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Heathrow scraps liquid container limit

bbc.com

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Re: Heathrow scraps liquid container limit

#181

Post by breppp »

jandrewrogers wrote: post #71

This just adds confusion as to the purpose of all this. The motivation behind the liquid limits is that there are extremely powerful explosives that are stable water-like liquids. Average people have never heard of them because they aren’t in popular lore. There has never been an industrial or military use, solids are simpler. Nonetheless, these explosives are easily accessible to a knowledgeable chemist like me. The…

most of airport security rests on the notion of going over a series of long tests will elicit unusual (fear, stress) responses from malicious actors and these can then be flagged for even thorougher checks which will then eventually lead to discovery, banning or removal of luggage

so it's not the test accuracy by itself but rather then the fact that these tests are happening at all

Re: Heathrow scraps liquid container limit

#182

Post by ssl-3 »

bruce511 wrote: post #140
unclad5968 wrote: post #112

Earlier quoted context omitted.

> In the US, the TSA is just a government jobs program for the lowly skilled or unskilled. It's all security theater. This matches my experience. I recently flew out of a small airport that flies 2 fairchild metro 23 turboprop planes up to 9 passengers. There were four TSA agents to check the 5 of us that were flying.

You gotta love the TSA. They serve no real purpose, but its a monster too big to kill, staffed by people who desperately cling to the notion they're doing something important. They don't stop hijackings (locking the cockpit door does that), they don't stop bombings (there are much better targets for that, which don't involve killing the bomber), they don't stop weapons (lots of airports outside the US have simple met…

The grunts working for TSA on the floor at airports aren't desperately clinging for the notion that they're doing something important, or working towards some lofty, noble, and/or altruistic goal.

It's just a job.

They're principally motivated to do this job by the promise of a steady paycheck and decent benefits -- the same motivation that most other people with steady paychecks and decent benefits also have.

Re: Heathrow scraps liquid container limit

#183

Post by thaumasiotes »

closewith wrote: post #167
bruce511 wrote: post #140

Earlier quoted context omitted.

You gotta love the TSA. They serve no real purpose, but its a monster too big to kill, staffed by people who desperately cling to the notion they're doing something important. They don't stop hijackings (locking the cockpit door does that), they don't stop bombings (there are much better targets for that, which don't involve killing the bomber), they don't stop weapons (lots of airports outside the US have simple met…

> they don't stop bombings (there are much better targets for that, which don't involve killing the bomber), I think you should read: https://en.wikipedia.org/wiki/Timeline_of_airliner_bombing_a... The only reason you believe aircraft bombings aren't being stopped is because you live in a world where rigourous security has stopped all aircraft bombings.

There's a pretty strong trend in that timeline of two types of "bombings":

(1) Bombings in which the bomb is supplied by someone who isn't flying on the plane;

(2) Failed hijackings in which there was no intent to bomb the plane, but a bomb accidentally went off.

Re: Heathrow scraps liquid container limit

#184

Post by BrenBarn »

kstenerud wrote: post #148
jandrewrogers wrote: post #71

This just adds confusion as to the purpose of all this. The motivation behind the liquid limits is that there are extremely powerful explosives that are stable water-like liquids. Average people have never heard of them because they aren’t in popular lore. There has never been an industrial or military use, solids are simpler. Nonetheless, these explosives are easily accessible to a knowledgeable chemist like me. The…

It's about making people feel safe. We're not rational beings, so what do you do about an irrational fear? You invent a magical thing that protects from that irrational fear. You're orders of magnitude more likely to die in a road accident, but people don't fear that. They fear terrorist attacks far more. You can't protect against an opponent who's motivated to learn the inherent vulnerabilities of our systems, many…

I seriously doubt that most people are happy with the tradeoffs of safety vs. convenience provided by the TSA. The general idea of x-ray, metal detectors, sure, that's all good. But the stuff with taking off your shoes, small containers of liquid, etc., no. I think if we reverted to a simpler system with fewer oddly specific requirements layered on top, most people would not feel significantly less safe, but would feel less inconvenienced.

