do not let us know any element of this calculation.

This was a supposed to be a funny question, nobody was supposed to take it seriously. But seeing how you do not have a sense of humor I humbly beg your apology and retract my question.

If you do know any physicists with a sense of humor, show this to them.

Good day to you sir.

 

[malawi_glenn]

How could you come to that statement of yours without having any mathematics to back it up? That is a riddle for me..

And if you think the books you have read is "real stuff" then welcome to reality, try this one for instance: "A First Course in General Relativity" by Bernard F. Schutz

 

[humanino]

This was a supposed to be a funny question, nobody was supposed to take it seriously. But seeing how you do not have a sense of humor I humbly beg your apology and retract my question.

Well, we probably do not have the same sens of humour

If you do know any physicists with a sense of humor, show this to them.

I myself know quite a few physicists with quite a good sens of humour !

edit
Besides, this is the physics discussion forum, not the science-joke forum (which exists somewhere else).

 

[humanino]

I thought that it would also be cool if we got a BH and didn't know about it.

Assuming this kind of physics is right, then you have virtual BHs popping in and out of existence around your own self in the vacuum, but you can't know it. Now, that is funny to me.

 

[Max85]

You mean BS, right?
Anyway, being young (21) I still think the universe is governed by cool.
If it's cool it works, if it isn't, it doesn't.
How cool is that?

 

[cristo]

Besides, this is the physics discussion forum, not the science-joke forum (which exists somewhere else).

Precisely!

Max: Where in your post do you say that this is a joke? If it posted in the technical forum, then we take it to be a serious physics question. If you wish to joke around, then please use general discussion.

 

[HarryWertM]

LHC Hazards

I have seen endless debate regarding the risk of Black Hole production at the LHC. The possibility seems to be thoroughly answered. But I have found nothing regarding the the risk of of 'strangelets'. Has that also been answered? If so, where? -Harry Wertmuller

 

[derekmcd]

CERN's

Here's a pdf of CERN's most recent report:

http://cern.ch/lsag/LSAG-Report.pdf

 

[ZapperZ]

Just to add to what derekmcd has linked to, the report relied heavily on the study done by Goodings and Mangano. This study appeared on ArXiv this morning.

http://arxiv.org/abs/0806.3381

Zz.

 

[daschaich]

For that matter, the report itself appeared on the arXiv this morning: http://arxiv.org/abs/0806.3414 (submitted last Friday). Goodings & Mangano only address black holes, though in much greater depth than the safety review itself.

 

[phsopher]

Are there any estimates on how likely it is that some sort of black holes would be produced?

 

[malawi_glenn]

Are there any estimates on how likely it is that some sort of black holes would be produced?

Have you read the articles?

 

[humanino]

Are there any estimates on how likely it is that some sort of black holes would be produced?

It is a very hard question. I would advise you to read Randall's papers, or lectures.
Warped Extra-Dimensional Opportunities and Signatures

 

[phsopher]

Have you read the articles?

I've read the LSAG report and I get that if the black holes are produced they are unlikely to be stable and even in the case they are they are probably harmless. I get that there is no reason for concern, that's not what I'm asking about. I'm interested in the likelihood of any kind of black hole being produced. I haven't read the Giddings/Mangano article, but it appears to be focusing on the effects of black holes should they be produced rather than the likelihood of them being produced. If there are such estimates within the article I would appreciate it if someone who has read it would point them out. Thanks.

 

[daschaich]

I've read the LSAG report and I get that if the black holes are produced they are unlikely to be stable and even in the case they are they are probably harmless. I get that there is no reason for concern, that's not what I'm asking about. I'm interested in the likelihood of any kind of black hole being produced. I haven't read the Giddings/Mangano article, but it appears to be focusing on the effects of black holes should they be produced rather than the likelihood of them being produced. If there are such estimates within the article I would appreciate it if someone who has read it would point them out. Thanks.

