Do you think the LHC should be turned on?

[Gaspode]

The Large Hadron Collider (LHC) is a particle accelerator and collider located at CERN, near Geneva, Switzerland

<snip>

When switched on, it is hoped that the collider will produce the elusive Higgs boson particle — often dubbed the God Particle — the observation of which could explain how other elementary particles gain mass and fill in the gap in the Standard Model theory.http://en.wikipedia.org/wiki/Large_Hadron_Collider

Some scientists have stated that there is a 1 in 50,000,000 chance that during a ten year period of operation, an experiment in the LHC could destroy the entire planet and possibly the whole universe.:eek:

So, ahead of a Horizon program on the LHC, the BBC are running an identical poll to this one (which I've shamelessly ripped off) on their Science & Nature (http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/universe/vote/) website . Currently those in favour of switching on the LHC are 52.4%. Not exactly a vote of confidence!

I'm naturally skeptical when I hear of people predicting catastrophes of this kind, especially with odds that large. So I voted yes. Was that the right choice? :covereyes

[Paul C. Anagnostopoulos]

Here's my honest opinion: I very much doubt that the LHC can eat the universe. However, let's say one day it did. Who really cares? We'd all just evaporate and that would be it. It's such an unimaginably broad mode of destruction that I can't get worried about it.

~~ Paul

[cj.23]

I talked about this one the forum a while back actually: neither strange matter or black holes bother me at all, and at those odds I'd say we were pretty safe, but the possibility of inadvertantly triggering a quantum vacuum collapse did actually cause me to lose a couple of nights sleep, as I was not sure how to predict the odds of it. I gained a little reassurance from posters on this forum: providing one is merely replicating events already known to occur in the universe I am not worried at all. Move to creating new types of event, and as the wikipedia article notes there is a theoretical risk.

If the risk is greater than 0 of destroying the universe, well hell we have a right to be concerned: how much bigger, that is the question!

cj x

[ponderingturtle]

This strikes me as being similar to how people predicted that an atomic explosion would set of a chain reaction in the atmosphere incinerating the entire planet.

If strange matter where so much more preferable why wouldn't it be the standard? The idea that the universe is tenuously perched on a very small island of stability is very strange to me.

[Myriad]

I'm fine with it, as long as no one's going to be turning it on and off 50,000,000 times! :D

Respectfully,
Myriad

[RenaissanceBiker]

I still haven't forgiven Senator Mitch McConnell and others on the Senate Appropriations Committee for shutting down our super-conducting super-collider project.

[Ashles]

When the terrorists start protesting, that's when you'll know you've gone too far.

[Mobyseven]

Methinks that the scientists may be providing those odds just to give people an idea of the power this thing has. I highly doubt that there is any real danger in flipping the switch...particle physicists may be a thrill-seeking mob, but I doubt they're losing too much sleep over the possibility of destroying the universe as we know it.

[kalen]

I think the risk is waaay smaller.

Whatever concern there is comes from the fact that the LHC will be colliding protons together at the order of 10^12 eV energy. There is speculation at what we will find/make in this unexplored territory: micro-blackholes, rifts in the fabric of space time, some weird particle that will change the nature of matter on earth in some kind of domino-type effect.

It turns out that nature has been colliding particles at this energy, and at much higher energies, for a very long time. We're talking about energies upwards of 10^20 GeV. We know this from the observation of cosmic showers. A cosmic shower happens when a high energy particle from space interacts with atoms in the Earth's atmosphere. Because of the high energy, more particles are produced and those can go on to interact further with the atmosphere. This cascading effect produces a shower of particles that are detectable on the Earth;s surface. In fact, a number of cosmic shower particles have gone right through you since you started reading this article.

The Earth is nowhere particularly special to receive these high evergy particles from space. It follows that collisions on the LHC energy scale and above have been going on throughout the universe for a very long time. Evidence suggests that we are all still here and doing fine. If these high energy collisions were even remotely detrimental to the universe as a whole, we wouldn't be here.

As for locally producing a black hole, and having it eat up the earth? I'm not sure what to say about that. Do we know why gamma ray bursts happen yet?

BTW, I voted for turning the LHC on. If we blow up the earth, it will be totally worth it.

[cj.23]

Yep, makes sense. My only concern would be if we create effects not seen before in the universe, and therefore unquantifiable?

cj x

[Ashles]

I don't mind whether they turn it on or not but Jesus they need a webpage designer:

It's as bad as a site about mind mapping or crystals (nearly) (http://lhc.web.cern.ch/lhc/)

Anyway, it'd be too weird to think we all may be goners in a year.
The world was destroyed, and Bernard Manning was there at the end. Ugh.

