Tom Scott

If you wander the footpaths and bridleways of Britain, you might stumble across a special crossing for horses.

Helicopters in London have a simple rule that means they're safer for everyone in the city. I stand on something a bit too high in order to explain it.

I'm joined by Felix Cohen from http://manhattansproject.com to learn how to make orange oil go up in flames. Add flavour, aroma, and a touch of danger to your cocktails. Personally, I don't drink, but that doesn't mean I can't learn to mix 'em. Please drink responsibly.

There's a hidden pattern on banknotes, all around the world, that means photocopiers refuse to copy them.

I'm up in the Arctic Circle, by a large ship on the Hurtigruten line, to talk about the longest TV program in the world, and why Norway excels at something called "slow television".

In the Norwegian city of Tromsø, there's a bit of city planning straight out of science fiction: an underground road network, complete with junctions and roundabouts, bored into the mountains around the city.

When you film with an iPhone or other smartphone in Europe at night, there's often a weird rolling banding effect over your footage. The reason has to do with power grids, frequencies, and some rather American-centric smartphone makers.

A message from the Interstellar Safety Council. What if the rest of the universe wasn't built on "survival of the fittest"?

Since 1624, Members of Parliament haven't been allowed to resign. And yet, they do: how do they manage it.

Joseph Bazalgette moved most of the Thames stink away, but there's still some 19th-century dodginess in the river now and again.

There's a hidden nodule on some British pedestrian crossings that provides a vital clue for folks who might otherwise not be able to cross the road safely.

Using edible gold leaf, gold that's been rolled out to a fraction of a micron in thickness, you can have a gold plated tongue, at least for a few seconds. File this one under 'stupid human tricks'.

Zeppelin trivia expert Simon Willison (@simonw) explains why the world's first in-flight radio message was "Roy, come and get this goddamn cat".

I was walking through Kings Cross, spotted Platform 9¾, and thought I'd share something you might not know: thanks to redevelopment of the station, right now it's in the wrong place. It won't be for long, though.

I spin a (fictional) tale of the day that Google accidentally opened everything. Performed at GeekyConf, with thanks to Betsy Weber and Natalie Downe on camera.

In the first of two videos filmed rough-and-ready in an alley behind a pub, all-round lovely person Norm (@cackhanded) teaches me how to safely strangle someone on stage.

In the second of two videos filmed rough-and-ready in an alley behind a pub, all-round lovely person Norm (@cackhanded) teaches me how to safely slap someone across the face on stage.

We go back to our old-school YouTube days, and try to cook bacon with a thing that isn't designed to cook bacon. It doesn't go well.

Why don't wind farms always turn, even if there's a lot of wind?

We'll hopefully never know what's written in the letters of last resort: top secret, handwritten notes from the British Prime Minister to be opened by submarine captains in the event of nuclear war. This video contains an error: I say "Trident-class", but that's the name of the missiles. It should be Vanguard-class.

Ninety metres above the river is really tall for a cable car. Why build it so high, and spend so much? Well, other than the Mayor of London being a bumbling buffoon, there's a reason it's got to be that high.

Have you noticed? That reversing beeper you find on trucks has been replaced by a squelch of white noise. Today, standing on a lay-by next to a busy construction site, I explain why -- while trying not to get run over.

I'm flying to the US. Ten hours on a plane is a long time, so I'm filming a video in an airplane bathroom, about something that makes sense in an airplane bathroom: relativity. "Galilean invariance" is the idea: centuries before Einstein, someone else had the idea that there's no privileged frame of reference.

I honestly thought this was an urban legend until I looked into it, but it's true. (The urban legend is that Margaret Thatcher invented it.)

Things that can hurt you just by looking at them are science fiction and fantasy, right? Well, not quite. Inside Walt Disney World, home of the most terrible earworm known to humanity, I talk about the McCollough Effect.

Hitting someone in the chest with a bucket of water looks impressive at close range, sure. But on stage, there's a different technique you need to use to make sure the back row is just as impressed.

(YouTube ate this first time around, so I've reuploaded it.) From the flame trench of Launch Complex 39 at the Kennedy Space Centre, under the pad from which the Apollo astronauts went to the moon, here's the reason that orbit is so damn hard to get to.

