How does Britain know what time it is?
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- Опубликовано: 25 авг 2024
- Did I need to get a radio controlled clock and travel to Anthorn to film this video? Absolutely not. But for a few minutes, that clock was really, really accurate. • Thanks to the team at NPL! More about NPL Time: www.npl.co.uk/... - their Open Day is on 20th May! www.npl.co.uk/...
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And if you're wondering why "coordinated universal time" abbreviates to "UTC": that's because it officially stands for "temps universel coordonné", and this way neither English or French speakers are happy. Compromise!
Hi
hate to break it to you, but:
*clears throat*
neither English **nor** French speakers
I'm surprised the British even allowed French near their time.
CUT or TUC. No. We go with. UTC. why. Who knows?
Politics in a nutshell
"How does Britain know what time it is?"
Not by looking at where the sun is. I can tell you that much.
actually they do. Just not by eye ;)
Funny :) Interesting tidbit: turns out the 13th century Vikings had a system for telling the direction of the sun even through cloud cover by using a polarizing crystal.
I like this joke
🤣
A cargo ship used to sail past my workshop, we knew it had passed because it changed the time on all our clocks and watches with whatever signal it was broadcasting. Had to switch to manual change devices.
How and/or why would it do that? I doubt that it would be legal to transmit such a signal at your location.
@@leocurious9919 likely to keep all the clocks/devices onboard in the timezone of the departure port.
@@uberfuzzy time on board ships and the like drifts gradually through the voyage afaik, so when you get to London from shanghai you aren't like 10 hours jetlagged
How are you getting jetlagged on a 40 day journey? There's no jet involved to introduce any lag.
@@joetoaster447 If everyone aboard kept living by the time of their port of departure they might be many hours out of step with their destination's clocks. As Agustin Venegas pointed out, it's easy to slowly adjust the shipboard clocks during the voyage so that everyone arrives operating on the destination's schedule.
For perspective on how little power you need to consume this signal: I once had a digital clock with a capacitor that could keep it running, accurately, for weeks after removing the single AA battery
Nice avatar.
Woah.
It uses only nanoamperes.
4:45 "Standing by the ocean with a domestic appliance" is just normal Tom Scott behaviour at this point xD
Honestly that old Teasmade video is one of my favorite.
Previous time I can recall was also about time synchronization. It's a pattern.
And it's definitely not going to be the last time either 🙃
I understood that reference
@@KHoos I could not find the Easter egg in this episode yet, but I think this is related.
Tom Scott: consistently answering questions I never thought I had
He's just that guy
Best description
Just wait till you find out what questions you didn't know about next week.
That is so true
@@christhildpaschelke4502 that guy who'll make interesting videos.
I bought some radio-controlled clocks at auction. They were quite cheap, which more than made up for the fact they're fixed to the DCF77 signal out of Germany not the MSF signal out of the UK so they're technically an hour out. I took them apart and adjusted the hour hand so when it thinks it's 12 o'clock the hand points at 11 o'clock - and nobody is any the wiser. Apart from daylight savings transitions when the clock adjusts itself an hour before you'd expect.
I’m sorry mate but your clocks have one purpose, and that’s to tell you the time!
I brought a couple of digital clocks that can be radio-controlled if desired from Europe to the UK. I was quite happy to discover that, as I've been moving around the country, they still always pick up the German signal - even in Northern Ireland (though sometimes it takes a couple of attempts). Thankfully they also have a "correct by X hours" function, so I can see GMT/BST without opening them up and doing weird things to electronics :D
I was wondering if there was some way to adjust or switch which signal they were picking up. Although I guess it has to be hardcoded based on the fact that each transmitter sends data in a completely different format.
I had to do the same with my German clock.
I bought one of these from the UK as well. However Australia is just a bit too far to pick up the signal!
I live 6 miles from the national atomic clock transmitter in the USA that does the same thing. However, the timezone and daylight savings settings must also be selected on the clock for it to be accurate for the region. The UK has a great advantage with just one time zone. Great video.
The UK has daylight saving time too. There's GMT (Greenwich Mean Time, which is also UTC) and BST (British Summer Time which is UTC+1)
DCF77 (the german time transmitter) has two bits to encode if it is DST or not (so no need to set it) and a third bit that will announce the switchover from DST to normal time or vice versa, so the clock can switch even if it isn't receiving at the second the switch is made. Most consumer clocks don't sync constantly, but use a regular quartz clock for the time in between, which is "good enough" for a normal clock showing only whole seconds. There's even a leap second announcement bit... From what I can see, the MFS format used in Britain has about the same features.
