LHC complications

bwanaaa

Senior member
Dec 26, 2002
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Correct me if I am wrong, but isnt the LHC based on spinning charged particles around a very big circle at high energies? Wont this effectively create a large magnetic field that will distort the Van Allen belt? Wont that result in an aurora borealis over switzerland? Wont that result in an excess of skin cancer from all the cosmic rays that can now penetrate to that part of the earth because of the hole in the VanAllen belt? If the LHC runs long enough, wont it cause the magnetic north pole of the earth to wander off, the wrong way?

This has gone on long enough, this is speculation not HT
bsobel


 

bwanaaa

Senior member
Dec 26, 2002
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well, it's satursay night and this is what one drunk geek worries about. but really serves the swiss right after their behavior in WW2.
 

Foxery

Golden Member
Jan 24, 2008
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Yeah, let's hop on the ignorant "end of the world" bandwagon that the tabloids are pushing. :roll:

The LHC is just a particle accelerator. We've been using several for decades... see CERN. If CERN killed us all, I must have missed it.
 

Gibsons

Lifer
Aug 14, 2001
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Originally posted by: bwanaaa
Correct me if I am wrong, but isnt the LHC based on spinning charged particles around a very big circle at high energies? Wont this effectively create a large magnetic field that will distort the Van Allen belt? Wont that result in an aurora borealis over switzerland? Wont that result in an excess of skin cancer from all the cosmic rays that can now penetrate to that part of the earth because of the hole in the VanAllen belt? If the LHC runs long enough, wont it cause the magnetic north pole of the earth to wander off, the wrong way?

The number of charged particles they're spinning is very small, so the Van Allen belts are safe for now.
 

bobsmith1492

Diamond Member
Feb 21, 2004
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The magnetic field will fail, the Van Allen belt will collapse, cosmic rays will turn all living life into mutant freaks for a generation or two, then everyone will die. Except global warming will kill us first.
 

bwanaaa

Senior member
Dec 26, 2002
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how do i find out how many protons they are spinning up? apparently, each proton will be accelerated to 7 tera eV.
 

Mark R

Diamond Member
Oct 9, 1999
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Magnetic field from the spinny bits shouldn't be that large.

Nominal beam current is about 0.5 A - and as you have 2 beams going in opposite directions, they more or less cancel.
 

silverpig

Lifer
Jul 29, 2001
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The superconducting magnets used to steer the beam are MUCH more powerful than the magnetic field generated by the hardons.
 

Cogman

Lifer
Sep 19, 2000
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Ah, the LHC. I find this thread pretty funny really. "what unknown damage will we now wreak on the world". Thats like saying "How many unknown worlds are in the universe?" Nobody will answer you because it's Unknown. As far as physicist know, nothing too dramatic will happen other then new data becoming available. If most of them thought that a particle accelerator would destroy the world, We probably would have built one, now would we?

Leave it to the media to take something that could benefit man in large ways and then twist it to the point where people fear it and think it will be the end of the world. No wonder people seem to get dumber and dumber as time goes on, the media has almost convinced them that science is the root of all evil (Time to go into another dark age...)
 

Biftheunderstudy

Senior member
Aug 15, 2006
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The unfortunate part is that the level of education required to understand what is happening at CERN is much more than the general public has. Instead, they hear words which sound like other concepts they've heard of and automatically assume they're the same thing ie. black holes. The only things I can think of that are "bad" about the LHC are:
1: Its tremendous cost
2: Its large size may potentially disrupt the ecosystem
3: Syncrotron radiation
None of these are really large concerns though since it was well thought out and planned for many years.
The biggest concern is, what happens when they find the higgs and just a higgs with nothing else. Means they have to build an even bigger and more expensive collider, and with all the whacko's associated with the LNC I don't know if they'd get the funding.
Mind you, if they find the higgs with a pile of other stuff, then they'll need to build a bigger collider to find more stuff. If they find nothing, they need to build a bigger collider to reach higher energies to find stuff.......
 

bwanaaa

Senior member
Dec 26, 2002
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well, i'm sorry i stirred up a hornet's nest--my question was very specific .....and logical. Simply put, the magnetosphere is part of our ecosystem and I am simply thinking about very basic physical laws-the generation of magnetic fields by accelerating charged particles. ok, i didnt realize they were going to have to counterrotating particle beams (how do you do that with one set of magnets anyway?) so that point is moot.

to get back to the philosophical question and equally philosophical reaction of FUD, i suppose one might look at the energy accounting:
anything requiring massive amounts of energy has the potential for massive damage to our biosphere.

