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Dan Q posted a note for GC1TPTP Constellations 9

This checkin to GC1TPTP Constellations 9 reflects a geocaching.com log entry. See more of Dan's cache logs.

A shame that this one was still absent as I toured the area – attempting to “finish” the Constellations series I first attempted many years ago! Hopefully if it returns I’ll be able to come down again.

Enjoyed the Church Micro on the same path, though!

Dan Q found GC7XEYY Church Micro 12106…Standlake

This checkin to GC7XEYY Church Micro 12106...Standlake reflects a geocaching.com log entry. See more of Dan's cache logs.

Seven and a bit years ago my old geocaching buddy presquevu and I attempted half of the Constellations series (which was in a bit of a different configuration back then) and this morning I finally decided to cycle to Standlake to complete it. In the meantime, though, this cache has sprung up, so I decided to pick it up as well.

I spent about 10 minutes hunting for this cache before I saw it: turns out I’d been mostly looking up the wrong part (and, perhaps, looking “up” too much and “away” not enough). Luckily it was quiet today – I didn’t see another soul at this early hour – so I was free to hunt in peace without need for stealth skills. This allowed me to detach the front light from my bike and scan it around the search area to try to catch a glint of the container’s reflection under the dim cover of the surrounding foliage.

Next step: Constellations 8!

SL, TFTC.

Churchyard gate at the end of a tree-lined path.

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Dan Q found GC7NQA3 Constellations 1

This checkin to GC7NQA3 Constellations 1 reflects a geocaching.com log entry. See more of Dan's cache logs.

Continuing my morning quest to complete the Constellations series after a seven year pause, this was my second cache of the day. I’d cycled right past it on my way to Constellations 2, where I’d begun my trail, so now I turned around to come back and find it. I briefly stopped at a bench on the way back along.

Found the cache quickly with the help of the hint; however this cache is in very poor condition: the container is waterlogged and the logbook beginning to disintegrate.

Dan wearing a cycle helmet sitting on a wooden bench.

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Dan Q found GC1TPPC Constellations 2

This checkin to GC1TPPC Constellations 2 reflects a geocaching.com log entry. See more of Dan's cache logs.

A little over seven years ago, presquevu and I enjoyed a walk around here and found what are now Constellations 3, 4 and 5, among other caches which are no longer around. This morning, I decided, would finally be the time that I’d complete the circuit! Nowadays I live just on the other side of Stanton Harcourt, so I took the excuse of a Saturday morning’s exercise to cycle down to Standlake and proceed up the path to this first cache.

Apparently presquevu and I walked right past this one without making an attempt to find it back in April 2014: we were possibly distracted at the time and not paying full attention to the GPSr as we walked the path from Medley Brook to the footbridge over the Windrush. This time, though, I honed right in on the hiding place and managed to retrieve the cache with a minimum of nettle stings and thornpricks.

As others have noted the cache container is looking a little worse for wear and has a significant hole in it. However, the waterproof logsheet is holding up remarkably well and was still definitely signable. TFTC.

Quickly Solving Jigidi Puzzles

tl;dr? Just want instructions on how to solve Jigidi puzzles really fast with the help of your browser’s dev tools? Skip to that bit.

This approach doesn’t work any more. Want to see one that still does (but isn’t quite so automated)? Here you go!

I don’t enjoy jigsaw puzzles

I enjoy geocaching. I don’t enjoy jigsaw puzzles. So mystery caches that require you to solve an online jigsaw puzzle in order to get the coordinates really don’t do it for me. When I’m geocaching I want to be outdoors exploring, not sitting at my computer gradually dragging pixels around!

A completed 1000-piece "Where's Wally?" jigsaw.
Don’t let anybody use my completion of this 1000-piece jigsaw puzzle over New Year as evidence that I’m lying and actually like jigsaws.

Many of these mystery caches use Jigidi to host these jigsaw puzzles. An earlier version of Jigidi was auto-solvable with a userscript, but the service has continued to be developed and evolve and the current version works quite hard to make it hard for simple scripts to solve. For example, it uses a WebSocket connection to telegraph back to the server how pieces are moved around and connected to one another and the server only releases the secret “you’ve solved it” message after it detects that the pieces have been arranged in the appropriate relative configuration.

A nine-piece jigsaw puzzle with the pieces numbered 1 through 9; only the ninth piece is detached.
I made a simple Jigidi puzzle for demonstration purposes. Do you think you can manage a nine-piece jigsaw?