Trump wanted to get rid of the American transmitter to save money.
I guess it's safe now....
@@TJ-up8vj America's problem is that different states have different timezones and rules for DST. For example some states have daylight saving time, but some do not. Britain has DST, but it has only one timezone and one rule for DST. Not so for the US, so the equipment must be much more complex.
At the tone, 12 hours, one minute, coordinated universal time.
I used to work tech support for a radio controlled clock company. The amount of people that called in worried about the device being labeled with "atomic time" and having concerns about being irradiated was slightly concerning.
Best not to tell them that the clocks are set by electromagnetic radiation...
@@gdclemo AAAHH! Radiation! Think of the children!
Well with clocks that is not that odd to think. If you think about it. not that long ago watches with uranium was a thing. (glows)
@@gdclemo no one tell them that we have a run-off fusion reactor 150 million km away showering all of us with electromagnetic radiations for half the day...
@@adarshmohapatra5058 and not just EM radiation, also α and β, too! Not to mention the whole lot of space that's trying to cook us and ruin our radio and analog tv signal with _microwaves_ , just like the ones in the oven!
I always find it amazing when I hear about these lesser known organisations which perform such vital work for the UK and the world. Great video, Tom!
The British parliament could stop existing and nothing bad would happen for months, the NPL stops existing and the concept of time ceases to exist.
This was invented in the US in 1948 and has been used here for decades...
@@ErikUden OMG then how would we know the length of a piece of string As NPL was the master reference model.
@@FJB2020 ok?
@@mojoich2736 You'd have to
*Shudders*
Ask the French.
*Dramatic brass ensemble*
They're the keepers of metric units.
This was...bonkers. Had no idea could have clocks that 'set themselves' via radio control.
Honestly! It's kinda cool to think about clocks setting themselves, that too by radio; I wish we had these in the U.S. tbh 😞
@@prayagsuthar9856 We do. The transmitter is in Colorado, with call sign "WWVB", and it's run by the National Institute of Science and Technology (NIST). Every Wal-Mart I've ever been in has had clocks that will sync to this signal.
Got a clock at home that did that for many years until the battery stopped recharging.
I've had the privilege of being involved in conducting peer review of Australia's equivalent of NPL and visited the clocks held by the National Measurement Institute of Australia, which maintain that country's connection to UTC. Fascinating stuff!
I appreciate that this video was done in "real-time" with the physical clock still ticking during the interview
If you think about it, everything is done in real time.
@@vigilantcosmicpenguin8721 they mean that at the begging the clock shows 10:40, by the end of the 5 min video it shows 10:45. Tom has done his segments with specific gaps for the interviews so the clock keeps time with the video
@@jsworpin If you look carefully, its not in synch with the time on the video. It jumps forwards and backwards
@@jsworpin It seems to be off by 2 seconds. At the beginning, the clock was behind by 5 seconds ( video timestamp was 0:09 and clock said 10:40:04 ) At the end of the video, the timestamp was 4:49 and the clock said 10:44:46 , approximately.
@@jasonrubik 2 seconds isn't bad at all. :)
My workplace got one of those! Too bad they forgot the control room is 20 meters from a 20MW induction furnace. It constantly tried setting itself to random times of day.
they need a lead shield hehehe
It's actually a conspiracy to get you to work for free.
My school once got one of them for every classroom but somehow they showed the wrong hour, minutes and seconds were always correct but the hours were always wrong like the were in the wrong timezone or something like that. If you tried to change it to the right time the clock changed it self back to whatever wrong hour it used to be. In our complete school were just wrong clocks.
@@jwider96 we’re you on the south coast? Might have been getting French time more clearly than uk signals…
@@jwider96 Most Radio-Controlled clocks have a switch to set for the time-service of the (nearest) country you're in - UK, Germany (Central European Time), USA or Japan - maybe the school's clocks were set for Germany/CET? (You'd probably get the German time signal in most of the UK).
