So this is again, less of an 'invention' more of a question 'Why can't this be done?'
The electromagnetic force is mediated by photons. These particles have to be exchanged by objects for them to 'feel' the electromagnetic force.
Since photons can be deflected (say by them travelling through media with different refractive indices) can i deflect or reflect magnetic field lines and hence magnetic force? What's stopping me doing this?
Practical application of my electromagnetic mirror (though, again i don't want to get hung up on the engineering problems which would be er *challenging*): nuclear fusion. I think the basic problem here is getting energy focussed to a tight enough spot, since there has to be loads of it to give the positive nuclei enough energy to overcome the EM force keeping them apart. Once they're close enough, the strong force becomes the big player and we're done - fusion. Sorry for the simple fusion tutorial. Anyway, if i can deflect the photons carrying the force between nuclei, can't i (shaky theory) reduce or negate the force between nuclei, requiring less energy to get them close enough to interest the strong force?-- hennessey, Feb 20 2009 Schrödinger's cat http://en.wikipedia...C3%B6dinger%27s_cat [zen_tom, Feb 20 2009] //The electromagnetic force is mediated by photons.// I think the problem is in this statement - and, like you, I'd like to understand this better - but, for me, it's this particle dependent idea that I find difficult to understand. e.g.
Imagine a bar-magnet floating in space with nothing anywhere near it.
You can visualise the invisible electromagnetic field surrounding the magnet - but I don't think there is a stream of photons, electrons, or anotherkindofons streaming through those invisible lines of force. Is there?
Take another bar magnet - surrounded by a similar force, only oriented differently, so that fields of force from each magnet repel and exert a force on one another - what happens? At a certain distance, do the two magnets suddenly release a stream of photons at one another? Where do they come from? Is there some particle exchange that happens as soon as one magnet becomes 'aware' of the other? How does one magnet 'know' that the other one is there?
I have absolutely no answers to any of these questions, but (at the time of writing) am in need of convincing of the validity of the 'force mediation by particle' theory.-- zen_tom, Feb 20 2009 The Standard Model says this is exactly what happens - that carrier particles (in the case of EM force, the photon) are exchanged between matter when a force is 'felt'. The first, and most important caveat here is that there's much I don't know about this. Secondly I, exactly like you [zen_tom], am not of the impression that streams of photons exist along the force lines (indeed i know the force lines to be purely imaginary). If there were photons, you could manipulate them (depending i suppose on their wavelength/energy) in all sorts of ways, thereby manipulating the force associated with them. I'm not sure if my "why won't this idea work" thing is deemed valid by Halfbakery. Perhaps i'm just being soft and pre-empting the inevitable "you clearly don't know about the [...] effect" line that will set me straight. But that's the line i'm looking for.-- hennessey, Feb 20 2009 Yes, those lines of force can't be "blown away" - which suggests that they can't be "real" in any sense - they are probably some kind of ghostly Schrodingian extension of the probable locations of these particles *if* they were real - except that they're not - but *could* be if required.
If that's the case, then you need to figure out a way to deflect something that isn't, to all intents and purposes, there - which might be tricky.
"The hardest thing of all is to find a black cat in a dark room - especially if there is no cat."-- zen_tom, Feb 20 2009 mmm, the field lines are just a mathematical construct to help visualise what's going on, but their (lack of) existence isn't the point. My confusion still remains: if the EM force is mediated by photons, can i deflect them and manipulate the force felt?-- hennessey, Feb 20 2009 But what I meant was that if those force lines are Schrodingian (meaning that their existence and non-existence is both true, at a probabilistic level) then the actual point at which you positively know that a photon is there is after it's appeared and completed its interaction, by which time it's already too late - the horse having already bolted.
It's like having a cat resuscitation system on standby outside of Schrodinger's experiment* and expecting that if you can bring the cat to life, you can avoid the decay of the radioactive material.
*see link-- zen_tom, Feb 20 2009 //the horse having already bolted// I thought it was a cat?-- coprocephalous, Feb 20 2009 Those force lines aren't "schrodingian" - they're definitely not there. And photons: certainly i can't be sure exactly where one is prior to interaction, but as soon as I interact with it, there it is, bold as brass. It doesn't have to have completed what it set-out-to-do kind of thing. It propagates from one place (as a wave) to another, so I should be able to it interact with it anytime i fancy. Quantum mechanics is a really very well understood theory (tho not by me i confess), and makes excellent and experimentally verifiable claims about where particles are (though yes, as probability density wavefunctions). The whole weird "ghostly existance / non-existance / alive / dead cat" deal is really interesting, but a bit of a side show.