[ponderingturtle]

Yep, makes sense. My only concern would be if we create effects not seen before in the universe, and therefore unquantifiable?

cj x

matter can release a significant portion of its rest mass as energy falling on a neutron star, and super nova and black holes produce high energy particles.

There is no reason to think that the universe is so unstable that anything we could possibly do would set of some hidden chain reaction.

The only reason why any odds are given is that they can not be truely sure that something like that can not happen, given that we are in territory that has not been gone through before. So they are reluctant to say something is impossible

[Gaspode]

The poll results were pretty much as I expected. I won't be losing any sleep.

When I first heard this story I was reminded of this quote by Douglas Adams:

There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.


Maybe this has been done before ...

[Yllanes]

This issue comes up every couple of months or so. The idea that the LHC could destroy the Earth is completely silly, there already are in our atmosphere protons with 100 000 000 times the energy of the ones in the LHC. Already running is the Tevatron at Fermilab, which is capable of 1/7 the energy of the LHC.

I always link to the report (http://forums.randi.org/showthread.php?postid=2319101#post2319101) that was made during the planning of the RHIC at Brookhaven, which addresses similar concerns.

[cj.23]

This issue comes up every couple of months or so. The idea that the LHC could destroy the Earth is completely silly, there already are in our atmosphere protons with 100 000 000 times the energy of the ones in the LHC. Already running is the Tevatron at Fermilab, which is capable of 1/7 the energy of the LHC.

I always link to the report (http://forums.randi.org/showthread.php?postid=2319101#post2319101) that was made during the planning of the RHIC at Brookhaven, which addresses similar concerns.

Thanks Yllanes - I think you put my mind at rest when I raised it. I often thinking alleviating fears and helping public understanding is an important part of science, and while I retain niggling doubts I wanted to take this opportunity to thank you.

j x

[Yllanes]

You are welcome. But really, you shouldn't give this problem a minute's thought. When you come down to it, the only thing the LHC does is collide particles. And there are plenty of more energetic natural collisions.

Of course, some of the things they hope to do there are a bit more refined. For example, they want to collide bunches of nuclei to create a quark gluon plasma (http://en.wikipedia.org/wiki/Quark_gluon_plasma), which is something that doesn't exist in the universe since 13.6 Gy ago (the RHIC I mentioned earlier is also doing this). But the fact that there are no QGP around is only because you need a very well colimated group of nuclei and this doesn't happen by chance. We are already being hit by much more energetic nuclei from the cosmic rays. (This paragraph was just an excuse to mention the QHP, which I think is both very interesting and unheard of by the general public).

[Gaspode]

You are welcome. But really, you shouldn't give this problem a minute's thought. When you come down to it, the only thing the LHC does is collide particles. And there are plenty of more energetic natural collisions.

Of course, some of the things they hope to do there are a bit more refined. For example, they want to collide bunches of nuclei to create a quark gluon plasma (http://en.wikipedia.org/wiki/Quark_gluon_plasma), which is something that doesn't exist in the universe since 13.6 Gy ago (the RHIC I mentioned earlier is also doing this). But the fact that there are no QGP around is only because you need a very well colimated group of nuclei and this doesn't happen by chance. We are already being hit by much more energetic nuclei from the cosmic rays. (This paragraph was just an excuse to mention the QHP, which I think is both very interesting and unheard of by the general public).

Thanks for that.

No doubt the issue will come up again! :)

[Yllanes]

Thanks for that.
No problem, it is a good topic for a thread actually.


No doubt the issue will come up again! :)
Well, seeing as how this thread was started by a member of the Tag Team, let us hope it will be easy to find in future searches. Do you have any tag for doomsday scenarios? It would surely dig up some estimulating threads. Seriously, let me take this opportunity to congratulate the taggers for their work, I think it will be well worth it.

[cj.23]

You are welcome. But really, you shouldn't give this problem a minute's thought. When you come down to it, the only thing the LHC does is collide particles. And there are plenty of more energetic natural collisions.

Of course, some of the things they hope to do there are a bit more refined. For example, they want to collide bunches of nuclei to create a quark gluon plasma (http://en.wikipedia.org/wiki/Quark_gluon_plasma), which is something that doesn't exist in the universe since 13.6 Gy ago (the RHIC I mentioned earlier is also doing this). But the fact that there are no QGP around is only because you need a very well colimated group of nuclei and this doesn't happen by chance. We are already being hit by much more energetic nuclei from the cosmic rays. (This paragraph was just an excuse to mention the QHP, which I think is both very interesting and unheard of by the general public).

Thanks. My niggling doubt came from


To summarize, under plausible assumptions the cosmic-ray data exclude the possibility of dangerous processes in heavy-ion colliders like RHIC or the LHC, but the worst-case scenario cannot be excluded based on these data alone.

from the safety evaluation report of 2003. Still I figure that folks capable of creating this know what they are doing - and the fact that RHIC seems to be functioning OK makes me less concerned.