Not that there will necessarily be damage that our earth cannot absorb, but certainly the potential is there. Where do they get the electricity to run that thing and how much does it use?

Personally, I would wait until we have a sentient network/computer and let it ask the right questions. I can imagine how stupid we'll feel when that machine tells us the answer and that we've been wasting our time and money.
 

Born2bwire

Diamond Member
Oct 28, 2005
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Where do they get the electricity? Easy, probably from the nukes in France. Damage to ecosystem, probably minimal since it is underground. Radiation, practically nonexistent. Fermilab, previously the highest powered accelerator until LHC, emitted (when observed at the perimiter of the faciility) something on the order of less radiation than a person would normally receive from natural sources. With the LHC underground I doubt there would be much radiation emitted.
 

dinkumthinkum

Senior member
Jul 3, 2008
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I hear there's this large source of charged particles which really buffets the Earth's magnetosphere.

It's called the Sun.

If we turned off the Sun, those van Allen belts would be safe. Bonus: no more global warming!
 

TheDoc9

Senior member
May 26, 2006
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Some people seem to think science will prevail on this one, others aren't sure. I fall into that category myself. I've read that the odds of a disaster quoted by one scientist on the project to be one in 50 million.

My first thought was that people play the lottery all the time with odds in the 100's of millions, but someone inevitably hits the 'jackpot'. M. Asher on DT suggested that subatomic black holes will be created, but that they will evaporate instantly because of hawking radiation - radiation that isn't proven to exist but if the black holes evaporate then that constitutes it's existence. It doesn't take much to see the problem with both of these situations.

Bottom line is this, a few people who are considered smart have decided that the cost of proving a few theories out-ways the risk of a disaster that could potentially alter life forever on earth. Who knows what kind of disaster could occur because it's all theory anyway, but one thing's for sure we won't know if we don't try it.

And while a problem is unlikely to occur, dis-regarding life in pursuit of knowledge is a tragedy. There's always a price to pay for everything on this earth and hopefully this knowledge will only cost in dollars and man power.
 

f95toli

Golden Member
Nov 21, 2002
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Originally posted by: TheDoc9
Some people seem to think science will prevail on this one, others aren't sure. I fall into that category myself. I've read that the odds of a disaster quoted by one scientist on the project to be one in 50 million.

I don't know where you read it but it is simply wrong, no scientist would ever put any odds on something like this (at least not if he/she was serious).
The upper atmosphere is CONSTANTLY being bombarded by particles that have the same energy (or higher) than the ones that are now being prepared in the LHC (the main reason why we can't use cosmic rays to study particle physics is because we don't have any detectors in the upper atmosphere).
The earth has been around for quite a while so we know that the risk (if it at all exists) is very small; remember that we don't even know if miniature black holes exist; not to mention that IF they exist it is very unlikely that they can be created by colliding particles.
Hence we CAN be sure that the riskt must be very small; us causing a few extra collisions now and then in a controlled environment will certainly not change anything,

Note that no scientist can EVER tell you that the risk of something is exactly zero. In science we can never be 100% sure about anything; it is just the way science works.






 

bwanaaa

Senior member
Dec 26, 2002
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Originally posted by: silverpig
The superconducting magnets used to steer the beam are MUCH more powerful than the magnetic field generated by the hardons.

so the little hardons really cant do much damage. what about the giant magnets then>do they distort the magneotsphere enough to create a 'drain' for all the solar particles hitting earth to funnel into?

how can one calculate how many tesla are needed to 'dent' the magnetosphere sufficiently? My superficial ogling of google reveals:
'The strength of the field at the Earth's surface ranges from less than 30 microteslas (0.3 gauss) in an area including most of South America and South Africa to over 60 microteslas (0.6 gauss) around the magnetic poles in northern Canada and south of Australia, and in part of Siberia.'