I recall the time signal originally being transmitted from Rugby, Warwickshire, indeed i have a radio time controlled wrist watch i bought after 2007 (when they switched to Anthorn) which still referred to "Rugby Time"
I remember hearing one of the NTL time group members complain about their shiny new building. It was made of metal and was expanding and contracting by mm with the ambient temperature changes. Antennas on the building associated with time transfer were now seen to be moving in time during the day. Their previous brick building was less prone to this effect.
The German version of this (DCF77) used to have a few bits just for the engineers to receive a few error codes. Today those bits transmit encrypted weather data and there's just one error bit. I built a receiver that shows those 60 bits on LEDs, and you could listen to the bips (100 or 200 ms each second) and decipher them on a piece of paper if you needed to.
Why is the weather data encrypted?
@@640kareenough6 Short answer: Because of the money.
The weather data transmission isn't operated by the PTB but by a private company that sells licences for the decrypting data technology.
France overlayers their signal on an AM radio broadcast at 162 kHz, the Russians use 66.6 kHz, and the Japanese 40 and 80 kHz. I forget which the Chinese use, but if you have a GPS disciplined oscillator you can coherently integrate their carriers and pull them all out of the noise floor from Europe, though bit decoding can only be done with the local ones.
They use a speed of 1 bit/sec !
@@RN1441 The radio station on 162kHz went silent some years ago but the frequency is still active just to carry the phase modulated time/data signal.
I remember seeing a demonstration of Einstein's Theory of Relativity where they had two synchronized Cesium clocks and they took one of them on an airplane and flew for an hour at about 600mph and, sure enough, when those clocks were re-compared the one that flew in the airplane was a few billions of a second behind the one that stayed on the ground, proving that time actually does slow down as you move faster.
The time dilation effects of gravity also have to be taken in to account when designing satellites. The on-board clocks of GPS satellites, for example, are designed to tick at a slightly slower rate than ground-level clocks, because the passage of time for an object appears to speed up as it moves farther away from a massive object.
@@jacksonlarson6099 as far as I know they even coded a switch, so they can take Einstein in account or not. The reason was, that his theory wasn't really proven when GPS was designed
Does that mean we can find out what speed is absolute 0mph in deep/inter-galactic space by comparing the speed of time at various vectors?
@@C.I... assuming you mean completely flat spacetime with no gravitational time dilation, even intergalactic space has some of it going on due to the gravitationally-bound “local group”. As far as we know, there’s no place in the universe with a total absence of gravitational waves
I think they did something similar with the Apollo flights - onboard clocks were behind the earthbound ones when they got home.
The US has a similar system. NIST has the radio station in Colorado, WWV, transmitting at 2.5, 5, 10, 15, and 20 MHz. It's designed to cover most of the US. The site is shared by its longwave cousin, WWVB, transmitting at 60kHz. And in Hawaii, theres WWVH transmitting at 5, 10, and 15 MHz. All 3 stations use UTC for their time codes
Love that system, I can pick up Hawaii and Colorado on 10mhz on my hf rig
@@greg2092 I really like that they have a phone number you can call and listen in. Shame it autodisconnects after 5 or 10 minutes
The instructions for my clock have a suggestion for when it has trouble receiving the signal inside a building: "Take the clock outside and point the back of the clock in the general direction of Fort Collins, Colorado."
@@tvdan1043 Seems reasonable. As long as you know which way Colorado is from you
@@thomasvlaskampiii6850 If you don't, knowing the current time might not be the highest priority.
I’ve still got my radio alarm clock that uses this transmitter must be over 20 years old! Always on time 👍🏼
If I had a nickel for ever time I stood with a domestic appliance by an ocean, I would have two nickels. It’s not a lot, but it’s weird that it happened twice.
I guess you have never been camping that the sea side.
can you produce more nickel please? the world is having a shortage of nickel currently
we all have the same reflex, which is amazing
@@ironicjason257 Unfortunately, melting a coin for its metal carries a 5-year prison sentence. Though you can probably avoid that by melting outside the US.
Is that a Doofenschmirtz reference? If it is, I'm so proud of you
Here in Germany we actually have a similar institute in Frankfurt. It is called DCF77 and broadcasts at 77khz. Apparently the signal of DCF77 can still be received in Spain and Britain. I know that because I am currently doing my final exam as an it clerk here in Germany. My topic is actually about NTP, Wich is a protocol used to distribute time across a network. So this is a somewhat scary coincidence.