If a GPS goes over 1200mph or 60,000 feet, it'll shut down. And the reason why is linked to here, at the Kennedy Space Centre, and the Cold War.

A few days ago I was pushed into a pool. This is how to get pushed into a pool properly.

There were a lot of embarrassing things on TV in the 1990s, and Andy Crane in a baseball cap was just one of them.

Oneironauts are "dream travellers": folks who say they can become aware of, and control, their dreams. But how do you tell if you're dreaming? Well, there's this one weird trick...

SPF is meant to be a multiplier, but it's much more complicated than that. And as a Brit in Florida, I have to take care about burning.

The corporate behind-the-scenes workings of Walt Disney World are interesting, to say the least. They've got their own private city.

Remember the "dumbest dot-com", AllAdvantage? They paid you to surf the web, at least for a while. And one day, they announced that they were incredibly popular in rich Beverly Hills, California. The reason connects them to the US Postal Service... and Jason Priestley.

Rivers change course. They leave behind old channels, oxbow lakes, and a dozen other things you learned about in geography class. The trouble is, some rivers can't be allowed to move any more.

I'm not saying that you shouldn't trust moss if you have absolutely no other options. I am saying that you shouldn't get lost in the woods in the first place.

If I were in Iceland, I'd have a different name: and not only that, but the Icelandic government would have made my parents pick a name from a list. But there are more lessons to learn about names, particularly for those of us from the English-speaking world...

Bar billiards is a little-known British pub game. And in the tradition of video game "let's plays" -- only in the real world -- I got some folks together for a match. THE RULES: Pot the balls in the holes. Each hole's worth some points. Red ball's worth double. Don't knock over the pegs. And you only score those points when you play a legal shot that doesn't pot anything. Don't worry, you'll work it out soon enough.

There aren't that many places in the world where you can find geysers: even fewer where they blow regularly. Here, amongst the volcanic landscape of Iceland, is one of them. Here you'll find the original Geysir, plus its more regular cousin Strokkur. And a lot of wind.

It's a good question: with so many medical advances, how is "a cure for the common cold" still shorthand for "something that'll never exist"? Well, there's a good answer too -- and your body already knows it.

I'm joined by tef (@tef - http://programmingisterrible.com) who explains the Miura fold, a fancy origami fold that has uses both up in space and down on the ground.

There's a famous British euphemism: "tired and emotional". Which means drunk. But if you're being recorded, or writing down your thoughts, you might want to stay away from it - because the British legal system is terrifying.

In every Hollywood movie where someone dials a phone number, it starts with 555. Turns out Britain's got a similar system, and it's one of the few good decisions Ofcom's ever made.

When there's no room left to be buried, the dead will... take a train? It's hard to believe, but the London Necropolis Railway has a history.

And this particular tank, although it's a Soviet one, is accessible at the corner of Mandela Way and Pages Walk in Bermondsey. (And I know the term's "combat vehicle", I just prefer using "fighting machine".)

There were lots of Victorian engineering plans that never got off the drawing board - but one attempt at a Channel Tunnel remarkably did.

At the front of Notre Dame cathedral in Paris sits a mostly-ignored marker. Mostly ignored, that is, until one person arrives and takes pictures, at which point everyone crowds round it and ruins the shot.

As ever, I'm not a lawyer -- but even professional lawyers can't give consistent advice on this. I'm still a bit worried that I'm going to get sued in France.

Facebook bought Oculus Rift for $2bn. Yep, two billion dollars. I made them a commercial. They probably won't like it.

A few years ago, there were a lot of news reports about Paris Syndrome, an affliction that hit people whose ideas of Parisian delight were a long way from reality. A correction to this video: tachycardia is accelerated heartbeat, not irregular. The video's also a very early one that, in hindsight, I'm not particularly proud of, but that's not technically a correction. All corrections can be found at https://www.tomscott.com/corrections/

Out in the countryside near Canterbury, on the London to Ramsgate line, there's a strange level crossing - one that requires human effort. It's strange what railway history leaves us with. (Thanks to @quixoticgeek on camera duty!)