Re: Heathrow scraps liquid container limit

#185

Post by jandrewrogers »

wyldfire wrote: post #128
jandrewrogers wrote: post #106

Earlier quoted context omitted.

I am not up-to-date on the bleeding edge but that explanation doesn’t seem correct? The use of x-rays in analytical chemistry is for elemental analysis, not molecular analysis. (There are uses for x-rays in crystallography that but that is unrelated to this application.) At an elemental level, the materials of a suitcase are more or less identical to an explosive. You won’t easily be able to tell them apart with an x…

Here's an article that talks about Dual-energy CT [1]. And another one talking about material discrimination using DECT [2]. [1] https://en.wikipedia.org/wiki/Spectral_imaging_(radiography) [2] https://pmc.ncbi.nlm.nih.gov/articles/PMC2719491/

Neither of those articles seem to support the idea that you can do molecular analysis with x-rays. They are all about elemental analysis, which is not useful for the purpose of detecting explosives.

Re: Heathrow scraps liquid container limit

#186

Post by School-Cotton »

chipsrafferty wrote: post #124
ascorbic wrote: post #104

Earlier quoted context omitted.

This might make sense if there weren't shops selling large bottles right after security. Ones full of highly flammable liquids, even.

Like what? Alcohol isn't flammable unless it's over 63%, and you aren't allowed to bring duty free alcohol on the plane.

Alcohol is flammable around 40%. French cooks aren’t using overproof brandy to do flambé.

Gunpowder doused in alcohol is, very famously for people interested in the history of rum, flammable if the alcohol is around 57.1% or higher, but straight alcohol/water without gunpowder is flammable at a lower strength than that.

Re: Heathrow scraps liquid container limit

#187

Post by reeredfdfdf »

closewith wrote: post #167
bruce511 wrote: post #140

Earlier quoted context omitted.

You gotta love the TSA. They serve no real purpose, but its a monster too big to kill, staffed by people who desperately cling to the notion they're doing something important. They don't stop hijackings (locking the cockpit door does that), they don't stop bombings (there are much better targets for that, which don't involve killing the bomber), they don't stop weapons (lots of airports outside the US have simple met…

> they don't stop bombings (there are much better targets for that, which don't involve killing the bomber), I think you should read: https://en.wikipedia.org/wiki/Timeline_of_airliner_bombing_a... The only reason you believe aircraft bombings aren't being stopped is because you live in a world where rigourous security has stopped all aircraft bombings.

Yeah. The "security theater" absolutely does play its part in stopping attacks. Without it, airplanes would be an extremely easy target for any nutjob to commit mass murder in. They wouldn't even necessarily need a bomb, anything that can cause a big enough fire mid-flight could be potentially catastrophic. Over past few decades many airliners have crashed because out of control fire in the cabin / cargo hold. I really don't want it to be easy for any random person to cause such fire.

Re: Heathrow scraps liquid container limit

#188

Post by vasco »

darth_avocado wrote: post #32
jbellis wrote: post #2

Not because of a sudden outbreak of sanity, but because they have CT scanners now.

3-1-1 is rarely enforced. I always got confused why the 100ml limit existed, since I could just take multiple bottles of 100ml of whatever I wanted and it was okay. Then I realized that technically I only could take 3 bottles but I’ve been getting away with more for decades.

Then you hide them somewhere inside and go back out and in again

Re: Heathrow scraps liquid container limit

#189

Post by BrenBarn »

closewith wrote: post #175
kstenerud wrote: post #148

Earlier quoted context omitted.

It's about making people feel safe. We're not rational beings, so what do you do about an irrational fear? You invent a magical thing that protects from that irrational fear. You're orders of magnitude more likely to die in a road accident, but people don't fear that. They fear terrorist attacks far more. You can't protect against an opponent who's motivated to learn the inherent vulnerabilities of our systems, many…

> You can't protect against an opponent who's motivated to learn the inherent vulnerabilities of our systems, many of which can't be protected against due to the laws of physics and practicality - short of forcing everyone to travel naked and strapped in like cattle, with no luggage. And even then, what about the extremist who works for the airline? This is said as an axiom, but we have protected against the motivate…

Have we protected against the motivated terrorist, or only the motivated terrorist on an airplane?
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