I would expect any such estimates to be very model-dependent. To my (very limited) knowledge, to get black holes at the LHC, the fundamental scale of gravity (Planck scale) must really be the TeV scale, not the very high energy scale it seems from naive dimensional analysis. You could get this from theories of large extra dimensions or warped extra dimensions, or apparently just by dictating it, and the production predictions depend on which model, with which parameters, you're considering. All of this is very speculative.

A quick http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=find+t+black+hole+LHC&FORMAT=WWW&SEQUENCE=" recent paper uses non-observation of black holes in cosmic ray experiments to try to determine a "model independent limit for the four-dimensional reduced Planck mass", though they seem to work in a "model recently proposed to solve the hierarchy problem by lowering the Planck scale to the TeV region without the introduction of extra-dimensions". The article humanino posted should give some estimates in warped extra dimensions models.

So you can check out those papers and references therein for predictions of black hole production in the framework of various BSM models.

 

[IBY]

I doubt if there was a black hole, that it would absorb the world because of hawking's radiation. If it forms black holes, I highly doubt it will destroy the world, since fast collisions like that happens all the time, though detection could be difficult, so there is a possibility. World destruction, not a possibility.

 

[humanino]

I doubt if there was a black hole, that it would absorb the world because of hawking's radiation. If it forms black holes, I highly doubt it will destroy the world, since fast collisions like that happens all the time, though detection could be difficult, so there is a possibility. World destruction, not a possibility.

You seem to agree with the physicists community. World destruction : not even wrong as he would say

 

[ajassat]

From what I read of the report it seems the likelihood of microscopic black hole formation is high. However the likelihood of a stable microscopic black hole appearing is low. If Hawking Radiation is true - then it is likely that the black hole will break down into the matter from which it was first formed. Thus, there would be no real danger (typical of normal stable black holes found in space).

 

[daschaich]

From what I read of the report it seems the likelihood of microscopic black hole formation is high...

Only in certain highly speculative models of physics beyond the Standard Model, to my knowledge. In particular, models with large or warped extra dimensions.

 

[art_mos]

Dear All,

I've read so many articles on LHC and all sorts of hazards it might craete.
I just have a very simple question to the scientists(may be not only to them):

If you know what to expect from the experiement then why are you doing it?
My suspicion is that scientists don't know what is going to happen. And all those theories and calculations they present to us are only hopes and desparations. Scientists are desparated, and that is the main reason they built this huge/expensive apparatus to have some order in their theories and calculations. So, I wouldn't trust to their claims about the risks and everything.

One more thing: they are trying to recreate the big bang. I hope they "WILL NOT BE ABLE TO DO THAT"!

 

[humanino]

If you know what to expect from the experiement then why are you doing it?

This is philosophically a perfectly valid point. We don't know what is going to happen. We never know what is going to happen in an experiment.

Now think about the validity of your argument. Are you aware that you never know what will be the result of the next time you will breath ? There is a likelihood that all the air in the room will fill your lungs, that it will kill everybody in the room, you included. Are you willing to take that responsability every other second ?

What is the most likely to happen ? LHC destroying the world, or you killing your entire family at the next dinner meeting ? Think about it next time you claim scientists don't know what they are talking about. With knowledge comes freedom and with freedom comes responsabilities. It is a very basic fact in philosophy.

 

[WarPhalange]

If you know what to expect from the experiement then why are you doing it?

Because it wouldn't be the first time scientists did an experiment and got completely different results than they expected.

My suspicion is that scientists don't know what is going to happen. And all those theories and calculations they present to us are only hopes and desparations. Scientists are desparated, and that is the main reason they built this huge/expensive apparatus to have some order in their theories and calculations. So, I wouldn't trust to their claims about the risks and everything.

It's a good thing nobody cares about suspicions, then, huh?

You're right in a way, though. They built the giant apparatus in order to have some order in their theories and calculations. It's called "science". You need to test your theories and calculations or else they are meaningless.

One more thing: they are trying to recreate the big bang.

Err... what makes you think that? More importantly, what makes you think that they would be able to?