Buffer exploits are one of the basic bugs of computer science. They're responsible for glitches in games, for all sorts of viruses and exploits, and any number of technical disasters. Here's the basics of how they work, and a non-technical breakdown of Heartbleed, this week's rather startling attack.

In towns and cities across Britain, Europe, and occasionally the rest of the world, there are still some odd circular scaffolding structures. And younger viewers might not know what they are -- or why there aren't many left.

We've invented a new game: Chess Clock Jenga. It's... well, it's Jenga with a chess clock, but you probably worked that out already.

Despite the rather mythical title to this video, it's actually mostly about technicalities. And not about the dodgy vampire books.

With thanks to all the team at the National Railway Museum, York! You can ride in the passenger section behind Rocket on certain days; get in touch with the Museum at nrm.org.uk for details.

In ninety minutes, one of the most watched TV events of the year will happen. I'm there. It's going to be close. This is what happens if it's too close.

From tracking a point, to analysing pixels, to plotting 3D camera moves: here's how you go from shaky handheld shots to that "gliding through the Matrix" effect. Thanks to Matt Gray for his excellent camera work - he's at http://mattg.co.uk - @unnamedculprit

Angels. Gentle people with wings, and puffy-faced children with serene faces. Right? Wrong. Thrones and cherubim? According to the great Biblical scholars, they're like terrifying aliens.

Originally, I was going to try and tell this story while inside the bubble. That plan lasted until the very first tackle.

Who'd be stupid enough to put an actual nuclear reactor in the middle of London? Well, the Royal Navy, for more than thirty years, at the Old Royal Naval College in Greenwich -- that place that got blown up in Thor 2. It's not quite as bad as it seems, though. Thanks to David and Oli for sending this in, and to Rob Blake on camera! PS: here's my favourite Thor joke. A man in a Viking helmet with a giant hammer walks into a bar. The bartender says "hey, are you Thor?" And the man replies, "No, I alwayth walk like thith."

"Fail-safe" doesn't mean "we have a backup", it means "if this fails, nobody gets hurt". So I went to see the master of inventions that aren't failsafe, Colin Furze, for a more visual demonstration.

It should never have happened. Defending against cross-site scripting (XSS) attacks is Web Security 101. And yet, today, there was a self-retweeting tweet that hit a heck of a lot of people - anyone using Tweetdeck, Twitter's "professional" client. How did it work? Time to break down the code. (Remember the old Myspace worms? They worked the same way.)

In Trinity Buoy Wharf lighthouse in London -- and a few other science museums around the world -- sits Longplayer, a musical composition designed to last a millennium. How do you keep something running for that long? Thanks to Rob Blake for holding the camera through the many takes. This one took a while... And thanks to Martin Deutsch for reminding me about Longplayer!

A few centuries ago, the arbiter of "local noon" wasn't the mechanical clock, it was the sundial. The pseudoscientific-sounding "equation of time" is how you convert between the two -- and perhaps not the way you'd expect.

If you've tried to tweet a national flag emoji lately -- I can't imagine why -- you'll have noticed that you can only fit 70 of them into a tweet. The reason why is buried in a bit of technical specification, and shows how your phone can lie to you...

Reserve your username now: http://emoj.li - your username, of course, has to be emoji. Matt Gray and Tom Scott present Emojli, the first emoji-only social network.

ALL THE ELECTRICS I USED WERE UNPLUGGED. DO NOT DO THIS. Yep, I'm going all patriotic again. And while I'm willing to bet that a good number of British folks know the first half of this video, there's one thing about slack in here that I only just learned myself.

I know, technically everywhere has the same "gravity", but there's less gravitational pull from the Earth in some places. You try fitting that into a YouTube title. (Filmed at Zip World Titan in Blaenau Ffestiniog. That's not product placement, I paid for my ride just like everyone else, it's just that I know loads of people will ask if I don't mention it.)

I was passing by the Thames Barrier today, and figured it'd be a good time to talk about Scotland -- and how it's quite literally rising up. With "post-glacial rebound" and "glacial isostatic adjustment", though, not the referendum.

I'm getting a bit linguistic in this week's video, from the Welsh village of Llanfair­pwllgwyn­gyllgo­gery­chwyrn­drobwll­llanty­silio­gogo­goch. And as often happens with linguistics, the answer depends on how you define things. What counts as a word, after all?