Thanks once again
cj x

[Gaspode]

Well, seeing as how this thread was started by a member of the Tag Team, let us hope it will be easy to find in future searches. Do you have any tag for doomsday scenarios? It would surely dig up some estimulating threads. Seriously, let me take this opportunity to congratulate the taggers for their work, I think it will be well worth it.


Thanks!

I've only just started tagging in this section, being confined mainly to Conspiracy Theories for my sins. But I visit Science almost as often so I think I will spend some more time here. I need a break from the conspiraloons!

Before I started this thread I did a search for other threads about LHC to see if the subject had been brought up before. If you click on the tags above you'll see the two threads I found on the subject and subsequently tagged.

[Mobyseven]

I've only just started tagging in this section, being confined mainly to Conspiracy Theories for my sins.

Who did you piss off to get that job? ;)

[becomingagodo]

Were all going to die.Think about it the initial condition for the big bang had to be special to create something out of nothing. I see it like this if you had a exposive device and then made a replica then should you risk testing the replica. I think looking for a unexistant particle is not worth dystroying everything. Most of the theory behind it needs the Higgs particle to exist, but what if the Higgs particle doesn't exist?
Now 1 out off 50,000,000 could be assuming that the Higgs or other wrong theories(string theory) is correct. I don't normally hate people, but that lady in the program makes the anger come. We going to die
When are they turning this on as it would proberly make me scared all day thinking I'm going to die.
BTW, I voted for turning the LHC on. If we blow up the earth, it will be totally worth it.
Your sadistic. If you want to die vote yes on turning on LHC.

Why does this stupid generator warrent a whole program? As someone said earlier a other machine runs on 1/7 off this generator power. I don't see how this creates the condition of the big bang and how magically a Higg particle is going to show up. Well unless you believe in high temperture Symmetry theory.

[Yllanes]

Were all going to die.
Eventually.
Think about it the initial condition for the big bang had to be special to create something out of nothing.
The LHC may be powerful, but is quite far from the Big Bang...

I think looking for a unexistant particle is not worth dystroying everything. Most of the theory behind it needs the Higgs particle to exist, but what if the Higgs particle doesn't exist?
Even better. There are many candidate particles waiting just fot that to happen. If the Higgs doesn't show up, then the Standard Model is wrong and particle physics becomes incredibly exciting again.


Now 1 out off 50,000,000 could be assuming that the Higgs or other wrong theories(string theory) is correct. I don't normally hate people, but that lady in the program makes the anger come. We going to die
When are they turning this on as it would proberly make me scared all day thinking I'm going to die.

I don't know where that number comes from. It doesn't make sense. The probability of something wrong happening is as close to zero as to be inexistant.


Why does this stupid generator warrent a whole program? As someone said earlier a other machine runs on 1/7 off this generator power. I don't see how this creates the condition of the big bang and how magically a Higg particle is going to show up. Well unless you believe in high temperture Symmetry theory.
I said that precisely to point out that the LHC is not going to be something magical, new. It is going to be more powerful than current accelerators, but it is still in the same order of magnitude, so there is even less reason to think it will trigger the end of the world.

It warrants a whole programme because the Tevatron is just at the energy threshold for the Higgs to appear, but probably not quite. The LHC covers the whole energy range where the Higgs may appear. We have both lower and upper bounds (for theoretical and experimental reasons). The window that remains is very thin and the LHC should cover it. So if they don't find the Higgs at the LHC then it doesn't exist and they have to find something else in its place.

Also, the LHC is going to do more than just search for the Higgs. Supersymmetry, quark-gluon plasma, antimatter, CP violation, exotic decays, etc. It is going to probe a wider range of energies and to shed a lot of light into many areas of nuclear and particle physics.

[Mobyseven]

becomingagodo:

I understand that technology can be a frightening thing, especially if you do not understand it. But there are people out there who DO understand this technology (enough of it at least to assure you that this will not be able to replicate the Big Bang, for example), and I would suggest that you put your trust in them for this.

As far as scientific discoveries go, the LHC will provide us with the biggest one of recent times - regardless of whether the Higgs boson exists or not just knowing this now with relative certainty will shape the future of particle physics...it may rock some of the foundations we take for granted.

This is not a discovery you want to pass up because you fear unknown, incredibly improbable consequences.

My two cents...

[tracer]

THE HIGGS BOSON IS TAMPERING IN GOD'S DOMAIN!!

