Hacker News

New stories

Live mirror
30 storiesupdated just nowView source snapshot
  1. Beyond Images: Bringing Rust Brotli to Edge Network Stack(microsoftedge.github.io)
    discuss
  2. Navigation with only addition, subtraction, and tables(johndcook.com)
    discuss
  3. Show HN: I built a post-mortem debugger for native Windows x64/x86 crashes(forensicdbg.com)
    discuss
  4. GPT-6 Astra Breaks an Old Enigma Message(schneier.com)
    discuss
  5. Bloat Hurts Development Speed(orib.dev)
    discuss
  6. iFixit Steam Frame Teardown [video](youtube.com)
    discuss
  7. Redenormalisation: Building a search index, the other way(slatecave.net)
    discuss
  8. How to Write a Git Commit Message(cbea.ms)
    discuss
  9. Chicago Police Made Nearly 200k Secret Traffic Stops Last Year(boltsmag.org)
    discuss
  10. Yardbird files for Chapter 11 bankruptcy(nrn.com)
    discuss
  11. Sailboxes(sailresearch.com)
    discuss
  12. Show HN: Meeting Recording and Transcription for Agents(github.com/nfishel48)
    discuss
  13. Show HN: TypeBook.lol: Gamified reading by typing novels(typebook.lol)
    discuss
  14. Empirical results fine-tuning π0.5 on a real manufacturing task(dream-machines.eu)
    discuss
  15. CropIntel – crop disease detection from a leaf photo(cropintel.org)
    discuss
  16. 8 in 10 people aged 16-34 say smartphone use harms their everyday life(nltimes.nl)
    discuss
  17. Screen Lane(nickalexander.org)
    discuss
  18. Jensen Huang on AI Alarmists – NYT Ezra Klein Show(nytimes.com)
    1comments
  19. Data centers are black boxes, but California wants to change that(theverge.com)
    discuss
  20. A lightweight terminal UI for Colima on macOS(github.com/leodeim)
    discuss
  21. Show HN: SDF Studio – Create 2D SDF scenes, compile to GLSL(linkdd.github.io)
    discuss
  22. How to serve trillions of tokens for trillion-parameter coding agents(modal.com)
    discuss
  23. Google Beam expands to new countries(blog.google)
    discuss
  24. Brazil's Lula Campaign Dataset(huggingface.co)
    discuss
  25. Starbucks Korea CEO dismissed, what about startups?(2nd-look.vercel.app)
    discuss
  26. GitCaliber, swap github.com for gitcaliber.com to get a Git repo explained(gitcaliber.com)
    discuss
  27. Show HN: I made an app that transform your daily habits into a medieval(reddit.com)
    discuss
  28. City council can approve license plate cameras without you ever finding out(alprradar.com)
    discuss
  29. My relationship with AI: seductive, frustrating and always demanding vigilance(theguardian.com)
    discuss
  30. Dr Tricks Senior Dev N2 Taking Job W AI
    discuss

Fixing the Portobello Police Station Clock

266 pointsby 4h agopointinthecloud.com
63 comments
3h agoHN ↗

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.

3h agoHN ↗

Is the solution to a positive swab really to keep swabbing until negative?

3h agoHN ↗

Apparently! That or I just have a trustworthy face haha

3h agoHN ↗

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.

3h agoHN ↗

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).

7m agoHN ↗

Those guys must have a lot of fun with vapes. The liquid is 50-70% glycerine, and you get the stuff everywhere.

3h agoHN ↗

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".

11m agoHN ↗

TIL! I appreciate the explanation, never considered them to be that sophisticated.

1h agoHN ↗

Or to assume it's a false positive.

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.

11m agoHN ↗

In my experience if they test positive the tech will stop and wipe down the machine before trying again. They're highly prone to false positives.

16m agoHN ↗

This happened to me at SFO years ago after wearing a pair of jeans I had go-karted in earlier that day, but I ended up with almost a strip search.

3h agoHN ↗

They don’t seem to be in contact with the people who actually fixed it.

3h agoHN ↗

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.

3h agoHN ↗

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.

1h agoHN ↗

I used to use Morse to blink out status codes in similar things but I think by the mid-2000s I'd moved from PIC16F628s to atmega328.

