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View Full Version : Radio waves cause pain, but no harm?


Quixote
5th November 2007, 11:40 AM
The Pentagon has announced it has a weapon that uses high energy radio waves to induce pain. Non-Lethal Weapon Emits Invisible Rays of Pain ( http://www.npr.org/templates/story/story.php?storyId=15739254&ft=1&f=1).

Does this lend support to the belief, supported so far only by anecdotal evidence, in cell phone induced brain tumors? Or am I confusing apples and oranges? Or perhaps oranges and bergamots (i.e., does size matter)?

DavidS
5th November 2007, 12:00 PM
The Pentagon has announced it has a weapon that uses high energy radio waves to induce pain. Non-Lethal Weapon Emits Invisible Rays of Pain (http://www.npr.org/templates/story/story.php?storyId=15739254&ft=1&f=1).

Does this lend support to the belief, supported so far only by anecdotal evidence, in cell phone induced brain tumors? Or am I confusing apples and oranges? Or perhaps oranges and bergamots (i.e., does size matter)?
Of itself, no. For example, I'm fairly confident that tossing a fifty pound bag of potatoes at somebody from 50 yards will induce pain, but that hardly supports a claim that potatoes cause cancer.

ponderingturtle
5th November 2007, 12:02 PM
The Pentagon has announced it has a weapon that uses high energy radio waves to induce pain. Non-Lethal Weapon Emits Invisible Rays of Pain ( http://www.npr.org/templates/story/story.php?storyId=15739254&ft=1&f=1).

Does this lend support to the belief, supported so far only by anecdotal evidence, in cell phone induced brain tumors? Or am I confusing apples and oranges? Or perhaps oranges and bergamots (i.e., does size matter)?

What that seems to be is a system that functionaly heats up your skin. That does not seem like something that could give you cancer. The energy levels are too low to produce chemical instead of thermal effects.

sthomson
5th November 2007, 02:32 PM
Cancer can be caused by ionizing radiation (http://en.wikipedia.org/wiki/Ionizing_radiation). Microwaves (which cell phones use) and radiowaves (which army pain machines use) are NOT forms of ionizing radiation. Like ponderingturtle says, non-ionizing radiation has enough energy to heat things up, but not enough energy to chemically change cells.

Edited to add: interesting enough, is ultraviolet light considered ionizing or non-ionizing? The internet seems to have it both ways.

scotth
5th November 2007, 02:34 PM
Quixote, as soon as one understands enough physics to understand the photoelectric effect, cellphones causing brain cancer is a completely laughable suggestion.

scotth
5th November 2007, 02:36 PM
Cancer can be caused by ionizing radiation (http://en.wikipedia.org/wiki/Ionizing_radiation). Microwaves (which cell phones use) and radiowaves (which army pain machines use) are NOT forms of ionizing radiation. Like ponderingturtle says, non-ionizing radiation has enough energy to heat things up, but not enough energy to chemically change cells.

Edited to add: interesting enough, is ultraviolet light considered ionizing or non-ionizing? The internet seems to have it both ways.

It depends on where in the UV range. The ionizing threshold is crossed somewhere in the UV band.

sthomson
5th November 2007, 02:43 PM
It depends on where in the UV range. The ionizing threshold is crossed somewhere in the UV band.

Ah, thanks. Is it a gradient thing? Could I develop a sunbed at the low end of the UV spectrum that causes a tan but doesn't expose the user to harmful radiation? Or is it pretty much "melanin response in humans = too much ionizing radiation"

scotth
5th November 2007, 03:22 PM
Ah, thanks. Is it a gradient thing? Could I develop a sunbed at the low end of the UV spectrum that causes a tan but doesn't expose the user to harmful radiation? Or is it pretty much "melanin response in humans = too much ionizing radiation"

I suspect that tanning is caused by the ionizing radiation, but you need to find someone much more expert than me in physiology to confirm.

BenBurch
5th November 2007, 03:29 PM
Diathermy machines have been doing this in medical treatment for about 70 years now.

ponderingturtle
5th November 2007, 06:23 PM
Cancer can be caused by ionizing radiation (http://en.wikipedia.org/wiki/Ionizing_radiation). Microwaves (which cell phones use) and radiowaves (which army pain machines use) are NOT forms of ionizing radiation. Like ponderingturtle says, non-ionizing radiation has enough energy to heat things up, but not enough energy to chemically change cells.

Edited to add: interesting enough, is ultraviolet light considered ionizing or non-ionizing? The internet seems to have it both ways.

Looking into it, it seems that they can cause chemical effects but do not fully ionize anything. They are not literal knocking electrons off as such. At least that was the impression I got from a previous EM and cancer thread and looking into it.

Quixote
6th November 2007, 08:24 AM
Quixote, as soon as one understands enough physics to understand the photoelectric effect, cellphones causing brain cancer is a completely laughable suggestion.

