Latest challenger

[Carn]

How? The current is not transmitted to the body. I think you are confusing electricity eith electromagnetic radiation.

Ok, basics, if you have a magnet and a copper wire and you move it past the magnet you will have a current(dependant on magnet strength, how you move past, wire,...) inside the wire, because the magnetic field inside the wire changes. Thats physics.
Any current causes an electomagnetic field, so if you move a wire past any active electric device, there could be a current caused inside, dependant on what currents flow inside the device.
Main advantage of copper wire is, that it has high conductivity, so already small changes in electromagnetic field will cause a current.
[/B]

Would the em field changes induce currents within the human body? And if so what receptors would detect that?
[/B]

Here i would also need a lot of knowledge in biology to answer this exactly, but human nervous system has some conductivity, so a change in em field could cause a current the same way a current is caused inside a copper wire in a changing em field, only copper wire is far more suited for the task.
The receptors that detect the normal currents our nerves use to pass information, could also detect the current caused by induction, would depend on the strength of current and on how exactly a current flows inside nerves.
The exact sensation would depend on which part of nervous system the changing em field can induce a current in, which depends on the electrical parameters of nervous system, e.g. conductivity, capacity,..., and what exact information are transmitted via parts where a current is induced, e.g. it could be pain, contracting muscles, dumbness and maybe other things.

[/B]

The links only emphasise the point I'm making.


You are expressing a personal opinion without evidence and likening it to a completely different effect (gravity). The two are not connected.
It's like me saying I can detect a small torchlight on a nearby hill with my eyes so I must be able to see infrared beams, although your comparison is worse because it involves completely different mechanisms.
[/B]

On how strong em field changes have to be and what em frequencies have to be involved, that human nervous system can detect the current, that is induced inside it, i can only guess as i do not know the relevant parameters of nervous system.
My guess is that the ability of a human to detect whether a nearby electrical device is on or not via the change of sensations , that could be caused by induced currents is as zero as human ability to detect the position of the moon via the weight change that is caused by different position of the moon.
I added this to emphasize that although there might be some effects of em fields on human nervous system, these are in no way a reason why dowsing and so on should work.
[/B]

No, those are completely different things. Lights use very different electric frequency to power them, but they all give off visible light.
[/B]

The visible light is caused by electrons changing their position in atoms or molecules and this changing is at least in normal lights caused by the the heating of the wire, so the frequency of emitted light is material and temperature dependant. The heating is caused by a electric current flowing through and this is normally done by a AC(or is it called DC, i confuse the terms often as i'm not natural english speaker) current with a frequency of 50 Hz, but if you heat the wire with a flame(without destroying the light), it would just emit the same light.
And current causes a em field, that of course changes as the current changes, so will oszilate with the same frequency of 50 Hz and could be detected by an current it induce in another device, though only if the detection device is able to detect that frequenzy.
[/B]

Like I said, if you did that the human would detect it, but only by being hit by a bolt of lightning.
[/B]

No, a direct exposure to the current is not necessary, there could be even a vacuum between the human and the current, its just a matter of strength and right frequency, if human detects anything.
At the last if the field is strong enough to change or destroy molecular bindings(which are electrical in nature so could be effected by em fields), human will notice some indirect effects, but humans would likely notice something beforehand, as vast currents would be induced.

[/B]

Look at static electricity - it can raise the hair off your head, but do you feel it until you get a shock? [/B]

But if you can exclude any other cause for hair raising, you can come to think that you are charged, just as i said if an em field change induces a current inside nervous system, you could, after excluding all other possible options, conclude that there is a changing em field.

Carn

 

[Carn]

Apart from the discussion whether a current under special circumstances via the change of em field, which then might induce a current inside nervous system, which then maybe would allow human to detect something has change and then might allow conclusion that the cause of change is a nearby power line, i realized that part of the applicants claimed abililty might be normal physical process.

He claims to be able to detect neaby power lines via a metal rod.

