How fun! Once, after climbing around in a dusty old church attic like this, I had to head straight to the airport for a flight. Barely made it on because something in the dust kept flagging as dangerous. They were using a test strip on my backpack and clothing and analyzing it in some kind of machine. Stressful as I was already pressed for time! Finally got a clean test and they let me through.
If this was in the US, it's all security theater. Basically if you get flagged, they swab everything in your bag to find what's getting flagged, and if it's legitimate they pass you through, or they keep swabbing you if its just your hands/arms because they also inspect your bag. It's kind of dumb, but also kind of makes sense.
For extra fun times, baby wipes / wet wipes get flagged as explosives in the US when they use the sniffer devices.
I will be the first to join you on "most of TSA is security theater"; the baby wipes are glycerine getting flagged by ion mobility spectrometry. The machines are fast because they just look for basic chemical building blocks, not doing full spectrometry to figure out the whole compound. So glycerin, nitrates, etc. set it off (and someone else's sticky glycerin e.g. sunscreen can gunk up the machine for multiple subsequent people).
The system is also likely designed to have false positives so they can validate that the security people are doing their job. This is more obvious on the x-ray machines but resembles the "can you spot the phishing email" emails that often get sent out in corporate environments to detect people who need additional security education.
Ion mobility spectrometry is the tech that powers these, and they're VERY sensitive and VERY prone to false positives because it's just looking for ion signatures ("I smell a nitrate/glycerin/etc."). I'm not sure if they're changing modes on the machines between swabs or something, but the machine is a cue for more in-depth inspection, not "zomg I found a bomb". So, some repeated scanning to rule out a false positive or burn off gunk that's accumulated in the machine i.e. we just got a speck of something on the wand or something is gunking up the scanner as opposed to "someone covered in residue that is scary".
Also, it's not illegal to travel when covered in nitrate dust. Maybe you really were working with explosives or fertilizers earlier in the day. So it really should be just a flag to check that you don't still have the explosives with you.
Do you know if they also scan for drug residue using those devices? A while back I was travelling through a German airport, and got pulled aside to get the skin on my stomach and the inside of my bag swabbed, and I assume tested in the same kind of machine. I don't know what I did to warrant a further inspection, but I wasn't going to make a fuss. I sometimes wonder what would have happened if they'd pulled aside one of the guys in my group who were definitely using drugs
Shortly after 9/11 I was flying out of Hawaii back to the mainland and I watched the screen when they swabbed my bag. It reported as positive for every single type of explosive (to the best of my knowledge, I was not carrying anything even remotely explosive). The tech looked at the results, said "that can't possibly be right" and waved me on.
In my experience, UK airports seem to not want you to leave the country — contra to the perception the government project regarding not wanting you to stay in the first place. :/
Had a number of experiences where their identity scanners (for some destinations they scan you at the start of security and just before the gate to ensure you get on the right aircraft) failed to be operational resulting in delays that ultimately may have forced me to miss my flight and stay in the UK. On the other hand, arriving from Ireland to the UK results in no checks because of the common travel area — you get waved through a special gate which is reserved for passengers from Ireland. LOL
These things are also notoriously prone to false negatives. I know a person who uses the same laptop briefcase to take their handgun to the local indoor shooting range, with magazines and ammo, and also uses that bag as a carry on for travel.
The bag goes right next to the shooting bench at the firing line. It presumably gets a decent amount of powder residue on it, and yet it's been swabbed several times and not set off anything. My buddy is scrupulously careful to remove anything non-airport-approved before taking it on a trip, so the fact that something "bad" was previously contained in the bag has been double/triple checked to be absent before they show up to the airport.
Heard similar stories from many people. I have my own--
I was at a range shooting this old revolver with worn seals. Every shot, unburnt (or sometimes burning) powder was flying backward onto my face and arms. I basically took a gunpowder shower.
Got up like 6 hours later and went to the airport to get on a plane. Got swabbed. Came back negative. Got on the plane.