If there’s one thing I enjoy more than jigsaw puzzles – and as previously established there are about a billion things I enjoy more than jigsaw puzzles – it’s reverse-engineering a computer system to exploit its weaknesses. So I took a dive into Jigidi’s client-side source code. Here’s what it does:

  1. Get from the server the completed image and the dimensions (number of pieces).
  2. Cut the image up into the appropriate number of pieces.
  3. Shuffle the pieces.
  4. Establish a WebSocket connection to keep the server up-to-date with the relative position of the pieces.
  5. Start the game: the player can drag-and-drop pieces and if two adjacent pieces can be connected they lock together. Both pieces have to be mostly-visible (not buried under other pieces), presumably to prevent players from just making a stack and then holding a piece against each edge of it to “fish” for its adjacent partners.
Javascirpt code where the truthiness of this.j affects whether or not the pieces are shuffled.
I spent some time tracing call stacks to find this line… only to discover that it’s one of only four lines to actually contain the word “shuffle” and I could have just searched for it…

Looking at that process, there’s an obvious weak point – the shuffling (point 3) happens client-side, and before the WebSocket sync begins. We could override the shuffling function to lay the pieces out in a grid, but we’d still have to click each of them in turn to trigger the connection. Or we could skip the shuffling entirely and just leave the pieces in their default positions.

An unshuffled stack of pieces from the nine-piece jigsaw. Piece number nine is on top of the stack.
An unshuffled jigsaw appears as a stack, as if each piece from left to right and then top to bottom were placed one at a time into a pile.

And what are the default positions? It’s a stack with the bottom-right jigsaw piece on the top, the piece to the left of it below it, then the piece to the left of that and son on through the first row… then the rightmost piece from the second-to-bottom row, then the piece to the left of that, and so on.

That’s… a pretty convenient order if you want to solve a jigsaw. All you have to do is drag the top piece to the right to join it to the piece below that. Then move those two to the right to join to the piece below them. And so on through the bottom row before moving back – like a typewriter’s carriage return – to collect the second-to-bottom row and so on.

How can I do this?

If you’d like to cheat at Jigidi jigsaws, this approach works as of the time of writing. I used Firefox, but the same basic approach should work with virtually any modern desktop web browser.

  1. Go to a Jigidi jigsaw in your web browser.
  2. Pop up your browser’s developer tools (F12, usually) and switch to the Debugger tab. Open the file game/js/release.js and uncompress it by pressing the {} button, if necessary.
  3. Find the line where the code considers shuffling; right now for me it’s like 3671 and looks like this:
    return this.j ? (V.info('board-data-bytes already exists, no need to send SHUFFLE'), Promise.resolve(this.j)) : new Promise(function (d, e) {

    Javascirpt code where the truthiness of this.j affects whether or not the pieces are shuffled.
    I spent some time tracing call stacks to find this line… only to discover that it’s one of only four lines to actually contain the word “shuffle” and I could have just searched for it…

  4. Set a breakpoint on that line by clicking its line number.
  5. Restart the puzzle by clicking the restart button to the right of the timer. The puzzle will reload but then stop with a “Paused on breakpoint” message. At this point the application is considering whether or not to shuffle the pieces, which normally depends on whether you’ve started the puzzle for the first time or you’re continuing a saved puzzle from where you left off.
    Paused on breakpoint dialog with play button.
  6. In the developer tools, switch to the Console tab.
  7. Type: this.j = true (this ensures that the ternary operation we set the breakpoint on will resolve to the true condition, i.e. not shuffle the pieces).
    this.j = true
  8. Press the play button to continue running the code from the breakpoint. You can now close the developer tools if you like.
  9. Solve the puzzle as described/shown above, by moving the top piece on the stack slightly to the right, repeatedly, and then down and left at the end of each full row.
    Jigsaw being solved by moving down-and-right.

Update 2021-09-22: Abraxas observes that Jigidi have changed their code, possibly in response to this shortcut. Unfortunately for them, while they continue to perform shuffling on the client-side they’ll always be vulnerable to this kind of simple exploit. Their new code seems to be named not release.js but given a version number; right now it’s 14.3.1977. You can still expand it in the same way, and find the shuffling code: right now for me this starts on line 1129:

Put a breakpoint on line 1129. This code gets called twice, so the first time the breakpoint gets hit just hit continue and play on until the second time. The second time it gets hit, move the breakpoint to line 1130 and press continue. Then use the console to enter the code d = a.G and continue. Only one piece of jigsaw will be shuffled; the rest will be arranged in a neat stack like before (I’m sure you can work out where the one piece goes when you get to it).

