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Comment by randyrand | Hacker News Reader

All electronics yes. But (nearly?) everything emits radiation. Candles, fire, your body. and those things are not FCC approved.

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That's equivocation at its best. Candles do not emit ionizing radiation in measurable quantities. X-Ray machines do. There's a huge distinction, similar to the distinction we make between shining an incandescent bulb up at a helicopter or passenger plane, and shining a laser pointer.

So we regulate X-Ray machines keep the radiation leak below the level that would oblige to ask people in the area for consent. GP has a point. The concern in this thread is based entirely on the notion that "radiation" is a scary-sounding thing.

No, the concern in this thread is based entirely on the notion that innocent people are potentially being exposed to X-rays, without their knowledge or consent.

You're arguing against a strawman. HN commenters aren't idiots. The technology in question is using ionizing X-rays, which can have harmful health effects.

I never assume HN commenters are idiots. That's the very reason I hang out here - I learn a lot from what people say in this place.

Having said that, this thread is dominated by commenters who refuse to do the math. X-rays sound scary but they aren't death rays; if you add up the numbers you'll see that it's not even worth to talk about them here. There's higher probability they'll harm someone by introducing more cars onto streets.

EDIT: oh, I forgot. The Chart: https://xkcd.com/radiation/.

What if there is a machine malfunction? Lack of proper maintenance? Operator error? Sure there should be fail-safes, but accidents happen.

Bouncing around in the back of a van, something goes wrong. Instead of a rapidly moving beam of x-rays that doesn't stay in one location long enough to cause problems, you get a focused beam.

Those are fair concerns. I haven't seen the estimate for maximum amount of radiation the X-ray machine could generate when malfunctioning. We need those to see whether or not there is something to worry about.

If it works anything like the backscatter machines the TSA was using (rapidly moving beam), a failure mode like what I mentioned is definitely enough to be dangerous. There was a physics professor from Arizona state who said that the TSA machines could even cause radiation burns if the fail-safes failed and the beam kept going while stuck in one position.

It many not work that way though. Who knows? That's the problem with being secretive about the whole thing. They don't publicly release data on potential malfunctions.

One of my biggest concerns is the amount of training the operators receive on recognizing and reporting potential malfunctions. I suspect it's not sufficient, but again who knows? They won't talk about it because terrorists.

I agree, those are causes for concern. It doesn't matter if they're using radiation - whether they'd be using chemicals, biological agents or voodoo, as the issues of proper training and secrecy around a device that fails dangerously is a serious matter. They should be opposed as everything from waste of tax money to being a public safety issue, just not because of the radiation per se.

I disagree. I think it is worth it to talk about them, for three main reasons:

1. Even if this machine only gives off radiation equivalent to, say, a dental X-ray, I still did not give my consent for it, whereas I did give my consent for the dental X-ray. Consent is important. There are a lot of things that are OK with someone's consent, but not OK otherwise, and we don't have the right to make these decisions for someone. 2. Medical X-rays have positive expected trade-offs for receiving the dose of radiation. Compare this to an X-ray police van than I happen to walk past; there's not really any argument that can be made for why my exposure to this X-ray radiation is worth it for me. 3. The machine can malfunction, or be used improperly, and give off substantially more X-ray radiation than expected or designed. Safeguards are in place for other uses of X-ray to protect against this, e.g. you wear a lead apron to protect the rest of your body during a dental X-ray, and the assistant taking the X-ray leaves the room entirely. Safeguards of these sort aren't possible with the presence of an unknowing public.

There's also of course the entire privacy aspect that we haven't even delved into yet, but the health issues alone are concerning.

"radiation" is a scary-sounding thing.

That's because scientists who know about this sort of thing have repeatedly warned the public that it can kill you dead in a very scary manner.

So, in any case, the FCC has set limits for acceptable amounts of radiation exposure from certain classes of the electronics that we find all around us every day, and I guess I was just wondering how those limits would compare to the radiation dosage of these vans.

It might not be approved by the FCC, but if it's equivalent to something that the FCC would allow you to carry around in your pocket anyway, it's hard to justify being upset these vans driving around from the perspective of being exposed unawares to their radiation.

There are a number of other reasons to be upset about such vans, though.

Go point a laser directly in your open eye. Don't worry. Any blindness you endure is FCC approved.

A banana dose is equivalent here to light bouncing from my skin directly in your open eye. Does my skin need to be FCC-approved?

I didn't expect HN of all places to fall into "radiation sounds scary therefore its bad for you" line of thinking.

So why don't you try the laser experiment. Use a 1 milliwatt laser. That's _less_ energy than the light bouncing from your skin. That's nothing. And it's non ionizing radiation. So it's totally safe. Point it right in your eye. See what happens. By the completely over simplified thinking that you are undertaking here you will be fine. Right?

I meant that light bouncing from skin to eye is a proper analogy for banana dose.

But since you challenge me - I shined the usual ~5mW red laser pointers many times straight into the eye, and had strangers shine them at me as well. It's annoying, but it doesn't hurt. My vision is ok. I'm totally fine.

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