Exploring the Risks of the Large Hadron Collider

In summary, the popular books on physics suggest that when the LHC goes on this summer we might accidentally create a black hole and destroy the planet. But physicists know what they are doing and the LHC will not destroy the Earth. Otherwise claims are simple displays of scientific misunderstandings.
  • #141
Vanadium 50 said:
Personally, I think the standard Kent sets for risk ([tex]10^{-22}[/tex]) is absurd. Consider the risk that if we open a bottle, an angry genie will emerge from it and wipe out all life on earth. Since we've made maybe a trillion bottles to date, and this hasn't happened yet, we only know that the risk is less than around ([tex]10^{-12}[/tex]), a full ten billion times larger than Kent would permit. According to his argument, we should ban bottles.

I think this is an important point to make indeed. There are two kinds of risks associated with "doing new things". One risk is the objective probability that it will go wrong and do something evil, like eat up the earth. If the objective probability of such an event is stated to be p (say, 1 in 1 000 000 for instance) that means that if we were to repeat this experiment on, say, 100 million earth-like planets, that 100 of them on average would be eaten up/blown up whatever it was, and that 99 999 900 of them would be ok.

The other risk is the subjective risk (Bayesian "belief" risk) of weird things happening. This is not a probability in the frequentist sense, but a belief or not in the existence of a specific phenomenon, like evil genies popping out of bottles. Although certain theorists might feel insulted, posing the hypothesis of making tiny black holes at LHC energies which would not undergo Hawking radiation are, to me, not very far from genies popping out of a bottle. What "risk" is associated with such hypothetical phenomena ? If the phenomenon doesn't exist - that means, if it was just a quirk in the mind of a theorist or a story teller - then you can repeat the experiment on a gazillion earth-like planets, it will NEVER happen. If on the other hand, the phenomenon exists, it can occur at ANY rate, even "for sure". What do we do then ? It cannot be excluded that totally unexpected and weird things happen, and if we really do something totally new for the very first time in the universe, it is totally impossible to know. We might offend a deity which collapses the entire universe just by uttering a new phrase, we might get a genie out of a bottle, we might invoke the "coming of the great white handkerchief", or we might turn the Earth in a black hole.
Happily, most things (except for uttering phrases) we can do happen already somewhere in the universe, so by analyzing these things, we can sometimes obtain upper limits for the probability of the phenomenon happening under the hypothesis that the phenomenon is possible in the first place. But note that these estimates are not estimates of the probability that this will happen: they are conservative upper bounds.

Of course, from a decision PoV, Bayesian "ignorance" probability is probably to be treated on the same level as "genuine frequentist probability".
The danger of fixing too low probability levels for weird things to happen, is that we will for ever be stiffled in attempting new things - even at first totally inoffensive things, like writing phrases (which might invoke magical powers).
 
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  • #142
vanesch said:
I think this is an important point to make indeed. There are two kinds of risks associated with "doing new things". One risk is the objective probability that it will go wrong and do something evil, like eat up the earth. If the objective probability of such an event is stated to be p (say, 1 in 1 000 000 for instance) that means that if we were to repeat this experiment on, say, 100 million earth-like planets, that 100 of them on average would be eaten up/blown up whatever it was, and that 99 999 900 of them would be ok.

The other risk is the subjective risk (Bayesian "belief" risk) of weird things happening. This is not a probability in the frequentist sense, but a belief or not in the existence of a specific phenomenon, like evil genies popping out of bottles. Although certain theorists might feel insulted, posing the hypothesis of making tiny black holes at LHC energies which would not undergo Hawking radiation are, to me, not very far from genies popping out of a bottle. What "risk" is associated with such hypothetical phenomena ? If the phenomenon doesn't exist - that means, if it was just a quirk in the mind of a theorist or a story teller - then you can repeat the experiment on a gazillion earth-like planets, it will NEVER happen. If on the other hand, the phenomenon exists, it can occur at ANY rate, even "for sure". What do we do then ? It cannot be excluded that totally unexpected and weird things happen, and if we really do something totally new for the very first time in the universe, it is totally impossible to know. We might offend a deity which collapses the entire universe just by uttering a new phrase, we might get a genie out of a bottle, we might invoke the "coming of the great white handkerchief", or we might turn the Earth in a black hole.
Happily, most things (except for uttering phrases) we can do happen already somewhere in the universe, so by analyzing these things, we can sometimes obtain upper limits for the probability of the phenomenon happening under the hypothesis that the phenomenon is possible in the first place. But note that these estimates are not estimates of the probability that this will happen: they are conservative upper bounds.