OH NOES!!!!!!11one1

[Schneibster]

I still haven't forgiven Senator Mitch McConnell and others on the Senate Appropriations Committee for shutting down our super-conducting super-collider project.Nor have I. But you have to thank Sherwood Boehlert, R-NY, for leading the charge in the House; and that's what killed it. The House voted 280-150 to kill it, but the Senate voted 57-42 to keep it going. The Congresscritters were sent back to the joint committee with instructions to kill it.

We have destroyed the careers of a generation of American high energy particle physicists; we have sacrificed what it took most of the 20th century to build up in the way of expertise. It was unconscionable. We also wasted a billion dollars that had already been spent, and another billion on shutting it down. At the time there were supposedly a bunch of small science projects that were supposed to benefit; what we got was lies about how effective condoms are for our kids, banned stem cell research, suppressed climate research, and Halliburton in Iraq. Thanks, Republicans.

[Momzahippie]

The results of the poll so far are quite interesting. At 41 votes only 3 have voted no. Skeptics are more willing to take a very small risk for new knowledge?

[Badly Shaved Monkey]

This issue comes up every couple of months or so. The idea that the LHC could destroy the Earth is completely silly, there already are in our atmosphere protons with 100 000 000 times the energy of the ones in the LHC. Already running is the Tevatron at Fermilab, which is capable of 1/7 the energy of the LHC.

I always link to the report (http://forums.randi.org/showthread.php?postid=2319101#post2319101) that was made during the planning of the RHIC at Brookhaven, which addresses similar concerns.


This may be stupid, but snice nature already provides us with these high energy particles, what stops us asking the questions with nature's ready made high-energy collisions. Is it an issue of creating enough of them to get a statistically useful sample to look for low probability events, or is it because the detectors have to be these huge devices that would be tricky to hang from a balloon high up in the atmosphere?

[Slimething]

Turn it on. Just as long as a guy named Gordon Freeman doesn't get anywhere near it, I'm happy.

[Yllanes]

This may be stupid, but snice nature already provides us with these high energy particles, what stops us asking the questions with nature's ready made high-energy collisions. Is it an issue of creating enough of them to get a statistically useful sample to look for low probability events, or is it because the detectors have to be these huge devices that would be tricky to hang from a balloon high up in the atmosphere?

Both. Sometimes you need many particles colliding head to head (as in the QGP I mentioned earlier), for example. Also, we have to make very precise measurements, which requires very sophisticated and very big detectors (the Compact Muon Sollenoid at CERN weighs 12 500 tonnes).

So size is an issue. And even if you could detect natural particles in this way, you would have to wait until the interesting ones came. The flux of cosmic rays drops very quickly with energy.

Another problem is that you can't just make two protons collide and see what happens. You have to make 109 collisions per second and maybe one produces the desired output. That's why we need such sophisticated detectors: they have to identify the itneresting trajectory among all the noise. Some of the cross sections (probability per unit area) are very small. It is not a matter of just detecting new particles, we have to make very precise measurements of half-lives, cross sections, etc. and for that we need a lot of equipment.

Also, the highest energy cosmic rays are not detected directly. You cannot put a satellite with a calorimeter on orbit and hope it catches one, as we do with more moderate ones. We detect the air shower they generate (a cosmic ray collides with the atmosphere and generates a shower of hadrons, electrons and radiation). This goes for very energetic cosmic rays. If we want to go to the highest energies (108 more than the LHC) we see that only about 1 per square km per arrive each century. To get a reasonable detection sample, an array of detectors covering an area the size of Rhode Island has been built in Argentina (Pierre Auger Observatory (http://www.auger.org/)). And even this is going to measure different things than the LHC.

[Cuddles]

As has already been said, the chance is actually zero. The Earth, and pretty much everything else, is constantly being hit by particles with much higher energy than we can get in labs. Since the universe hasn't ended yet, the LHC is not capable of destroying the universe, or even a little bit of it.

On the other hand, the LHC certainly should not be turned on because it isn't finished yet.

[andyandy]

On the other hand, the LHC certainly should not be turned on because it isn't finished yet.

what's the schedule like for the switch on? Last I heard [from Ylllanes last month :) ], there'd been a serious failure with one of the magnets....

has that been sorted?

[Cuddles]

what's the schedule like for the switch on? Last I heard [from Ylllanes last month :) ], there'd been a serious failure with one of the magnets....

has that been sorted?

It's not just one of the magnets, there are four dectectors around the ring, and each one has two sets of focussing magnets, one before and one after, to make the two beams actually hit each other. What failed was the structure holding these magnets, and it seems that it almost certainly failed due to a design flaw, which means that all of them are bad, not just the one that actually failed under testing. A repair has been proposed and will be tested in June, and if that works then the overall timetable probably won't be affected too much, assuming that this won't actually prevent other work continuing. As far as I know, the schedule is still the same, and speaking from experience it will probably stay the same right up until the day it is supposed to start. Whether it actually starts then is a different matter.

