0:00:06 > 0:00:09Have you ever noticed how completely dependent we are
0:00:09 > 0:00:12on knowing the exact time? I mean, we take time for granted now,
0:00:12 > 0:00:16but just 150 years ago, it was all very different.
0:00:19 > 0:00:23For instance, back then, America had hundreds of towns
0:00:23 > 0:00:26each using its own different local time,
0:00:26 > 0:00:29and 50 railroad companies each with its own time.
0:00:32 > 0:00:36It was a total nightmare trying to take a train around the country.
0:00:37 > 0:00:41I mean, you'd have to be a math major to figure out what time it is.
0:00:41 > 0:00:44And you could forget about ever owning a watch,
0:00:44 > 0:00:46unless you were incredibly wealthy!
0:00:47 > 0:00:48Back in the mid-1800s,
0:00:48 > 0:00:53handcrafted luxury watches were the only kind on the market.
0:00:53 > 0:00:55So, who fixed these problems?
0:00:57 > 0:01:01Well, it was a railway clerk and a cobbler's son.
0:01:01 > 0:01:03These guys are classic examples
0:01:03 > 0:01:07of the kind of people who actually made the modern world.
0:01:07 > 0:01:09People you've probably never heard of.
0:01:12 > 0:01:15These are hobbyists and garage inventors...
0:01:18 > 0:01:21..maverick characters doing extraordinary things.
0:01:24 > 0:01:28The thing about these pioneers is that they didn't just master time.
0:01:28 > 0:01:32They also set in motion an amazing chain reaction of ideas.
0:01:34 > 0:01:37Resulting in innovations that would go on to affect
0:01:37 > 0:01:40every aspect of our lives.
0:01:40 > 0:01:42From how we navigate...
0:01:42 > 0:01:44to how we work.
0:01:46 > 0:01:48Enabling sophisticated technology,
0:01:48 > 0:01:50and time travel into the past.
0:01:54 > 0:01:55I want to show how the link
0:01:55 > 0:01:58between all these apparently unconnected worlds
0:01:58 > 0:02:01starts with the heroes of time.
0:02:05 > 0:02:08All my career, I've been fascinated
0:02:08 > 0:02:10by ideas and innovation, from writing books
0:02:10 > 0:02:13about the great British innovators of the Enlightenment
0:02:13 > 0:02:15or the Industrial Revolution,
0:02:15 > 0:02:18to my work with Silicon Valley start-ups,
0:02:18 > 0:02:20and what I've learned about innovation
0:02:20 > 0:02:22is that the experiences of the past
0:02:22 > 0:02:25are still the best roadmap for our future.
0:02:25 > 0:02:30And that's why I want to tell you the story of how we got to now.
0:02:42 > 0:02:44Sounding, 758...
0:02:44 > 0:02:48'If you want to completely mess with your sense of time,
0:02:48 > 0:02:53'this is the place to come - the nuclear submarine USS Ashville.'
0:02:54 > 0:02:56Steven, third wake-up, time to get up.
0:03:00 > 0:03:02Most of us, when we wake up or go to sleep,
0:03:02 > 0:03:07we're following the natural cues of the sun rising or setting,
0:03:07 > 0:03:11but on a submarine, when you're out on the ocean,
0:03:11 > 0:03:13underwater for months at a time,
0:03:13 > 0:03:16you have none of those cues available to you.
0:03:16 > 0:03:20So people living on a modern submarine are as far removed
0:03:20 > 0:03:24from the natural rhythms of time as any human beings on the planet.
0:03:27 > 0:03:30This submarine is about to leave port for the next month.
0:03:32 > 0:03:34Up scope.
0:03:34 > 0:03:36'The only view Lieutenant Commander Jason Deichler will have
0:03:36 > 0:03:40'of the outside world is through this periscope.'
0:03:40 > 0:03:43That's a really clear image but, gosh, it must be amazing
0:03:43 > 0:03:46to go for like 30 days and that's your only glimpse of sunlight.
0:03:46 > 0:03:48That's our only glimpse of topside.
0:03:48 > 0:03:51That's our only chance to ever see the sunlight.
0:03:51 > 0:03:54I feel like a... Can I just fulfil a lifelong fantasy here,
0:03:54 > 0:03:56- if you don't mind?- Absolutely.
0:03:56 > 0:03:58Here we go, I'm going to do it. Dive! Dive!
0:03:58 > 0:04:00KLAXON BLARES
0:04:03 > 0:04:06'But the crew aren't just deprived of the sun.
0:04:06 > 0:04:09'They've also got six hours taken out of their day.
0:04:11 > 0:04:14'Because every day aboard the USS Ashville is sped up
0:04:14 > 0:04:16'to the cycle of an 18-hour clock.'
