Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: ScientificSorcerer on 08/03/2015 05:55:31
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The Creation Of A New Type Of Magnetism
~The Photon Magnet~
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.newscientist.com%2Fdata%2Fimages%2Fns%2Fcms%2Fdn22406%2Fdn22406-1_300.jpg&hash=352cbdc6d3a0e31928936fbaa802dfb3)
I am making this post because I have come up with an experiment that will theoretically create a "Photon magnet" which means that the experimental set up would create a beam of electromagnetic radiation (microwaves) which generate a magnetic field which would be capable of attracting or repelling objects much like a conventional fridge magnet. The device in the experiment would create a "microwave tractor beam" that would effect ferro, para and dia magnetic materials, attracting them or repelling them.
If this experiment works then it could lead to tractor beams capable of magnetically levitating objects from great distances. As well as a lot of other awesome applications.
THE EXPERIMENT
In order to understand the way this experiment works you need to know a bit about "microwave optics" "The Faraday effect" and how "Interferometry" works. This experiment utilizes a microwave interferometer. to split a polarized microwave beam and cause the beam to interfere with itself. When dealing with microwave optics, copper plates are used in the place of mirrors and things like bakelite can act like a half silvered mirror used for splitting the microwaves.
along one arm of the split beam's path is a Faraday effect coil that acts a lot like a liquid crystal and causes the microwave's polarity plane to shift at 90 degrees.
when the Faraday effect coil is turned on the microwave's polarity is shifted, making the microwaves stop interfering with each other when the 2 beams meet back up. The Idea is to pulse the Faraday effect coil at 2 times the frequency of the microwave beam so that the wave crest is in a different polarity from the wave trough.
This will cause only the wave crests to interfere with each-other destructively or constructively (it dose not matter). The end result is a beam of microwaves which dose not have equal wave crest and trough amplitudes, meaning that the microwave now has a net magnetic field.
This super rapid polarization shifting of the microwave is what makes this possible. You shift the polarization so rapidly that wave crests and wave troughs are in different polarization planes. then you interfere that wave with it's split counter part inorder to cause interference but the wave can only interfere with half of the wave because the other half of the wave is in a different polarization.
This would not be possible with ordinary light simply because of it's high frequency, it's not like you can alternate an electromagnet at such huge frequencies, but microwaves and radio waves are a different story, you can more easily alternate a coil at those frequencies. plus the Faraday effect works better at lower frequencies making it easier to twist microwaves in the coil then regular light.
lastly I wonder if this is all possible or not, that's were you guys come in and do what you do best. [|)]
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The electric and magnetic fields are always at rightangles to one another, so if you rotate the plane of E polarisation you will also rotate the plane of H. Thus if the E fields interfere, so will the H fields, in the same sense.
You can buy teaching-laboratory microwave apparatus from educational suppliers, and have lots of fun demonstrating waveguides, diffraction and suchlike. Enjoy, but don't expect to discover too many flaws in Maxwell's equations.
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anancalverd
Can you tell me what would happen if this experiment was done?
2 beams from an interferometer are overlapping and interfering like normal then one of the beams polarization begins to alternate at 2 times the frequency what happens to the interference pattern? It would help to note that every polarization alternation occurs when when the wave crosses the x axis.
can polarization occur at such high frequencies? do you think that this could also create an electric field along with the magnetic field?
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Polarisation occurs, in principle, at any frequency, though I'm not sure how to control it for cosmic gamma radiation.
You can predict the effect of frequency mixing by simply adding sine waves. Easy if one is twice the other. So add the E fields to get the resultant , and the H field will be perpendicular to it and proportional to dE/dt - which is easy for sinusoidal E.
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ScientificSorcerer: your idea won't work because what you think of as the electric field variation is the spatial derivative of four-potential, whilst the magnetic field variation is the time derivative. See wiki (http://en.wikipedia.org/wiki/Electromagnetic_radiation#Derivation_from_electromagnetic_theory) where you can read this: "the curl operator on one side of these equations results in first-order spatial derivatives of the wave solution, while the time-derivative on the other side of the equations, which gives the other field, is first order in time". To visualize this, imagine you're in a canoe in a flat calm ocean, and a single wave comes at you. This wave has no trough, it's just a "hump" of water. You go up the wave, and E relates to the slope of your canoe, whilst B relates to how fast it's tilting. At the top of the wave your canoe is momentarily horizontal and not tilting, so E and B are zero. Then you go down the other side, and your canoe tilts down, then the wave has passed, and your canoe is horizontal and not tilting again. Once you've got that, appreciate this: you can't have a situation where your canoe only tilts up.
