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Comment by perihelions | Hacker News Reader

The case is technically about special fissionable material (regulation of nuclear weapons)—not radiological hazards—but all your points stand. Absurd lack of common sense all around.

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Well, the police also said he bought mercury, which "can be used in switches for a dirty bomb", which is such a stupid thing to say, because a mercury switch is just an old form of a tilt switch. The idea that someone would buy mercury for making his own tilt switch is just so wild, but of course, they just put this BS out there to scare people and justify their completely overblown reaction.

Mercury can also be used to make felt hats, and criminals often wear hats to disguise themselves, so it's better to be safe than sorry when it comes to Mercury.

The Mercury is also the name of a Tasmanian newspaper. Tasmanians are stereotyped as having two heads, so Tassie criminals wear 100% more disguise per disguise.

Suspect is hatless, repeat, hatless!

This is hat speech and should be prosecuted! Only tinfoil hats are allowed here.

Oh, as switch, I was thinking they were thinking that the mercury would be used in a DIY detonator. I always figured the 'dirty' bomb would need more raw materials rather than less - though the materials wouldn't need to be fissible.

That’s stupid as fuck as they still use mercury wetted relays to this day in some places.

I get the whole screeching about hazmat aspect to it but a mercury bulb with embedded copper contacts will cycle reliably basically forever at earthly temperatures. They are very good at what they are.

Are mercury thermometers no longer a thing? My parents had a few while I was growing up in the 80’s

I had a recollection that they were banned but it looks like the EPA convinced NIST to stop providing calibration services for mercury thermometers back in 2011.

There are two or three mercury switches in my house and they were all installed maybe ten years ago.

This case is almost as dumb as the Boston PD got in the couple of years after the Marathon incident. But at least they had ptsd as an excuse.

I've had several analog thermostats that use a mercury tilt switch. I assume it'd be easier to just buy an old thermostat than to make your own switch.

I mean they are still sold at your local hardware store. The bulb in the tilt switch below is the same as the mercury tilt switches that have been around for 100 years.

https://www.homedepot.com/p/Hiland-Anti-Tilt-Switch-Mechanic...

OMG that's a switch and switches are used in nuclear weapons! (lol!)

Of course this is even a step further removed. He had mercury and some tilt switches use mercury and switches are used in nuclear weapons therefore he was making a bomb!

Wait until the work out mixing household bleach and vinegar liberates free chlorine.

Chlorine can also be used as a chemical weapon.

The guy also had explosive and a triggering device in his car! It's a good thing for him police didn't seize his air-bag as evidence. (Being sarcastic.)

As a child I bought mercury tilt switches from a tandy store (in Australia) with the intent of making a tilt game controller input for my terrible 8 bit computer (this was decades before acceleromters in game controllers). It was too laggy and had to be debounced and it sat in a box for years. Also had a collection of mineral ores in a drawer near my bed which probably included some dodgy stuff. This case was bullshit and appears to be more about agency politics than public safety.

So if everyone in Australia ordered one of these, what would they need to do to make it into a bomb?

The Pu is from an old soviet smoke detector, containing roughly 40μg of Pu, which creates a few μCi of radiation needed for smoke detection. For fission, you need at least several kg of pure Pu239. For a "dirty bomb", any amount will do, of course.

The trick is to rob the smoke detector plant for their plutonium stash.

> For a "dirty bomb", any amount will do, of course.

By that logic, one smoke detector is enough?

I probably wouldn't want to eat a smoke detector, but if one was added to a bomb I probably wouldn't be very concerned about the impact of the smoke detector.

Using that definition of dirty bomb, a firecracker inside a banana is enough. Perhaps it should include a minimal threshold, like it's enougt to kill 1 person in the linear no threshold model.

I mean, hell, a pack of cigarettes contains polonium and lead -210. And Australians smoke quite a bit, last I checked.

Not at the current price levels of $50 a pack they don't. (Which is inevitably leading to hugely profitable smuggling and increasingly violent turf wars, but I digress.)

Jeez, and here I was thinking the 25 CAD a pack was bad.

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