Of course, from a decision PoV, Bayesian "ignorance" probability is probably to be treated on the same level as "genuine frequentist probability".
The danger of fixing too low probability levels for weird things to happen, is that we will for ever be stiffled in attempting new things - even at first totally inoffensive things, like writing phrases (which might invoke magical powers).



you mean, the LHC experiment is an objective risk?
 
  • #143
vanesch said:
Of course, from a decision PoV, Bayesian "ignorance" probability is probably to be treated on the same level as "genuine frequentist probability".
The danger of fixing too low probability levels for weird things to happen, is that we will for ever be stiffled in attempting new things - even at first totally inoffensive things, like writing phrases (which might invoke magical powers).

The problem with making decisions this way is how do you make an objective comparison about the risks of opening the bottle and releasing an angry genie versus not opening the bottle and risking the wrath of the god of bottle-opening? According to this line of reasoning, neither of the two mutually exclusive actions has acceptable risks.
 
  • #144
chinatruth said:
you mean, the LHC experiment is an objective risk?

No. It is rather a subjective risk: we will do "new" things, and an exotic phenomenon which might have an evil effect can hence, by ignorance, not be excluded (just as vanadium's genie from the bottle). If we were really doing something unique in the LHC, then there would be no way to tell whether or not this might actually happen, and anybody's guess would be as good as any other.

However, what is going to happen at the LHC is not unique in the universe. From that given, we can try to derive an upper limit to the eventual objective probability of some evil effect, under the hypothesis that it even exists. THESE are the numbers you find scattered around. They are *upper bounds* for an unknown objective probability, which might very well actually be 0 (said phenomenon doesn't exist).

Vanadium gave the perfect example: it is not unconceivable that there is a low objective probability that an evil genie that will destroy the Earth pops out of a bottle when we open it. But from the fact that we already opened 10^12 bottles, and that this didn't happen, we can deduce that IF ever such evil genies exist, the probability for them to pop out of a bottle cannot be larger than about 10^-12. That doesn't mean at all that we estimated the probability of evil genies to exist to be about equal to 10^-12 - honestly I don't believe they exist at all. But I have no scientific way to prove to you that this won't happen, and hence the best I can do is to say that opening a new bottle will represent a probability smaller than 10^-12 to destroy the earth. If you require (as Kent does) insanely low risk levels, well, then 10^-12 is not good enough, and hence from now on it is prohibited to open any bottle. Do you realize the burden such requirement for extremely low risk levels entails ?

Now, opening bottles is a very common activity, and that's what allowed us in the first place to give the upper bound of 10^-12. But imagine that we said the same for, say, landing on the moon. Imagine that somebody fears that we might wake up a monster hidden in the moon, which will eat the earth. As we haven't done many moon landings, this time we don't have a 10^12 trials at our disposal. Only a few tens or at most hundred (if you include robotic landings and such). So "landing on the moon could have a 1% chance of destroying the earth!". Nobody made the argument, so we didn't worry. In the 60ies, there weren't many moonlandings and then "landing on the moon could have a 30% chance of destroying the earth". We didn't know. We took a huge risk waking up the monster in the moon. Turns out there wasn't such a monster... or actually, we still don't know - there's still a 1% upper bound on the risk of waking up the monster if ever we do a new moon landing. Should we risk the Earth ?

