LHC switch-on fears are completely unfounded: new research paper

Sep 05, 2008

(PhysOrg.com) -- A new report published on Friday, 5 September, provides the most comprehensive evidence available to confirm that the Large Hadron Collider (LHC)'s switch-on, due on Wednesday next week, poses no threat to mankind. Nature's own cosmic rays regularly produce more powerful particle collisions than those planned within the LHC, which will enable nature's laws to be studied in controlled experiments.

The LHC Safety Assessment Group have reviewed and updated a study first completed in 2003, which dispels fears of universe-gobbling black holes and of other possibly dangerous new forms of matter, and confirms that the switch-on will be completely safe.

The report, 'Review of the Safety of LHC Collisions', published in IOP Publishing's Journal of Physics G: Nuclear and Particle Physics, proves that if particle collisions at the LHC had the power to destroy the Earth, we would never have been given the chance to exist, because regular interactions with more energetic cosmic rays would already have destroyed the Earth or other astronomical bodies.

The Safety Assessment Group writes, "Nature has already conducted the equivalent of about a hundred thousand LHC experimental programmes on Earth – and the planet still exists."

The Safety Assessment Group compares the rates of cosmic rays that bombard Earth, other planets in our solar system, the Sun and all the other stars in our universe itself to show that hypothetical black holes or strangelets, that have raised fears in some, will in fact pose no threat.

The report also concludes that, since cosmic-ray collisions are more energetic than those in the LHC, but are incapable of producing vacuum bubbles or dangerous magnetic monopoles, we should not fear their creation by the LHC.

LHC collisions will differ from cosmic-ray collisions in that any exotic particles created will have lower velocities, but the Safety Assessment Group shows that even fast-moving black holes produced by cosmic rays would have stopped inside the Earth or other astronomical bodies. Their existence proves that any such black holes could not gobble matter at a risky rate.

As the Safety Assessment Group writes, "Each collision of a pair of protons in the LHC will release an amount of energy comparable to that of two colliding mosquitoes, so any black hole produced would be much smaller than those known to astrophysicists." They conclude that such microscopic black holes could not grow dangerously.

As for the equally hypothetical strangelets, the review uses recent experimental measurements at the Brookhaven National Laboratory's Relativistic Heavy-Ion Collider, New York, to prove that they will not be produced during collisions in the LHC.

Citation: The published version of the paper "Review of the Safety of LHC Collisions" (J. Ellis et al, 2008 J. Phys. G: Nucl. Part. Phys. 35 1150004) can be viewed at www.iop.org/EJ/abstract/0954-3899/35/11/115004/

Provided by Institute of Physics

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User comments : 20

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kniedzius
4.5 / 5 (4) Sep 05, 2008
well fear or no fear we will find out everything pretty soon.
However, if we will be sucked into a micro black hole I sure hope there will be internet.
Noumenon
5 / 5 (45) Sep 05, 2008
Are the conditions with regard to cosmic rays, the same as that will occur in the LHC? It seems a weak argument to point to some other, though similar phenomenon and say, well its not happening over there, so...

The argument should be won or lost resoundingly within experimentally verified and accepted theory,.. and i'm sure that it was, but it would have made for a more interesting article.
D666
3 / 5 (2) Sep 05, 2008
well fear or no fear we will find out everything pretty soon.
However, if we will be sucked into a micro black hole I sure hope there will be internet.


There will, and it will be a series of tubes :-)
Rossen
not rated yet Sep 05, 2008
I have a question. How do you think why does all this story with LHC produce so big noise? All media (scientific and nonscientific) speak only about LHC and its start after five days. In the past there was many other important scientific projects, but none of them has had so big attention. I have one very unpleasant doubt. All this story will be much ado about nothing. But miliards euros are spent. Thousands scientific careers are involved. Many companies are made expensive equipment. So that, it isn't easily to say: It was a failure. And media noise must covers the inconvenient truth. Let's hope it may not prove so.
googleplex
4.2 / 5 (9) Sep 05, 2008
IMHO the LHC is safe with 99.99% certainty. However to say that is is 100% safe is false. Current physics knowledge is far from complete. So a research paper based on only a partially complete set of assumptions cannot ever be 100% accurate.
Sirussinder
1.5 / 5 (2) Sep 05, 2008
CERN can do as much PR to dispel the public legitimate fears. But the truth is no one knows all the outcomes of the experiments the LHC is planned to do.