I try not to do too many "look at this thing" videos, because it's better to have an interesting backdrop and an interesting fact. This time, though, I'll make an exception. Welcome to Bounce Below. No product placement here, by the way: I booked and paid like everyone else! Bounce Below is at the Llechwedd Slate Caverns in Blaenau Ffestiniog, and you can find out more here: http://www.bouncebelow.net/

Back at the same pub where he taught me to strangle someone, stage-fighting and lovely improv person Norm (@cackhanded) returns to show me how to break someone's neck in the movies. Listen to the warnings on this one, folks.

Remember Heartbleed? Well, this is probably worse. Here's a (somewhat simplified) explanation of what Shellshock actually is. Don't worry: I haven't included instructions on how to actually exploit it. The moral of the story is: keep your security patches up to date!

Another close call with gravity, this time with a little more coherence and on an alpine slide. Although I'll be honest: this is one of those times where "I told you that story so I could tell you this one".

A brief introduction to password hashing for the uninitiated -- and why you should never trust a site that emails your password back to you!

Why don't we use mixer taps? I've talked about the British plug before, and how it's a wonderful design: British plumbing, on the other hand, still leaves a lot to be desired.

A filming drone, video goggles, a Mazda MX-5 Miata and a disused airfield. Paul and Oli compete to answer the question: can you drive in a third person view? The stunts in this video were performed by trained drivers on a closed course. Do not try this at home. Paul is on Twitter at @cr3 and http://cr3ation.co.uk - Oli's at @coldclimate and http://www.theapproachablegeek.co.uk/ Thanks to our aerial filming crew, Neil and Rob from Skypower, http://skypower.co.uk - they stepped in at very short notice to make it happen!

Welcome to the Kelston Toll Road: Fed up with a 14-mile diversion caused by a landslip, businessman Mike Watts has taken a £300,000 risk and set up his own private toll road. It costs £2 for cars to travel the 400 metres -- which is slightly less than the cost of the petrol to take the detour. And the odd thing is this: despite the Kelston Toll Road not being approved by the local council, Mike is still on the right side of the law. Many thanks to Mike Watts and the team at the Kelston Toll Road: they can be found on Twitter at @KelstonTollRoad and, obviously, between Bath and Kelston on the A431!

No, seriously. Here's how to read text when all you can see is a bunch of 0s and 1s. It's easier than it seems. I... I think I might have gone off the deep end a bit here.

Those potions in Macbeth are a lot less mysterious than you might think. The Harry Potter ones don't really work, though. Thanks to the Warner Brothers Studio Tour for letting me film, and to Amy Louise Gwynne for spellcasting!

The mammalian diving reflex is a quirk of evolution that means a shock of ice water does the unexpected: it lowers your heart rate. I demonstrate using not a bucket, but a bathtub. This was probably a bad idea.

Emojli, our emoji-only messenger, has launched! Today at Electromagnetic Field, the UK hacker camp, Matt Gray and I gave a talk about how it was made, why it was made, and why we never want to build anything like it again.

A £20 ultrasonic fogger, some rum and vodka, and a lot of style: put them together and you get Toby Jackson's (@matingslinkys) Marvellous Booze Fogger, part of Nottinghack's contribution to the Electromagnetic Field festival this weekend. Always drink responsibly!

Some folks might leave their heart in San Francisco, but over at Waterside Plaza in New York, there's a much more real and physical souvenir: a part of Bristol, a port town in the south west of England, that literally makes up the foundation of a development near the East River.

At dConstruct 2014, I spin a tale of the future: not to make a prediction, but to put our current world in perspective. Thanks to all the dConstruct folks at the Brighton Dome: crew, volunteers, and audience!

On a busy street in Manhattan, there was once a place called Tad's 30 Varieties of Meals -- or possibly Tad's 57 Varieties, or maybe just Tad's. It closed long ago, but the idea was this: diners would pick a frozen meal, take it to their own table, and put it in their new, shiny, space-age microwave oven. Needless to say, it didn't catch on: but there's more history there than you might think.