The thing with the LHC is similar. Normally, the LHC won't make black holes. It is only in very contrived theoretical speculations that spacetime is warped in such a way that the low LHC energies could do so, and even in that case, if they respect the second law of thermodynamics, they should evaporate immediately. This kind of theorist's invention is IMO not very far from evil genies, as it is based on not much more than a whole load of speculation.
But we don't know for sure, as this is new. So one looks at the number of natural collisions at LHC energies that would have had the potential to do so and tries to estimate an upper bound of the probability that an evil thing could have happened (from the fact that it didn't). This gives us then an upper bound of having anything seriously evil in the LHC. If no collisions ever happened in nature at LHC energies, we would not be able to find such an upper bound. We would be left with an upper bound of "100% chance that we destroy the earth".
 
  • #145
Vanadium 50 said:
The problem with making decisions this way is how do you make an objective comparison about the risks of opening the bottle and releasing an angry genie versus not opening the bottle and risking the wrath of the god of bottle-opening? According to this line of reasoning, neither of the two mutually exclusive actions has acceptable risks.

Damn! We're doomed either way !

This is unbearable. Let us make a quick end to it and flip that switch on the LHC :rofl:
 
  • #146


humanino said:
And on the public part, realization of what fundamental research has brought to society down to one's daily life is the minimum level of gratitude, even if one does not care about pure knowledge.

I personally do not worry the slightest bit about getting money for my research. It has been difficult, it is difficult, it will be difficult. But in any case, "we must know, we will know".

Please do not tell me that the WWW is what we all should be grateful to CERN about. This does not in my mind rank as a significant scientific development, this would of occurred anyway, regardless of CERN. Significant reserach funding should be given to those areas of reserach that have a clear and measureable effect upon humanity as a whole. I think funding in the Biological sciences for example can yield much more useful and pratical benefits to the majority of Humanity. In the area of Physics for example more meaningful money could be spent upon the development of using new devices and technologies that could harness the power of other bodies, apart from our Sun, in order that we as a species might have some shared future. I simply don't believe that in the future we will be able to justify both the time and money that has been poured in projects like CERN.
 
  • #147


james77 said:
Please do not tell me that the WWW is what we all should be grateful to CERN about. This does not in my mind rank as a significant scientific development, this would of occurred anyway, regardless of CERN. Significant reserach funding should be given to those areas of reserach that have a clear and measureable effect upon humanity as a whole. I think funding in the Biological sciences for example can yield much more useful and pratical benefits to the majority of Humanity. In the area of Physics for example more meaningful money could be spent upon the development of using new devices and technologies that could harness the power of other bodies, apart from our Sun, in order that we as a species might have some shared future. I simply don't believe that in the future we will be able to justify both the time and money that has been poured in projects like CERN.

But how can you guess what use something will be in the future if we don't understand it at present? Relativity, say, had no "use" when Einstein discovered it back in the 1900's, but I doubt you'd be able to live without it today!
 
  • #148


cristo said:
But how can you guess what use something will be in the future if we don't understand it at present? Relativity, say, had no "use" when Einstein discovered it back in the 1900's, but I doubt you'd be able to live without it today!
Same story about electromagnetism.
 
  • #149


james77 said:
I think funding in the Biological sciences for example can yield much more useful and pratical benefits to the majority of Humanity. In the area of Physics for example more meaningful money could be spent upon the development of using new devices and technologies that could harness the power of other bodies, apart from our Sun, in order that we as a species might have some shared future. I simply don't believe that in the future we will be able to justify both the time and money that has been poured in projects like CERN.
How do you get biology if we had not do physics in the first place ? Don't you think understanding atomic structures and having microscopes powerful enough to unveil the ADN (for instance) had any use to biology ? Do you hope to understand cell microbiology and chemical mechanisms without any use of physical concepts ? Are you aware that more and more biology teams hire physicists ? This is just a non-discussion on our part, we can not list you all that has been made possible though fundamental physics, neither can we tell you what future will be.

If you restrict physics to applied physics, it is only due to your lack of perspective. Are you aware that we will need to leave this planet at some point, due to limited ressources, if humanity is to survive ?

All right, check that out if you want another example :
http://www.eu-egee.org/ [Broken]
 
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  • #150
Kudos to Vanesch and others for discussing intelligently the real risks - or lack thereof - involved with the LHC, rather than dismissing people's concerns as "baloney" as others have. Just because we are not - this week - going to destroy the Earth does not mean that we might not one day. A little humility really needs to enter into this community, more than ever when we start to play god by recreating the Big Bang.
 