The diagram below shows the sinusoidal waveform which is the derivative of the "hump" of potential beneath.
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JohnDuffield
I see your point of view, I like how you used water as an example. But electromagnetic waves are not quite the same as waves of water. Water forms longitudinal waves and photons form transverse waves. In your example of longitudinal waves your right in saying that
"you can't have a canoe that only tilts up"
That's not what I am trying to accomplish here, though I see why you might think that.
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I will use pictures to illustrate the effect I'm trying to accomplish because such an abstract concept is difficult to visualize.
First off check out this picture it is a visualization of wave interference
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.ducksters.com%2Fscience%2Fphysics%2Fwave_interference.gif&hash=b8183d7c8cb3b9bea0b5d3dbbe312e49)
electromagnetic waves can interfere constructively and destructively with one another "BUT ONLY" if the waves have the same polarization. This next picture better illustrates the electromagnetic wave.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhyperphysics.phy-astr.gsu.edu%2Fhbase%2Fphyopt%2Fimgpho%2Fpollin.gif&hash=f96af261b95f21b27ad0c9dd68c976bb)
what we have here is a depiction of a normal electromagnetic wave, it has an oscillating magnetic field (blue) and electric field (red) they are in polarization planes one is vertical and the other is horizontal. The wave which I am trying to create looks like the wave depicted below in the attachment.
notice how the middle hump has changed it's polarization from the other 2 humps. If a wave like this was to interfere with a normal wave of the same frequency then only wave crests would interact with this wave and wave bottoms would not interact, if the wave interfered constructively then the wave crest amplitude would be 2 times the strength of the wave bottom amplitude. If the wave interfered destructively then wave crests would cancel each other out wile wave bottoms remain the same amplitude.
either way you end up with a magnetic field which might possibly be a mono-pole. [:o] And you get an electric field as well but The strange part is that protons and electrons wouldn't make these fields the electric field would attract charged particles but be unable to discharge and the magnetic field would be similar, capable of attracting magnets but without a body of electrons or mass.
I feel like I nailed explaining that one [;D] But what do you guys think?
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I'm sorry, you haven't nailed it because electromagnetic waves aren't really electric waves and magnetic waves. They're electromagnetic waves. The thing you think of as the electric wave doesn't really exist in its own right. Ditto for the magnetic wave. It's depicted as orthogonal to the electric wave, but it isn't, not really. There aren't two waves going along in perfect harmony. See Wiki (http://en.wikipedia.org/wiki/Electromagnetic_field#Dynamics_of_the_electromagnetic_field): "Over time, it was realized that the electric and magnetic fields are better thought of as two parts of a greater whole — the electromagnetic field". The electric wave and the magnetic wave are two "aspects" of the electromagnetic wave. One's the spatial derivative, the other is the time derivative. It's more like the canoe than you appreciate, and water waves are transverse waves (https://www.google.co.uk/search?q=water+wave+transverse+wave&biw=1366&bih=571&tbm=isch&tbo=u&source=univ&sa=X&ei=pXT9VLuBNcf5Us_YgtgF&ved=0CDkQsAQ). There are no magnetic monopoles either, just as there are no things that have a front and no back. I'm afraid you're advocating a "my theory" idea here without understanding electromagnetism. Sorry.
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If the [Electric] wave interfered destructively then wave crests would cancel each other out while wave bottoms remain the same amplitude.... you end up with a magnetic field
Maxwell's equations show that if you cancel the oscillating Electric field, then the Magnetic field also becomes zero.
Equivalently, if you have an oscillating Magnetic field, the Electric field is non-zero.
See: http://en.wikipedia.org/wiki/Electromagnetic_field#Reciprocal_behavior_of_electric_and_magnetic_fields
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The "tractor wave" diagram is very neat, but it can't be synthesised by adding sine waves. Just consider the two positive red humps. One source must have generated a negative red hump between them, which can only have been cancelled by adding a positive red hump in the same plane, but what is shown is a perpendicular positive red hump, again with no corresponding negative bits.
Damn vectors, spoiling an otherwise beautiful dream.
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alancalverd
I don't think I explained My wave correctly. The "tractor wave" is just an ordinary electromagnetic wave BUT it's polarization plane is alternating between vertical and horizontal each time the wave crosses the X axis. That's the tractor wave in a nut shell. It is made in a microwave frequency faraday effect coil, It is not a product of 2 waves interfering. When the tractor wave interferes with a regular photon beam of the same frequency (of only one polarity) only when the tractor wave interferes with a normal wave of the same frequency, traveling in the same direction is the true photon magnet made.
