Digest for August 2018


This month, I shared photos of a mystery box I discovered in a meeting room at work which turned out to be an adapter to a proprietary kind of 13A plug socket and developed a software tool which pixel-scrapes open mapping data to estimate what percentage of a given graticule (degree of latitude by degree of longitude) is covered with water, which could be expected to affect the challenge level for geohashers based in that graticule. This coincided with two consecutive-day geohashing expeditions of my own: one to East Adderbury (with accompanying vlog) where I met some cows and was served an unexpected number of eggs at a pub, and one to the South Downs National Park (with accompanying vlog, and via three geocaches: 1, 2, 3).

I also attended Oxford’s first ever IndieWebCamp and achieved a life goal when my local radio station asked me on-air to stop texting them puns.

All posts

Posts marked by an asterisk (*) are referenced by the summary above.





Reposts marked with a dagger (†) include my comments or interpretation.


Note #10132

One off the #bucketlist this morning when local radio station @JACKfmOxford said, on-air, “Dan, please stop texting us puns.”

Swiss startup Energy Vault is stacking concrete blocks to store energy — Quartz

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


Thanks to the modern electric grid, you have access to electricity whenever you want. But the grid only works when electricity is generated in the same amounts as it is consumed. That said, it’s impossible to get the balance right all the time. So operators make grids more flexible by adding ways to store excess electricity for when production drops or consumption rises.

About 96% of the world’s energy-storage capacity comes in the form of one technology: pumped hydro. Whenever generation exceeds demand, the excess electricity is used to pump water up a dam. When demand exceeds generation, that water is allowed to fall—thanks to gravity—and the potential energy turns turbines to produce electricity.

But pumped-hydro storage requires particular geographies, with access to water and to reservoirs at different altitudes. It’s the reason that about three-quarters of all pumped hydro storage has been built in only 10 countries. The trouble is the world needs to add a lot more energy storage, if we are to continue to add the intermittent solar and wind power necessary to cut our dependence on fossil fuels.

A startup called Energy Vault thinks it has a viable alternative to pumped-hydro: Instead of using water and dams, the startup uses concrete blocks and cranes. It has been operating in stealth mode until today (Aug. 18), when its existence will be announced at Kent Presents, an ideas festival in Connecticut.

Oxford IndieWebCamp is go!

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

Save the dates folks!

On Saturday 22nd September and Sunday 23rd September we will be having the first ever Oxford IndieWebCamp!

It is a free event, but I would ask that you register on Eventbrite, so I can get an idea of numbers.

IndieWebCamp is a weekend gathering of web creators building & sharing their own websites to advance the independent web and empower ourselves and others to take control of our online identities and data.

It is open to all skill levels, from people who want to get started with a web site, through to experienced developers wanting to tackle a specific personal project.

I gave a little presentation about the Indieweb at JS Oxford earlier this year if you want to know more.

Huge thanks to our sponsors for the event, Haybrook IT and White October.

I couldn’t be more excited about this! I really hope that I’m able to attend!

Before You Turn On Two-Factor Authentication

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

Many online accounts allow you to supplement your password with a second form of identification, which can prevent some prevalent attacks. The second factors you can use to identify yourself include authenticator apps on your phone, which generate codes that change every 30 seconds, and security keys, small pieces of hardware similar in size and shape to USB drives. Since innovations that can actually improve the security of your online accounts are rare, there has been a great deal of well-deserved enthusiasm for two-factor authentication (as well as for password managers, which make it easy to use a different random password for every one of your online accounts.) These are technologies more people should be using.

However, in trying to persuade users to adopt second factors, advocates sometimes forget to disclose that all security measures have trade-offs . As second factors reduce the risk of some attacks, they also introduce new risks. One risk is that you could be locked out of your account when you lose your second factor, which may be when you need it the most. Another is that if you expect second factors to protect you from those attacks that they can not prevent, you may become more vulnerable to the those attacks.

Before you require a second factor to login to your accounts, you should understand the risks, have a recovery plan for when you lose your second factor(s), and know the tricks attackers may use to defeat two-factor authentication.

A well-examined exploration of some of the risks of employing two-factor authentication in your everyday life. I maintain that it’s still highly-worthwhile and everybody should do so, but it’s important that you know what you need to do in the event that you can’t access your two-factor device (and, ideally, have a backup solution in place): personally, I prefer TOTP (i.e. app-based) 2FA and I share my generation keys between my mobile device, my password safe (I’ll write a blog post about why this is controversial but why I think it’s a good idea anyway!), and in a console application I wrote (because selfdogfooding etc.).

Update: Years later, I’ve finally written a blog post about why keeping 2FA generation keys in your password safe is controversial, and why I do it anyway.