Can confirm. Am near London and have two clocks synced from DCF77 at home.
Yep, in Slovakia with 3 clocks. Altough In some corners or rooms, the clocks gets properly synced only in night. Otherwise they just stay at 00:00. I guess there is less interference at night.
I think I saw clocks that receive DCF77 for sale in one of the German based discount supermarkets here in London last week. But I didn't buy it because I couldn't work out how it dealt with timezones and daylight save time. There didn't seem to be anywhere on it to tell it what timezone you wanted.
@@charliedobbie8916 When they made the bright idea to move the transmitter from Rugby to Anthorn a lot of the South UK had (still has?) to use DCF as the signal did not reach.
Has the British equivalent a lower range than DCF77? That is quite surprising to me since it is using a somewhat similar frequency.
I've been a mild timezone/time-keeping geek since childhood when I learned about Greenwich Mean Time and Time Zones as a five-year-old. These very British timekeeping quirks bring me much joy.
40 years ago when I used to TSD Rally (Time-Speed-Distance, you can calculate any one of them if you know the other two), we used to synchronize all out clocks/watches to WWV.
WWV (the shortwave station that broadcasts time in the US) has been in operation since 1919, 103 years...
It’s never really occurred to me how radio controlled clocks work beyond “probably some kind of radio signal somehow” but they’re fun to watch when the hour changes
The signal is also encoded into BBC Radio 4 LW Transmission.
As a dumbass American, could you please elaborate on why it's fun to watch when the hour changes? Is that when it syncs up or something?
@@emmanotsostrong At least the ones I’ve seen and from what I remember (it’s been a while) the hands whizz round and round for a bit until they settle on the new time
@@emmanotsostrong They're not usually digital clocks - they're analogue. So they tick away as normal but then daylight savings changes and the hands spring into action and whirl around until they settle on the new correct time. It's something quite unexpected to see from something that's usually just a crystal oscillator and and bunch of plastic cogs.
The only good thing about daylight savings is the way the clock goes 'round.
The best thing about those radio controlled clocks is my 88 year old mum doesn't have to get a neighbour in to reset the one high up on her kitchen wall when the clocks go forward/backward.
That is a GREAT feature! A fall for an older person can be very dangerous.
Do you still have to change the battery, or is it wired or solar?
@@TheQuark6789 I have changed it when visiting, just to be on the safe side.
I met Leon Lobo 4 years ago as my company used to sell UTC synchronisation and traceability to big financial institutions.
I didn’t manage to get a single contract signed but it was fun going to Teddington and meeting the team there! Leon is a top bloke.
Hey Tom, Years back I had a similar discussion with an USAF expert. The USA national standard is a clock in Denver Colorado. It is critical to know how far the sender radio is to the receiver clock. Then a range adjustment is made, so that satellites line up, bombs hit on target, and official top secret communication is made in real time. BTW, the adjustment from Denver to Scott AFB, just outside St. Louis where I live is a +4000/second.
isn't it in Boulder, at NIST?
@@valkyrie_pilot Perhaps it is now. I believe I was told it was in Denver, years ago. But what you say makes sense because USAF has a large presence in Boulder. For instance, the Air Force Academy is in Boulder. Anyway your presentation was excellent. And my second point is that the EXACT time adjusted around the globe is critical for TOP SECRET communications. So, today, exact time is more critical than it was 20-30 years back when this plan was hatched.
@@MrMockingbird1313 The Air Force Academy is in Colorado Springs, about an hour south of Denver (Boulder is a half hour northwest). The time standard, at least currently, is in Boulder, I had an internship there a few years ago (the time-standard atomic clock itself is sort of anti-climactic, looks like a server farm). That time-standard sends a signal to an antenna array similar to the one in this video located north of Fort Collins.
@@quillmaurer6563 Your information is more current and accurate. But, my information goes back 20 years. I just remember vividly that secure transfer of information depends on an accurate time standard and the transmitter was 4000/second west of here. Funny stuff? Thanks for your correction.
Tom is really good about finding stuff that interests me but that I would otherwise have no clue existed.
Hats off to Mr. Leon Lobo for the very eloquent explanations. Thx.
Dr*
Tom Scott is 100% one of our favourite RUclips. The quality of his videos with the level of research etc…
Answering questions no one thought they needed to know!