Not really. I understand the photoelectric effect, but not its connection with cancer. Without that connection, cellphones causing cancer is not laughable. It appears to be wrong, but it's not laughable.

scotth
6th November 2007, 08:43 AM
Not really. I understand the photoelectric effect, but not its connection with cancer. Without that connection, cellphones causing cancer is not laughable. It appears to be wrong, but it's not laughable.

If you understand the photoelectric effect you understand that it is dependant on the energy of each photon (wavelength of EM) and not quantity of them (brightness of EM). No matter how intense the light, nothing happens unless the individual photons exceed a minimum energy level.

To potentially increase the risk of cancer, DNA must be damaged/broken. In exactly the same way as the in the photoelectric effect, there is a minimum energy per individual photon that must be met to have any chance of disrupting chemical bonds (necessary to damage/break DNA). Light/EM of a frequency/energy great enough to potentially disrupt any chemical bond is named ionizing radiation. The line in the sand for ionization is somewhere in the UV spectrum. Any photon of less energy than that minimum can not directly damage DNA, even in principal.

Cell phones radiate at a frequency many orders of magnitude below the minimum energy required to disrupt a chemical bond. It isn't even close. The only way to do damage with that band of radiation is to raise the intensity so high that the damage is caused by thermal effects. (to literally cook the target)

Understanding of the photoelectric effect provides the minimum understanding of the quantum/quantized nature of photon behavior to see why/how the spectrum is split into ionizing/non ionizing bands.

Quixote
6th November 2007, 08:47 AM
That does not seem like something that could give you cancer.

Could you make that a bit more tentative?

I'm just kidding. That's a perfect sceptics answer.

ponderingturtle
6th November 2007, 12:39 PM
If you understand the photoelectric effect you understand that it is dependant on the energy of each photon (wavelength of EM) and not quantity of them (brightness of EM). No matter how intense the light, nothing happens unless the individual photons exceed a minimum energy level.

To potentially increase the risk of cancer, DNA must be damaged/broken. In exactly the same way as the in the photoelectric effect, there is a minimum energy per individual photon that must be met to have any chance of disrupting chemical bonds (necessary to damage/break DNA). Light/EM of a frequency/energy great enough to potentially disrupt any chemical bond is named ionizing radiation. The line in the sand for ionization is somewhere in the UV spectrum. Any photon of less energy than that minimum can not directly damage DNA, even in principal.

Photographic film and Infrared sensitive film would seem to alter that equation. There are certainly chemical reactions that can be caused by non ionizing radiation.

scotth
6th November 2007, 01:12 PM
Photographic film and Infrared sensitive film would seem to alter that equation. There are certainly chemical reactions that can be caused by non ionizing radiation.

Ionizing radiation is defined relative to the substance being ionized. For DNA bonds, it is into the UV spectrum. Visible light (and near ultraviolet) is ionizing to a very few substances and photographic emulsions are unsurprisingly made of some of those.

Radio and microwave are not ionizing to any known substance.

BenBurch
6th November 2007, 02:07 PM
Again, RF diathermy machines have existed since the 1930s, and have been used in medical treatment ever since. If they caused cancer, it would have been apparent by now!

Now, whether this weapon, misused, could cause serious burns and death through hyperthermia, that is a good question.

DavidS
6th November 2007, 06:46 PM
Of itself, no. For example, I'm fairly confident that tossing a fifty pound bag of potatoes at somebody from 50 yards will induce pain, but that hardly supports a claim that potatoes cause cancer.
Seeing the subsequent posts and believing what I do of JREF, I feel a need to clarify:

Does the electromagnetic radiation emitted by a cellphone or the weapon described in the OP link cause cancer?

I really don't think so, and my reasons for thinking not are pretty much in line with the other responses above, but I don't really know with enough certainty to confidently debate the point in detail with a radiological expert who believes otherwise.

But that hardly matters; the question asked and answered was more along the lines of:

Does this [the report or the weapon's reported existence and effect] lend support to the belief in cell phone induced brain tumors?

No.

Even if it's actually true that the weapon and/or cell phones really do induce brain tumors, the report makes no such claim and no evidence has been established that causing pain is evidence of inducing tumors. Even if one wants to make the leap that these classes of EM radiation can induce tumors, that presumption isn't supported by the report.

Myriad
6th November 2007, 07:45 PM
Considering what happens to aluminum foil in a microwave oven, I have to ask...

What happens if this weapon is used against a target wearing a tinfoil hat?

Respectfully,
Myriad

Paulhoff
7th November 2007, 03:22 PM
Considering what happens to aluminum foil in a microwave oven, I have to ask...

What happens if this weapon is used against a target wearing a tinfoil hat?

Respectfully,
Myriad
If you understand microwave ovens and how they work, you can use aluminum in the microwave.

Paul

:) :) :)