Battle of the Bulge: Why We’re So Fascinated by Superhero Codpieces

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

There’s a YouTube video from 2014 simply titled “Batman Suit-up Compilation.” As that description suggests, the 106-second clip, which has received approximately 1.86 million views, is a highlight reel of different times in Batman movies in which the Caped Crusader dons his Batsuit.

It’s a fairly innocuous video, but it’s generated more than 550 comments. And the first responder basically sums up the discussion that continues down the rest of the page: “Was there any point of showing Batman’s ass? Furthermore, why were Bats and Robin wearing codpieces? ”

Geohashing near Winchester (2018-08-23 50 -1)

My original plan to divert to the 2018-08-23 51 -1 hashpoint during my planned journey North-to-South along almost the entire length of the 51 -1 graticule was ruined somewhat by the hashpoint turning out be farther North than my starting point! So I changed plans and overshot my destination in order to visit the 50 -1 hashpoint, instead (and find a couple of geocaches on the way). Here’s how that went.

Also available on YouTube and on QTube.

Geohashing expedition 2018-08-23 50 -1

This checkin to geohash 2018-08-23 50 -1 reflects a geohashing expedition. See more of Dan's hash logs.


Hyden Wood, near Chidden. The woods look to be criss-crossed with footpaths, so this might be pretty achievable.



I’d originally planned on heading to 2018-08-23 51 -1 because I anticipated that it’d be on or near my route travelling South along almost the entire length of the 51 -1 graticule, but I didn’t bargain on such a Northerly hashpoint so I’ve changed plans and am now aiming to get to this one some time in the morning (I’m hoping to be in Winchester by lunch).


The full story’s in vlog format, but here’s the summary:

  • Wasn’t originally planning to come to this graticule but instead was going to go to the 51 -1 graticule where I live ([2018-08-23 51 -1 see here]): I was going to be driving almost the entire length of 51 -1 on a journey from Oxford to Winchester anyway, so I figured it’d be easy to divert to any hashpoint. But when the Dow numbers came out, it turned out that the hashpoints in this quadrant of the Earth are all in the North-East corner, and so my journey would be in the opposite direction. Oh no! So instead I decided to “overshoot” and go for this graticule instead, and thus (if successful) expand my Minesweeper Achievement level.
  • Hashpoint deep in woodland in the beautiful South Downs National Park. Parked at The Sustainability Centre (and later made a donation via their website in thanks for the use of their car park despite not using their other facilities) and walked initially through woodland they manage and use for natural burials: this was really cool – I’ve always been a fan of body disposal in a low-environmental-impact, no-permanent-markers kind-of way, so I’m going to look more into what they offer. I was really interested to see that many families had left “named” bird nesting boxes in memory of their loved ones, which is awesome too.
  • Found geocache GC2X5BJ just outside the burial area and close to a point that gave me a great view across a valley towards the woods in which I believed I’d find the hashpoint.
  • Had to go some way off track to get to the hashpoint, but discovered a network of old, overgrown, long-abandoned (and not on any map I can find) trails in-between the thicket. In fact, the hashpoint eventually turned out to be on the edge of such a track, which I was able to follow to help me find my way back to a road.
  • Found a sign pointing to “Droxford”. Oxford is so-named because its location coincides with the most-downstream point on the Thames at which it’s possible to ford the river while driving cattle (i.e. “ox ford”) – incidentally, I’m told, the ford was at the point that Folly Bridge now stands. But what’s the etymology of Droxford, I wonder. What the hell is a drox???
  • On the way back, diverted by geocache GC5P5KN and found it: this was a great cache with the best-made variant of the particular kind of container it used that I’ve ever seen.

Update: A little research later, it seems that the “ox” in each of Oxford and Droxford have completely different etymological roots! Droxford is derived from an ancient name for the area from some time prior to the Middle Ages: Drocenesforda. “Drocen” means “dry”: the name means “dry ford”. The River Meon, which flows through the area, flows shallow over a chalky bed and is easily forded in many places, as these motorcyclists show. The things you learn!




Dan Q found GC5P5KN SDGT South Downs Way Mile 20

This checkin to GC5P5KN SDGT South Downs Way Mile 20 reflects a geocaching.com log entry. See more of Dan's cache logs.

It’s been a long time since I’ve seen a geocache hidden this way: FP for that alone! A lovely spot to drop in on in my way back from a successful hike to the (not too far away) 2018-08-23 50 -1 geohashing hashpoint this morning.

( finding this geocache featured in my geohashing expedition described at http://wiki.xkcd.com/geohashing/2018-08-23_50_-1 and in my vlog of the expedition, found at https://www.youtube.com/watch?v=k3pvFOkaHnc [minor spoilers in the video])

Dan Q found GC2X5BJ Small Down Boogie 3

This checkin to GC2X5BJ Small Down Boogie 3 reflects a geocaching.com log entry. See more of Dan's cache logs.