AREA of LHC~100 sq km=1x10^8 sq m

Assuming earth's magnetosphere on avg is 50 microtesla=5x10^-5 tesla
then the total magnetic force at LHC is 5x10^-5 X 1 x10^8 sq m = 5000 webers

The LHC should be able to do many times that.(8 tesla) in fact, it is ~1.5x10^5 times stronger than the earth's magnetic field.

So if we are creating a magnetosphere bare region on the earth, then why wont all those CERN types get the same solar damage that astronauts do? Will they wear spacesuits or carry special umbrellas? or is that why they are underground?
 

Born2bwire

Diamond Member
Oct 28, 2005
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If the magnetic field was in anyway perceptible, I doubt they would have any kind of ferrite metal around the facility. For the love of Benji, Lord knows what the consequences would be if 100 sq km of French and Swiss countryside had a constant 8 T of magnetic field. If I recall correctly, Fermi lab (and by extension LHC most likely) used quadrupole magnets, and a quadrupole moment falls off as 1/r^4 where as the normal magnet source is a dipole moment, 1/r^3. So let's say that we want a focused 8 T at the origin of the quadrupole. For sake of proper normalization, let's just say that at a distance of 1 foot, the magnetic field is 8 T. Then 100 feet away, the magnetic field has already dropped to 80 nT from quadrupole magnets and 8 microT from the dipole magnets.

As for being underground, it's the best place to put it. The darn thing has a circumference of 27 km, a radius of 8.6 km. The Earth is not going to distort magnetic fields appreciably. Very few materials have a permeability greater than unity. The obvious and most plentiful exception is iron or other ferrite compounds. However, you need a large block of iron to distort magnetic fields. It's generally easier to shield magnetic fields by simply using another magnet that is placed in such a way as to minimize the fields outside a specified area. This is what they do in "magnetically shielded" speakers.
 

f95toli

Golden Member
Nov 21, 2002
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Originally posted by: bwanaaa

The LHC should be able to do many times that.(8 tesla) in fact, it is ~1.5x10^5 times stronger than the earth's magnetic field.

So what? The LHC is just a very small ring located at the ground; remember that the magnetic field falls off very quickly (how quickly depends on the geometry) so there is no way it can affect the magnetosphere even locally. In most installations the field has dropped to below 50 uT just a few meters from the magnet.

Also, there are litteraly thousands of magnets around the world with field stronger than 8T (we have a couple of 12T magnets at work8T is not very much; even standard MRI magnets can have fields of 3-5 tesla.




 

bwanaaa

Senior member
Dec 26, 2002
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off i go to google to learn about quadrupoles....i thought all magnetic fields were equal falling of with r^2. i thought a magnet is a magnet. i thought that if you have a magnetic field at the earth's surface many times stronger than the earth's magnetic field, then you would distort the weak magnetosphere. I dont understand why 8T cant affect the magnetosphere locally if the magnetosphere is SO much weaker.

and once a dimple is created in the magnetic field, it would act as a funnel and concentrate all the solar particles from a large surface area into the dimple-basically a magnetic lens.
 

Cogman

Lifer
Sep 19, 2000
10,286
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Originally posted by: bwanaaa
off i go to google to learn about quadrupoles....i thought all magnetic fields were equal falling of with r^2. i thought a magnet is a magnet. i thought that if you have a magnetic field at the earth's surface many times stronger than the earth's magnetic field, then you would distort the weak magnetosphere. I dont understand why 8T cant affect the magnetosphere locally if the magnetosphere is SO much weaker.

and once a dimple is created in the magnetic field, it would act as a funnel and concentrate all the solar particles from a large surface area into the dimple-basically a magnetic lens.