0:04:18 > 0:04:21'The crew gets six hours on watch,
0:04:21 > 0:04:24'six hours on light duties and recreation,
0:04:24 > 0:04:27'six hours of sleep, and then it begins all over again.'
0:04:32 > 0:04:34'By completely detaching from sunlight,
0:04:34 > 0:04:37'the crew's sense of time can be heavily manipulated.'
0:04:43 > 0:04:47I have a lot of questions about this, it's fascinating, but why do you do it?
0:04:47 > 0:04:51Well, we have limited amount of resources and men on board the ship
0:04:51 > 0:04:54and it's our way to get through the day and maintain the amount of sleep
0:04:54 > 0:04:56that you need and rest you need to stay on watch.
0:04:56 > 0:05:00And so, not only are you guys breaking from the 24-hour day,
0:05:00 > 0:05:02but everybody's on a different clock, right?
0:05:02 > 0:05:04Somebody's night-time is somebody's daytime?
0:05:04 > 0:05:06Absolutely, and that shifts continuously
0:05:06 > 0:05:08because of the way the 18-hour clock rotates.
0:05:08 > 0:05:11So when a man wakes up, all he knows is "I need to get on watch."
0:05:11 > 0:05:14He's not as concerned if it's light or dark outside,
0:05:14 > 0:05:16cos we don't get the chance to see the light or dark
0:05:16 > 0:05:18as much as the people on the surface do.
0:05:18 > 0:05:19Those strange surface-dwellers!
0:05:19 > 0:05:21Yes, the surface-dwellers.
0:05:21 > 0:05:24We just disrupt everything that has to do with the clock.
0:05:24 > 0:05:27We kind of become masters of our own time, in a way.
0:05:32 > 0:05:36Most of us would have a hard time living on an 18-hour day,
0:05:36 > 0:05:39so far removed from the sun, but the truth is,
0:05:39 > 0:05:42almost all of us today are living on artificial clocks
0:05:42 > 0:05:44of one form or another.
0:05:44 > 0:05:49How did we get so far out of sync with the natural rhythms of the sun?
0:05:49 > 0:05:52That's a story that takes us back more than five centuries.
0:05:55 > 0:05:57CHURCH BELL RINGS
0:05:58 > 0:06:02For millennia, we'd rise with the sun and go to bed at dusk.
0:06:04 > 0:06:08The very notion of time-keeping was all pretty relaxed.
0:06:08 > 0:06:12I mean, you wouldn't want to set your watch
0:06:12 > 0:06:16by this typical 14th-century mechanical clock in Tuscany,
0:06:16 > 0:06:19which could lose or gain up to 30 minutes a day.
0:06:20 > 0:06:25Back then, time-keeping was a comically imprecise pursuit.
0:06:25 > 0:06:27I mean, a clock like this one would be corrected
0:06:27 > 0:06:30with occasional readings of a sundial
0:06:30 > 0:06:33or sometimes just looking up at the sky and making a ballpark guess.
0:06:33 > 0:06:36Which meant that every clock in every town
0:06:36 > 0:06:39was telling a different and irregular time.
0:06:39 > 0:06:44But the thing is, no-one really cared back then because, 500 years ago,
0:06:44 > 0:06:48the whole idea of split-second accuracy in timing
0:06:48 > 0:06:52would have been as useful as a satellite dish.
0:06:57 > 0:07:01Back then, meeting times were set by the movement of the sun
0:07:01 > 0:07:05and time was measured by the daily tasks required to work the land.
0:07:05 > 0:07:08For example,
0:07:08 > 0:07:11if I wanted to arrange a meeting with someone in 15 minutes' time,
0:07:11 > 0:07:14I might say something like, "I'll see you in the milking of a cow."
0:07:17 > 0:07:20This was all rather vague and, as a result,
0:07:20 > 0:07:23daily schedules were completely unregulated.
0:07:30 > 0:07:36But our relationship to time was about to change, thanks to this guy -
0:07:36 > 0:07:37Galileo.
0:07:38 > 0:07:42A born rebel, he became a legend for proving that the sun,
0:07:42 > 0:07:46not the Earth, was at the centre of our solar system.
0:07:46 > 0:07:53But in 1583, he was just an unknown student who would discover something
0:07:53 > 0:07:57that would forever change the way we travelled, traded and worked.
0:07:59 > 0:08:03You ready? Hold it up, use all your strength. Perfect.
0:08:03 > 0:08:05- Thank you so much.- Sure, sure.
0:08:07 > 0:08:11Of course, we had a bunch of professionally trained cameramen around,
0:08:11 > 0:08:13but they asked me to do it.
0:08:13 > 0:08:17Most people come to Pisa for its leaning tower.
0:08:17 > 0:08:20Yeah, there? Oh, my God, it's really heavy.
0:08:21 > 0:08:23But the origins of modern time as we know it
0:08:23 > 0:08:28can be found close by, in the city's magnificent cathedral.