So... yeah, not really sure what the swabs are doing. I have to assume it's more an issue of "they're not intending to detect that" than "failures to detect" because otherwise the repeated misses here are just a little too big to believe.
Most likely there is no quality control for the security process so no one has noticed that the swabs aren't working properly. Most such processes do not have any QA or QC as far as I can tell and the people actually doing the work have no interest in the effectiveness of the process or influence over it.
The swabs are looking for mercury as well as nitrates and things. A small bit of mercury can do a lot of damage to an airframe - nitrates too of course, but in larger quantities.
If you've been around mercury vapor, you'll set off alarms at the airport. Old church attics are often quite heavy metal.
Also, airports in places with free/open gun culture tend to have their weak spots, I'd imagine, when it comes to false positives ..
> The "Status" LED flashes some kind of code - long long, short short short. I assumed the number of flashes would correspond to the time but apparently not. We didn't have time to figure this out before we had to leave.
long-long-short-short-short is 7 in morse code. They don't say what time they tried this or if it ever changed, though, so that's just a hypothesis.
It's almost certainly this. I suspect the advance button can be used to advance the time via morse code LED flashes and only then committed when you get to the right hour.
Perhaps the long-press commits the hour, which is why it rang once initially.
To anyone other than a computer engineer, I would bet Morse code would be preferred at least 10 to 1. Most people who aren’t computer science majors could barely decode binary “10” correctly, whereas writing down the dots and dashes and googling “Morse code chart” is something I’d bet over 50% of non-engineers could do accurately.
How is this any different than decoding binary? If you can read a chart of codes involving either dot or dash surely you can also read a chart of codes with either 0 or 1.
I didn't know the Morse code digits before I saw the parent comment earlier today, but having looked them up, I have to admit that they are much easier to decode from a flashing light than binary and I'm pretty good doing binary in my head:
Also, if I see a light with short and long blinks and a pause in between, I'm going to immediately think Morse, not binary, and decoding it is almost intuitive.
FWIW, sometimes you hear of prisoners communicating by tapping out Morse code. I've never heard of anyone communicating by tapping out ASCII in binary.
It's not so much that it's different, it's just that Morse is the canonical dot-dash/beep-boop communication format in the UK, and binary is a niche distant second known only in the abstract as "it's all ones and zeros" to most non-tech people. So while an engineer would expect a beep-boop to be binary, a police station caretaker would expect it to be Morse, and I'd expect the people building that system to build it for the caretaker.
I had that thought too when I saw the parent comment appear, but then I looked up the Morse code digits and I have to admit that they are much easier to decode from a flashing light than binary and I'm pretty good doing binary in my head:
Also, if I see a light with short and long blinks and a pause in between, I'm going to immediately think Morse, not binary, and decoding it is almost intuitive.
The battery on that circuit looks very much like a backup battery we have connected to our house alarm.
We moved in to the house in 2003 and that battery died this year, so I would imagine that it is already or will very soon die. That said, if it's a backup battery and the electricity supply is stable then it may not make any difference.
Big Clive (a Youtuber from Scotland) often reverse-engineers circuits, resulting in him drawong the schematic in purple sign marker, often while commenting on the virtues (or lack thereof) of the design.
I was just starting to think "doesn't Big Clive visit Edinburgh periodically?" and then OP's suggestion scrolled into view. :)
Yeah I repair old cameras these days. The amount of cameras I've fixed by just poking at random stuff until it unjams is surprisingly high. Even more so the number I've "fixed" by just replacing the batteries.
What a lovely blog in general: some really fun retro-computing projects, written up in a very thoughtful, human way. Feels like a throwback to the earlier hacking spirit of the internet. Thank you, Colin: your "experiment with writing" is a success as far as I'm concerned!
Seeing the number of holes in that ceiling I really am concerned that the floor the clock is on is the same as the one with the holes, and I would advise that you secure the floor if you return to the attic.
The other thing of course is that those beams are *massive*. They weren't dicking about when they built it. It wasn't built down to a price like things are today.