There's a press release about it here (http://user.web.cern.ch/user/QuickLinks/Announcements/2007/LHCInnerTriplet_3.html).

[hgc]

It's times like this that I wish hammy were still here. The Higgs Boson is his hobby horse of anti-materialism.

[Ratatoskr]

Turn it on, what's the worst that could happen?

Oh well, besides THAT...

[Dancing David]

matter can release a significant portion of its rest mass as energy falling on a neutron star, and super nova and black holes produce high energy particles.

There is no reason to think that the universe is so unstable that anything we could possibly do would set of some hidden chain reaction.

The only reason why any odds are given is that they can not be truely sure that something like that can not happen, given that we are in territory that has not been gone through before. So they are reluctant to say something is impossible

My feelings as well. there are places where energy far in excess of that of the LHC is created.

Now if the earth goes supernova. that might be a problem. ;)

[malbui]

I live right next door to CERN, so if things do go pear-shaped when they switch on the LHC I'll be the first to kn

[Overman]

So is our new god the Large Hadron Collider or the person who turns it on?

;)

[Cuddles]

I didn't see the Horizon program, some friends were talking about it at work today. Apparently it was just about the biggest pile of drivel that has ever been broadcast under the title of "physics documentary" that failed to have anything meaningful about physics, let alone the LHC, in it. To have a poll based on this pile of dog vomit shows just how pathetic the BBC has become.

What is really sad is how people who are supposedly educated can actually take this garbage seriously. Apparently there is talk among students at Oxford of boycotting the LHC. Although quite how that would work no-one is entirely sure. Presumably people will refuse to buy their Higgs bosons from CERN or something.

[GreedyAlgorithm]

The results of the poll so far are quite interesting. At 41 votes only 3 have voted no. Skeptics are more willing to take a very small risk for new knowledge?
Or perhaps we realize that some scientists saying something has a 2e-8 chance of occurring does not actually mean it has a 2e-8 chance of occurring?

[cj.23]

Or perhaps we realize that some scientists saying something has a 2e-8 chance of occurring does not actually mean it has a 2e-8 chance of occurring?

Yes, it is that realisation which disturbs me. :)

cj x

[Ashles]

What is really sad is how people who are supposedly educated can actually take this garbage seriously. Apparently there is talk among students at Oxford of boycotting the LHC. Although quite how that would work no-one is entirely sure. Presumably people will refuse to buy their Higgs bosons from CERN or something.
Oxford and Cambridge have really gone downhill recently - time was when they would be in the forefront of this new research, not boycotting it because it might endanger their future career as management consultants.

[Michael Redman]

Currently those in favour of switching on the LHC are 52.4%. Not exactly a vote of confidence!Especially when you consider that at least 2.4% are voting yes because they hope it will destroy the universe.

That why I voted yes, anyway.

[Badly Shaved Monkey]

Apparently there is talk among students at Oxford of boycotting the LHC. Although quite how that would work no-one is entirely sure. Presumably people will refuse to buy their Higgs bosons from CERN or something.

Perhaps if the LHC discovers the Higgs boson the boycotters will refuse to have mass by way of protest.

"Turn that thing off now, or I'll go all ethereal and float away. Ha!"

[Wat Tyler]

FAO Cuddles:
The 'meeja' types at the BBC show a lamentable ignorance of matters scientifick, and always have.

One has only to look at the absolutely howling scientific errors in the plotlines of their various sci-fi shows.

But can you imagine the uproar that would occur from among the meeja hierarchy if a show written by Science graduates got the name of, say, one of the Brontë sisters' minor characters wrong?
:mad:

I reckon that this guff about the LHC being able to destroy the planet/universe was put about by none other than the people at CERN responsible for building the LHC.

Not only does it make it sound 'cool', and thus much more likely to attract funding (heck, if it can destroy planets, maybe there's a military application in there somewhere), but also, when it fails to destroy the planet, it makes their application for the next generation of particle accelerator more likely to be successful.

I, for one, am only interested in a PA with a diameter of at least the same size as Jupiter's orbit - think of the science you could do with one of those buggers!
<drools>

Then again, it is time for my Meds again....
;)

[cj.23]

I reckon that this guff about the LHC being able to destroy the planet/universe was put about by none other than the people at CERN responsible for building the LHC.

;)

It was indeed : see their 2003 risk assessment document, linked earlier in the thread. It's a real risk, just a very remote one which is nothing to worry if our maths and our understanding is correct...

cj x

[Fnord]

There is not much to worry about with regards to the LHC being switched on, except for maybe a few lamps that might flicker in town, and maybe the telly would have a bit more snow on the screen, but it isn't as if the LHC would trigger a recursive time loop! I mean, There is not much to worry about with regards to the LHC, except for maybe a few lamps that might flicker in town, and maybe the telly would have a bit more snow on the screen, but it isn't as if the LHC would trigger a recursive time loop!