Now some personal experience, i once visited a great chemical plant, where through just sticking a big positive and negative pole inside water with lot of NaCl(not realy certain about that, but it was along those lines), pure Na and Cl was produced(cannot remember how the principal process is called, but its school physics).
As each the Na and Cl move to different poles and are charged this process produces a current proportional to the produced amounts of Na and Cl. As they produced there a lot of Na and Cl, the current was very high and the em field caused by the current was so high, that it was a safety rule that any metal object had to be left outside the area.
The staff demonstrated that it was not possible with human strength to keep a small metal rod from turning itself, so its parallel to the magnetic field.
Anyone entering the room with a metal rod would have immiediately noticed that its rod is bend in a certain direction.

So if the dowser is close enough to the power lines and they are strong enough and he has big enough metal rod of the right material, his rod will react in some way. Therefore it would be neccesary to ask the dowser, what power lines, distance, rod and so on and then give the data to someone used to calculate such things(e.g. people designing transformators or so) to see whether its normal physical process.

Carn

 

[EHocking]

Here i would also need a lot of knowledge in biology to answer this exactly, but human nervous system has some conductivity...

can I suggest that you wander over to the Science Forum here and look up this thread. It is a Q&A on just this subject where you can get the good oil on all that you are theorising about.

This Q&A session came someone with knowledge about electromagnetism etc volounteering to educated someone who has similar beliefs to you on this subject.

 

[Ashles]

Ok, basics, if you have a magnet and a copper wire and you move it past the magnet you will have a current(dependant on magnet strength, how you move past, wire,...) inside the wire, because the magnetic field inside the wire changes. Thats physics.

I think it's a bit rich to get patronising about physics when you are continually getting things confused.

For example:

The visible light is caused by electrons changing their position in atoms or molecules and this changing is at least in normal lights caused by the the heating of the wire, so the frequency of emitted light is material and temperature dependant. The heating is caused by a electric current flowing through and this is normally done by a AC(or is it called DC, i confuse the terms often as i'm not natural english speaker) current with a frequency of 50 Hz, but if you heat the wire with a flame(without destroying the light), it would just emit the same light.
And current causes a em field, that of course changes as the current changes, so will oszilate with the same frequency of 50 Hz and could be detected by an current it induce in another device, though only if the detection device is able to detect that frequenzy.

Firstly AC is Alternating Current DC is direct current. Alternating Current means the current continually changes direction.
Secondly are you absolutely sure you understancd what is meant by frequency here? Just because a current is 50HZ this does not alter the frquency of the emitted light/electrmagnetic radiation. the bulb is hot so it glows, it isn't giving out fifty pulses a second of light - the elctrical frequency is irrelevant to the produced em radiation from the bulb.
Hz is literally only a measure of frequency - meaning events per second.
What kind of detection device is programmed to detect '50 events per second'? A stopwatch? Devices are there to detect the actual phenomonena - an em detector will detect em radiation and tell you the wavelength (or frequency) of that radiation. This is not the same as measuring how fast pulses of the radiation are being emitted.
I could shine a torch off and on once per second, that would be a frequency of 1Hz, that does not however mean the wavelength of the light is 1.

I will have to come back to the rest of your post later.

 

[Ashles]

Very interesting post by estahl on the other thread EHocking has linked to:

I would like to make a slight correction here... well not really a correction, a clarification.

Don't imagine an electric current like all those stupid science shows have with sparks jumping across things and little lightning bolts on the cell. Electron flow is not what makes nerves work (well, not directly anyway). The membrane of a nerve cell has transport proteins for Na+ ions. When not activated, the cell actively sets up an imbalance, with more Na+ on the outside, using active protiens in the cell. This sets up electric potential. Since the cell membrane is a lipid, these ions cannot cross on their own. When a nerve impulse "fires", channel protiens (different than the ones that put the Na+ outside the cell in the first place) open allowing the ions to find equilibrium, but wouldn't you know it, when Na+ contacts these channels on the *inside* it opens them up. So we have a propagation. This is why nerve impulses do not move at the same speed as currents in a computer or radio, why our nerves conduct electric potential with out really being conductors, and why nerves must have a "reset" period before they fire again... they have to get that imbalance across the membrane back. At the synapses, other chemicals are used to first activate the ion channels.

In fact, you can actually think of nerves as the exact opposite of what we normally think of as electric action.

 

[Carn]

I think it's a bit rich to get patronising about physics when you are continually getting things confused.

