electromagntic pulse and similar threats

[nihil]

Awwww! c'mon guys...............

What about neutron bombs?

We all know they are there?

[killerbeesateme]

Neutron bombs cook your Thanksgiving turkeys pretty well. Although, you'd be too busy being dead to eat it. Neutron bombs are actually pretty sweet. I read an article by one of the original designers. It was built as an ethical bomb. There aren't any wounded, just dead. Although, it kind of lacks the pizazz of vaporizing a few city blocks and then incinerating a mile out, followed by collapsing structures with shockwaves for another couple miles, and then collapsing buildings with pressure differences more miles out from that.

The whole magnetic side of things with EMP, thats new to me. You learn something everyday. I guess you better have a Linux LiveCD in the CDROM drive of that faraday cage just in case.

As far as the laser beam project, check out the Laser FAQ, do a google search it'll be in the top 10, there's a bunch of cool stuff you can do with lasers. You can build a 14400 baud modem out of a laser pointer, some radioshack stuff and serial cables. I haven't tried it yet but it seemed like it would be pretty sweet. The Audio over a laser pointer project seemed pretty cool too. I was going to buy a lot of 10 laser pointers on ebay for about $10 and try some of that stuff.

[neel]

Originally posted here by dopamin
cds are optic media light is more likely to harm them than emp, and pvc is an insulator

Yeah doh, but on the subject of EMP, a cd is not made of pvc only. There's other materials in there too wich aren't insulators. Microchips have a ceramic (or whatever) casing, but they still get fried inside.

[catch]

Sheesh, a lot of you need to go back and take another (or perhaps a first) physics class.

anyway, unless you have some money burning a hole in your pocket that you have absolutely NOTHING else to spend on, i wouldnt spree for a faraday cage. they are more used for protecting vital governmental or corportate data from freak lightning strikes and the ocassional alien spacecraft or mad scientist. and if its nuclear blasts you shouldnt be worrying about losing the 60GB of downloaded music and pron on your computer

A faraday cage is a concept... not some prepackaged thing. Hell my old apartment was a pretty good faraday cage (cordless phones only worked on a line of sigh basis etc)... cost me nothing beyond rent. Out here in California with the earthquake requirements a lot of buildings act in this way thanks to all the rebar.

Your car is a type of faraday cage as well... if you are inside and lightning strikes it, you'll be fine. So is your microwave, what did you think that wire mesh in the door was?

Ah but killerbees, don't forget about the wonders of wireless keyboards and mice. Although the faraday cage would probably screw up most of those as well. Unless you had an infra-red set...

You've lost me here... you're sitting in your cage with the EMP device just outside? Wouldn't it be better to use a modem? God knows the kinds of cancers you'd be begging for otherwise.

Please give me a little while, but I will post some fonts that will not resolve under a TEMPEST attack...................honest, I kid you not

This is very questionable and even still, better to eavesdrop on the CPU rather than the monitor.

So, there is a chance that the artificially generated EMP could cook the data on the CD/DVD, depending on proximity.

Microwaves are not hot, they (if operating at 2.45GHz) merely excite water molecules. I don't know about you, but I tend to keep my optical media fairly dry.

Anyhow... have you ever purchased a cable that has a dB rating on it? That is the level of shielding and it directly corresponds to the protection from EM interference that cable will have. Cheap cables use a magnet tied to each end. This way you just raise the signal and the noise floor and ideally strip out all the noise and weaken the signal enough to be usable at each end. the same would apply for your cables around an EMP device... shield them (a magnet strong enough to strip the EMP would kill the signal under normal use) Shield your computer in a similar manner. Normal shielding would be just an all metal case and issues of material and design become more complicated as your requirements go up.

To further protect your device, you'd want a shielded UPS and against shield the connections and you'd want a fuse on the wall line. In addition to shielding your system and input devices, you should also shield your monitor... though by shield I mean "read up if this is for fun or buy a TEMPEST protected system if your requirements demand it".

If you follow these principals on your home AV system you will notice clearer sound and picture as well.

cheers,

catch

[rapier57]

Microwaves are not hot, they (if operating at 2.45GHz) merely excite water molecules. I don't know about you, but I tend to keep my optical media fairly dry.

But, what about the spilled soda and stuff from the cupholder? Mine keeps kicking in and out and spills my soda and it also gets all over my Meatloaf CDs.

[neel]

catch,

Microwaves are not hot, they (if operating at 2.45GHz) merely excite water molecules. I don't know about you, but I tend to keep my optical media fairly dry.

Water doesn't have anything to do with it. Microwaves are electromagnetic waves and they can cause discharges in all kinds of things. For proof just google for cd+microwave or something. Example: http://hamjudo.com/notes/cdrom.html
Didn't you ever put an iron cup in the microwave ?

edit:
because striek (3 posts down) kinda misunderstood me... water does have something to do with the workings of a microwave over. I'm sctricly talking about the effect on a cd though. The effect on a cd is not caused by water molecules.

[!mitationRust]

Radio waves in this frequency range have an interesting property: they are absorbed by water, fats and sugars. When they are absorbed they are converted directly into atomic motion -- heat. Microwaves in this frequency range have another interesting property: they are not absorbed by most plastics, glass or ceramics. Metal reflects microwaves, which is why metal pans do not work well in a microwave oven. In microwave cooking, the radio waves penetrate the food and excite water and fat molecules pretty much evenly throughout the food. You can put metals in the microwave. No sharp corners.

http://home.howstuffworks.com/microwave2.htm

Edit#####

He said cook the data out....hmmmmmmmm..............I don't know if the data would be destroyed. The thin layer would be in fragments, but I don't know if you could extract data from the fragments.

[rapier57]

neel, you DUDE! You found THE solution to all those AOL cds!

DISCLAIMER:
Kids, don't try this at home. Leave these kinds of things strictly to us perfessionals.

[Striek]

Water doesn't have anything to do with it.

When reheating food, it does. The microwaves physically excite the water molecules. Water molecules have a different charge on each side of them, since they are triangular in shape with the hydrogen atoms on one side an the oxygen atom on the other. The microwaves act on this polarized molecule by physically flipping them around based on the apexes and dips in the waves' power cycles. The EM field generated by the microwaves attracts one side of the molecule more than the other.

In terms of heating, microwave radiation can only act on such polarized molecules. This is why the food heats up so much more than the plate it's sitting on, but every once in a while you seem to have a plate that always heats up really well in the microwave.

But as for electrical discharge due to the release of static charges, I have no idea...

[catch]

The circumstances for that CD to pop are very specific... I can assure you that metal isn't exploding around Elmendorf AFB or other such installations (though you prolly could cook meak on the ground 100yds out).

cheers,

catch