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Comment by _0w8t | Hacker News Reader

As lithium batteries are opaque to X-Rays, perhaps a ban on laptops with batteries should be considered. This will surely push for standard swappable batteries and standard power supplies so the laptops could be used on board without batteries.

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What? No, that's a wholly unnecessary solution (though more standardization of batteries would certainly be nice). Swab the outside of the laptop for bomb residue, which would be especially difficult to clean from a laptop because the stronger solvents to clean with (like acetone) would mark the plastic. Or hire more dogs. Or make a "puffer machine" for laptops (blasts with air and then samples the air for explosive trace). Or come up with another solution -- this is HN! :)

Does swabbing work? I can imagine that the "batteries" (ie bomb) would be prepared, sealed and cleaned by one person, and then inserted into the laptop by another person so there's no contamination.

It's hard to remove all trace, but yes, in theory you could avoid it by being really careful. Then again, if you work in a "bomb factory," there's trace everywhere, so it may be quite difficult.

Also, the "turn on your device" thing they sometimes do offers some mitigation against this. Obviously, you can think of ways that may defeat this too, but to defeat all of the security, accurately, in one small package that doesn't look sketchy, is not easy. Fortunately, most terrorists are not the brightest people in the world.

Asking people to turn on the device seems stupid. Just do half battery half bomb and make it functional enough it will work for 10 min.

That would already cut the amount of explosives in half. Modern laptop batteries are not exactly huge to start with. So it is much less likely to do big damage to the airplane. Add to that, it is not trivial to make a battery half the size which still has enough voltage to power the laptop - you would need cells half the size for that. And all bombings of airplanes have been done with bombs in the cargo bay.

Typical laptop battery has pairs of cells in parallel, so removing half of them is trivial.

Is the puffer machine a thing? Or you just came up with it?

Nope, they're a thing:

https://en.wikipedia.org/wiki/Puffer_machine

> The machine operates by releasing multiple puffs of air at a passenger who is standing upright within the machine. This will flush out any particles on the person inside the machine then analyze and identify them in seconds.[6] According to an article in the 16 June, 2005, New York Times, it is capable of screening up to 180 passengers an hour.[7] This sample is then analyzed using IMS or MS technology to search for specific explosive or narcotic compounds. If a substance of concern is detected, the security personnel are notified by a visible and/or audible alarm.

They had puffer machines for people in 2006. They stopped using them because they required regular maintenance. Then they replaced them with the body scanners, which cost more than the puffer machine and a full time maintenance person in every airport in the country combined.

They are not opaque to X-Rays, much less the ludicrous penetrating power used in baggage inspection. Baggage X-rays can happily penetrate inches of metal, nothing short of lead brick will obscure contents and that's going to raise other questions. Where did you get that nonsense from?

X-ray machines have to be calibrated. While you could turn up the power to see through metal, you would then be unable to see the less dense items. This makes it difficult to do a full inspection in the few seconds that the screener has.

So .. there's no HDR setting on them?

There's beyond HDR, you can switch between multiple penetration levels and do automatic detection of materials even with ones made 2 decades ago. None of this is really new, insightful, or particularly revolutionary.

>Where did you get that nonsense from

From the article: "since lithium batteries are completely opaque to x-rays"

I probably should have been more clear that they are completely opaque to the x-ray systems commonly in use in airports for carry-on screenings at their standard intensity setting(s). But that's a mouthful.

Yes, we should ban lithium batteries because to make flying more inconvenient even though it is safer than it's ever been.

Everyone can go around with battery-less laptops so they can't use them in the few planes that get retrofit, and no other place without plugs.

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