All three of us got the plane down on a perfectly still day with no wind. But an autopilot could do that. That's not nearly as interesting.

I was walking through New York and found a couple of seemingly-abandoned liquid nitrogen tanks on the street. Except they weren't abandoned: they were full, making a very quiet hissing noise, and plumbed into... somewhere. I did a bit of research, and found out why they're really there. Thanks to David Bodycombe, who tipped me off to the tanks' existence: I was planning to go looking for them, but instead I just found them, casually sitting on the street corner, while I was headed to the Rockefeller Center...

With many thanks to the South Street Seaport Museum! Visit them at http://southstreetseaportmuseum.org/ or at Pier 16 in New York. These days, if you have dangerous, underwater shoals and you need a lighthouse, you build a big tower and anchor it to the seabed. But a hundred years ago, that technology wasn't there: and so you'd build a lightvessel: a floating lighthouse with a crew of twelve, who's stay out in the dangerous channel in all weathers. At the South Street Seaport Museum, Mike Weiss, the waterfront foreman, gave me a tour around the Lightship Ambrose. (Apologies for the audio on this one: I was shooting quickly, and it turns out it's windy on the East River in New York!)

Lincoln's Gettysburg Address is one of the great moments of American history. There's a myth that he wrote it on the train to Gettysburg -- which isn't true -- but I want to dive into something a bit more linguistic. Those opening words: "four score and seven years ago": why do they sound so resonant? And where might you have heard something similar?

Around the United Kingdom there are odd concrete pillars on the top of hills, built to last for decades if not centuries. They've got a cryptic marking on them, and the words "Ordnance Survey Triangulation Station". What are they? (They're trig points.) Who put them there? (Brigadier Martin Hotine and thousands of people working with him.) And why? (To get an accurate map of the UK, with maths.)

There's been a "Life Pro Tip" going around the internet lately saying that the numbers on toaster dials are actually minutes. I was so sure it was false. Oh, I was so sure. I got four toasters set to "2", and I had one take to film it all in a back room at my office. This is that one take. Thanks to Dan W (@iamdanw) on camera and Jonty (@jonty) on toaster-wrangling! UPDATE: 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.

On Swanscombe Peninsula sits Gravesend Weather Station: a Met Office station that consistently records the hottest temperatures in the UK. Is it particularly warm there? Or have they put it in the wrong place? And what'll happen when they have to make room for Paramount London, the coming BBC-linked theme park?

On the winter solstice, I trekked out to a cold and muddy Avebury Henge, out in Wiltshire, to talk about two things: first, the peculiar and mostly-British belief of ley lines, and second, the fact that it's basically a hipster version of Stonehenge: bigger, cooler, and you've probably never heard of it. Oh - and if you want to play about with ley line data yourself, I made http://www.tomscott.com/ley/ a couple of years ago. It still gets me occasional disappointed emails from believers. And yes, I know that's Ben Goldacre in the by-line of the Guardian. He wrote the article about it; Matt Parker did the mathematics, but most of those references have since gone offline. (I'm willing to bet someone'll comment about that without reading the description within the first few hours after this goes up.)

There's an old saying: that it's "too cold to snow". Can that really be true? It started snowing outside, on the day after Christmas, and so I thought I'd do a bit of research, check my facts, then hurry out to film something in the cold.

In 1993, the New York Times called rabies a "shared national nightmare" for Britain. For younger viewers, and those outside the UK -- say anyone who doesn't remember the Channel Tunnel opening -- "rabies" may just be one of those things you hear about on the news sometimes. But there are a lot of people who are proud of Britain being free of it. Here's why. I'm indebted to Pemberton and Worboys' wonderful "Mad Dogs and Englishmen: Rabies in Britain 1830-2000" - http://amzn.to/1xr1x2B - for a lot of fact-checking here, as well as inspiration. It turns out this is a properly fascinating subject: I had to cut so many fascinating things out of my script. (A five-minute monologue to camera on a windy beach isn't interesting.) I recommend you at least get the book from your local library. For example... FACT: The requirement for muzzling dogs extended to tiny, tame lapdogs, but not to "sporting" dogs, those used for hunting -- because the men writing the laws didn't want to muzzle their...