The tractor wave was wrongly named as it is not the finished product (the photon magnet is the finished product), the tractor wave is incapable of doing anything special by it self, only when it interferes with a normal wave in a interferometer beam do you get the photon magnet effect
So now you have an electromagnetic wave alternating it's polarization plane at every 1 half of it's wave length... Picture a sine wave.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.bit-101.com%2Fblog%2Fwp-content%2Fuploads%2F2010%2F07%2Fsine_smooth.png&hash=136dbb264cccac0b701a3807512de1be)
This sine wave is in the vertical polarization plane BUT right in the middle of this sine wave the polarization suddenly flips to the horizontal polarization plane
then at the end of the wave the polarization flips back to it's original orientation.
When you have a light wave doing this and interfering with a normal light wave traveling in the same direction and same frequency the interference pattern is unequal
you would end up with a strange interference pattern, were the tractor wave would only interact with the normal wave when it's in the same polarization plane (which is only half the time)
Please understand I am trying to make this clear but the message isn't getting across [:-'(]
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ScientificSorcerer: you are still not appreciating the fact that the electric sine wave is merely the spatial derivative of four-potential. See the Aharonov-Bohm effect (http://en.wikipedia.org/wiki/Aharonov%E2%80%93Bohm_effect#Potentials_vs_fields) on Wikipedia, and note where it says this: "In fact Richard Feynman complained[citation needed] that he had been taught electromagnetism from the perspective of electromagnetic fields, and he wished later in life he had been taught to think in terms of the electromagnetic potential instead, as this would be more fundamental." What you are describing is the electromagnetic equivalent to a slopey staircase of water coming at your canoe. You just can't do it.
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ScientificSorcerer: your idea won't work because what you think of as the electric field variation is the spatial derivative of four-potential, whilst the magnetic field variation is the time derivative. See wiki (http://en.wikipedia.org/wiki/Electromagnetic_radiation#Derivation_from_electromagnetic_theory) where you can read this: "the curl operator on one side of these equations results in first-order spatial derivatives of the wave solution, while the time-derivative on the other side of the equations, which gives the other field, is first order in time". To visualize this, imagine you're in a canoe in a flat calm ocean, and a single wave comes at you. This wave has no trough, it's just a "hump" of water. You go up the wave, and E relates to the slope of your canoe, whilst B relates to how fast it's tilting. At the top of the wave your canoe is momentarily horizontal and not tilting, so E and B are zero. Then you go down the other side, and your canoe tilts down, then the wave has passed, and your canoe is horizontal and not tilting again. Once you've got that, appreciate this: you can't have a situation where your canoe only tilts up.
The diagram below shows the sinusoidal waveform which is the derivative of the "hump" of potential beneath.
Do you actually understand what curl represents?
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Yes of course. Maxwell introduced the term, and drew the picture below showing convergence, curl, and both together. See page 7 of this paper (http://www.clerkmaxwellfoundation.org/MathematicalClassificationofPhysicalQuantities_Maxwell.pdf).
[ Invalid Attachment ]
For something shorter, this (http://www.rfcafe.com/references/articles/OnThePhysicalMeaningOfTheCurlOperator.pdf) isn't a bad little article. The curl or rotation associated with a charged particle is an "all round" rotation, but for a sinusoidal electromagnetic wave, it isn't.
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Yes of course. Maxwell introduced the term, and drew the picture below showing convergence, curl, and both together. See page 7 of this paper (http://www.clerkmaxwellfoundation.org/MathematicalClassificationofPhysicalQuantities_Maxwell.pdf).
[ Invalid Attachment ]
For something shorter, this (http://www.rfcafe.com/references/articles/OnThePhysicalMeaningOfTheCurlOperator.pdf) isn't a bad little article. The curl or rotation associated with a charged particle is an "all round" rotation, but for a sinusoidal electromagnetic wave, it isn't.
OK Then is it calculated using the dot or cross product. Quick John google it.
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perhaps this can better be explained in steps.
First of all this effect relies on rapid polarization shifting. Can polarization occur at twice the frequency of an electromagnetic wave? Some would say that Polarization occurs, in principle, at any frequency. But can polarization shifting occur at twice the frequency of the wave? Picture a EM wave going through half a sine wave then shifting it's polarization plane then finishing the sine wave then shifting it's polarization plane back to the way it was. This would cause the wave crest and trough to be at right angles to each-other.
If a EM wave can do this, then the next question would be, what would such a wave look like? would it look like the picture scientificsorcerer made in Photoshop? the so called "tractor wave" he posted a few days ago, what would be the effects of this wave?