 

[art_mos]

Dear (Huma)nino,

First of all no one touched your family so leave mine alone.
"There is NOT a likelihood that all the air in the room will fill my lungs, that it will kill everybody in the room, me included." You know that and everyone out of 6.5 billion on this planet know that. In case of LHC only a very small group of people know what is the likelihood. So what you said is not valid.

 

[humanino]

First of all no one touched your family so leave mine alone.
"There is NOT a likelihood that all the air in the room will fill my lungs, that it will kill everybody in the room, me included." You know that and everyone out of 6.5 billion on this planet know that. In case of LHC only a very small group of people know what is the likelihood. So what you said is not valid.

I claimed that there is such a probability. It is given by the ratio of exponentials of minus the energies for both configurations counted in units of the temperature times the Boltzmann constant. Everybody who understands about physics knows that. The likelihood you get for this to happen is indeed comparable to the kind of likelihood you are talking about, actually I think it is much much much more probable that you kill yourself and your family in this manner. You touched my family when you said I would be partly responsible, by supporting LHC, to the killing of ALL families in the world.

If you want more polite answers, don't come in a physicist's community calling them names. Otherwise, well, you get what you are searching for.

 

[art_mos]

And I calim that there is NO such a probability.
And who is Bolzman by the way?

Bye!

 

[humanino]

And I calim that there is NO such a probability.

Unfortunately you are wrong.

And who is Bolzman by the way?

Boltzmann, one of the most important physicists ever, who has done work with Maxwell, another of the most important physicists ever, on the foundation of statistical physics (among other things, of course). Google is you friend.

 

[Astronuc]

If you know what to expect from the experiment then why are you doing it?

It's called confirmation.

My suspicion is that scientists don't know what is going to happen. And all those theories and calculations they present to us are only hopes and desparations. Scientists are desparated, and that is the main reason they built this huge/expensive apparatus to have some order in their theories and calculations. So, I wouldn't trust to their claims about the risks and everything.

Not quite. It takes such big apparatuses to achieve the energies necessary to do the research/experiment to provide confirmation of models and theories.

One more thing: they are trying to recreate the big bang. I hope they "WILL NOT BE ABLE TO DO THAT"!

One is misinformed. No one is trying to recreate the Big Bang. The energies are too low. Cosmic ray particles are several orders more magnitude interact with particles in the Earth's atmosphere more or less daily. No Big Bang.

Bye! Please shut the door gently on the way out.

 

[dmitrrr]

Suppose mini black hole (BH) is created and suppose the Hawking radiation
isn't working (see doubts in Wikipedia).
Haw fast this black hole will destroy the Earth?
Under gravitational attraction BH will fall towards center of the planet.
Soon BH drops into liquid magma. Because it is liquid, then
the event horizon will be under pressure. So, particles of magma will be like
free falling into BH, constantly crossing the event horizon. Because time of free fall
into BH is very limited, soon the all magma will be sucked into BH.
The Earth core without support of magma will crush together.
Even if BH somehow remains on the surface of the planet,
the event horizon will be under pressure of the Earth atmosphere.
So, like in case of the magma, the air will very soon disappear.

 

[humanino]

Haw fast this black hole will destroy the Earth?

This depends on the cross section for absorption of matter around. You need to provide an estimation of the size of the BH. Assuming a quantum amplitude of 1 (which can not be larger anyway) then you will get an upper for the time required for absorption to occur merely from available phase space. This is were the pressure will come about, by the density of matter around. I think the time you will get is something like the age of the Sun...

 

[ZapperZ]

I've merged two threads together because we have way too many of these threads already. Any future threads started on the same issue will be merged to this one.

Zz.

 

[dmitrrr]

While discussing LHC one safety argument is, that mini black holes
would evaporate via Hawking radiation. I can't get clear picture from
Hawking's original paper
[S. W. Hawking, Commun. math. Phys., 43, 199 (1975),
(downloadable from Wikipedia)]. Can there be a contradiction?
Namely on page 207 is written:
"no particles on j^{-}" but on page 208 is written:
"the wave... propagate... out on j^{-}".
In the "particle description" the wave function corresponds
to particles. So on page 208 there are particles on j^{-}.