Its unfortunate that these outcomes could be either positive or negative and all the outcomes may not be even detected till perhaps years later.

The main problem here is CERN is determined to rush in and play with the unknown at the same time hold everyone else hostage.
Glis
3.6 / 5 (5) Sep 05, 2008
"... so any black hole produced would be much smaller than those known to astrophysicists."

Huh?! That's not comforting. Even following this up with saying that they are too small to do any significant damage is scary. It's a friggin black hole surrounded by mass. How can't it be dangerous?

Either way, I say fire it up. If it works as advertised then we get all kinds of new technology and possibly get out of the funk we're in. If not, we destroy a planet run by criminals. Like I said, either way.
Alizee
Sep 05, 2008
This comment has been removed by a moderator.
Geek_Prophet
4.2 / 5 (5) Sep 05, 2008

This is NOT true from many simple reasons. At first, the highly energetic collisions comming from Universe are always formed by the single accelerated particle, not by whole compact beam of protons - this changes the situation a lot because of surface tension phenomena.

The "beam" is nothing but a series of individual impacts. There are no "surface tension phenomena" involved.
At second, such particle collides with solar corona or Earth's atmosphere, the density of which increases gradually and rather slowly: if some metastable products are temporarily created by such collisions, they're formed in rather sparse environment, where they cannot grow and to propagate at distance.

Incorrect. The sheer number of cosmic ray impacts in question would inevitably involve surface impacts with the Earth, or deep in the corona. In addition, the energy of the collisions is such some of the generated strangelets or other odd phenomena would have a high velocity in relation to the atmospheres they hit. The higher this velocity, the greater the effective density of the atmosphere as they pass through it, and the greater the chance that they would reach the surface before they "evaporated". As a result, they would collide with atoms more often in their travels through the atmosphere than anything created in the LHC would impact going through solid matter, giving them a *richer* environment than the LHC.

Lastly, there exist countless objects such as the Moon, with little or no atmosphere, but which still have not been eaten by miniature black holes, stable strangelets, or other phenomenon. Even if the atmosphere somehow did protect the Earth and the Sun, the Moon would never have survived, and the universe would still be full of strangelet objects or planet-sized black holes, which have never been observed.
At third, the highly energetic particles from Universe are moving so fast, they cannot interact with matter of Sun for very prolonged time. While in LHC the products of head-to-head beam collisions can obtain the zero momentum towards the Earth, so they would have enough time to interact with it with full consequences.

First you suggest that the atmosphere or corona presents a shield that prevents cosmic rays from reaching the Earth or the Sun, and now you suggest that passing through the entire planet or star doesn't slow down these objects enough to cause interaction with them. In both cases, you are incorrect.

Even if it may be possible for one of these strangelets or black holes to pass through the Earth without interacting enough to slow down after being generated, it wouldn't happen every time. Given the enormous numbers of such events that would have occurred naturally if the doomsayer's theories are correct, a great many such particles would have slowed enough to be captured and destroy us.


And at the very end: we don't know about true reason of occasional solar corona flares and magnetic storms. Maybe they're really initiated by strangelet impacts - why not?


In which event they are common enough that impacts with the Earth would have wiped out all life, over and over again. The solar corona flares and magnetic storms in question would, if that were the case, be proportionately as common on the Earth for its surface area as the Sun, and just as large, as the size of the target wouldn't matter, only the energy of the particle causing the impact. As a result, the damage done by the collisions would have wiped us out long ago, as well as left tell-tale signs on every planet in the solar system.

The simple fact of the matter is that miniature black holes big enough to threaten us, or stable strangelets that eat worlds, etc., etc., would, if the doomsday theories are true, have already had countless billions of opportunities to have eaten planets, stars, and other objects throughout the universe. This has happened so seldom that we have never found any indication of these bodies of matter anywhere in the universe.

Even *if* the LHC could create such dangerous particles, the sheer number of opportunities for this to happen in the universe, combined with the complete lack of observed phenomena that would fit, proves conclusively that it must be an incredibly rare phenomenon.
Soylent
4 / 5 (3) Sep 05, 2008
Are the conditions with regard to cosmic rays, the same as that will occur in the LHC?