An easy find while taking a shortcut through the woods on my way to the 2018-08-23 50 -1 geohashing hashpoint (an expedition that was eventually successful, though not without its challenges)! Container was exposed so I placed nearby stick on top of it to better conceal it. TFTC!

( finding this geocache featured in my geohashing expedition described at http://wiki.xkcd.com/geohashing/2018-08-23_50_-1 and in my vlog of the expedition, found at https://www.youtube.com/watch?v=k3pvFOkaHnc [minor spoilers in the video])

Dan Q found GCTNZ6 V’s own @ M4 – J13

This checkin to GCTNZ6 V’s own @ M4 - J13 reflects a geocaching.com log entry. See more of Dan's cache logs.

Better than your usual services cache-and-dash, I really appreciated that this cache took me away from the service station and along up a delightful little bridleway, this morning, not to mention the decent-sized container!

I’m on my way down the A34 from Oxford in an expedition to the 2018-08-23 50 – 1 geohashpoint, before doubling back to my actual destination of Winchester. With this cache, you not only gave me a welcome break, but also an excuse to stop and eat breakfast. TFTC!

Geohashing expedition 2018-08-22 52 -1

This checkin to geohash 2018-08-22 52 -1 reflects a geohashing expedition. See more of Dan's hash logs.


Field with public footpath, East Adderbury.



I’m keen to get to level 2 of the Minesweeper Geohash achievement, and this far-South-of-graticule hashpoint represents an opportunity to achieve that. I’ll be at work during the day, but – energy levels permitting after what’ll have been a long day! – I’ll find a way to get up here and see if I can get to the hashpoint, aiming to arrive probably around 18:30.


It had been a long day at work, but it looked to be a beautiful evening and I promised myself a pub dinner if I made it to the hashpoint, so I set out by car and by foot to East Adderbury, the village nearest to the hashpoint. The village itself is stunning: lots of old stone buildings, a very traditional bridge, and beautiful green spaces. I spotted not one but two candidate pubs (The Red Lion and The Coach & Horses) as I passed through the village, which was a reassuring start, and then pressed on down a lane which quickly became a narrow trail, waving to some cows along the way (why do I always seem to meet cattle on my hashing adventures?).

The trail was full of blackberries so I wasn’t short of a snack, but it soon became clear that it wouldn’t get me any closer than 35m to the hashpoint. I returned to the entrance to the cows’ field and, hopping a stile, crossed it. The cows looked puzzled as I paced around, getting to ground zero, but didn’t object. After shooting the traditional silly grin, I turned tail and headed back into the village and to the Coach & Horses, which proved to be the very essence of a British village pub: a husband and wife couple running it, dogs everywhere, a jar of pickled onions behind the bar, and more beers than you can shake a stick at.

I did enjoy a rather unusual conversation at the bar, though –

 Me: Can I get a ham, egg, and chips please. And a pint of bitter shandy.
 Barman: One egg or two?
 Me: Oh! Two, please.
 Barman: (Pause) We haven't got any eggs.
 Me: Uhh. Okay; no eggs then.
 Barman's wife: We've got one egg.
 Barman: We've got one egg.
 Me: I'll have one egg, then.
 (I go and sit outside; after a while, my meal arrives. There are two eggs.)
 Barman's wife: I found another egg.
 Me: ...

A fuller description of the entire adventure can found in the vlog I made along the way.



I filmed my adventure in a vloggy format, complete with doubling-back, talking to cows, and anecdotes about pub food. Watch it on YouTube or on QTube.



Minesweeper geohash empty.png Minesweeper geohash flag.png Minesweeper geohash empty.png
Minesweeper geohash empty.png Minesweeper geohash 2.png Minesweeper geohash flag.png
Minesweeper geohash empty.png Minesweeper geohash empty.png Minesweeper geohash empty.png
Dan Q achieved level 2 of the Minesweeper Geohash achievement
by visiting coordinates in Swindon, United Kingdom and 2 of the surrounding graticules.

Review of The Coach and Horses

This review of The Coach and Horses originally appeared on Google Maps. See more reviews by Dan.

Good food at spectacular prices. Friendly staff and free WiFi. A serendipitous find as I was exploring the village on my way back from a geohashing expedition: I’d certainly come back if I find myself in this neck of the woods again.

No.33: Twatt

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

Earlier this year, 2 friends and I decided to take on a hitch-hiking challenge to raise money for a charity called ‘The Campaign Against Living Miserably’. Last Friday Magnus, Sergio and I set off from Brick Lane with the intention of reaching the town of ‘Twatt’ on the Archipelago of Orkney – we gave ourselves…

An especially-good post by Robin as part of his 52 Reflect series in which (among other adventures), he… hitches a lift on an aeroplane! Well-worth reading!