  • #151
peter0302 said:
Kudos to Vanesch and others for discussing intelligently the real risks - or lack thereof - involved with the LHC, rather than dismissing people's concerns as "baloney" as others have.
Same applies to people requesting answers who have not dismissed published papers as "baloney" :smile:
 
  • #152
aquitaine said:
On another note CERN is getting flooded with phone calls from panicky people either pleading to shut the machine down or giving them death threats.

Telegraph_UK said:
Some sceptics remain unconvinced about its safety. Prof Otto Rossler, a German chemist who is one of a group of scientists attempting a last-minute court challenge to the project, is especially worried about the creation of black holes.

I see this as a bad career move. If true, there won't be much upside - not many Nobels will be issued to recognize figuring it out when Sweden's gone - and of course in the case nothing of the sort happens, it just makes the fellow look foolish. (But then again he is a chemist opining on black holes?)
 
  • #153
vanesch said:
No. It is rather a subjective risk: we will do "new" things, and an exotic phenomenon which might have an evil effect can hence, by ignorance, not be excluded (just as vanadium's genie from the bottle). If we were really doing something unique in the LHC, then there would be no way to tell whether or not this might actually happen, and anybody's guess would be as good as any other.

Of course we are doing something unique with the LHC. If not, show me another LHC. The "genies" argument is spurious because no one is seriously suggesting that such genies can exist in any circumstance. But Kent, Rees, et.al. are pointing out that there is a very, very small but finite chance of black holes and strange matter appearing that could cause us problems. This chance seems to be so much smaller than even the chance of winning the lottery, that personally I'm not losing any sleep over it (for the same reasons I don't do the lottery!) But physicists should at least join Rees in a united front of admitting that an incredibly small risk of human annihilation does exist. Then they should trust the politicians and public to weigh that risk, and accept their decision on whether to take that risk or not.
 
  • #154
From that Telegraph article:

"One of the leading figures behind the experiment is Dr Lynn Evans ... who said his fascination with science started as a boy, when he would create small explosions with his chemistry set at his council house in Aberdare.

Another is Prof Brian Cox of Manchester University, who played keyboards with D:Ream, whose hit Things Can Only Get Better was adopted by the Labour Party as its 1997 election anthem ... [he said] "Anyone who thinks the LHC will destroy the world is a t---."

Bet that makes the worried feel a whole lot better. Satire who needs?
 
  • #155
mal4mac said:
Of course we are doing something unique with the LHC. If not, show me another LHC. The "genies" argument is spurious because no one is seriously suggesting that such genies can exist in any circumstance. But Kent, Rees, et.al. are pointing out that there is a very, very small but finite chance of black holes and strange matter appearing that could cause us problems. This chance seems to be so much smaller than even the chance of winning the lottery, that personally I'm not losing any sleep over it (for the same reasons I don't do the lottery!) But physicists should at least join Rees in a united front of admitting that an incredibly small risk of human annihilation does exist. Then they should trust the politicians and public to weigh that risk, and accept their decision on whether to take that risk or not.

But here is where you need to think on how the public would interpret something like that.

One has to understand that in physics, almost everything has a non-zero probability of happening. There is a minute, but still, non-zero probability of an proton-antiproton pair appearing spontaneously out of thin air with enough energy that the LHC is producing to cause the same collision. Do we need to be worried about that?

Ask someone off the street how likely he/she think that a broken vase, when thrown onto the ground, would reassemble itself back into the vase? That person will likely tell you that it is NOT going to happen. Yet, in physics, there is still a non-zero but miniscule phase space where such an even CAN happen. So you have a general public that has decided that such an event is impossible, and physics that says that it most likely won't happen, but still, has a non-zero probability. Do we confuse the public by telling them that it cannot happen, or do we say, it won't likely to happen, but there's still a small probability that it can? How small are we talking about? Do we then have to make comparisons with things they know like being striked by lightning?

