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 happen is machines who will send multiple wavelengths of X-ray through the material: since different materials absorb light differently, your machine can distinguish between materials, which lets you be more sure that that 2litre is (mostly) water, and then they can discriminate
These machines don't really detect what kind of materials stuff is composed of, much of that is just a crude classification based on density. True identification requires broadband x-rays emission with spectral analysis.
it has been such a godsend flying out of Frankfurt where they have the new scanners and you don't have to empty out your bag anymore. So much smoother. Then I fly back and get all annoyed at the other airports. I was told Oslo airport is holding out until it becomes regulation to use the new scanners. Security-Theater is still what it is. It is super weak imho, despite never having seriously attempted a heist or trying to get contraband on a plane. I miss the good old days where you handed your luggage to a guy just before boarding the plane.
Germany has a very sad and weak airport security story. The security personal are hired and paid by the state (Land), and thus the state plans their capacity and workflow. The airport owner (i.e. FRAport) has no say in their internal work organization, as it is basically contracted out policework. For whatever reason, most german Airports I regularly use, use the same machine and broken workflow: There is only a limited amount of containers to put your stuff in to go through the x-ray, and the machine itself has an integrated container-return system using conveyors. As a result, each machine has only a single small table with a container dispenser to serve passengers. On that tiny table, only 2-3 people at the same time can get undressed, get water out of their handlugagge etc. Waiting passengers behind them are blocked.
I contrast that with my experience in Spain: Several meters before the machines, there is a large amount of unoccupied, huge tables with containers stacked everywhere, so everybody can get undressed and pack their stuff into the container trays at their pace of choice. Staff assists and tells the rules to individuall travellers. Once you are done sorting your stuff into the containers, taking off your belt etc - only THEN you take the containers towards the x-ray conveyor line. So there is hardly any blocking the line. Instead of a container-return system, a single human stacks the containers past the scan and returns them to the beginning. This is so much more effective.
Classic example of government run workflows: No one cares to optimize the workflow, and the one who would benefit from a speedup (the airport and the airlines) in terms of increased sales, have no say in the process.
Interesting. I can only speak for FRAports Terminal A where the Lufthansa flights go and they use the new bag scanners where I just need to get rid of my coat and belt to be scanned by the infamous "Nacktscanner". The first time I went through I thought liquids were allowed from all airports in the EU until I found out it was bag scanner dependent. Smaller airports are usually OK because queues are short and then I have the time to walk TSA through each individual item personally. FRAport has started adopting the "snake-through-duty-free" before the gate (pioneered by Stansted as far as I can tell) which is criminal in my opinion (it's not as bad as Stansted yet). Commercial workflows are thus not always better when the optimize time customer has to spend "not buying" overpriced meals and consumer garbage.
Exactly. Plus belts, watches, removing phone/wallet/headphones from your pockets etc. And taking Laptop OUT of your luggage onto separate trays, your liquids into a clear plastic bag, etc. Very often, during that process, the staff members recognize people having liquid containers with more than 100ml capacity (shampoo, hair gel, etc.) and can tell the people that they can't take it aboard etc. I happen to fly frequently to what are busy tourist destinations, and especially older people seem to be completely unaware of any regulations what you can and can't carry along - even though those regulation have been in place for 20+ years. That is very time intensive.
I think if an MRI was ever used for airport security screening it would cause more damage and disruption than the terrorist bombs it purports to detect.
Both. 1.5/3 T is standard, >3 T machines (such as 5 T from United Imaging) are becoming more popular (and affordable) and at the same time ultra low field ones keep improving and now they make some things that were impossible before now actually doable such as bed-side MRI (not in clinical practice of course, but there was nice engineering proof of concept with ultra low field MRI machine that could be powered by normal power outlet).
The idea behind the recent boom in low-field stuff is that you'd like to have small/cheap machines that can be everywhere and produce good-enough images through smarts (algorithms, design) rather than brute force.
The attitude on the research side is essentially "por qué no los dos?" Crank up the field strength AND use better algorithms, in the hopes of expanding what you can study.
I know nothing about the "industry" of MRIs, but from the physics side, (everything equal) more Tesla is better - at the end of the day, harder magnetic field gets you a stronger signal
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
It's a specific liquid scanner that's done on bottles that have been pulled aside for extra scanning (at least, that's what Frankfurt was doing a couple weeks ago)
As far as I know, it's not. You're now specifically told to not take liquid out of your luggage.
At least that was the situation when I flew out of London Gatwick last time - they had people going up and down before the scanners admonishing people to leave everything in their bags to avoid delay.
We had 4 bags go through, 3 had liquids (2 water bottles and one Barenfang) in them. All three were pulled for secondary screening, at which point they put the specific liquid bottles in a secondary scanner and cleared them.
So, yes, they stay in the bag, but then they're pulled out and scanned separately, at least in Frankfurt.
I've noticed every airport is different, and major airports are usually more likely to have the big fancy looking scanners that help keep the crowd moving along, without taking everything out. Smaller airports seem to have less of that tech and are thus often more of a hassle.
And yet somehow, airport security staff frequently get impatient when people in line ask whether to remove their shoes, laptop, etc. As if the travelers are stupid for asking.
This is a fairly new change - the new scanners are being rolled out "everywhere", but not everyone has them again, and there were some snafu's last summer that caused them all to be decertified within the EU, and at least for a while only scanners from one company had been recertified.
It'll probably be chaos for the next couple of years while this sorts itself out.
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 happen is machines who will send multiple wavelengths of X-ray through the material: since different materials absorb light differently, your machine can distinguish between materials, which lets you be more sure that that 2litre is (mostly) water, and then they can discriminate