I'm betting we're being shown one of the engineering labs in the facility rather than a production time source, because that lack of cable management screams "test bench" and not "permanent infrastructure"
Ah, yes. My kids' elementary school had these in every classroom. They were usually waaaay off, or exactly right, or forever spinning to recalibrate, or whatever whimsical thing they wished to be doing. Mostly being wrong.
Hehe we have saying in Germany: Only a broken clock is right twice a day.
Schools full of clocks usually have a controller on location.
@@DoctorWhom Yup, there's a central clock somewhere (usually a panel in the school office), wired to remote clock faces in every room. The remote faces are electric clocks running off synchronous motors, that turn with the power line frequency -- evidenced by the second hand turning constantly rather than ticking along.
It was kinda cool to see those clock faces re-synchronize, too. They would all stop for about a minute, then suddenly advance one minute and start turning normally again.
Though my high school temporarily replaced most of the remote faces with regular battery-powered quartz clocks. The central clock had no battery backup for power cuts -- and the power was being shut off multiple times (outside of school hours) while the school was being added onto and remodeled. ...Which led to the system being hours off from the actual time until construction was complete. It was a couple years _after_ construction had finished before they finally got around to putting all the old clocks back, though.
@@AaronOfMpls in our school, they were just like Tom's.
We've got a bunch of these radio synced clocks at work. Shame no-one checked to see if they'd be able to pick up any reception where they were placed...!
Tom the reason why they did not let you near the clocks in London... they saw your Tower Bridge video and the same day it broke!
I was at the NPL this week and based on what I was told the clocks are in the main building. The hydrogen mazers are in the same building as well. All very interesting.
I used to run a call center that took financial trades over the phone. Trading in the US stops at 4pm EST. We read the time off our desktop but it turns out that each desktop was running it's own independent time and it became obvious that across the call center there was a variation in time of more than 60 seconds. So depending on who answered the call at near 4pm, a person's trade happened today or tomorrow. That's when I discovered the importance of time.
I always love it when you show us the amount of work that goes behind providing us with luxuries we take for granted.
Not enough work tidying up all those cables, though. Yikes...
"standing, by the ocean, with a domestic appliance"
Funny enough, also talking about time and synchronization of devices.
When this video popped up, I was actually retro-fitting radio controlled clock mechanisms into all of my wall clocks!
I’ve asked myself this question many times before, but never thought to seek out the answer. Thanks for giving it to us!
...the last time Tom stood by the ocean with a domestic appliance was with a Teasmade on the Isle of Grain. Also an interesting video!
this is one of those extremely cool things which hide behind very mundane objects or occurrences. Great video as always!
I've seen these radio masts as I live fairly near and had no idea they were for radio clocks. Excellent Tom!
My favorite wristwatch has this feature, the Citizen Radio Controlled series update every night and have a little dial to show whether or not it got reception last night. It’s really cool during spring forward when it stops, twitches, then the hour hand springs forward on its own.
The same thing is inside a lot of G Shock watches. One of the things that makes the M5610-1ER the best watch ever made. Keeps perfect time with radio and don't need to change the battery with solar
Mine is over 15 years old and is still going strong on its original battery, because it's solar powered.
Not even close to the best watch ever made, but very accurate.
@@Jabber-ig3iw A watches purpose is to tell the time and do so accurately, if it can fulfil those functions reliably for vast periods of time then it works, there is no "best" about anything here if the watch fulfils its main purpose. That is of course unless you are getting into the inane world of watch snobbery that cares more about brands and percieved value than anything tangible.
I’ve had a small alarm clock linked to this for about 30 years - and people don’t believe me.
Sadly it had never really kept itself set so whenever there’s a stupid time change like BST I have to manually prod the hour or take the batteries out.
At least it’s survived 3 decades of me dropping it.
Ha! That's funny! Cause my kitchen electronic clock did not survive dropping it. The antenna inside wasn't attached strongly enough and it snapped with a wire. Didn't know that until the clock started drifting by a minute or two. Then I opened it, soldered and secured the antenna back in place. Works like a charm ever since. And it just recently switched itself to summer time too.
@@ragnkja The time signal (MSF) itself does have a summer time flag, but I guess the clock didn't honor that.
My analogue one would adjust itself. Most fun when the clocks went back but it could only go forward so it spun around until it skipped 23 hours.