One simply cannot spew off statements to someone without understanding the level of comprehension of the listener. You may be saying one thing, but what you said can easily be misinterpreted by the listener. That is what scientists must always guard against. If I say that the formation of a catastrophic black hole at the LHC won't occur, I am using the level of understanding of a typical person who has already accepted that the vase will NOT reassemble itself from the hundred of pieces. If one accept that as not happening, then one should also accept other events with similar or lower probability of occurring.

Zz.
 
  • #156
mal4mac said:
The "genies" argument is spurious because no one is seriously suggesting that such genies can exist in any circumstance.

You might not have been following "Islamic Science", which is sort of the muslim world's answer to creationism. They certainly think of genies - or djinn - as real.

I also don't think the world-eating black holes are "seriously suggested" either, at least not by anyone with a level of understanding sufficient to be serious. These putative objects, as has been pointed out by several people, have mutually contradictory properties. I don't see why an imaginary object with self-contradictory features is intrinsically more likely than a mythical being.
 
  • #157
Just in time for the first circulating proton beam at the LHC tomorrow, a http://physics.aps.org/articles/v1/14" [Broken] of SLAC has appeared that analyzes the paper published by Giddings and Mangano, which, btw, is available for free.

Zz.
 
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  • #158


cristo said:
But how can you guess what use something will be in the future if we don't understand it at present? Relativity, say, had no "use" when Einstein discovered it back in the 1900's, but I doubt you'd be able to live without it today!


You can´t guess what "use" any theortical concept will or will not have in the future, you have to develop a type of technology in order for any theory to be of use in the real world, and the notion of use implies value, which again is a relative term. As we all know the same Science can be used to develop very different things. But, the important point is that life can and indeed would continue to exist with or without the knowledge we have about Relativity, Electromagnetism or Particle Physics. It´s doubtful in terms of what values these subjects mean to humanity as a whole, what these discoveries have really mean´t to the average person on the street. Have the resultant technologies not further estranged people from each other, yet it would be foolish to deny the positive effects they have brought too.
 
  • #159
if the LHC creates a black hole...

just wondering, if somehow a black hole is created by the LHC that can destroy the earth, would there be a way to close the black hole? or would we all just be doomed?
 
  • #160
mal4mac said:
Of course we are doing something unique with the LHC. If not, show me another LHC.

There are very high-energetic particles out there in space, you know. Particles which have millions or billions of times more energy than what we give them in the LHC. So there are no elementary processes happening in the LHC that haven't happened in the upper atmosphere, in Jupiter, etc...

The "genies" argument is spurious because no one is seriously suggesting that such genies can exist in any circumstance. But Kent, Rees, et.al. are pointing out that there is a very, very small but finite chance of black holes and strange matter appearing that could cause us problems.

I'm sorry but they can't. They can at most give you an UPPER BOUND to that probability. If they have a LOWER BOUND, which is what it means to say that there is a finite chance (that is, you state that it is not zero), then that means that they are SURE that such a reaction is physically possible, but they can't. There's only two ways to make such a statement scientifically, and that is by having observed it already, or by using firmly established principles to derive the happening. It has not been observed yet, I guess you can agree with that, but moreover, the principles on which one could even suggest it to happen are very very highly speculative (and have even to contradict things we thought we knew rather well, such as the second law of thermodynamics).

What is correct (see my post on subjective and objective probability) is that the best we can do is give an upper bound for the probability for something bad to happen under the hypothesis that it can happen - just like the genies from the bottle.

You have to understand where these "black hole theories" come from. For decades, theorists have been speculating (it's their job) about extensions of the standard model. In the beginning, they made observable predictions, but that had the disadvantage of being contradicted rather quickly with new observations. Then some of them embarked on very highly speculative ideas like string theory and the likes, which would normally give observable things only at such crazily high energies, that there was no hope ever to build a machine on Earth that would verify them. Then, they got the accusation that they were not really doing science, as their predictions would not be practically falsifiable. So they fiddled and twisted and turned their theories (that means, introduced funnier and stranger hypotheses) until they could make *something* eventually appear at LHC energies. That's why there are papers on the possibility of making micro black holes appear at the LHC. It's not that they sat down and said "gees, the LHC is going to produce black holes", they sat down and said "how can I change something in my theory SO THAT there might be a chance of the LHC to make black holes".
But until there, nothing dangerous, because if black holes respect the second law of thermodynamics, then they have to emit Hawking radiation - it would even be a feat to observe them before they blew up in random particles which would look as just an arbitrary collision.
 