I didn't build the chime box but it looks like the sort of thing I used to do back then.

8m agoHN ↗

As an engineer i would never think that complicated - morse code?

Couldn't it be just binary

long-long-short-short-short

11000

Which is - to everyones surprise - 24 as in hours.

3h agoHN ↗

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.

2h agoHN ↗

I agree with the 2023 decode there, but there is still a bit of a puzzle:

If someone knew to replace the battery just three years ago, I would expect they also would have enough knowledge to set the clock itself. Or at least explain what was going on. Maybe this person isn't connected with the building anymore. But I would expect the new owners would be able to contact the old owners for help on this instead of sending a generalized call for help.

31m agoHN ↗

I would GUESS that someone tried figuring it out in 2023 and replaced the battery as troubleshooting. If it were me, I'd probably do the same then stop when I hit a wall so I didn't damage it further. I don't wanna be the guy who damages a 100+ year old public clock

I could just hear the clockmaker James Martin calling me a butcher in his disapproving manner

45m agoHN ↗

Could also be YYMMDD In most of Europe it would be DDMMYY - but seeing how the English still measure stuff in feet and inches I wouldn’t be surprised if they have some illogical way of structuring the dates as well

21m agoHN ↗

YMD is Sweden or Hungary. MDY is US and pre-1960s UK. YDM is Latvia. DYM and MYD are up for grabs.

3h agoHN ↗

Send it to Big Clive with a felt pen enclosed.

3h agoHN ↗

Genuinely underrated way to understand circuits. When I was younger and dumber I thought his practice was a bit silly, but man, it really is king.

10m agoHN ↗

For someone who is unfamiliar with that person/channel, what is that way to understand circuits?

3h agoHN ↗

Such a pleasant surprise to wake up and see my hometown at the top of hackernews!

3h agoHN ↗

This sounds like such a fun project, especially to share with like minded friends.

3h agoHN ↗

I dunno if setting the time counts as fixing...

3h agoHN ↗

sure it does. the mechanism was no longer functioning properly. and its a repair even moreso considering the unknown nature of the system.

sometimes you get paid because you know things, sometimes you get paid because you know how to figure things out.

2h agoHN ↗

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.

2h agoHN ↗

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!

2h agoHN ↗

i wish i could fix The Sun clock on Broadway and Chambers

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

2h agoHN ↗

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.

1h agoHN ↗

The ceiling is fixed to the underside of the joists, the attic floor is fixed to the top side.

1h agoHN ↗

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

1h agoHN ↗

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!

2h agoHN ↗

This is what I want the internet to be. Great read.

2h agoHN ↗

I'm confused… You don't want to read about the newest LLM models on the HN front page all day long, every day of the week? SAD!!

1h agoHN ↗

You could almost say like it was TIME something like this hit number 1 !

badoosh

....I'll see myself out

2h agoHN ↗

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.

2h agoHN ↗

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.

2h agoHN ↗

One of many old clocks in Edinburgh that needs fixing. The one on the Balmoral Hotel had to get a lot of work done.

There were three identical street clocks in Edinburgh that the council there have tried to remove. They succeeded with the one at Tollcross.

2h agoHN ↗

"a circuit board which definitely was not from 1877" ;)

2h agoHN ↗

Obviously, the next logical step is a Home Assistant integration.

2h agoHN ↗

I love this. Any advice how to get involved in my local community in a similar way? I'd be so into doing some community project during my free time.

1h agoHN ↗

Depends on your local community, worth considering what spaces there are and just reaching out or showing up.

53m agoHN ↗

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.

1h agoHN ↗

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.

1h agoHN ↗

Does it work on a gear and pinion principle or an AC synchronous motor?

59m agoHN ↗

Written on 11th April

I had hoped we could do a "test" by letting the clock chime thirteen

What in the Orwell

28m agoHN ↗

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 to fame: "The clockworks is the largest four dial gravity driven non-chiming clock in the world with the magnificent 24ft dials."

https://imgur.com/a/PjAv85o

https://www.bromoseltzertower.com/about/virtual-tour

(The elevator motors are also up there so there's a lot going on.)

21m agoHN ↗

Wild seeing local stuff on HN. My dad used to work in that police station, probably the first (and only) HN story I’ll send him.