Update 2023-03-09: I’ve not had time nor inclination to re-“break” Jigidi’s shuffler, but on the rare ocassions I’ve needed to solve a Jigidi, I’ve come up with a technique that replaces a jigsaw’s pieces with ones that each show the row and column number they belong to, as well as colour-coding the rows and columns and drawing horizontal and vertical bars to help visual alignment. It makes the process significantly less-painful. It’s still pretty buggy code though and I end up tweaking it each and every time I use it, but it certainly works and makes jigsaws that lack clear visual markers (e.g. large areas the same colour) a lot easier.

An almost-solved Jigidi jigsaw striped and painted to make solving easier.

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Dan Q found GC7PEG1 The Cachington Tour

This checkin to GC7PEG1 The Cachington Tour reflects a geocaching.com log entry. See more of Dan's cache logs.

I happened to be passing through with a little time to spare so I thought I’d take another run at this one. Unfortunately my first attempt had seen me make my notes on the back of my hand (and I’ve washed them since then!) so I’d have to collect the clues again. At least I already had the one from the church (thanks, CO!), so I parked at the Village Hall and went about (re) collecting the others.

To my surprise, the pub seems have repainted its windows since my last visit: clearly in a specific effort to fool and confuse geocachers! Luckily I knew broadly where I was looking so I wasn’t caught out.

Soon I was on my way to the cache. The hint was definitely needed as I hadn’t expected a container of this design in a location like this one! SL. TFTC, and special thanks to the attentive CO who provided an extra hint for people who, like me, got stuck outside the locked church.

Dan Q found GC97N47 SideTracked – Oxford Parkway

This checkin to GC97N47 SideTracked - Oxford Parkway reflects a geocaching.com log entry. See more of Dan's cache logs.

I needed to divert from my journey from Summertown to Eynsham anyway to stop at the nearby Sainsburys, so I took the opportunity for a quick stroll down to find this cache. Do you think the nearby gate is always left locked-open? That seems surprising! A relatively quick find although some stealth skills were needed. SL, TFTC.

Dan Q found GC98N6Q Tar Lakes/South Leigh Loop #14 Final Destination

This checkin to GC98N6Q Tar Lakes/South Leigh Loop #14 Final Destination reflects a geocaching.com log entry. See more of Dan's cache logs.

After all the amazing containers and hiding places I’ve seen on this excellent series, this final destination almost felt… mundane, by comparison. Not that that’s a problem, and I was still happy to reach the end, be treated to a great view of the last of the sun disappearing over the horizon, and find a good sized logbook complete with the notes and praises (for the series!) of cachers who’d come before me.

An altogether delightful series that I’ve been really glad to have explored. I’m looking forward to coming back and searching for #9 again sometime soon! TFTCaches!

Dan Q found GC98N69 Tar Lakes/South Leigh Loop #13 Black Hawk Down

This checkin to GC98N69 Tar Lakes/South Leigh Loop #13 Black Hawk Down reflects a geocaching.com log entry. See more of Dan's cache logs.

Lots of deer in the fields tonight! The sun was beginning to set as I approached this, my penultimate cache for the day, so my bike lights went on again and now stayed on. I felt sure I knew what I’d be looking for, but I was nevertheless delighted by the imaginative cache container.

Leaving this GZ, I made a few wrong turns before eventually working out which path I needed to follow to the finale: for some reason, the correct path doesn’t appear on my (OSM-derived). I’ve kept a tracklog, though, so I’ll try to get the map updated!

Dan Q found GC98N5T Tar Lakes/South Leigh Loop #12 Clockwork Orange

This checkin to GC98N5T Tar Lakes/South Leigh Loop #12 Clockwork Orange reflects a geocaching.com log entry. See more of Dan's cache logs.

As I worked my way to this, the third cache in my tour for today, I realised that my local sparrowhawk – who lives up a tree behind my house in Sutton – seemed to be following me. I’d seen him atop a couple of telegraph poles earlier on and I’d heard him screech a few times, and when I looked up I saw that he was still above me. Perhaps he’d decided to come on this expedition too?

One of the things that I love most about this series is the diversity of quirky and unusual cache containers, of which this was no exception. I was also pleased to find a fresh, clean log sheet, and added my name as the first on the list. TFTC, and FP for the surprise!

Dan Q found GC98N5E Tar Lakes/South Leigh Loop #11 One Tree Hill

This checkin to GC98N5E Tar Lakes/South Leigh Loop #11 One Tree Hill reflects a geocaching.com log entry. See more of Dan's cache logs.