Guess what, i'm from german and the language of the university courses i visited about electrodynamics and so on were in german, so if i translate terms into english i'm not certain whether its the correct english term.
Second i was not willing to look up exact formulas and explanations from books, i was just trying to give rough explanations from what i remeber from reading books about electromagnetism.

For example:

Firstly AC is Alternating Current DC is direct current. Alternating Current means the current continually changes direction.
Secondly are you absolutely sure you understancd what is meant by frequency here? Just because a current is 50HZ this does not alter the frquency of the emitted light/electrmagnetic radiation. the bulb is hot so it glows, it isn't giving out fifty pulses a second of light - the elctrical frequency is irrelevant to the produced em radiation from the bulb.

If you read my posts you would have noticed that i said there are several things causing em fields, first there are electron changing energy niveaus because of movement cuased by heat and those cuase visible em fields and then there i the em field caused by the current thats used for heating and this em field will have a frequency of 50 Hz and therefore a vacuum wave length of c/50Hz. Thats undetecable by human eyes, but not undetecable by a closed circuit with an amperemeter and an adequate inductivity(one of german words i do not know how to translate correctly).

Hz is literally only a measure of frequency - meaning events per second.
What kind of detection device is programmed to detect '50 events per second'? A stopwatch? Devices are there to detect the actual phenomonena - an em detector will detect em radiation and tell you the wavelength (or frequency) of that radiation. This is not the same as measuring how fast pulses of the radiation are being emitted.
I could shine a torch off and on once per second, that would be a frequency of 1Hz, that does not however mean the wavelength of the light is 1.

I will have to come back to the rest of your post later. [/B]

Now guess what, the formula that allows to calculate how much current is induced via an em field is among other things dependant on the capacity and inductivity of the used device and these allow to calculate a resonance frequency the em field must have to cause the maximum possible current, the greater the difference between the frequency of the em field and the resonance frequency of the detecting device is, the lesser the induced current will be.

As the human nervous system has a limited conductivity, has some inductivity and capicivity(any material where electrons are flowing has this), there are some frequencies em fields can have where no current is induced in nerve system, but human nerve system might have a resonance frequency and em fields that have this frequency and are strong enough will induce a current inside human nervous system.
Which then might cause some sensations.

What i do not know is inductivity, capicivity and conductivity of different parts of human nerve system and shielding ability of skin, etc. for the resonance frequencies that are connected to these values, so i cannot say how big induced currents will be, but i guess that realy strong fields will induce a current(unwritten lax physical rule, if something gets big enough something will happen).

You want me to look up formulas and maybe find internet pages explaining how currents are induced?

Carn

 

[Carn]

Very interesting post by estahl on the other thread EHocking has linked to:

I would like to make a slight correction here... well not really a correction, a clarification.

Don't imagine an electric current like all those stupid science shows have with sparks jumping across things and little lightning bolts on the cell. Electron flow is not what makes nerves work (well, not directly anyway). The membrane of a nerve cell has transport proteins for Na+ ions. When not activated, the cell actively sets up an imbalance, with more Na+ on the outside, using active protiens in the cell. This sets up electric potential. Since the cell membrane is a lipid, these ions cannot cross on their own. When a nerve impulse "fires", channel protiens (different than the ones that put the Na+ outside the cell in the first place) open allowing the ions to find equilibrium, but wouldn't you know it, when Na+ contacts these channels on the *inside* it opens them up. So we have a propagation. This is why nerve impulses do not move at the same speed as currents in a computer or radio, why our nerves conduct electric potential with out really being conductors, and why nerves must have a "reset" period before they fire again... they have to get that imbalance across the membrane back. At the synapses, other chemicals are used to first activate the ion channels.

In fact, you can actually think of nerves as the exact opposite of what we normally think of as electric action.

Thanks for that, it shows that not thinking about how exactly current flows inside nerve system, is a big blind spot about my argument.

But the only main distinction i can see between this biological current flow and technical currents is the fact that Na+ ions carry charge, that there number is so limited it cannot be ignored and the effective mass of the charged "particles"(Na+ attached to some molecules) is far bigger and might be even changing.

As for cell membrane sometimes blocking the Na+ and sometimes allowing them to pass, this can be adequately approximated by a capacity which can be bipassed by a normal resistance, which is open or closed with a switch.