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  • #161
So we're all about to die.

I've been thinking about what it would look like if the "ice-9" stranglet scenario actually happened, and the LHC turned the planet into strange matter. (I know this won't actually happen, but humour me :tongue:)
As I understand it, the idea is that essentially all protons and neutrons would have their quark composition changed to uds, which is charge neutral. So watching the impending goo would be like watching everything getting ionized at once.
Two questions:
1)Would this just look like everything turning black?
2)Would the radiation kill us before we turned into strange matter?

Have a nice day now y'all :biggrin:
 
  • #162
Oh and Cristo: the best thing about that Daily Mail article is the caption in which they state that physicists are trying to recreate the conditions of the big band :biggrin:
 
  • #164
hey guys I am new to the forum :) I am very interested in space etc and i know quite a lot i think, well for an average 18 year old. ( i got a C GCSE in single science lol, don't know why i meantioned that.) anyway i have a few questions about this LHC, that hopefully a few more educated people could answer.
is it just me or is this experiement very risky? putting the whole world at risk just for an experiment?
anyway, here are a few questions?
black holes are created when high amount of energy/mass is concentrated down to a small point, am i right?
so didnt they say that their sending billions of protons down a tube only a hair's length wide? how much energy/mass are they concentrating down into this tube and with how much force?
they say that nature is creating these collisions all the time, but in the LCH these collisions will be concentrated in a small area with no room for the particles to spread out.
also when the protons collide together they said micro black holes might be created but how many exactly? they also said they would evaporate but what if lots are created and some formed together before they evaporated? i mean like they merge into a bigger black hole which doesn't evaporate.
finally if you did have 1 single micro black hole that didnt evaporate, how much damage could it possibly do?
thanks!
 
  • #165
Please read the link I gave in Msg. #165.

Zz.
 
  • #166
ZapperZ said:
Please read the link I gave in Msg. #165.

Zz.

i have just read it but its a bit too deep for my understanding. the formulas are meaningless to me :S sorry
 
  • #167
chippy! said:
i have just read it but its a bit too deep for my understanding. the formulas are meaningless to me :S sorry

Then you need to consider the possibility that maybe, this might be a bit difficult to comprehend for you, and that at some point, you have to depend on the experts who have done quite a bit more studies on the nature of the risk. I'm not saying that you shouldn't ask. But when you question the validity of the safety conclusion, then you need to present your objection not based on ignorance.

The same can be said about the formation of such "black holes". You can see the difficulty in explaining the nature of such black holes, or what Peskin called "slippery" black holes, if you do not have the capability of understanding the physics. Try explaining geometry to a 2-year old and see if he/she can solve a trig problem after that. This doesn't mean you shouldn't ask, but you need to be aware that the problem isn't easy and require a lot of "prerequisites" to comprehend.

Zz.
 
  • #168
ZapperZ said:
Then you need to consider the possibility that maybe, this might be a bit difficult to comprehend for you, and that at some point, you have to depend on the experts who have done quite a bit more studies on the nature of the risk. I'm not saying that you shouldn't ask. But when you question the validity of the safety conclusion, then you need to present your objection not based on ignorance.

The same can be said about the formation of such "black holes". You can see the difficulty in explaining the nature of such black holes, or what Peskin called "slippery" black holes, if you do not have the capability of understanding the physics. Try explaining geometry to a 2-year old and see if he/she can solve a trig problem after that. This doesn't mean you shouldn't ask, but you need to be aware that the problem isn't easy and require a lot of "prerequisites" to comprehend.

Zz.

no, i am able to understand if someone just answered my questions directly. if someone was to explain it simply without the full in depth 'workings out'. is that too much to ask?
 
  • #169
Ontoplankton said:
Do any of you happen to know whether there's a nonzero (or greater than let's say one in a million) chance of accidental universe creation at LHC, as is sort of suggested here: http://www.newscientist.com/channel/fundamentals/mg19125591.500-create-your-own-universe.html ? If there is, then does nature do it also? It wouldn't affect us if it happened but it still seems ethically dubious.