Deer were prancing around the fields as I came through, and I realised that the hiding place for this cache must be near a place I’d thought about once as a possible hiding place myself, when I first moved to the area and took a walk this way (before I’d looked at the local caches!). While retrieving the cache a dog walker came the other way and, seeing a cyclist on a not-entirely-cycle-friendly path, probing around looking for something, asked about my activity. He’d never heard of geocaching, but he’d heard of hide-and-seek and he’d heard of orienteering, and seemed happy enough to accept that it was some combination of these two.

Dog walker in a recently turned-over field.

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Dan Q found GC98N4Z Tar Lakes/South Leigh Loop #10 Up

This checkin to GC98N4Z Tar Lakes/South Leigh Loop #10 Up reflects a geocaching.com log entry. See more of Dan's cache logs.

Came out for a cycle tour today to complete the loop: I covered the first half – with the exception of a DNF at #9 – last month, and I was itching to get out and complete the second half. (Having gotten home after this second expedition I see that #9 has been repaired/improved, so I’ll fly by and give that another go sometime soon!)

I was glad to have brought my bike lights: even though it’s a while until sunset it was helpful to find my way in the wooded area that surrounds this cache. Great hiding place for this one: the only cache I’ve come across of a remotely similar design was my own GC7R0HB (which sadly got muggled one too many times and had to be archived a few years ago).

Dan cycling towards South Leigh.

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London civil servant’s bus odyssey sparks Twitter storm

This is a repost promoting content originally published elsewhere. See more things Dan's reposted.

When Jo Kibble, a 39-year-old civil servant from Greenwich, set out to travel as far as he could from London in one day only using public bus routes it was supposed to be a personal project. But he ended up sparking a Twitter storm, causing a debate about how to build a fairer country along the way.

“I like travelling by public transport and by bus; I think it’s a great way to see the country,” Mr Kibble explains.

..

Mr Kibble figured the furthest he could get in one day would be Morecambe in Lancashire – some 260 miles from Charing Cross, the geographical centre of London.

I’m sure that many of you, like me, really enjoyed The Political Travelling Animal‘s Twitter adventure up the country, last week. If you missed it (and you should really go read it if you did): Jo decided to see how far he could get from London within 24 hours via local bus routes only, and live-tweeted the entire experience for the world to enjoy too. Perhaps unsurprisingly, I particularly enjoyed that fact that he gave a nod to Preston’s unusual and iconic bus station.

Reading it, though, I found myself reminded of a time, long ago, that I planned (although never took) a similar journey. In 1999 I moved away from my family in Preston to Aberystwyth to go to university.

Before he became a bus my father was a bus industry professional and at a rest stop during the journey to Aberystwyth as he dropped me off, he and I perused the (paper) timetables to explore a hypothesis that the pair of us had come up with.

Our question: Is it possible to travel from Aberystwyth to Preston, in a single day, using local bus routes only?

After much consideration, we determined that yes, it was possible, but better than that: it was possible to do so (at the time) entirely on Arriva buses. This presented an unexploited opportunity: for the price of an “all day” Arriva ticket (£2.20, IIRC), an enterprising and poor student could, in a pinch, find their way back from Aberystwyth to Preston over the course of about 16 hours for only a fraction more than the price of a pint of beer.

This was utterly academic: in the years that followed, I would almost invariably leave Aberystwyth by train. Sometimes I’d do this to go to London: a route for which, I discovered, I could catch the 6am train, hide aboard it as it was vacated at its Birmingham New Street terminus and take a nap, safe in the knowledge that the same rolling stock would subsequently become a train to London Euston! Other times I’d return to Preston; a journey for which not even floods could stop me.

But regardless, for my first full term at university I kept on the corner of the desk in my study room the sum of £2.20, as an “insurance policy”. No matter what happened in this new phase of my life, that small pile of coins could, at a stretch, get me back “home”.

By Christmas 1999 I’d re-purposed the coins to do my laundry (the washing machines in the halls’ laundrette took pound coins and the dryers 20p pieces, so this was a far more-valuable use of spare change in those denominations). By this point I’d settled in and had become confident that Aberystwyth was likely to be my home almost year-around, and indeed I’d go on to live there another decade before saying goodbye for Oxfordshire.

But we answered the question, at least in theory: a hypothetical but symbolic question about the versatility and utility of an interconnected network of local bus routes. And that’s just great.