@@ragnkja it'll stay accurate for as long as the battery can deliver enough power to move the mechanics fast enough.
You’d be lucky if an alarm clock made today lasted 3 years. The times have changed.
Tom Scott has all the answers!
We have those radio clocks at work. Always puzzled me how it works. Thanks Tom!
"Standing by the ocean with a domestic appliance..."
The beginning to a long lost Robert Frost poem.
I think it's actually the title of the original draft of Sittin' on the Dock of the Bay.
“DO NOT TOUCH THE MASER” I wasn’t going to but now I want to
All signs exist for a reason. You just know someone dropped a pen behind there and unplugged the entirety of Britain from time trying to reach back and pick it up
In a previous job, when the UK signal was moved from Rugby up to Anthorn i was task with moving our receive antenna slightly to compensate for the different location. The antenna was a ferrite rod in a white plastic box so it was directional. Being located on the south coast of the UK, we could pick up the DCF77 signal much stronger than Anthorn.
I would have been interested in the radio protocol for transmitting the time data. What exactly gets sent over the air and how often does it update? Is it time only or date also? How much is there error correction for improving resilience? What kind of chips do the clocks contain to decode the data? Etc.
Wikipedia has all the details. See also NPL's website.
I remember these from school. There was always at least one that was stuck ticking away the same second over and over.
Needed a new battery.
"and so we beat on, clocks against the current, borne back ceaselessly into the past..."
*caesium-137ly
The southern hemisphere manages to tell the time okay with out a radio transmitter transmitting the time
Time has stood still in Australia.
That reminds me of the DCF77 radio broadcasting station at Mainflingen between Offenbach and Aschaffenburg in Germany. The clocks for the time signal are located in Braunschweig, quite a bit away. Fascinatingly even my little wristwatch can pick up the long wave signal to synchronize itself every night.
Tom should visit the DLR in Braunschweig in Germany. That's where the German time is measured. The room itself looks fantastic (I once visited it). It is a room with copper walls to avoid any electromagnetic influence from the outside. The time signal is then transferred to Frankfurt from where it is transmitted via longwave at 77.5 KHz.
Funny enough the transmission towers are very close to the 50°N 9°E point - which is in a nearby forest, maybe about a kilometer away.
I bought small weather station in Lidl that said it's "radio controlled". I thought that refers to the temperature sensor being radio connected. But then was surprised when clock got set up by itself
I have a Lidl LCD lounge clock - time, date, moonphase, temp. one slide switch to change from UK to Germany timezone. ~£15 in the bargain bin and I've had it for years.
"Do not touch the maser" taped to the box.
Perfection.
I have visited the room at the US Naval Observatory where they keep time for the military and as a backup to the NIST master clock. The clocks were kept behind bullet resistant glass. Also at the Washington DC TV station I worked at we used a rubidium atomic clock to keep in sync with the NBC network. When it failed we didn't bother replacing it because we no longer needed to be synchronous. Then we got a call from NASA and they wanted to know why our color subcarrier frequency was drifting more than it used to. NASA had been using our super stable signal as a transfer standard to calibrate their own devices. They would send out a daily message noting the frequency offset from their own master clock. When we explained that we were well within FCC standards and didn't plan to install a new atomic clock, they sent us one of their cesium clocks.
We have three of these in my church. One in each of the vestries and one in the tower. Yes the one in the tower is used to set the time on the Victorian tower clock. I’m very impressed at the single take and that Tom must have waited for exactly the right amount of time for each segment from NPL to be edited in. The elapsed time in the video and the clock match to the second, very impressed indeed.
The wire management for that hardware is horrendous. Didn't they even TRY to clean up before the Tom Scott inspection?!? 😆😜
I paused 49 seconds into the video due to the, OMG CABLE MANGEMENT IS A THING!, issue. I think anyone who has worked in IT in almost any capacity would have a similar reaction.
@@jjosua probably no one wants to arrange the down time in case it doesn't come back up again
It's meticulously organised that way, because if they move the cables, it might change the official time by half a nanosecond.
@@DaedalusYoung don't want to add extra length to the cables, it could set us back thousands of years
After the scene with these messy wires I can't focus on the topic anymore. I just keep thinking how is it possible that such a big and important organisation can't make cables right!
