Heathrow scraps liquid container limit • Hacker News Board

Re: Heathrow scraps liquid container limit

#71

Post by jandrewrogers » Tue, Jan 27, 2026, 4:58 AM UTC

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.

These explosives can be detected via infrared spectroscopy but that isn’t going to be happening to liquids in your bag. This reminds me of the chemical swipes done on your bags to detect explosives. Those swipes can only detect a narrow set of explosive chemistries and everyone knows it. Some explosives notoriously popular with terror organizations can’t be detected. Everyone, including the bad guys, knows all of this.

It would be great if governments were more explicit about precisely what all of this theater is intended to prevent.

Re: Heathrow scraps liquid container limit

#72

Post by guerrilla » Tue, Jan 27, 2026, 5:06 AM UTC

nilamo wrote: post #69

guerrilla wrote: post #53

Earlier quoted context omitted.

> a few pennies (sorry, those don't exist now, how about for a few nickles?) Wait what? https://en.wikipedia.org/wiki/Penny_(United_States_coin)

From your link: > In late 2025, the Mint halted the production of pennies for circulation, largely due to cost.

Ah damn, that was buried. They ought to change the rest to past tense then.

Re: Heathrow scraps liquid container limit

#73

Post by danilafe » Tue, Jan 27, 2026, 5:08 AM UTC

This is funny because just a few months ago, I was forced at Heathrow to chug -- not allowed to pour out! -- my entire water bottle that I had filled prior to my flight. The security person watched me do it and added, "bathroom's over there".

Re: Heathrow scraps liquid container limit

#74

Post by wbl » Tue, Jan 27, 2026, 5:09 AM UTC

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…

Won't asking people to take a swig solve a bunch of those issues?

Re: Heathrow scraps liquid container limit

#75

Post by jrockway » Tue, Jan 27, 2026, 5:10 AM UTC

wbl wrote: post #74

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…

Won't asking people to take a swig solve a bunch of those issues?

People travel with liquids they don't intend to eat. Shampoo and all that.

There is also nothing that precludes explosives from being non-toxic. Presumably your demise is near if you are carrying explosives through security. What do you care about heavy metal poisoning at that point?

Re: Heathrow scraps liquid container limit

#76

Post by JellyPlan » Tue, Jan 27, 2026, 5:11 AM UTC

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…

I wonder if the improvements can detect trigger mechanisms better rather than testing the liquid itself.

Re: Heathrow scraps liquid container limit

#77

Post by scq » Tue, Jan 27, 2026, 5:13 AM UTC

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.

Re: Heathrow scraps liquid container limit

#78

Post by PcChip » Tue, Jan 27, 2026, 5:15 AM UTC

danilafe wrote: post #73

This is funny because just a few months ago, I was forced at Heathrow to chug -- not allowed to pour out! -- my entire water bottle that I had filled prior to my flight. The security person watched me do it and added, "bathroom's over there".

How did they force you to do that?

Re: Heathrow scraps liquid container limit

#79

Post by SanjayMehta » Tue, Jan 27, 2026, 5:15 AM UTC

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…

Security theatre.

And speaking of theatre in the air, most Indian airlines will make an announcement of turbulence just before food service starts.

This is to make the sheep - strike that - passengers go back to their seats and sit down.

Re: Heathrow scraps liquid container limit

#80

Post by jandrewrogers » Tue, Jan 27, 2026, 5:15 AM UTC

wbl wrote: post #74

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…

Won't asking people to take a swig solve a bunch of those issues?

This was done! It created terrible publicity incidents like the TSA forcing women to drink their own breast milk to prove it was safe. And not all liquids subject to this are things a person should swig even if they aren’t explosives. The extremely negative PR rightly stopped this practice.