I guarantee you that the current flowing via such a single cell membrane can be influenced seriously by an em field, as even when membrane is closed a AC can flow using the Na+ as moving charged particles.

Now things get complicated like hell, by the fact that are thousands of cells, that may change from blocking to opening several times during each second, so effecting the entire nervous system via a single em wave will not work, it would need many different em fields, that also might need to change frequency several times per second or it would have be limitated on a small area on a small time scale.

But nonetheless a em field can influence the amount of Na+ moving around, if its just the right field at the right time in the right area, and thereby enhance or suppress a sensation.
I always said "special circumstances", because i suspected it would be rather unlikely to simply apply a em field and change it to all frequencies, till some reaction shows.

Carn

 

[Ashles]

movement cuased by heat and those cuase visible em fields and then there i the em field caused by the current thats used for heating and this em field will have a frequency of 50 Hz and therefore a vacuum wave length of c/50Hz. Thats undetecable by human eyes, but not undetecable by a closed circuit with an amperemeter and an adequate inductivity(one of german words i do not know how to translate correctly).

That would be in the region of radio waves. Are you saying that any electric circuit running at 50HZ wil only give out em radiation of 50HZ?
For a start wavelength isn't measured in Hz, it's a measure of length. The frequency is the number of waves passing a point per second. 50Hz is in the radio area of the spectum,
You are still confusing the Hz of electricity and the electromagnetic waves.

But nonetheless a em field can influence the amount of Na+ moving around, if its just the right field at the right time in the right area, and thereby enhance or suppress a sensation.
I always said "special circumstances", because i suspected it would be rather unlikely to simply apply a em field and change it to all frequencies, till some reaction shows.

These special circumstances are quite ridiclous. You plan on bombarding the human body with a full spectrum of em radiation? Microwaves, X-Rays Gamma rays? Er, that would cook and kill the subject in a variety of ways.

And it still doesn't get around the point that no direct detection of non-visible em radiation is possible by a human being. Other than cooking or burning them and having them feel pain, but this is still an indirect method.

I guarantee you that the current flowing via such a single cell membrane can be influenced seriously by an em field, as even when membrane is closed a AC can flow using the Na+ as moving charged particles.

But as posted by estahl:

Since the cell membrane is a lipid, these ions cannot cross on their own.

I think you're making this up as you go along.

 

[drkitten]

Other than cooking or burning them and having them feel pain, but this is still an indirect method.

Indirect, shmindirect. As long as it gets me the million bucks, who cares?

 

[Carn]

That would be in the region of radio waves. Are you saying that any electric circuit running at 50HZ wil only give out em radiation of 50HZ?

Certainly not "only", but if you have an electric circuit running at 50 Hz, you can measure near the circuit a changing em field, that will have a frequency near 50 Hz
I'm just uncertain, whether/how much this frequency also depends on what sort of devices operate inside the circuit.
But if you take just a cable and a small resistance and a 50 Hz source, then you will get a em field with a frequency close to 50 Hz.
Aren't radio waves around kHz to MHz?
Doesn't matter, if you have an em field of the wrong frequency affecting your radio, you will have problems hearing the program.

For a start wavelength isn't measured in Hz, it's a measure of length. The frequency is the number of waves passing a point per second. 50Hz is in the radio area of the spectum,

Yes, frequency is not identical to wave length, but there is a formula connecting the wavelength with wave speed and frequency.
So as long as the speed of the wave does not change, there is little difference if you talk about frequency or wave length, as one can be calculated from the other.
And the speed of light is nearly the same in air and in vacuum, so when talking about em waves in atmoephere you can use both and make only very small mistakes.

You are still confusing the Hz of electricity and the electromagnetic waves.

Em waves have a frequency and a wave length and the frequency certainly depends on how the em field is created, so will depend on the frequency of the power source of the device creating the em wave.

These special circumstances are quite ridiclous. You plan on bombarding the human body with a full spectrum of em radiation? Microwaves, X-Rays Gamma rays? Er, that would cook and kill the subject in a variety of ways.

It would not require the full spectrum, the exact wave lengths required depend on lots of properities of the biological system, e.g. number of Na+ ions, movement speed via "open" membran, movement speed inside the cell, number of cells, maybe what drugs human has taken in past hours, awake or asleep,...

