Magnetic monopoles of DOOM!

[zosima]

So I asked this question in another post that got buried, but I'm impatient and it was part of another comment. So...it was claimed in the suit against the LHC that a magnetic monopole could be part of some disaster scenario that would end the world.

So please anyone, what kind of woo are they talking about when they claim that magnetic monopoles are dangerous? I could understand how strangelets or micro black holes could do this(however improbable), but I don't have any clue how a magnetic monopole would. As I understand it a magnetic monopole is just like an electron except with a magnetic charge instead of an electric charge, pretty much the same equations etc....I just don't get it

 

[arthwollipot]

I've no idea. I just couldn't resist the title.

 

[Reality Check]

Defintely woo. Note the following from their web site:

c) Magnetic Monopoles: Under this theory, the high energy of the
collision would be converted into two massive particles known as north and south magnetic monopoles. Each would carry a fundamental unit of magnetic charge. Such particle might have the ability to catalyze the decay of protons and atoms, causing them to convert into other types of matter in a runaway reaction.

Magnetism of any kind has no effect on "the decay of protons and atoms".

 

[athon]

I've got some magnets at work which have been cut in half. Did you want the north or south monopole? I'll mail it to you.

Athon

 

[sol invictus]

First of all, we are pretty sure protons are not exactly stable. Basically that's because they do not have a conserved charge which protects them (baryon number is not quite conserved); they can decay, for example, to a positron and a neutral pion. However experiment tells us that the lifetime must be longer than about 10^33 years (recall that the age of the universe is about 10^10 years, so that's a very long lifetime).

If we wanted to make a proton decay, one way to do it would be to heat it up to an extremely high temperature. Magnetic monopoles tend to have extremely large masses (for example, of order the GUT scale in grand unified models). When they pass close to a proton, they can essentially "heat it up" and stimulate it to decay. Note that the magnetic field plays no important role in this (other than to stabilize the monopole).

Would this be dangerous... first of all, LHC is far, far, far below the energy where it could even create a monopole in standard GUT models. Second, even if it did create some, I suspect the rate at which they would cause proton decay in matter is pretty low (I could check, but I'm lazy). Third, if one could control this process (and I don't see why not - in fact I think it would be rather easy) it could actually be incredibly useful - it woud solve the energy problems of the human race forever.

 

[zosima]

That makes sense, thanks sol, for the clear and insightful explanation.

 

[GreyICE]

First of all, we are pretty sure protons are not exactly stable. Basically that's because they do not have a conserved charge which protects them (baryon number is not quite conserved); they can decay, for example, to a positron and a neutral pion. However experiment tells us that the lifetime must be longer than about 10^33 years (recall that the age of the universe is about 10^10 years, so that's a very long lifetime).

If we wanted to make a proton decay, one way to do it would be to heat it up to an extremely high temperature. Magnetic monopoles tend to have extremely large masses (for example, of order the GUT scale in grand unified models). When they pass close to a proton, they can essentially "heat it up" and stimulate it to decay. Note that the magnetic field plays no important role in this (other than to stabilize the monopole).

Would this be dangerous... first of all, LHC is far, far, far below the energy where it could even create a monopole in standard GUT models. Second, even if it did create some, I suspect the rate at which they would cause proton decay in matter is pretty low (I could check, but I'm lazy). Third, if one could control this process (and I don't see why not - in fact I think it would be rather easy) it could actually be incredibly useful - it woud solve the energy problems of the human race forever.

I think you're thinking this through too much. Given the original claim, it's far more likely their logic was "monopole sounds like a contagious disease!"

 

[ponderingturtle]

First of all, we are pretty sure protons are not exactly stable. Basically that's because they do not have a conserved charge which protects them (baryon number is not quite conserved); they can decay, for example, to a positron and a neutral pion. However experiment tells us that the lifetime must be longer than about 10^33 years (recall that the age of the universe is about 10^10 years, so that's a very long lifetime).

