Corrections and Clarifications

Last updated 19th December, 2022

Here's a list of significant corrections and clarifications to videos on my main YouTube channel, in reverse chronological order by video publication date.

What counts as a significant correction

The error being corrected should materially affect the video. If I misspelled a word in a caption, or if there was a graphical glitch, the error is not going to be listed here. Rest assured that it will, most likely, still haunt me for the rest of my days.
The video should be public. Videos like channel updates are automatically set to private a couple of weeks after they're published as they're no longer relevant, and a very small number of early videos have been removed from public view as their entire premise was inaccurate.
If you know of a significant correction not listed here, please do email me.

2022

The giant chainmail box that stops a house dissolving: This video originally implied that all the individual chainmail rings were hand-sewn together. While the sheets of chainmail were linked that way on-site, ring by ring, the individual rings within those sheets were connected by machine! As this was an easy line to crop out in YouTube's editor, it's been removed.

2021

The shooting range where you fire over a busy road: “Schusswaffen”, firearms, was mistakenly transcribed as “Schutzwaffen”, defensive weapons. It's a minor but important distinction. My transcriber and translator was German, but not Swiss German!
The Islands With Too Much Power: Hornsdale Power Reserve didn't catch fire! It was the newer Victorian Big Battery, near Geelong. Complete blunder on my part, apologies to the Hornsdale team.
Why 18th-Century Firefighters Let Some Buildings Burn: This video has an entire corrections video.

2020

Five Things You Can't Do On British Television: The “sixth thing”, the rule on advertising breaks, was superseded in 2008 by a different set of rules that require that “the integrity of the programme is not prejudiced” and adverts must be placed “where natural breaks occur”. The old Code is still on Ofcom's site, and I missed the replacement. Back when Millionaire started, those throws-to-commercial were definitely not allowed, but it's now more ambiguous.
For 21 Years, No-One In Britain Knew How Long An Inch Was: The on-screen graphic should show a metre as being 1/299792458 light-seconds, not 1/1299792458. I copied and pasted a 1 into the wrong place.

2019

What's Your Computer Actually Doing?: I say “Mac instead of PC”, which should be “a phone instead of a PC”. I also say “every sixth cycle”, which should be “every ninth cycle”.

2018

Lateral, Game 6: The Grand Final: A question mistakenly included the word ‘eastern’ rather than ‘western’. Note: clicking through to this video is inherently a spoiler for the whole season of Lateral. If you've not seen the show, you should start with Game 1.
Freezing 200,000 Tons of Lethal Arsenic Dust: In the opening narration, I say “200,000 tonnes of gold” was mined. That should be 200,000kg: the 200,000 tonne figure is for arsenic dust.

2017

Zero-G Experiments on Earth: The Bremen Drop Tower: I oversimplified the calculations for freefall and ended up quantising them. Yes, the speed increases by 10m/s², but that doesn't mean it travels 10m in the first second. It'd travel 5m, then 15, then 25, and so on. Several physicists reviewing that script didn't notice the error, either!

2016

Pod Cars of the Past and Future: The Morgantown PRT: An interviewee from the university said that the “PRT never shuts down”. That's not true: it's got some reliability problems, and it's closed on University holidays and semester breaks. That line shouldn't have made the edit.
The Problem With Renewable Energy (and how we're fixing it): I said that turbines spin thousands of times “per second” when I meant thousands of times “per minute”.
Driving Through Russia Without A Visa: The Saatse Boot: Further research revealed that the camera tower Matt spots is, almost certainly, just a regular cell tower. Or, at least, that's what they want us to think.
Why You Should Write Down Your Goals: My conclusions in this are questionable and based on only a small number of research papers; Thomas Frank has a good video arguing the counterpoint.
Why 1/1/1970 Bricks Your iPhone: years after this video’s publication, Civilization creator Sid Meier confirmed that the “Nuclear Gandhi” bug was just a myth!

2015

The Collapsed Dam That Stopped Los Angeles: The St Francis Dam actually held back 47 million tonnes of water, 470 times more than I said. I mistook the dam volume for the reservoir volume when researching.
Britain's End-of-the-World Bunkers: “Ground burst” and “air burst” were reversed in the script: ground bursts spread significantly more and wider fallout.
The Sundial That Works 24 Hours A Day: Solstice, not equinox.
Concorde, Hovercraft, and the Dreams of the 1970s: A comma got moved in the script. The section about Concorde crashing should be “…after one of the planes crashed, in 2003 the airlines decided…”. Concorde crashed in 2000.

2014

Do The Numbers On Toaster Dials Mean Minutes?: An error pointed out by a couple of folks in the comments: modern toasters likely don't use bi-metallic strips. They either use a capacitor charged through a variable resistor, or specialised silicon. See this great Technology Connections video.
Is "Paris Syndrome" A Real Thing?: Tachycardia is an accelerated heartbeat, not an irregular one.
British Nuclear War from Beyond the Grave: The Letter of Last Resort: I said “Trident-class” submarines. Trident's the name of the missiles: the submarines are Vanguard-class.

2013

Gender Neutral Pronouns: They're Here, Get Used To Them: this video has a separate page for updates.

General notes on referencing

My referencing in Things You Might Not Know has often been poor, particularly in earlier videos.

If I've done deep research — looking up obscure academic papers, news articles or historical records — I will absolutely reference them. And in most of my recent videos, I'm interviewing experts in the subject rather than just monologuing.

But, particularly in 2016 and earlier, I have a tendency to not cite sources. I will endeavour to reference more completely in the future.