Whoa ... head rush!

[Cuddles]

I, for one, am only interested in a PA with a diameter of at least the same size as Jupiter's orbit - think of the science you could do with one of those buggers!
<drools>

Then again, it is time for my Meds again....
;)

Surprisingly little actually. As you go to higher energies the losses increase much more rapidly than any benfits you get from using bigger accelerators. It's all about linear accelerators these days. The LHC will probably be the last circular collider built.

It was indeed : see their 2003 risk assessment document, linked earlier in the thread. It's a real risk, just a very remote one which is nothing to worry if our maths and our understanding is correct...

cj x

That's the point, it's not a real risk. It is a number put on it simply so they can say "Look, we've calculated the risk and it's really small", rather than just saying "No, it can't happen" which people probably wouldn't believe. As has been said several times in this thread alone, collisions with energy everal orders of magnitude higher than anything we are capable of happen all the time in the atmosphere and all over the universe. The number was simply a PR effort to try to tell people there was essentially no risk, but unfortunatley many people have got the wrong end of the stick and think that because the risk is said to be very small, the important part is that there is a risk, which is just not true. The same things have been said about virtually every single accelerator that has been built, as well as for the initial atomic bomb tests. Unfortunately this time the media have got hold of it, and with the internet letting every Tom, Dick and Harry spout their opinion with no knowledge of reality whatsoever the issue has been blown far out of proportion.

[Orangutan]

[URL]Snip.. Some scientists Snip..

Ohh, <sucks teeth>, there's the problem mate, you've got a logical fallacy right there. It's your classical "Appeal to authority". Gonna cost ya to remove it and get a real authority, No, want to run the story anyway. Ok off ya go.

:)

The problem is that scientist say a lot of things, Who are these scientists and why do they have authority in this particular incident? I have Bsc so I guess I'm a scientist, and I know I spot crap have the time. ;)

I think I'll vote yes.

[cj.23]

That's the point, it's not a real risk. It is a number put on it simply so they can say "Look, we've calculated the risk and it's really small", rather than just saying "No, it can't happen" which people probably wouldn't believe. As has been said several times in this thread alone, collisions with energy everal orders of magnitude higher than anything we are capable of happen all the time in the atmosphere and all over the universe. The number was simply a PR effort to try to tell people there was essentially no risk, but unfortunatley many people have got the wrong end of the stick and think that because the risk is said to be very small, the important part is that there is a risk, which is just not true. The same things have been said about virtually every single accelerator that has been built, as well as for the initial atomic bomb tests. Unfortunately this time the media have got hold of it, and with the internet letting every Tom, Dick and Harry spout their opinion with no knowledge of reality whatsoever the issue has been blown far out of proportion.


No, that is not true. Yes I know the argument from Cosmic Rays -- but there are problems with it --

" To summarize, under plausible assumptions the cosmic-ray data exclude the possibility of dangerous processes in heavy-ion colliders like RHIC or the LHC, but the worst-case scenario cannot be excluded based on these data alone." -- from the 2003 report.

If you look at the report you will see it is quite clear why they came to their conclusions, and how small the risk is. They did not just make it up though - as they point out, certain particles which never collide in nature will in the LHC. I favour experimenting with it cautiously, but note this is not media hype, but an interesting ethical question.

The fact that scientists were wrong about the atomic bomb setting of the atmosphere, or any other doomsday risk, has absolutely no bearing on the strength or merit of this one. In fact logically if they had not been wrong, we would not be here to discuss the odds!

cj x

[ponderingturtle]

No, that is not true. Yes I know the argument from Cosmic Rays -- but there are problems with it --

" To summarize, under plausible assumptions the cosmic-ray data exclude the possibility of dangerous processes in heavy-ion colliders like RHIC or the LHC, but the worst-case scenario cannot be excluded based on these data alone." -- from the 2003 report.

You miss understand scientists. They don't like to say something is compleately impossible, especialy dealing with situations that have not been sceen before.

If you look at the report you will see it is quite clear why they came to their conclusions, and how small the risk is. They did not just make it up though - as they point out, certain particles which never collide in nature will in the LHC. I favour experimenting with it cautiously, but note this is not media hype, but an interesting ethical question.

The fact that scientists were wrong about the atomic bomb setting of the atmosphere, or any other doomsday risk, has absolutely no bearing on the strength or merit of this one. In fact logically if they had not been wrong, we would not be here to discuss the odds!

cj x

They where right about that, not wrong. No one seriously believed it, but they could not discount the possibility. Just like you can not discount the possibility anything we think about science could be totaly wrong.