If we wanted to make a proton decay, one way to do it would be to heat it up to an extremely high temperature. Magnetic monopoles tend to have extremely large masses (for example, of order the GUT scale in grand unified models). When they pass close to a proton, they can essentially "heat it up" and stimulate it to decay. Note that the magnetic field plays no important role in this (other than to stabilize the monopole).

Would this be dangerous... first of all, LHC is far, far, far below the energy where it could even create a monopole in standard GUT models. Second, even if it did create some, I suspect the rate at which they would cause proton decay in matter is pretty low (I could check, but I'm lazy). Third, if one could control this process (and I don't see why not - in fact I think it would be rather easy) it could actually be incredibly useful - it woud solve the energy problems of the human race forever.

Why would these monopoles be stable? If such a stable particle can exist it should exist in significant numbers and stars would likely not work by fusion.

 

[MattusMaximus]

I didn't think that it was even possible for a magnetic monopole to exist by Maxwell's equations - specifically Gauss's Law as applied to a static magnetic field. Am I missing something?

 

[sol invictus]

Why would these monopoles be stable? If such a stable particle can exist it should exist in significant numbers and stars would likely not work by fusion.

They're stable because they are the lightest particle with magnetic charge. It's impossible for them to decay, just as it's impossible for an electron to decay.

Their low density today is usually accounted for with inflation.

I didn't think that it was even possible for a magnetic monopole to exist by Maxwell's equations - specifically Gauss's Law as applied to a static magnetic field. Am I missing something?

You're not missing anything - Maxwell's equations get modified (they become symmetric under the interchange of E and B). If the density of monopoles is sufficiently low and they are massive enough, there's no tension with experiment - we've just never been lucky enough to see one or been able to produce a monopole/antimonopole pair at an accelerator.

 

[ponderingturtle]

They're stable because they are the lightest particle with magnetic charge. It's impossible for them to decay, just as it's impossible for an electron to decay.

Their low density today is usually accounted for with inflation.

Still if they created such a strong reaction with ordinary matter wouldn't you expect some observation of an effect demonstrating their existance?

 

[sol invictus]

Still if they created such a strong reaction with ordinary matter wouldn't you expect some observation of an effect demonstrating their existance?

It all depends on their density. Inflation would dilute them by at least a factor of e^-180 or so from their primordial density. Still, there have been at least a few experiments looking for them over the years, and at least one false positive detection.

 

[zosima]

As I understood it there are still some events on which the jury is still out as well. From what I've gathered they may only be interpreted when scientists are able to answer the question of whether or not they exist. Essentially situate these observations in a complete theory...of course they may just be erroneous.

I think what makes the LHC story a little more interesting, though, is that Wagner(the guy behind the LHC law suit), may have detected one of those events.

If that is correct, then that suggests several different things:
1. He actually saw one.
2. There was some malfunction.
3. They saw something else.
4. He made it up.

I think his subsequent behavior makes me think either he made it up or he actually saw one and that gave him some sort of prescient steely resolve.

 

[ponderingturtle]

It all depends on their density. Inflation would dilute them by at least a factor of e^-180 or so from their primordial density. Still, there have been at least a few experiments looking for them over the years, and at least one false positive detection.

Would they be likely to mutually annialate as well?

 

[Acleron]

I think what makes the LHC story a little more interesting, though, is that Wagner(the guy behind the LHC law suit), may have detected one of those events.

If that is correct, then that suggests several different things:
1. He actually saw one.
2. There was some malfunction.
3. They saw something else.
4. He made it up.

I think his subsequent behavior makes me think either he made it up or he actually saw one and that gave him some sort of prescient steely resolve.

So he saw one and the world didn't end, I feel safer now.

 

[sol invictus]

Would they be likely to mutually annialate as well?

That can happen, yes. There are some particle astro experiments looking for high energy gamma rays which might result from the annihilation of such relic particles and/or dark matter. And there are extremely high cosmic rays detected relatively routinely, the origin of which remains somewhat mysterious.