Protons and other particles have been bombarding us day in and day out since Earth was formed. Their energies span the spektrum from thermal to millions of times more energetic than LHC.

It seems a weak argument to point to some other, though similar phenomenon and say, well its not happening over there, so...


Really? It seems a very strong argument to me.

The argument should be won or lost resoundingly within experimentally verified and accepted theory,..


Oh, in that case, black holes are unlikely. If a black hole is formed it will decay through hawking radiation in an instant. At 7 TeV per proton any black-hole that is formed will have a mass of at most 15 000 protons; that corresponds to a schwarzschild radius of 4*10^-50 meters. That's not a ravenous beast that will gobble up the whole Earth.
Soylent
3.7 / 5 (3) Sep 06, 2008
Oh man, that's so much information it's hard to even know where to start.

At first, the highly energetic collisions comming from Universe are always formed by the single accelerated particle, not by whole compact beam of protons - this changes the situation a lot because of surface tension phenomena.


The "compact beam" is not compact, it's almost a vacuum. The only collisions happening in LHC is one particle colliding with another, even just a 3 particle collision is extremely unlikely.

At second, such particle collides with solar corona or Earth's atmosphere, the density of which increases gradually and rather slowly: if some metastable products are temporarily created by such collisions, they're formed in rather sparse environment, where they cannot grow and to propagate at distance.


And in the LHC the collision happens in near perfect vacuum, which is even better. Any black hole formed will necessarily be quite slow as the momentum of all particles formed sums to near zero.

Cosmic rays with energies exceeding 10^20 eV have been detected. That is >10 million times more energetic than LHC. Not only would any black-hole formed be much more massive and therefor far longer lived, it would also necessarily be far faster than any black hole formed at LHC as momentum is conserved, and the momentum of the collision products must sum up to an extremely large vector.

At third, the highly energetic particles from Universe are moving so fast, they cannot interact with matter of Sun for very prolonged time.


No, that just means they live longer(time dilation), have enough energy to overcome electrostatic potential and collide with nuclei and will move through many more particles with which they can collide before they decay.

While in LHC the products of head-to-head beam collisions can obtain the zero momentum towards the Earth[...]


Exactly; which is why they will not even be able to reach the wall in the time it takes for a black hole formed by a high energy cosmic ray to travel tens of kilometers down to Earth.

[...]so they would have enough time to interact with it with full consequences.


The exact opposite is true.
Alizee
Sep 06, 2008
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Alizee
Sep 06, 2008
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Alizee
Sep 06, 2008
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Velanarris
4 / 5 (1) Sep 06, 2008
And at the very end: we don't know about true reason of occasional solar corona flares and magnetic storms. Maybe they're really initiated by strangelet impacts - why not?


Because we wouldn't exist. All of the matter in our relative area would be converted to strangelets or annihilated.
wawadave
not rated yet Sep 06, 2008
If a propagate able black hole does forum it would only be a few minuets or less till we were devoured by it. so why worry.

It would be interesting seeing your feet stretching out on the accreation disk in a faster spiral in wards before the rest of you followed.
Dinotron
not rated yet Sep 07, 2008
..Cosmic rays with energies exceeding 10^20 eV have been detected. That is >10 million times more energetic than LHC..
I know, they're formed by single particles, the energy of which is given by high speed. They will penetrate the Earth in microseconds, with high momentum towards the Earth. Neverthelles, some strangelets are considered as the reason of particular earthquakes.

http://www.space....513.html

Why I should believe some anonyms here and not the informations, presented in mainstream press?


Your news sources are rather questionable.
I would rather trust the people in this discussion than your tabliodesque sources.

To quote from the first article:
"The work, reported in London's Sunday Telegraph, has not been confirmed, nor has it gone through the typical review process of a refereed scientific paper."

See? Big disclaimer that it really has no scientific validity.

The other stories are the same one spun twice and each time it is, again not true science. It is someone in a labcoat saying "I think... It might be..."
kniedzius
not rated yet Sep 08, 2008
Sometimes I really wonder, does Alizee have some kind of odd ms excel based database with all these links sorted by keywords and headlines? It would only take seconds to copy these links here and enjoy the never-ending discussions.
Velanarris
3 / 5 (1) Sep 08, 2008
Sometimes I really wonder, does Alizee have some kind of odd ms excel based database with all these links sorted by keywords and headlines? It would only take seconds to copy these links here and enjoy the never-ending discussions.