It being a municipal hall at first, I wouldn't be surprised the town wanted to spend a little extra, but at the same time, I imagine they needed to calculate the weight of the clock tower and over-engineered it in case the weight put too much strain on one end. Seeing that it's all stone on the outside. Were you referring to the white beams on the blue ceiling, or other beams? I'm guessing it's to support the weight of the machinery.
There's a non-zero chance the "floor" is just plywood laid across some of the beams and the holes are from people missing the beam in areas there's no plywood
Was just reading one of his posts earlier while having lunch, only a few miles from that very clock tower, the one in the post here. Other side of the capital!
I've embraced postmodernism and my latest hobby is using LLMs to connect ESP32s to random stuff in my house, so I can unironically WiFi-enable everything from my toaster oven to my 1950s 4-chime doorbell.
Fred Dibnah was a treasure. If you enjoyed 5 minutes of Big Ben, here's an hour of his day job in heavy industrial steeplejacking - "The Ups and Downs of Chimneys" https://www.youtube.com/watch?v=KK2wF_-yoEg
Fred Dibnah's steeplejacking videos are awe-inspiring and a little bit horrifying. Fred seems like he was quite a character. I definitely recommend watching any videos he was involved with.
I just got to tour Big Ben in July when I visited London. The mechanism is an amazing piece of technology and the precision achieved at the time of development was crazy. Also being able to stand next to the bell as it rang was truly an awesome experience.
No, the Jawbone still isn't there. There was talk of building a fibreglass version (probably the best option.) Animal rights people complained about it apparently.
Edinburgh Council has a habit of taking things into storage and not putting them back.
One pleasant exception: the Ross Fountain. That's back in Princes Street Gardens and is a) now working and b) looking better than it did back in the eighties and nineties.
Where I live there is a local "optimist club" that does volunteer events every few weeks. Lions club does similar in some towns. Knight of Columbus also (I think they are Catholic church related though so might not be for you). Shriner club, and Masons also come to mind for some cities. Now that my kids are in school there are a ton of organizations that need adult help (marching band, sports...) and people are starting to learn what I can do - I wouldn't be surprised if someone calls me for help in something else.
Of course the above all depends on the exact situation in your area. Some of them are just a social club, and some are not. Some of them have religious affiliations that you may not like. Some of them are good in abstract but you hate the particular people in them.
I was heavily involved in the local maker space where I previously lived. The place seemed to attract these kinds of problems. Some people want to fix a VCR, others might want to fix a clock tower (who knows). Being involved there meant being around people who could really do anything, and the community seemed to know that.
Gorgeous building and a nice wee pub across from it! A couple of friends of mine used to stay not far from there.
I've half an idea I did some networky stuff for the Community Wardens probably around the time that chime box was fitted - if you see anything marked Alvarion or Ceragon, it's probably got my real name on it somewhere.
I'd love to poke about in there some time, maybe if I'm down in that part of the world I can jump in and volunteer to help too.
Next time you're in Baltimore, be sure to visit the Bromo Seltzer Arts Tower where you can see its gravity-driven pendulum clock. It's a beautiful mechanism with a very specific claim: "The clockworks is the largest four dial gravity driven non-chiming clock in the world with the magnificent 24ft dials."
109 comments
[ 5.4 ms ] story [ 76.8 ms ] threadFor extra fun times, baby wipes / wet wipes get flagged as explosives in the US when they use the sniffer devices.
Shortly after 9/11 I was flying out of Hawaii back to the mainland and I watched the screen when they swabbed my bag. It reported as positive for every single type of explosive (to the best of my knowledge, I was not carrying anything even remotely explosive). The tech looked at the results, said "that can't possibly be right" and waved me on.