For example I think this type of wave would have strange heat characteristics. In a normal EM wave, light vibrates particles to generate what we call heat, but if the wave crests and wave troughs are at right angles to each-other then the vibration action would not occur, how would a particle move in the presence of such a wave?
If this EM wave was to interfere with a normal EM wave of the same frequency, what sort of interference pattern would form. EM waves in different polarization planes don't interfere so how would a tractor wave interfere with a normal wave of the same frequency?
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can polarization occur at such high frequencies? do you think that this could also create an electric field along with the magnetic field?
Polarisation can occur at any frequency. It certainly occurs with radio waves, microwaves and light. Like Alan I don't know how you would do it for Gamma waves.
For your specific application you have 2 conflicting requirements:
The change over of polarisation will need to be done in as short a time as possible. This means the rise and fall times of the magnetic field will need to be as short as possible.
However the induction of the coil (and rise/fall time) will increase with the strength of the magnetic field, but the amount of rotation of the wave is proportional to the strength of the field. So the two work against each other in a practical design. I suspect the strength of the coil needed will limit your maximum switching frequency.
In terms of the switching frequency, you need at least 2x the frequency of the wave, and in order to get a reasonable rise time I suspect you will need an equivalent frequency of at least 2x that ie 4x the wave frequency and it might be higher depending on the physical design of the system. For example, If you can tolerate 10% of your waveform being taken up by the changeover (rise+fall) you will need circuitry capable of handling an equivalent frequency of 10x the waveform frequency - rough rule of thumb.
The above is general to all waves, but I've never worked directly with microwaves so you will have to check the following.
I seem to remember there are microwave isolators which use ferrite as the dielectric. Rather than researching the properties of these and coil strength etc, why not approach a manufacturer, or as Alan suggests an educational supplier, and see what they have available.
Will it work? I think you need someone more immersed in the maths of EM waves, it would take me a while to work out what might happen.
Just a suggestion. If you could achieve a 180 rotation you would have the equivalent of a full wave diode rectifier which converts AC to DC. Every half of the wave would be in the same direction, no need for interference.
Interesting experiment. Have you done a literature seach to see if it's been tried before?
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Hi, I think it is Charles, Dr Charles Hall who writes about this from a few years experience in the USAF in the desert in his book. Millennial Hospitality, a series.
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The wave which I am trying to create looks like the wave depicted below in the attachment.
As I've said it could be theoretically possible to do what you want (given supercooled coils) but I'm not convinced that you will get what you expect. These are my thoughts:
Let's take a simple case of the sine wave you show. Reverse the negative halves so you now have a series of positive going humps similar to the waveform of a full-wave rectifier. It has some features of the waveform you desire. Although we can say that this waveform is all +ve we only do so in an electrical circuit because we can control the reference point. We could choose the peak as our reference, in which case the waveform would be negative. We could choose to normalise the DC offset and choose a point at the centre of the wave (equal area each side of the line), so we would now have a wave oscillating around the 0 line, with the rounded halves above the line and the pointy halves going below (excuse the technical terms).
In the case of an EM wave we have no control over the reference point and I think it would normalise itself around a new midline. In other words, the nett effect would be neutral.
The next question is whether this wave would maintain itself or, as has been suggested, collapse.
As this is not a single photon, but multiple, coherent photons I think there is a good chance it would continue, at least for a short while. If a sine wave is distorted the process creates harmonics at multiples of the fundamental frequency. So if a monochromatic laser light were passed through such a set up we should see additional spectral lines at multiples of the laser frequency, their exact amplitude and frequency can be calculated using Fourier analysis.
The limiting factor on waves such as this is the ability to sustain the highest frequency, but vacuum shows an ability to sustain frequencies far in excess of light so I don't think that will be a problem. Note: the highest frequency is defined by the pointy bits where there is a very rapid change of direction.
Complex waveforms like this are possible for radio waves so I don't see why they shouldn't be for light.
The bottom line is that although you will see some very interesting effects, you won't see an overall bias towards one side of the wave.
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"European Ocean" spoke of a person named Charles Hall. I had not heard of him before (I taught he was a scientist), so I googled him to see who he was, it turns out that he was some area 51 worker with a story to tell.
I didn't find out anything relating to Photon magnetism but he talked about ET technology a little, mostly optic cables being coiled like electromagnets and used in an interesting way. I wonder what would happen if you put my tractor beam into an optic cable and coiled it or passed the beam through a polarized film... It could be interesting.
Colin2B
you said, what if we could rotate the polarization plane by 180 degrees. I had not taught of that, it would make the wave 100% efficient at doing what I want it to do.... also very interesting [;D]