It might well be possible that the required em fields have also other side effects, but i intent with the argument was showing, that science might allow for a detection method of whether electric devices are on or not beside receiving an electric shock.
And now that i have thought about it and received this example of how current flows inside nerve system, i'm wuite certain, that all the elctectrical devices used so far by humans would not influence the working of the nervous system via em fields in a way noticeable for human beings and also also undetecable with today and near future measuring methods(e.g. when measuring brain activity, the activity will not change in any measureable way if a nearby power line is switched on or off, except for the effects it would have on the measuring device).

But i would not say that its impossible to construct a set of electric devices, that have em fields, that do affect the current flow inside nervous system to such an extent, that a human will feel a difference whether devices are on or not.

Though i do not expect thatz today technoloy would be good enough to constuct something like that

And it still doesn't get around the point that no direct detection of non-visible em radiation is possible by a human being. Other than cooking or burning them and having them feel pain, but this is still an indirect method.

I do not see where i said a direct detection of non-visible em is possible, i always pointed at the indirect method of em influences the flow of current inside nerve system, which then causes human to experience different sensations as compared to the exact same situation without em field.

I also do not know any direct detection method, but we started from discussing from a JREF applicant, who claims to be able to detect power lines and for passing JREF test it would be irrelevant whether detection method is direct or indirect.

quote:I guarantee you that the current flowing via such a single cell membrane can be influenced seriously by an em field, as even when membrane is closed a AC can flow using the Na+ as moving charged particles.


But as posted by estahl:

quote:Since the cell membrane is a lipid, these ions cannot cross on their own.

Sorry, an AC current can flow even if the charges cannot cross a certain point. Explanation will be in most beginner books about electrmagnetism or electricity, you will find it under condensator or capacitor, here is a page explaining how AC can pass a condensator, although no electrons get from one side to the other.
http://www.wordiq.com/definition/Capacitor

The same principle argument could work with Na+ ions inside cells, as long as these ions can move in some way and are not "attached" to the cell membrane.

I think you're making this up as you go along.

That impression is caused by the fact, that its 3+ years since i read the last book about em fields and so on, so my first argument was just guided by the feeling(=subconcious knowledge) one has about things one has learned and heard about a lot, but not recently.
Your further questions and arguments caused some thinking and remembering on my part, so the information i'm arguing with is changing the more i remeber of what i learned.

Also its caused by the fact that i do not no anything about how current is flowing inside nerves, i just know that wherever charged particles are moving around they will be influenced by em fields and if the right em field is applied whole groups of charged particles act in the same way, so any current can be changed in some way by em fields, no matter if the current is inside biological system and charged particles are not electrons, but something else, that changes only what em fields have to be used and what can be achieved with them.

The basic fact em field will interfere with the movement of charged particles allows the conclusion that nerve system might be affected by em fields and depending what effects can be caused without killing, this might cause sensations for the human.

Carn

 

[Ashles]

I do not see where i said a direct detection of non-visible em is possible, i always pointed at the indirect method of em influences the flow of current inside nerve system, which then causes human to experience different sensations as compared to the exact same situation without em field.

This would count as a direct detection - em radiation is stimulating the nervous system, thus direct detection. Indirect would be it burns you and you detect the burn.

But if you take just a cable and a small resistance and a 50 Hz source, then you will get a em field with a frequency close to 50 Hz.

Well as you were referring to wavelength when you first mentioned this I assumed you meant a wavelength of 50 metres, which is radio waves.

This links shows a guide to wavelengths and frequencies: 50 Hz (i.e. frequency) is way off the spectrum:
The Electromagnetic Spectrum

i'm wuite certain, that all the elctectrical devices used so far by humans would not influence the working of the nervous system via em fields in a way noticeable for human beings and also also undetecable with today and near future measuring methods

Well we agree on that at last.
Again, i'll have to come back to the other issues later on.

 

[rppa]

Originally posted by Carn
Certainly not "only", but if you have an electric circuit running at 50 Hz, you can measure near the circuit a changing em field, that will have a frequency near 50 Hz

True. Just as your CPU clock, running at MHz, emits signals in the MHz. These can be picked up by sensitive equipment. In the early days of calculators I remember finding out that an HP calculator, held next to an FM radio, caused extremely strong interference
(The commercial FM band is about 88 -108 MHz).

