# Nuclear EMP wave disable quartz & automatic watches?



## picard (Aug 28, 2006)

I have a silly question to ask everyone. Would a nuclear EMP wave disable quartz and automatic watches?


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## jtr1962 (Aug 28, 2006)

Probably. While the watch is in a metal case which technically should shield it from EMP the front of the case is open for the watch face. An analog watch might fare better than a digital if the face plate is metal. In general though EMP would affect long conductors like power lines (and the things attached to them) much more than something small like a watch. If the watch is stored in a metal box when the EMP wave hits then I'd say it would survive.

While these types of discussions are interesting after a nuclear attack the least of your problems would be not knowing what time it was.


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## carrot (Aug 28, 2006)

What I've read somewhere is that given the small "antenna" size of things such as cell phones and watches to actually receive EMP, it is quite possible that small personal digital devices would not be affected. Of course, that depends on the size of the airburst.

I did a little research into this in the past; here's a good starting point: http://en.wikipedia.org/wiki/Electromagnetic_pulse

and this often unseen page is of even better use to your question:
http://en.wikipedia.org/wiki/Talk:Electromagnetic_pulse


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## Jumpmaster (Aug 28, 2006)

I think a "true" automatic watch does not contain any electrical components...at least I don't think my Seiko SKX033 does. So it should not be affected at least not any moreso than a wind-up watch.

Have no idea about quartz watches, but I wouldn't rule it out.

JM-99


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## scott.cr (Aug 29, 2006)

I initiated this exact discussion years ago on a survival forum (it was a joke but everyone got all serious and started up with the rockthrowing).

Anyway, I did a fair bit of research on EMP eminations from atmospheric atomic/nuclear/thermonuclear detonations, and what I read indicated that the EMP itself isn't what causes damage to electrical equipment, it's the oscillating magnetic field setting up high voltages and currents in power lines. The effect could be likened to the power lines being a stationary linear armature with an alternating magnetic field being dragged over it at high speed. The voltage spike coming into your building through the mains is what causes things to blow.

So, battery-powered gear will probably be okay even in strong EMP environments. Plus, EMP is easily stopped by Faraday cage type structures (ie. anything in a metal enclosure). It is also a short-range type of radiation.


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## Isak Hawk (Aug 29, 2006)

According to wikipedia:

The resistance to EMP by device is listed below, from most to least vulnerable:


Integrated circuits (ICs), CPUs, silicon chips
Transistors
Vacuum Tubes (also known as thermionic valves)
Inductors, motors 
True automatic watches should be fine, as they are mechanical, not electrical. The automatic watches that use mechanical movement to charge a battery might die though.


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## Luna (Aug 29, 2006)

scott.cr said:


> Plus, EMP is easily stopped by Faraday cage type structures (ie. anything in a metal enclosure). It is also a short-range type of radiation.



Great, now you have done it. The freaks will start breaking out the aluminum foil!


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## Luna (Aug 29, 2006)

carrot said:


> and this often unseen page is of even better use to your question:
> http://en.wikipedia.org/wiki/Talk:Electromagnetic_pulse



I would discount alot of that discussion. Just the fact that they think that an EMP is detonated at 24kmiles is bad enough


A simple view is to look at EMP as being like static electricity. Capture the energy and bleed the potential to earth so that the components are not in line with the current and there is no issue. Let the current pass thru a component designed for low voltage/current and you will zap it.


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## Illum (Aug 29, 2006)

depends on how strong it is....Ive heard of articles discussing how nuclear testing in the pacific created a EMP that knocked out a few california coastal computers...

only electronic immune to this would probably be the ones that still rely on vaccum tubes....


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