Had a number of experiences where their identity scanners (for some destinations they scan you at the start of security and just before the gate to ensure you get on the right aircraft) failed to be operational resulting in delays that ultimately may have forced me to miss my flight and stay in the UK. On the other hand, arriving from Ireland to the UK results in no checks because of the common travel area — you get waved through a special gate which is reserved for passengers from Ireland. LOL
The bag goes right next to the shooting bench at the firing line. It presumably gets a decent amount of powder residue on it, and yet it's been swabbed several times and not set off anything. My buddy is scrupulously careful to remove anything non-airport-approved before taking it on a trip, so the fact that something "bad" was previously contained in the bag has been double/triple checked to be absent before they show up to the airport.
I was at a range shooting this old revolver with worn seals. Every shot, unburnt (or sometimes burning) powder was flying backward onto my face and arms. I basically took a gunpowder shower.
Got up like 6 hours later and went to the airport to get on a plane. Got swabbed. Came back negative. Got on the plane.
So... yeah, not really sure what the swabs are doing. I have to assume it's more an issue of "they're not intending to detect that" than "failures to detect" because otherwise the repeated misses here are just a little too big to believe.
If you've been around mercury vapor, you'll set off alarms at the airport. Old church attics are often quite heavy metal.
Also, airports in places with free/open gun culture tend to have their weak spots, I'd imagine, when it comes to false positives ..
long-long-short-short-short is 7 in morse code. They don't say what time they tried this or if it ever changed, though, so that's just a hypothesis.
Perhaps the long-press commits the hour, which is why it rang once initially.
I didn't build the chime box but it looks like the sort of thing I used to do back then.
Couldn't it be just binary
long-long-short-short-short
11000
Which is - to everyones surprise - 24 as in hours.
FWIW, sometimes you hear of prisoners communicating by tapping out Morse code. I've never heard of anyone communicating by tapping out ASCII in binary.
We moved in to the house in 2003 and that battery died this year, so I would imagine that it is already or will very soon die. That said, if it's a backup battery and the electricity supply is stable then it may not make any difference.
I was just starting to think "doesn't Big Clive visit Edinburgh periodically?" and then OP's suggestion scrolled into view. :)
Sounds like a great video idea for him, really.
sometimes you get paid because you know things, sometimes you get paid because you know how to figure things out.
it's literally kittycorner from City Hall, and hasn't been running for a while...
i'd do it for free if i knew who to even bother about getting up into it
https://www.reddit.com/user/dingdongbellguy/
We didn't put it at #1 though! That is a confirmation that we made a good pick.
badoosh
....I'll see myself out
With the popularity of this post the "SCP" reference made me think Hacker News had some kind of antimemetics department.
Then I saw it was the Second Chance Pool and was sort of disappointed.
Fred Dibnah was a treasure. If you enjoyed 5 minutes of Big Ben, here's an hour of his day job in heavy industrial steeplejacking - "The Ups and Downs of Chimneys" https://www.youtube.com/watch?v=KK2wF_-yoEg
https://www.youtube.com/watch?v=kl_UA36ouzM&list=PL2vJ5Cg-wl...
There were three identical street clocks in Edinburgh that the council there have tried to remove. They succeeded with the one at Tollcross.
Is the Jawbone coming back?
Edinburgh Council has a habit of taking things into storage and not putting them back.
One pleasant exception: the Ross Fountain. That's back in Princes Street Gardens and is a) now working and b) looking better than it did back in the eighties and nineties.
Of course the above all depends on the exact situation in your area. Some of them are just a social club, and some are not. Some of them have religious affiliations that you may not like. Some of them are good in abstract but you hate the particular people in them.
I've half an idea I did some networky stuff for the Community Wardens probably around the time that chime box was fitted - if you see anything marked Alvarion or Ceragon, it's probably got my real name on it somewhere.
I'd love to poke about in there some time, maybe if I'm down in that part of the world I can jump in and volunteer to help too.
> I had hoped we could do a "test" by letting the clock chime thirteen
What in the Orwell
https://ibb.co/album/RNZZrJ
https://www.bromoseltzertower.com/about/virtual-tour
(The elevator motors are also up there so there's a lot going on.)