But if you take just a cable and a small resistance and a 50 Hz source, then you will get a em field with a frequency close to 50 Hz

Also true. The wavelength of 50 Hz radiation is about 6000 km. Any reasonably-sized antenna will be a very inefficient collector of energy at 50 Hz. But not zero, and you will be able to detect it with an antenna and a tuned circuit.

Aren't radio waves around kHz to MHz?

Yes. AM radio is 0.5-1.5 MHz, FM as I said is around 100 MHz. The rest of the spectrum up into the GHz has been carved up as well, for instance to cell-phone users.

Doesn't matter, if you have an em field of the wrong frequency affecting your radio, you will have problems hearing the program.

I'm not sure what you're saying. When I drive under high-voltage electrical lines, the interference can be enough that I have to turn off the radio.

It might well be possible that the required em fields have also other side effects, but i intent with the argument was showing, that science might allow for a detection method of whether electric devices are on or not beside receiving an electric shock.
And now that i have thought about it and received this example of how current flows inside nerve system, i'm wuite certain, that all the elctectrical devices used so far by humans would not influence the working of the nervous system via em fields in a way noticeable for human beings and also also undetecable with today and near future measuring methods(e.g. when measuring brain activity, the activity will not change in any measureable way if a nearby power line is switched on or off, except for the effects it would have on the measuring device).

Since any biological detection involves the same mechanisms, i.e., interaction of EM waves with matter, that a radio does, I don't know why you believe there can be such a thing as frequencies that can be detected by humans but not by any conceivable mechanical receiver.

But i would not say that its impossible to construct a set of electric devices, that have em fields, that do affect the current flow inside nervous system to such an extent, that a human will feel a difference

Sure. We have those already. We call them radars. The same frequencies used in radar are also used to cook your food in microwave ovens (long ago, they were called "radar ranges"). If you are cooked by microwaves, your nervous system will certainly detect it.

whether devices are on or not.

Huh? You think that a device which is off, i.e., not emitting EM radiation, has the same EM effects as a device which is emitting EM radiation?

 

[Carn]

Originally posted by Carn


Doesn't matter, if you have an em field of the wrong frequency affecting your radio, you will have problems hearing the program.

I'm not sure what you're saying. When I drive under high-voltage electrical lines, the interference can be enough that I have to turn off the radio.

Just one of the examples i thought of, high-voltage electrical lines cause strong enough em fields of the right frequency to effect your radio, though i'm not certain, whether they do this by disturbing the working of antenna or by affecting the rest of the radio or the speakers.

It might well be possible that the required em fields have also other side effects, but i intent with the argument was showing, that science might allow for a detection method of whether electric devices are on or not beside receiving an electric shock.
And now that i have thought about it and received this example of how current flows inside nerve system, i'm wuite certain, that all the elctectrical devices used so far by humans would not influence the working of the nervous system via em fields in a way noticeable for human beings and also also undetecable with today and near future measuring methods(e.g. when measuring brain activity, the activity will not change in any measureable way if a nearby power line is switched on or off, except for the effects it would have on the measuring device).

Since any biological detection involves the same mechanisms, i.e., interaction of EM waves with matter, that a radio does, I don't know why you believe there can be such a thing as frequencies that can be detected by humans but not by any conceivable mechanical receiver.

Seems i have to get better in english.
I'm talking about directly influencing the the current flowing through nerves and that way cause sensations.
I stated above that, although some today devices might influence the current flowing through nerves, this would be neither detectable by technical devices measuring the nerve activity or by human concious.
Why do i think that?
Because the above described mechanism of Na+ movements through cell membrans alone(there might be other biological mechanisms, i do not know about) means, that electrical speaking the nerve system consist of thousands of capacitors arranged both parralel and sequential and each has a switch which bypasses it and each switch can open or close independently of others and is affected by the local capacitor field and biological factors,which are very likely unknown and therefore practical random. Those switches open and close in time scales of tenth part of a second.
A single em field cannot affect this whole system as it changes to fast, at most it can effect a small part where no switch open or closes during the time the em field needs to affect that part(it always takes some time till current is induced).
So i guess the right em field might keep a dozen nerve cells from firing for 0.1 seconds or so. That of course will not be noticed by anyone and any device measuring this would have to measure what those nerve cells are doing and what how the effect that would cause them to fire behaves, then you could conclude "these nerve cells fired 0.1 seconds later than they should have according ot the whatever effect triggers them to fire, so the em field had an effect". Such a devices do not yet exist, but could be possible, if all those nano dreams some scientist have today come true.