None of this gets away from the fact that a physicist could probably set me straight on the whereabouts of these force mediating particles and why i can't do anything with them-- hennessey, Feb 20 2009 I liked the analogy to the cat resuscitation system tho...-- hennessey, Feb 20 2009 //What's stopping me doing this?//
A mirror/filter of this type would be measured in an arena where its very size will make it subject to quantum principles. At this level you would have to add determinism, something not likely at a few, or less, angstroms. Any external (extra atomic) vehicle would vary/ interact with lots of elements of the "atom" and not particularily on your target (nucleus).
I don't know if you do, but it does seem that, you view the nucleus as a static arrangement of "snooker balls". The fact is that even these "heavy" particles have momentum and position that are not both definable. Trying to filter interactions like this (with a filter that is doing the same thing given its size) is spitting in the rain, or looking for a black cat in the dark.-- 4whom, Feb 20 2009 i'm not worried about the 'snooker balls' in the nucleus and no one is looking for a black cat. Determinism or any other philosophical concept wouldn't have to be 'added' since EM forces act on macroscopic scales and hence all the hocus pocus about cats and whatnot is an (admittedly alluring) irrelevance. My q is fairly straight forward: the Standard Model says: EM force mediated by photons. Where are the photons? What are their wavelengths/energies or where is the fundametal error in my assumptions. Are there any actual physicists who might comment? I appreciate the comments so far of course.-- hennessey, Feb 20 2009 //Are there any actual physicists who might comment?// I doubt it, they probably got better things to do, like not answer other questions.
Any macroscopic EM field will effect the electrons more than the protons. (it just one of those darned Maxwell equation things). Ergo your mirror is applied from within the nucleus. Ergo it will undergo the same uncertainties as your other intra-nuclear objects, unless you add some determinism (how is up to you). Ergo fucked!-- 4whom, Feb 23 2009 [zen_tom] It really is understood to be true that guage bosons are force mediators. Of these the photon is understood to mediate the EM field.
Given that it (the magnet) "sees" (via these photons) that there is another magnet there, how it "knows" whether to repel or attract is a function of the alignment of the spin of the majority of the electrons that have emmited these photons. In ferrous materials a lot of these electrons spin along a similar axis, creating a net dipole *field* effect. The photons are certainly not travelling along "lines of force" (they radiate out like all other photons). But their average behaviour "sets up" these lines of force. Like interference patterns in a bowl (sphere) of water.
Unlike us photon receptors, magnets are fields (due to an alignment of lots of their elements). And to conserve entropy they would really like to acheive a certain desired energy state. They can't accept photons from a similar spin electron, but they really like photons from an opposite spin electron (switch similar and opposite depending on your symmetry). And so the field moves to the desired energy state. Electrons don't really like giving away photons, and would like them back at some point. They will, however, lend some for a short (extremely short, in fact sometimes negative) amount of time. This is usually paid back by some mechanism, on the average (this is why magnets don't get colder just sitting there), in the absence of another magnetic field, but the photon debt gets paid back more quickly by another correctly oriented magnetic field. If there is a "no payment" gesture (incorrectly oriented magnetic field) then the entire field, or fields (remember it is happening to both), tries to "turn the other cheek" and collect that way.
Every substance is in some way ferrous. It is just that there is an insufficient field generated (not enough aligned electrons). That is why, with a large enough magnetic field you can magnetically levitate objects that would otherwise not. There will always be a group of electrons aligned, though not as uniformly as say a ferrous metal, that are willing to orient to achieve a certain energy level provided you give them enough of their photon debt. And that is also why substances lose magnetism at higher temps, the photon debt is being subsidised by the photons given off by the the more excited jiggely bits.
The Meissner effect, on the other hand is another whole kettle of fish.
You may have noticed that I have not once mentioned the poor old protons. Mainly because these "macroscopic" forces are mitigated by the "skanky" electrons. Sounding less like a force mirror and more like a force majeure.-- 4whom, Feb 23 2009 random, halfbakery