I thought he used a tldr generator and appended random links from the Stop CERN site.
kniedzius
not rated yet Sep 08, 2008
Sometimes I really wonder, does Alizee have some kind of odd ms excel based database with all these links sorted by keywords and headlines? It would only take seconds to copy these links here and enjoy the never-ending discussions.


I thought he used a tldr generator and appended random links from the Stop CERN site.


Well either way, we can assume that he has problems.
bhiestand
not rated yet Sep 08, 2008
Somebody tell that to The Daily Mail and Fox News. Look at the fud they're reporting: http://www.dailym...day.html
googleplex
not rated yet Sep 09, 2008
Are the BH advocates aware of the Tevatron? That has been running similar collisions for years. Slightly less energy and less luminosity.

The luminosity of the LHC does make it significantly different to ambient high energy collisions. Other than that there is no difference. So any BH argument needs to be based on the luminosity factor.

Don't be suprised tomorrow if they re-schedule the go-live date (or dead date depending on your perspective). This has been done time and time again.
Geek_Prophet
not rated yet Sep 10, 2008
...the "beam" is nothing but a series of individual impacts. There are no "surface tension phenomena" involved....
Nope, here's a synergy - the simple negation isn't argument. After all, this is why, we aren't using a single protons, when preparing black hole in RISC and LHC.
http://news.bbc.c...7613.stm
http://unisci.com...1012.htm

Of course, neither of those suggest there is a "surface tension" that is overcome by a "stream" of protons, as they both involve using complete ions, not streams of protons. So, your "evidence" that I am wrong says nothing of the sort.

This is because there is no "stream" of protons to overcome any "surface tension" that might exist, whatever you think "surface tension" is. Your so-called "stream" of protons is, in fact, a near-vacuum of individual high-speed protons, which naturally strike as a bunch of single protons.

..there exist countless objects such as the Moon, with little or no atmosphere, but which still have not been eaten by miniature black holes...
They're still full of craters.
By that logic, I could use the existence of people who died from neck wounds as evidence of vampires. After all, *some* of them *could* have had the wounds created by vampires.
By my opinion, it's a big mistake to consider, only ultradense state of matter (a black hole) can become dangerous for Earth existence.
As you are not an expert in physics, your opinions on what we should or should not worry about are pretty much moot. Nor is anybody making such an assumption, so your "warning" is pointless posturing. There are a number of suggested reasons for fearing the LHC that don't involve black holes, such as strangelets or neutron droplets. All have the same problem: unless either incredibly uncommon or outside the reach of the LHC, all would have already happened many times and thus revealed themselves by the damage they do. And a significant number are complete nonsense based upon a complete misunderstanding of the physics involved, such as the black hole theory.
Or to believe, such BH cannot interact with Earth fast.

This is a perfect example. Black holes could be created by the LHC. However, any such black holes, reacting "fast" or "slow", that can be created by the LHC *are not a threat to Earth*. The physics that show this are so solid that it is far more likely that black holes do not exist than that such a black hole could actually do the damage you are afraid of. The failure of the black hole to instantly evaporate is a violation of the very physics that predict black holes in the first place.

For example, the danger of strangelet is based on the assumption, it can react with ordinary matter under formation of another strangelets by avalanche-like, explosive mechanisms.
Correct. Which, if true, means one of four things:
1) This cannot happen.

2. This can happen, but it requires too much energy for the LHC.

3. This can happen, but it happens so rarely that we have little to fear from the LHC.

4. The Earth, Sun, and everything you see in the sky has already been eaten by strangelets and we are already dead, because it would have happened countless times before, all over the universe, because it is so easy.
But by my understanding, even the simple compact droplet of rather common particles, like the neutrons can become dangerous for Earth.
That would be because your "understanding" is complete nonsense. The polyneutron theory, if correct, claims that all kinds of common nuclear reactions, including a large number of experiments, already created the polyneutrons you fear. Notice how we haven't been destroyed by the chain reactions? The creators of the theory admit that the experiments that caused them to come up with the theory would already have created these chain reactions if the predicted chain reactions were real.
Glis
not rated yet Sep 20, 2008
For 6 billion I want a machine that can destroy half the solar system, it better at least crack the planet.

The world can't end until 2012, or else theres going to be a lot of nut jobs with mud on their face.

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