Nice to hear how much work goes into the network, I work for a school and they swopped the classic clocks for over 100 of these unfortunately they struggled with signal and would randomly set themselves to other times and to get the time back we had to rest them in a window for 20 minutes.. We replaced the clocks again a few years later.
Very cool and had no idea how important such a institute is 👍
Long may they keep time 😁
Thank you very much
I love the audio quality
🔥❤️🙏
Sixty years ago (when I was a kid), the local radio station transmitted a beep beep beeeeeep on the hour, every hour so you could adjust your clocks. I remember asking my dad why the clocks didn't adjust themselves automatically.
I listen to BBC World Service via SiriusXM satellite radio. The top of the hour beeps are noticably late, due to network latency. As much as 18s late (!!), the one time that I actually checked it.
I had a radio controlled watch once. That thing was great and was an unfortunate casualty to a car door, saved me from a broken wrist though.
This is such a coincidence - only this week did I realise that the round battery-operated 12-hour clock in my classroom automatically stays at the correct time, and I have been wondering every day how/why (Didn't bother to Google it, though - so thanks Tom!) :D
I think time services like that are really interesting, and was disappointed to learn in Australia we seem to have discontinued ours quite a long time ago
Oh that explains why I've never heard of this before. That's a shame :(
My "Citizen Eco-Drive" bought back in 2010 is set automatically by radio, changes to whatever local time I happen to be in and because of the solar panel in its face, never needs a battery or winding. The best watch I have ever owned (including Rolex).
Does it have GPS to get the time zone?
@@Motorman2112 Search for Atomic watch. I think watches capable of time syncing use 60KHz from WWV in US. Don't know what the standard is for other countries.
Even some Casio's have this tech ..
@@Joetechlincolns You still need the time zone. This requires your location to at least a reasonable level (or effectively so).
To really put it to the test, cross the border to or from the west of China in a north or south direction.
The video title really did a disservice to how interesting this video turned out to be! I only decided to watch because you can't go wrong with a Tom Scott video!
I have a little alarm clock that listens to the US version of this time signal, broadcast from Fort Collins, Colorado. I live about 1200 miles away in west Oregon. Works great, runs for about 5 years on a AA battery - over that time scale I don't know if the battery goes flat more from usage or the slow self discharge that limits its shelf life!
I have never seen a radio controlled wall clock with analog hands instead of a little LCD display; it never occurred to me that they exist. Now I want one.
These transmitters always fascinated me when I was younger (having been born and raised in Carlisle, a few miles away). They only recently became the time signal source after Rugby shut down. Was originally a low frequency transmitter for submarines I believe.
Then there's my dad trying to get down the clock to the exact time by spending half an hour and still failing.
I feel called out. ;-) :D
The timing of this vid was great. I'm watching it for the second time
I've had the same radio controlled alarm clock for around 30 years. It's only ever right. Thanks Grandma.
The Canadian version of this, CHU, is even more interesting; in addition to putting out a time signal on a low frequency, its 3330 KHz signal carries Bell 330 modem tones as well as the speaking clock.
Actually, the Canadian version of "this" is the USA's WWVB, which covers much of Canada. The shortwave signals (CHU, WWV) are sufficiently different purpose and usage that they should not be conflated with the VLF time signals topic here.
Nitpick. :-)
It's actually Bell 103-compatible time code.
Never heard about radio controlled clocks. Are these even a thing outside the UK?
Cool nonetheless.
edit: outside Europe?
My watch is radio controlled & yes Atomic timing is normal.
Yes they are. Had a watch on my wrist for years that could do it. I've never visited the UK - only been around Europe a bit and it always worked :)
There are transmitters in Germany, Japan, China and the US (and possibly elsewhere)
Yes. In the US there is an atomic clock in Fort Collins, Colorado.
We in Germany have that too
Thanks for the info. I love your videos because they are direct and a little humorous here and there. When you show locations can you show a map for those of us who might not know geology well. I know UK but not all the little areas. Thank you for all your videos do love them
I work at the NPL! The atomic clocks are there I believe but you can't go see it without clearance, although there is a monitor on the outside which you did show in the video. If you work there you can go calibrate your watch against that monitor!
If you ever come back please let me know, I'd love to show you around! Great vid!
4:46 I remember! the last time you were holding an electric kettle, which was also a clock!
Only half way through the video and falling asleep cos it’s late. Love this. J remember calling the talking clock back the in the 90s
I love that you're holding a clock showing BST that is perfectly aligned to the UTC digital clocks that you briefly cut to at NPL. Nice touch:)
What time is it?
