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Ask HN: Using a microwave oven as a Faraday cage in a big solar storm

2 points by sjcsjc ↗ HN
I have a feeling this is a stupid question, but I'll ask it anyway.

I've just been scaring myself with videos about the Carrington Event. Does anyone on here know if putting external hard drives in a microwave oven during a Carrington-level solar storm would protect them?

8 comments

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giantg2
It would probably be protective. It depends on the power and frequency. I don't know what frequencies we get from solar storms, but I think 1GHz might be close.

You could just get a metal ammo can and insulate the inside with something (even cardboard works). If you want extra protection you could replace the rubber gasket with an emf gasket (or aluminum foil as a gasket, or wrap the can in it, or tape the lid with duct tape, etc). I believe magnetic insulators are the newer tech to provide emp protection, but I know little about that.

robthebrew
Possibly, but you might not have a functioning computer to read them: https://www.quora.com/Could-an-EMP-or-solar-flare-wipe-out-a...
sjcsjc
Indeed, but that would be fixable within a decade or so. Lost data would be lost permanently.
giantg2
Or you put a Pi with screen, solar charger, etc in there too. Networks might not work, but you should be able read the data. It could all fit in something like an ammo can if one wanted to store it permanently.
scantis
That is not a stupid question, it is actually quite difficult to answer.

Short answer, such a faraday enclosure won't do as much against this type of radiation, but your hardrrives should be fine either way.

A microwave oven is optimally shielded for around 2.4 GHz. That is a very very high frequency compared to the solar flare. At lower frequencies, the shielding isn't as optimal and will only yield a minor reduction.

The solar flare puts some dents into the earth magnetic field, that swing back and forth at a much much lower frequency. This causes currents in the mesh of wires we put on top of the earth to power everything. This current then overloads most systems and destroys electronics on the substations level. Transformers blow out, everything with long wires stretched over a few hundred Kilometers can accumulate a ridiculous unwanted current. Protecting against this is difficult and expensive, so a lot of stuff goes byebye.

Your hard drive lying unconnected in the sun, will feel like it's raining lots of very tiny magnets. It will respond with a tiny surface current, but that would be it. This should not erase the data.

giantg2
I agree that the induced currents in infrastructure are the biggest risk since they have the least protection (both man-made and geomagnetic).

"Your hard drive lying unconnected in the sun, will feel like it's raining lots of very tiny magnets. It will respond with a tiny surface current, but that would be it. This should not erase the data."

I don't necessarily agree with this. There is a variety of radiation emitted during solar events. Most of the higher energy radiation that would cause corruption (above uvb) is protected against by the atmosphere and magnetic fields. However, even under normal conditions we see that solar radiation can cause corruption of data, particularly in aircraft. Large solar events that increase that radiation can see a higher number of that radiation reaching the surface of the earth (even if the overall amount is still low). So it's still unlikely to corrupt the data by flipping bits, but it is still a minor risk.

scantis
Right, assuming the flare is strong and long enough it is possible for UV and above to reach the surface.

Still you can take an x-ray of your HDD or SSD without data loss. There might be sweet spots of certain energies, that might cause data corruption.

The big guys, a barrage of protons and neutrons has much more potential to mess with the drives. Should whipe them out clean. But there are still a lot of molecules in the air, which will fend them off.

Against this throwing the hard drives into the swimming pool, would yield better protection.