8T is in some ways a pretty useless number. We could generate 20T in a very small space and that wouldn't make a difference in the earths magnetosphere. I don't know how I could compare it, you kind of have to be able to visualize what a magnetic field looks like (Think a ball on a giant rubber sheet).

the extremely powerful magnetic fields that we create are usually localized to a very small volume so to speak, where as the earths magnetic field is generated over a large body. Even if we could create a magnetic field big enough (not just strong enough) to punch a hole in the earths magnetosphere, the moment we turned it off the earth would recover.

The energy that we are generating is peanuts compared to the vast amounts of energy the earth has coursing though its mantel, It would take some pretty dang big breakthroughs in physics before we could generate enough power to make a dent (disrupt slightly) in the way the earth functions under ground. It is way too big (thankfully).
 

Born2bwire

Diamond Member
Oct 28, 2005
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Originally posted by: bwanaaa
off i go to google to learn about quadrupoles....i thought all magnetic fields were equal falling of with r^2. i thought a magnet is a magnet. i thought that if you have a magnetic field at the earth's surface many times stronger than the earth's magnetic field, then you would distort the weak magnetosphere. I dont understand why 8T cant affect the magnetosphere locally if the magnetosphere is SO much weaker.

and once a dimple is created in the magnetic field, it would act as a funnel and concentrate all the solar particles from a large surface area into the dimple-basically a magnetic lens.

Multipole expansions are very common topics whenever you are talking about potentials (electric, current, gravity, etc.). When you have a collection of potentials confined to a small volume, then if you observe that mass of potentials from far away, you can generally approximate it very well as a superposition of various multipoles. The way that a pole drops off for electric and magnetic potentials is equal to 1+level. So an electric monopole is a point charge, which has an electric field equal to q/(4 \pi \epsilon_0 r^2). That is, the monopole drops off as 1/r^2. If you have a positive and a negative charge close to eachother, then you have an electric dipole that can be approximated as a single dipole potential when looked from afar. The electric dipole drops off as 1/r^3. Note though, I am talking about the field strength. The potential of a dipole drops off as 1/r^2.

Magnetic potentials are at least dipoles because currently we do not allow monopoles (magnetic charge) to exist. So the strength of the magnetic field drops off ast best 1/r^3 or 1/r^4, depending upon the magnet configuration used. So it doesn't matter if we have 8T, 20T or even 1000T, the magnetic field is highly localized. Keep in mind just how bloody strong 8T is. The Earth's magnetic field, as weak as it is, can physically move the needle of a compass. The magnets in an MRI, which are on the order of 1 T, can draw chairs and other large metal objects into them, requiring a huge amount of exertion and leverage to extricate them (youtube has some amusing examples). There would be no way that CERN could operate the LHC where it is with personnel and the general populace in close proximity if the magnetic fields retained their strength over even a modicum of distances.
 

bwanaaa

Senior member
Dec 26, 2002
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i wonder if a magnetometer on the space station would be able to tell when the lhc is operating?

also, i suppose for the same reason that we dont distort the magnetosphere, then the currents in the mantle are left unmolested as well. Wouldnt it be wild if the iron flows in the mantle were altered and we slowed the rotation of the earth! or started a polar component to the rotation. then the whole world would be habitable with a temperate climate.
 

Cogman

Lifer
Sep 19, 2000
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Originally posted by: bwanaaa
i wonder if a magnetometer on the space station would be able to tell when the lhc is operating?

also, i suppose for the same reason that we dont distort the magnetosphere, then the currents in the mantle are left unmolested as well. Wouldnt it be wild if the iron flows in the mantle were altered and we slowed the rotation of the earth! or started a polar component to the rotation. then the whole world would be habitable with a temperate climate.

in space it would be completely undetectable when it is running and when it isn't running. We don't pick up when any MRI runs, why should we pick up the LHC?

There is no way for us to slow the rotation of the earth, even if we created a magnetic field to completely envelop the earth, I don't see how that would magically remove all the rotational momentum from the earth. If you are basing any scientific assumption of the move "The core" please, just stop now. Anybody that has watched that movie knows it is on of the most scientifically inaccurate movies out there.