[Cuddles]

" To summarize, under plausible assumptions the cosmic-ray data exclude the possibility of dangerous processes in heavy-ion colliders like RHIC or the LHC, but the worst-case scenario cannot be excluded based on these data alone." -- from the 2003 report.

It's entirely possible I'm being stupid, but I can't find a link to this report in this thread, and I can't seem to find it via Google either. Can you post a link please?

They did not just make it up though - as they point out, certain particles which never collide in nature will in the LHC. I favour experimenting with it cautiously, but note this is not media hype, but an interesting ethical question.

Particles which never collide in nature? Like protons? That is all the LHC will be colliding. It is possible to adapt it to collide other particles, but that is irrelevant to the question of whether to turn it on in it's intial state. This sort of argument might apply to ion colliders, but certainly not to the LHC.

The fact that scientists were wrong about the atomic bomb setting of the atmosphere, or any other doomsday risk, has absolutely no bearing on the strength or merit of this one.

Technically true, but I'm sure you can understand how those of us who actually understand the subject get annoted with people constantly crying "Wolf!". It's the same situation as with woo claims. Just because they've all been wrong before doen't mean the next one won't be right. However, experience says that it almost certainly won't be, so unless someone comes up with some actual evidence they will be ignored, whether they claim that they can fly or that we are going to destroy the world.

[cj.23]

It's entirely possible I'm being stupid, but I can't find a link to this report in this thread, and I can't seem to find it via Google either. Can you post a link please?

My apologies, it was linked on the Dawkins forum
http://richarddawkins.net/forum/viewtopic.php?t=13707&start=10

cj x

[ponderingturtle]

Technically true, but I'm sure you can understand how those of us who actually understand the subject get annoted with people constantly crying "Wolf!". It's the same situation as with woo claims. Just because they've all been wrong before doen't mean the next one won't be right. However, experience says that it almost certainly won't be, so unless someone comes up with some actual evidence they will be ignored, whether they claim that they can fly or that we are going to destroy the world.

It is exactly like asking "will this recent event bring about the rapture" sure every time someone has said that in the past they have been wrong, but that does not mean it can not be true. So what are the odds of the rapture happening on june 12 of this year? It involves to many unknowns to say that it is impossible, so we need to assign a value to it, what should that be?

20,000,000 to 1 sound good?

[Cuddles]

My apologies, it was linked on the Dawkins forum
http://richarddawkins.net/forum/viewtopic.php?t=13707&start=10

cj x

Thanks. What that report actually says is that there is no quantifiable risk. The important parts are on page 7, which states No rigorous proofs of the existence, let alone stability, of strange quark matter can be given.
and page 18, which states we conclude that black hole production does not present a concievable risk at the LHC
Page numbers refer to the pdf rather than the report pages.

Essentially what it is saying is that there is no possible risk from anything we know and that if there is a risk that we don't know about then we don't know about it.

Bear in mind that this report did not put an actual number on the probability of anything bad happening. A number may have been given in a press release, or even just in an interview, but the actual official safety report, which should be far more accurate, did not find the risk to even be quantifiable, let alone something worth worrying about.

[cj.23]

Bear in mind that this report did not put an actual number on the probability of anything bad happening. A number may have been given in a press release, or even just in an interview, but the actual official safety report, which should be far more accurate, did not find the risk to even be quantifiable, let alone something worth worrying about.

Completely correct. As I said, I'm in favour of the experiments, and note the public perception issue -- but that my slight hesitation is based upon the unknown issues. Still, we can revive this thread this time next year and discuss it then! :)

There is loads of alarmist stuff on the web, but it all comes down to that one word "unquantifiable". As I never saw the BBC documentary I'm arguing from ignorance, but I hope that the discussion has alleviated some fears. It has for me...

cj x

[Yllanes]

Particles which never collide in nature? Like protons? That is all the LHC will be colliding. It is possible to adapt it to collide other particles, but that is irrelevant to the question of whether to turn it on in it's intial state. This sort of argument might apply to ion colliders, but certainly not to the LHC.

To be fair, the LHC is going to do quite a bit of heavy nuclei collisions. Mainly lead, to try and stduy the quark gluon plasma I mentioned earlier. Still, there are plenty of lead nuclei around with those energies.

[Fnord]

Do massless particles, like photons, collide? Or do their wave components only interfere with each other? I know that their functions can "mix" in a non-linear medium, but do photons ever come in contact with each other?

[RecoveringYuppy]

Photons only contact each other in Star Wars movies.

Bosons (ex: photons) are particles which like to be together, Fermions (electrons, neutrons, protons) are particles that don't. Solid material, capable of "contact", is made up of Fermions.

