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Heathrow scraps liquid container limit

bbc.com

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Re: Heathrow scraps liquid container limit

#101

Post by bleepblap »

bleepblap wrote: post #83

there is actually a science change that happened, and it's not (entirely) just politicians changing their mind. The big thing going from X-ray (2d) to CT (spin an X-ray machine around and take a ton of pictures to recreate a 3d image) did a lot to let security people see inside of a bag, but the hitch is that if you see a blob of gray is that water, shampoo or something else? The recent advance that is letting this h…

There's a whole ton of people taking about MRI -- MRIs are a completely universe than CT/X-rays

Re: Heathrow scraps liquid container limit

#102

Post by chrisfosterelli »

deaux wrote: post #47

> For airport operations teams, the real benefit isn’t just traveler satisfaction. It’s throughput stability: > - fewer stoppages caused by liquids mistakes > - fewer tray-handling steps per passenger > - less variability at peak banks (which is where hubs like LHR get punished) Didn't know ChatGPT has started to call itself "John Cushma".

I noticed my eyes started automatically skimming right after that paragraph. It's funny my brain has learned to calibrate its reading effort in response to how much perceived effort went into writing it.

Re: Heathrow scraps liquid container limit

#103

Post by user3939382 »

Forgive my zooming out but the overton window on this topic is in the wrong place. Airport security is dehumanizing inconvenient and unacceptable. I’d only use planes in an emergency. The living memory of what air travel is supposed to be is just gone with the sands of time. I don’t accept the shit economy version starting #1 with the cattle screening.

Re: Heathrow scraps liquid container limit

#104

Post by ascorbic »

necovek wrote: post #64
nlawalker wrote: post #15

Let me get this straight. If the article is correct, the new capabilities are related to better detection of large liquid containers, not determination of whether or not the liquid is dangerous. So - you couldn’t take large amounts of liquids previously because some liquids in large amounts might be able to be weaponized. If you were caught with too much liquid (in sum total, or in containers that are too large) they…

It's not just large amounts of liquids: it was my understanding that this is both a restriction on large amounts of liquid, but particularly on large containers needed for an explosive of sufficient destructive power. You could always easily work around the liquid amount restriction (multiple containers over multiple people), but if you still need a large container, it becomes harder. I don't know if this is true or…

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

Re: Heathrow scraps liquid container limit

#105

Post by HNisCIS »

bleepblap wrote: post #83

there is actually a science change that happened, and it's not (entirely) just politicians changing their mind. The big thing going from X-ray (2d) to CT (spin an X-ray machine around and take a ton of pictures to recreate a 3d image) did a lot to let security people see inside of a bag, but the hitch is that if you see a blob of gray is that water, shampoo or something else? The recent advance that is letting this h…

Dual energy x ray has been around forever though, like decades.

Re: Heathrow scraps liquid container limit

#106

Post by jandrewrogers »

scq wrote: post #77
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…

From my understanding, the new CT machines are able to characterise material composition using dual-energy X-ray, and this is how they were able to relax the rules.

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-ray. This is analogous to why x-ray assays of mining ores can’t tell you what the mineral is, only the elements that are in the minerals.

FWIW, I once went through an airport in my travels that took an infrared spectra of everyone’s water! They never said that, I recognized the equipment. I forget where, I was just impressed that the process was scientifically rigorous. That would immediately identify anything weird that was passed off as water.

Re: Heathrow scraps liquid container limit

#107

Post by dexwiz »

nlawalker wrote: post #15

Let me get this straight. If the article is correct, the new capabilities are related to better detection of large liquid containers, not determination of whether or not the liquid is dangerous. So - you couldn’t take large amounts of liquids previously because some liquids in large amounts might be able to be weaponized. If you were caught with too much liquid (in sum total, or in containers that are too large) they…

Have you never been screened where they swab your items and stick it in a machine? That is to detect explosives. They can use the first machine to target people for follow up screening.

Re: Heathrow scraps liquid container limit

#108

Post by bleepblap »

HNisCIS wrote: post #105
bleepblap wrote: post #83

there is actually a science change that happened, and it's not (entirely) just politicians changing their mind. The big thing going from X-ray (2d) to CT (spin an X-ray machine around and take a ton of pictures to recreate a 3d image) did a lot to let security people see inside of a bag, but the hitch is that if you see a blob of gray is that water, shampoo or something else? The recent advance that is letting this h…

Dual energy x ray has been around forever though, like decades.

Certainly, but a) not at the prices people wanted to spend to get 25,000 of them b) not at the maintenance cost for 25,000 of them c) without the software to (by someone's metric) discriminate between shampoo and bomb with enough error

Re: Heathrow scraps liquid container limit

#109

Post by bulbar »

andai wrote: post #6
jbellis wrote: post #2

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

Yeah, I flew thru Eindhoven Airport in the Netherlands a few years ago, and I couldn't believe they let me through with water. The security used something I would describe as out of an Iron Man film, they were zooming around a translucent 3D view of my backpack. (It was on an LCD display instead of hovering midair, but I was still impressed. But the fact they let me keep the water was even more amazing, hahah.)

Tel Aviv has allowing this for quite some time (10 years?). I guess they update their security devices as soon as new technology becomes available.

They don't advertise it, I found out by accident, trying to empty my water bottle by drinking when a security person told me to just put it together with the rest of my stuff. I had no idea that was a thing and was pretty confused.

Re: Heathrow scraps liquid container limit

#110

Post by runarberg »

vjvjvjvjghv wrote: post #60
Fervicus wrote: post #35

How many man hours and how much money have we wasted over security theater at airports? Has it been a worthwhile trade off?

No hijacked planes, no terror attacks?

I don‘t think that is true at all. There have been numerous hijacked planes since 9/11 including two in the USA just this decade.

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

Plane hijacking has been on its way out anyway after the turmoil of the 1970s. And that has probably more to do with a) the relative political stability of the post cold war period, and b) a general sense that airplane hijacking isn’t actually that likely to advance your political goals. If you read the list above, you see people hijacking planes all kinds of dumb methods, hardly any of them involves carrying an actual bomb onto the plane.

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