My god. New Scientist sunk to the depth of a black hole :wink:

This is entirely speculative, but moreover, this is not science, as it is not falsifiable in principle.
What is said here is that WE would observe a micro black hole, but that "in fact" it is an entire universe, but we won't find out.
 
  • #170
chippy! said:
no, i am able to understand if someone just answered my questions directly. if someone was to explain it simply without the full in depth 'workings out'. is that too much to ask?

Read through this thread, and you might get an idea.
 
  • #171
vanesch said:
Read through this thread, and you might get an idea.

well i have read 2-3 pages but there is a lot to take in at once.
ok can i just ask, seeing as no-one wants to answer my questions.
overall then regarding this LHC experiement what are the odds of creating any black hole, of any size or length of time?
 
  • #172
chippy! said:
no, i am able to understand if someone just answered my questions directly. if someone was to explain it simply without the full in depth 'workings out'. is that too much to ask?

Let's look at your first question:

is it just me or is this experiement very risky? putting the whole world at risk just for an experiment?

If I just answered "No", would you be satisfied? Many people won't. And in fact, giving you just the answer "no" would be insulting to you, because it assumes that you will except everything that I tell you without proper justification. So now, it is THAT proper justification that is the issue here.

The link I gave you, while it is quite technical, has ALL the necessary answer. You can read the first few paragraphs to clearly get the answer to this particular question. Even his example from astrophysical observation should have a convincing argument that nature has done a lot more "LHC-type" experiments than the LHC would ever hope of doing. This you should have noticed clearly enough as the answer to your question.

Zz.
 
  • #173
ZapperZ said:
Let's look at your first question:



If I just answered "No", would you be satisfied? Many people won't. And in fact, giving you just the answer "no" would be insulting to you, because it assumes that you will except everything that I tell you without proper justification. So now, it is THAT proper justification that is the issue here.

The link I gave you, while it is quite technical, has ALL the necessary answer. You can read the first few paragraphs to clearly get the answer to this particular question. Even his example from astrophysical observation should have a convincing argument that nature has done a lot more "LHC-type" experiments than the LHC would ever hope of doing. This you should have noticed clearly enough as the answer to your question.

Zz.

ok, I am not one of these people against the experiment , I am sitting on the fence.
its just confussing me that why are some scientists saying that it isn't safe? do they have a vaild theory or reason why it could go wrong? i
 
  • #174
chippy! said:
well i have read 2-3 pages but there is a lot to take in at once.
ok can i just ask, seeing as no-one wants to answer my questions.
overall then regarding this LHC experiement what are the odds of creating any black hole, of any size or length of time?

You need to keep in mind that creating black holes is something they WANT. This isn't the issue. If GR is correct in this energy scale, then creating these micro black holes would not be surprising. I know of many people who would LOVE to be able to create AND detect them.

The issue is (i) the nature of such black holes and (ii) that they become stable and can create a catastrophe. This is the scenario that is creating such a brouhaha in the media. This is what has been argued to be extremely unlikely. It is as likely as you spontaneously vanishing.

Zz.
 
  • #175
chippy! said:
ok, I am not one of these people against the experiment , I am sitting on the fence.
its just confussing me that why are some scientists saying that it isn't safe? do they have a vaild theory or reason why it could go wrong? i

There are also "scientists" who claim Evolution is wrong. You need to separate out fringe opinions versus the majority, and in this case, an overwhelming majority.

Read Peskin viewpoint again, and pay attention to where he describes the level of assumption and theoretical speculation that is required to work out these things. This is where someone can pull out some numbers beyond what we have verified so far to come up with such disasters. As vanesch has mentioned earlier, many of these are not falsifiable as of yet, so you can simply speculate way. The key here is when we look at things that are reasonable, such as the astrophysical observation that we already know, these things just do not happen. The fact that the Moon is still there (to paraphrase the RHIC safety report) tells us that these experiments are not going to create such catastrophe.

Zz.
 

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