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Old 04-10-2008, 08:20 PM   #1
almora99
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Faraday cage for laptops ? Radiation?


What about electro-magnetic waves which laptops radiate?
Are they dangerous?
Does manufactures take precautions against radiation?
Please tell your opinion.

How can I build a basic faraday cage for my laptop?
 
Old 04-10-2008, 08:27 PM   #2
Jeebizz
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Can you demonstrate that laptops put out electro-magnetic waves? Granted, if the laptop has wireless built in, then it would just output radio waves. There is probably more of a danger of a faulty battery causing a fire than any other health risks, especially radio waves. Why wouldn't manufacturers make sure that their products are as safe as possible. Thats why each country has some form of government oversight for communications and electronsics, e.g. here in the states, the FCC.

Why would you need a faraday cage for a laptop anyways. This thread is curiously strange.
 
Old 04-10-2008, 08:35 PM   #3
pixellany
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In our daily lives, we are surrounded by sources of radiation, including light, radio waves, emissions from power equipment and transmission lines, UV, Infrared (heat), and high energy particles (from radioactive sources and from space). If you were able to add up the total energy, I think that any one device would be a small contributor.

Is there an effect from the totality of all sources? probably.
Can you avoid exposure to all sources? probably not.

I would worry more about getting hit by a drunk driver....
 
Old 04-11-2008, 04:26 AM   #4
brianL
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Wear a tinfoil hat and underpants.
 
Old 04-11-2008, 04:12 PM   #5
hbar
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If you take your laptop apart (just take one of the little panels off), you will see that the inside of the panel is covered in a thin metal plate. The entire inside of the laptop case has this layer.

....It's already inside a Faraday cage! (really, that's what the layer is doing there)
 
Old 04-11-2008, 04:53 PM   #6
almora99
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Jeebizz, I'm not talking about waves that radiated by wlan adaptor or wireless keyboard. Output power of these devices limited by some rules as you said. I'm talking about waves exhausted from electronic devices.

Jeebizz: "Can you demonstrate that laptops put out electro-magnetic waves?"

Get a world radio. Set it to listen long or medium waves.
And put radio near to laptop. Radio getting crazy?
So laptops put out some waves.

Jeebizz: "Why would you need a faraday cage for a laptop anyways. This thread is curiously strange"

Faraday cages absorbs these waves.

pixellany, yes we are surrounded a lot of radiation sources. Power equipmants, transmission lines...
But we are away from them. And distance between my laptop and me is just 20cm.

Calculate sum of radiation your body absorbes in an hour of daily life from all radiation sources (without laptop).
And
calculate sum of radiation your body absorbes in an hour from only a laptop near you.

If these two values almost equal, yes pixellany, you are absolutely right.
But what if raditaiton laptop exhausts ((more) or (more and more) ?) greater than radiation in a daily life ???

To make a decision about this topic, we should make some measurements. And I'm exactly asking this.

In other words;
we can say "Yes folks, you are absolutely right. We should wonder only about battery or a drunk driver."
only in a world which measurements are not important.
And in this world,
we can put our head into microwave oven, no problem.
And there is no need to wonder if an atom bomb explodes near your city.
because we are surrounded a lot of radiation sources already.

I know a lot of radiation source are around.
I'm wondering if radiation that computers radiate is dangerous for computer users who spend a lot of time too close to computers.
I'm exactly asking this.

brianL, I consider your words as humor, unfortunately.

Regards...
 
Old 04-11-2008, 06:04 PM   #7
hbar
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Quote:
Originally Posted by almora99 View Post
Faraday cages absorbs these waves.
Physics police here...you seem to have some misunderstanding as to what a Faraday cage can and cannot do....some frequencies will be attenuated by the metallic layer on the inside of the laptop case (see my last post, this is just skin depth, nothing to do with a faraday cage -- any conductor will do) but most will exit anyway. A Faraday cage in general has no magic tricks for stopping EM waves.

What it can do is stop a static electric field, and even that it can only do in one direction. The inside of the laptop is shielded from external electric fields, but it doesn't work the other way around.
 
Old 04-12-2008, 06:52 AM   #8
brianL
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Quote:
Originally Posted by almora99 View Post
brianL, I consider your words as humor, unfortunately.
Unfortunately, that was how they were intended.
 
Old 04-12-2008, 12:47 PM   #9
almora99
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Quote:
Originally Posted by hbar View Post
If you take your laptop apart (just take one of the little panels off), you will see that the inside of the panel is covered in a thin metal plate. The entire inside of the laptop case has this layer.

