Need some help with Electromagnetic radiation...

[Jonsy123]

The spectrum of electromagnetic radiation is devided into (in order of elevating frequency): Radio, Micro-wave, Infra-Red, Visible, Ultra-Violet, X rays, Gama rays.

 

Now, if you take a remote control, which operates by emitting Infra-red radiation, and block with your palm the radiation's direction to the TV, then the radiation would not be able to pass through your palm, and reach the TV.

 

Now, in the same way, visible light also can't penetrate much into anything (still doen't carry enough energy). But, if you jump to X rays, and then to gamma rays, the penetration factor jumps to a high level, because their photons carry a lot of energy.

 

Until now everything is fine. The higher the frequency, the higher the penetration.

 

My question is: how is it possible that radio waves, which can carry 10 orders of magnitude less energy than visible light (which can't penetrate almost anything) CAN penetrate through so many objects ?.

 

If you have a remote control that operate by radio waves, you can be at a totally different room than your TV, and yet the radiation will pass through everything in its way (walls, wood, body tissue, etc.) and reach the TV.

 

(It is the same with sound waves, where the penetration of low frequencies is extremely high, everybody knows that "bass" penetrates. But I'm not sure the analogy to low EMF is correct, because in order to create low sound frequencies, the speaker needs to move huge amounts of air, and hence the energy needed is even higher than the energy needed to produce higher sound frequnecies of the same amplitude, but in EMF, the lower the frequency you want to produce, the less energy you need to invest. Or am I wrong ?).

[danny8522003]

I Googled and found this.

 

I hope it helps...

[insane_alien]

the low frequency waves have such a big wavelegnth so that most objects are not big enough to absorb the photon.

[swansont]

danny's link is pretty good at explaining the basics: it's not the energy of the photons, per se, it's the energy compared to what can absorb those energies. It turns out that IR, visible and UV generally can be absorbed by many materials, so most things are opaque to them. There are exceptions, of course, like glasses being transparent in the visible, and if you looked carefully you'd find that the "higher enegy = more penetration" trend actually has a lot of exceptions.

[Jonsy123]

Do you think this could be part of the reason why low frequency electromagnetic radiation (like the one emitted by Cell phones, CRT monitors, high voltage electrical cords etc.) might be harmful to some of the biological processes in the body ?.

 

I mean, the fact it CAN penetrate our tissue (unlike visible and infra-red), and reach sensitive places inside our brain, might play a role here.

 

I know that Radio frequency is not energetic enough to break chemical bonds in DNA molecules (which are pretty sturdy), and now I've learned it can't be absorbed by most materials. But, in several recent articles published in several scientific journals, the results where that DNA mutations had occured in cells exposed to a certain amplitude (and up) of such radiation. It was then postulated in some of these journals, that this type of radiation, might have a negative effect on the activity of certain enzymes which are related to DNA multiplication and segragation in cell division, and by retarding these enzymes, DNA mutations might occur.

 

It could be that some of the molecules in our body (like some enzymes), ARE able to absorb low electromagnetic radiation to some sort, and this can affect their function.

 

Before the age of electricity, what things on earth generated electromagnetic frequencies of radio and below ?.

[insane_alien]

the microwave radiation isn't absorbed by a single atom it is absorbed by two(or more) bonded atoms wiggling at that frequency and makes the wiggle bigger. thats how a microwave heats water. only certain bonds will absorb microwaves so thats why they can penetrate to your brain without being absorbed.

 

note: i currently seem to be obsessed by the word "wiggle" if you want this post to sound more scientific replace "wiggle" with "vibrating" and "vibration" respecively, wiggle.

[Jonsy123]

So, why can't microwave radiation be absorbed by bonded atoms in some molucules inside cells, and damage their activity ?. What about frequencies lower than microwave ?.

[insane_alien]

it doesn't damage the activity. the microwaves rarely have enough energy to break the bonds wiggling at that frequency so all they do is heat the molecule.

[danny8522003]

Could your brain started overheating, causing adverse effects, because of excess microwave radiation, say from a phone mast?

[Jonsy123]

it doesn't damage the activity. the microwaves rarely have enough energy to break the bonds wiggling at that frequency so all they do is heat the molecule.

 

But insane_alien, in order for an anzyme to work efficiently, all the amino side chains at its active site should be at VERY precise distances from each other. Even small changes less than 0.5 angstrom, might have adverse effects on the enzyme's activity (and such a 0.5 angstrom change in distance between two side chains in the active site, might be caused by much smaller conformation changes in other places at the molecule enzyme - what is called an additive effect).

 

So, if the electromagnetic radiation, can bend (not break!) some of the bonds in the enzyme molecule, just a little bit, then the sum of all bends could translate into a malfunctioning enzyme.

 

Of course, once the radiation is removed, the enzyme might flip back to its original conformation. But, think how much time some of us sit near objects that emit low frequency electromagnetic radiation (including cell phones) - might be hours per day. During this time, you have millions of chemical reactions going on in your body, many of which depends on properly working enzymes.

 

Could your brain started overheating, causing adverse effects, because of excess microwave radiation, say from a phone mast?

Danny, at least for Cell Phones (which operate at 830Mhz - very close to microwave), the regulations permit amplitudes that will not cause any meaningful temp increases inside the tissue. The problem is, this is the only thing that the regulations checks for - temp increase inside the tissue. It does not check for any other effect, other than temp increases, that might interfere with biologocal proceses.

 

For example, take a look here (it is enough to read the abstract):

http://w4.eng.tau.ac.il/~jerby/62.pdf

 

Another one (here you only get the abstract):

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15869902&query_hl=1

 

It is important to understand that these articles do not imply that the damage to DNA is done directly by low electromagnetic frequencies, rather that there is probably an indirect mechanism at work, for example, through malfunctioning enzymes.

[swansont]

Before the age of electricity' date=' what things on earth generated electromagnetic frequencies of radio and below ?.[/quote']

 

Anything that had a temperature: blackbody radiation. That big yellow/orange fireball in the sky emits a boatload, too.

[Jonsy123]

swansont, do you know what is the amplitude of 830Mhz radiation that come from the sun and hit the land on earth ? (in microwatts per square centimeter).

[Jonsy123]

According to this, in relation to visible and UV, the radio and microwave amplitudes are pretty insignificant from the sun (as measured on earth):

 

Still doesn't say much about how much it translates in absolute terms.