[Cuddles]

To be fair, the LHC is going to do quite a bit of heavy nuclei collisions. Mainly lead, to try and stduy the quark gluon plasma I mentioned earlier. Still, there are plenty of lead nuclei around with those energies.

I was under the impression that it is purely a proton machine to begin with. Aren't heavy ions just plans for the future? So although they would have to be considered eventually, they aren't really relevant to whether it should be switched on at all.

[BPSCG]

When I first heard this story I was reminded of this quote by Douglas Adams:As long as we've introduced Douglas Adams into the discussion, we need to reflect on the insanely warlike Silastic Armorfiends of Striterax, and their supercomputer, Hactar:


It was the first to be built like a natural brain, in that every cellular particle of it carried the pattern of the whole within it, which enabled it to think more flexibly and imaginatively, and also, it seemed, to be shocked.

The Silastic Armorfiends of Striterax...
ordered Hactar to design for them an Ultimate Weapon. "What do you mean," asked Hactar, "by Ultimate?"

To which the Silastic Armorfiends of Striterax said, "Read a bloody dictionary," and plunged back into the fray.

So Hactar designed an Ultimate Weapon. It was a very, very small bomb that was simply a junction box in hyperspace which would, when activated, connect the heart of every major sun with the heart of every other major sun simultaneously and thus turn the entire Universe into one gigantic hyperspatial supernova.
When the Silastic Armorfiends tried to use it to blow up a Strangulous Stilletan munitions dump in one of the Gamma Caves, they were extremely irritated that it didn't work, and said so.

Hactar had been extremely shocked by the whole idea. He tried to explain that he had been thinking about this Ultimate Weapon business, and had worked out that there was no conceivable consequence of not setting the bomb off that was worse than the known consequence of setting it off, and he had therefore taken the liberty of introducing a small flaw into the design of the bomb, and he hoped that everyone involved would, on sober reflection, feel that…

The Silastic Armorfiends disagreed and pulverized the computer.

[Yllanes]

I was under the impression that it is purely a proton machine to begin with. Aren't heavy ions just plans for the future? So although they would have to be considered eventually, they aren't really relevant to whether it should be switched on at all.
The LHC has 5 approved experiments
ATLAS
CMS
LHCb
TOTEM
ALICEThe first two are big multipurpose detectors. The third is based on the study of CP violation and exotic decays and the fourth is a detector dedicated to measuring cross section using the independent luminosity method.

The last one, ALICE (http://aliceinfo.cern.ch/) (A Large Ion Collider Experiment), is a dedicated heavy ion detector. From the page I linked


The ALICE Collaboration is building a dedicated heavy-ion detector to exploit the unique physics potential of nucleus-nucleus interactions at LHC energies. Our aim is to study the physics of strongly interacting matter at extreme energy densities, where the formation of a new phase of matter, the quark-gluon plasma, is expected.


I'm not sure about the schedule. Obviously the LHC will start with pp collisions at moderate energies, which they will increase gradually. But there is going to be a fair proportion of heavy ion collisions. In any case, they are not going to do a full 7 + 7 TeV pp collision from the beginning, so the moment of 'turning it on' is not important.

The maximum energy per nucleon is going to be, I think, 5.5 TeV, a bit less than the maxim energy for the individual protons in pp collisions.

[Cuddles]

Considering the department I was in a couple of years ago is involved in both ALICE and ATLAS you'd think I'd be able to remember a bit more about them. As far as I can tell from the websites, ALICE will take measurements from p-p collisions as reference for later experiments. Presumably this is mainly because the LHC will be running with protons to start with, whether they like it or not.

So ion collisions aren't really relevant for the first start-up, but will probably be relevant a lot sooner than I'd assumed.

[Yllanes]

Yes, that's also my impression. I don't know anyone working in that project (in fact, ALICE is the only one of the LHC experiments with no Spanish participation).

[Mojo]

The 'meeja' types at the BBC show a lamentable ignorance of matters scientifick, and always have. Then again, it seems that a lot of people have trouble simply spelling (http://www.badscience.net/?p=238) "hadron".

As long as we've introduced Douglas Adams into the discussion, we need to reflect on the insanely warlike Silastic Armorfiends of Striterax, and their supercomputer, Hactar:



The Silastic Armorfiends of Striterax...I'm more worried about the Hagunenon.







Get off me, you filthy sofa!

[wahrheit]

Then again, it seems that a lot of people have trouble simply spelling (http://www.badscience.net/?p=238) "hadron".
I believe, however, that examples of serious documents in which hadron is mispelt “hardon” are immensely, hilariously funny. This may be a minority opinion.

No, I'd say the majority shares that opinion. :newlol

OT: Turn it on, of course. What a weird assumption that we could accidentally built a machine that sucks up the universe when they flip the switch.