....It's already inside a Faraday cage! (really, that's what the layer is doing there)
I checked my laptop but I can't see any metal plate. I can see RAM, HDD and other components directly from grid under the laptop. No any faraday cage-like metal. Which laptop are you talking about? IBM, Asus?

Quote:
Originally Posted by hbar View Post
Physics police here...you seem to have some misunderstanding as to what a Faraday cage can and cannot do...
Yes I'm not expert about faraday cages.

And what do you think about amount of radiation we absorb from computers? Is is greater than daily life absorbance?

Is there any other method to protect from computer radiation?
 
Old 04-12-2008, 02:21 PM   #10
Jeebizz
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Quote:
Originally Posted by almora99
And what do you think about amount of radiation we absorb from computers? Is is greater than daily life absorbance?
I would imagine that it is no more radiation than we absorb anywhere else. There is some kind of radiation that comes from underground (can't think of it at the top of my head, but is very negligible), plus the radiation from the sun. We are already exposed to a lot of radiation in our lifetime, but we are not affected by it mostly, because our bodies have developed a natural tolerance. It is not like you are purposefully exposing yourself to very high levels of radiation, such as Polonium, Uranium, or insert other radioactive element here.

As for your magnetic fields, we are living in one. How else do you suppose the very harmful rays of the sun, and even solar winds do NOT reach us? By the magnetic shield of the earth itself. Therefore, your last part of the question:

Quote:
Originally Posted by almora99
Is there any other method to protect from computer radiation?
If you are that worried about radiation, then get rid of all your equipment, don't use any lights, don't venture outside, and always keep yourself in a lead shielded suit or room. Also, the term radiation itself is a rather loose term. Radiation also just means plain-old, harmless heat. When you burn a candle, or a small fire it does output some form of radiation does it not? It is called heat. Not all that harmful, unless you get too close to burn yourself.

I don't know that much of physics either, but even I know some basics about physics and the laws of thermodynamics. Perhaps you might want to brush up on physics again, to try to better inform yourself, thus by dispelling these rather unjustifiable fears.

By the way, computer radiation, rather fancy word for 'heat', which is something that a computer would output the most of, as well as sound from the components. These are all by-products of what a computer gives out, as well as computations.
 
Old 04-12-2008, 04:44 PM   #11
dasy2k1
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http://tinfoilhat.shmoo.com/
a great linux distro to run on a laptop inside a Faraday cage
 
Old 04-12-2008, 05:03 PM   #12
almora99
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First, thank you for telling your opinions.

You generally say: Radiation is everywhere. If you don't want radiation, put yourself into a faraday cage.

No. I'm not talking about daily life radiation.
About daily life radiation, I'm agree with you at all.
I don't care if there is a laptop in my house.
I don't mind if there is a high voltage line on next street.
There is no need to worry about using cellular phone with headphone.

But I care, mind and wonder
if I sit 20cm close to a laptop 12 hours in a day,
if my house is under a high voltage line,
if I use cellular phone a lot at my brain.


As you said, our body has a system to tolerate daily absorption.
But;
we can't consider "a cellular phone on the table" and "a cellular phone attached to ear" as equal.
(What do physics polices think about that )

So, we should talk about measurement of radiation, not about where radiation is.
 
Old 04-12-2008, 05:22 PM   #13
almora99
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Quote:
Originally Posted by dasy2k1 View Post
http://tinfoilhat.shmoo.com/
a great linux distro to run on a laptop inside a Faraday cage
First, I consider that as a joke
But after read...
So interesting link.
Not about my topic but really interesting...
see these:
http://zapatopi.net/afdb/
http://zapatopi.net/mindguard/
 
Old 04-13-2008, 01:46 AM   #14
hbar
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Physics police wouldn't worry anyway...of course you can measure some EM radiation near your computer or your cell phone, but you should remember that not all forms of radiation are actually damaging.

The damaging kind is ionizing radiation (look up that term if you need to know what it means). Fundamentally it's the same as the EM radiation that's coming from your computer, but at a much higher photon energy (look up the electromagnetic spectrum while you're at it).

The absolute lowest photon energy that can ionize anything is around 13.6 eV, and so even the highest frequencies that you will find in your computer (I used ~3 GHz) are on the order of 1.09 million times too weak to have a biological effect.

So I wouldn't worry about it.
 
Old 04-13-2008, 07:02 AM   #15
crashmeister
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Quote:
Originally Posted by almora99 View Post
First, I consider that as a joke
But after read...
So interesting link.
Not about my topic but really interesting...
I consider this whole thread a joke and waste of storage space on the server.

Now if you want to look into this pls. - there is energy needed to create and store threads like this.

You are killing our environment and on top of that help create more of the waves you are so worried about in the process....
 
  


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