Time for a new Tom Scott video!
f
Adventure Time
I was literally looking up how radio clocks work 3 days ago. This is the second time tom has done this. 🤣
It wasn’t that long ago until I search difference between the Internet time and the atomic clock time differences. I’m so glad this video came up on my feed.
What's so great is that the time change on the clock is just as long as the video itself, so you did that presentation without any (significant) breaks.
We had a bunch of these clocks at my high school in the US. They were a massive improvement to the older hardwired clocks, which drifted by several minutes, and had to go through a reset cycle, every hour.
The best part was when the receiver failed on this particular model clock the clock just went haywire. It would spin forwards or backwards at a seemingly random speed until the battery was depleted. This was 20 years ago though, so I would hope the reliability has improved since then.
Ah, so that's what's happening to the clocks at our school!
Main voltage clocks are more the accurate enough for a school. The grid frequency (at least in europe and the UK) is adjusted so these clocks keep accurate to within seconds. They need to be set once ofcourse, but after that they will keep their time forever, as long as the grid keeps it 50Hz fairly accurate.
Now, my school just has quartz battery clocks, and for some reason they seem never to be right, and constantly need battery changes.
@@slome815 Well, you would still need to account for DST right? And if you imagine a building with 100 clocks, that gets annoying...
@@igorrinkovec6405 Yes, you still have to account for DST. It's not that much work if everyone just changes the time in their own desk / part of the building. At least you don't have to change batteries. Where I work it seems I'm the only one that changes batteries on dead clocks.
@@slome815 The traditional system is to have "slave" clocks which accept advance and reset signals from the master clock. You only need to set the time on the master unit and then every other clock in the building will set itself from that.
I have a watch that does this for over 20 years and have never had to set the time on it once, it even updated when the clock change from GMT to BST
Tom didn't mention that other countries - US, China, etc. - have essentially the same thing. They also compare their time to the one in Paris. Thanks, Tom for making the public aware of what makes our technologies work. ✔️✔️
Hallo Tom, great topic for a watch enthusiast like me. I receive my radio signal from the Mainflingen complex in Germany. Never had a problem receiving a good signal here in the Netherlands (for my Casio Waveceptor watches) . There are great videos about the way the signal itself works. Thanks!
Tom: "If you buy a clock that says radio controlled..."
Europe, US, Japan: "Ah yes, quite normal"
Rest of the world: "What sorcery is THIS!!!"
A catch is that time signals go beyond the country borders, so there are a lot more countries where radio-controlled clocks are a thing. For example South Korea has its own time signal (HLA) but the Japanese time signal (JJY) is more frequently used because you can receive JJY from SK just fine.
Also China
I tell you what I can't get over: that dude's cable management.
Oh my god! My oscilloscope is featured at 3:28 :D Who knew they'd still be using a good old 54645D :D That's awesome.
You can have a radio controlled watch too. Most popular is Casio's technology "Waveceptor" or "Multiband" (5 or 6) where you specify one of the 6 transmitters around the world (UK, Germany, USA, two in Japan, China) and your watch just synchronises every day some time after midnight, when there's least interferrence.
If you're out of range, though, you're out of luck.
I have a Casio G-shock GW-M5610U (a standard radio controlled, solar powered, abuse resistant watch with a classic 80's design) and it's nifty to set my other watches to it.
Because of Tom's clock it is again documented that Tom uses only one take for a video and rather tries to do it another time than to blend different takes together in one video ;)
Thanks Tom. ❤️
Cool beans! I used to work for the guy (Mark Witsaman) who invented and patented the method of deriving time from the radio signal to control a common clock.
We need to make a playlist of every time Tom has been standing somewhere random with an appliance.
Great video and NPL are clearly amazing but their cable management leaves a lot to be desired!! Haha
They specifically picked that location as a backdrop. Goodness only knows what the less aesthetic cabling looks like...
Oh no, my illusion of atomic clocks looking cool and sci-fi is completely shattered by this video. A lot less nixie tubes than I imagined.
Their are atomic clocks small enough to fit inside your laptop now. Conversely look up Cesium Fountain Clock for something more from your imagination that is bleeding edge.
atomic clocks just have one really big atom inside for increased accuracy