But i would not say that its impossible to construct a set of electric devices, that have em fields, that do affect the current flow inside nervous system to such an extent, that a human will feel a difference

Sure. We have those already. We call them radars. The same frequencies used in radar are also used to cook your food in microwave ovens (long ago, they were called "radar ranges"). If you are cooked by microwaves, your nervous system will certainly detect it.

But from a very theoretical viewpoint a single cell can be effected by an em field, if the em field changes the right way, whenever the cell does something different.
And em waves can cancel each other out, so if you have an individual em field for each nerve cell(!) and have a set of other fields, that cancel out these individual em field in all(!) other nerve cells, then you could control the current flow through the nerve cell to a very great extent and then would be able to cause concious sensations, without realying on effects like cooking,...

The only way i can think of something like this would be possible, is through placing a few "nanobots", capable of causing em fields, at each cell membrane, but that might still be impossible however far science advances.

Therefore i would not say "impossible", but "all devices i can think of are impossible with today tech and maybe even future tech".

whether devices are on or not.

Huh? You think that a device which is off, i.e., not emitting EM radiation, has the same EM effects as a device which is emitting EM radiation?

Bad wording, i meant that human could tell you if such a nerve effecting device is on or not. If its off, it will not affect him.

Ok, i had to flee to a very theoretical special point to keep the statement that em fields could effect the nerve system and that happened because i did not take time to think how the nerve system is actually working.

But i still think that my initial thought is true, there is no science law that forbids affecting nerve system via em fields, there are just "some minor" technical problems, that would have to be dealt with to achieve it.


Carn

 

[KRAMER]

Power lines project a hefty electromagnetic signature that is quite detectable via non-parnormal means. I think that it will be difficult to screen this claimant for devices that might tip him off.

I say make him detect groundwater or sulfide mineralization, which are also his claims and are not easily detectable by ordinary means.

This is what we have done. We are awaiting his choice.

 

[Hellbound]

On the subject of humans detecting EM fields:

The military's microwave-based non-lethal weapon currently in development works via direct stimulation of the nerves responsible for pain. Targets hit with it experience extreme pain on exposed areas, feeling like an "extreme sunburn in a hot bath". However, no physical damage is caused, likewise no burning occurs.

However, I wouldn't call this a case of a human detecting EM fields. This is a case of a specifically tuned, focused EM wave being emitted for the express purpose of affecting a human target. The idea that nerves would respond to a useful range of EM frequencies, such that some general or even useful detection capability exists, is not supported by any available evidence. One might as well argue that you can determine shape by throwing a golf ball repeatedly and measureing it's speed, direction of travel, and how long it takes to hit something. While this is technically possible, I would not call a golf ball a "detector of shapes." IT is neither made for this purpose, or particularly useful for this purpose.

 

[Ashles]

The military's microwave-based non-lethal weapon currently in development works via direct stimulation of the nerves responsible for pain.

Again I am curious as to how that would work.

Is there a source for this?

 

[Hellbound]

Story about the weapon, and oops!

Hmm, looks like I was wrong. It does work by heating water molecules, not by directly affecting nerves. I mis-remembered the earlier stories about its development.

I'm not maintaining a high track record this week for remembering things correctly...I need more sleep

 

[troy jones]

Again I am curious as to how that would work.

Is there a source for this?

Air Force fact sheet:
http://www.de.afrl.af.mil/Factsheets/ActiveDenial.html

Here's a news article about it:
http://www.dailytimes.com.pk/default.asp?page=story_9-8-2004_pg6_11

 

[Ashles]

Yes, but again the sensation is secondary to the actual effect.

As Huntsman states above, the microwaves are heating the water molecules and it is the heat from this that is triggering the nerves.

It is not a direct stimulation.