0:08:32 > 0:08:34It's here that Galileo has an insight
0:08:34 > 0:08:37that will revolutionise how we measure time.
0:08:38 > 0:08:41The story goes that it's 1583,
0:08:41 > 0:08:47Galileo is 19 years old, and he attends prayers here every day.
0:08:47 > 0:08:49But one visit, he gets distracted
0:08:49 > 0:08:53by something that most of us wouldn't even notice -
0:08:53 > 0:08:54a swinging altar lamp.
0:08:59 > 0:09:02Highly musical and sensitive to tempo,
0:09:02 > 0:09:04he studies the rhythmic movement.
0:09:07 > 0:09:10Galileo then uses his pulse as a metronome
0:09:10 > 0:09:14to time the swing of the altar lamp, and he notices something unusual.
0:09:16 > 0:09:20No matter how far or how short the lamp swings,
0:09:20 > 0:09:23it takes an equal amount of time to swing back and forth.
0:09:27 > 0:09:28This is what I love about Galileo.
0:09:28 > 0:09:30I mean, he's a teenager,
0:09:30 > 0:09:34and all the other kids are dutifully reciting the Lord's Prayer
0:09:34 > 0:09:37and he's nerding out on the physics of the pendulum.
0:09:39 > 0:09:41This is what's so critical
0:09:41 > 0:09:45to Galileo's contribution in changing time - his rebellious nature.
0:09:47 > 0:09:50Back then, a good scholar was supposed to simply quote
0:09:50 > 0:09:54existing scientific knowledge, not investigate it.
0:09:56 > 0:10:00But Galileo's more keyed in to the thrill of discovery than convention,
0:10:00 > 0:10:04and he sets up an experiment which confirms his observations.
0:10:07 > 0:10:12Galileo writes to a friend, "The marvellous property of the pendulum
0:10:12 > 0:10:18"is that it makes all its vibrations, large or small, in equal times."
0:10:18 > 0:10:22And it's that discovery, the idea of equal time,
0:10:22 > 0:10:26that will become one of the foundations of modern life.
0:10:29 > 0:10:33This gives Galileo the seed of an idea -
0:10:33 > 0:10:37a hunch that a pendulum's an important tool for measurement.
0:10:38 > 0:10:44So, what happens next? Well, nothing.
0:10:47 > 0:10:51That's partly because Galileo is busy becoming a genius in physics,
0:10:51 > 0:10:53mathematics and astronomy,
0:10:53 > 0:10:56alienating his academic colleagues...
0:10:56 > 0:10:57and struggling with money.
0:10:59 > 0:11:03But this seed won't actually bear fruit for almost 60 years
0:11:03 > 0:11:08because, right now, no-one actually needs an accurate clock.
0:11:08 > 0:11:11And this is the interesting thing about great ideas -
0:11:11 > 0:11:16just like plants, they often need the right set of conditions to flourish.
0:11:18 > 0:11:22So this insight is just parked in a corner of Galileo's brain.
0:11:24 > 0:11:27That is, until a new set of conditions come along
0:11:27 > 0:11:33which, luckily for Galileo, are backed up by a whole heap of cash.
0:11:40 > 0:11:44In 1598, King Philip III of Spain
0:11:44 > 0:11:47grabs the attention of every scientist in Europe
0:11:47 > 0:11:50by offering a life pension in ducats to anyone who can solve
0:11:50 > 0:11:56the greatest scientific challenge of the age - a way to measure longitude.
0:11:57 > 0:11:59Oh, boy!
0:12:00 > 0:12:05Ships in Galileo's day were sailing blind over vast new distances
0:12:05 > 0:12:07and frequently meeting with disaster.
0:12:10 > 0:12:14For the New World to be conquered, something had to be done.
0:12:15 > 0:12:18All right, so, what happens if I try and actually take the wheel?
0:12:18 > 0:12:20Yeah, I'm happy to give you the wheel.
0:12:20 > 0:12:23- I have no training whatsoever. - No problem.
0:12:23 > 0:12:26- Nothing can go wrong. - Carry on.- Thank you.
0:12:29 > 0:12:32So, I'm piloting or skippering or something -
0:12:32 > 0:12:35I don't even know what I'm doing with this sailboat -
0:12:35 > 0:12:40but I've been given the instructions here to follow 060 on the compass,
0:12:40 > 0:12:44which I'm kind of managing to do, although it's pretty hard.
0:12:45 > 0:12:48But the bigger problem is I have no idea where I am.
0:12:50 > 0:12:52So, what does any of this have to do with time?
0:12:55 > 0:12:57It was maritime navigation
0:12:57 > 0:13:01that would drive the advancement in our measurement of time.
0:13:01 > 0:13:06On land, there's no need for clocks that are accurate to the second.
0:13:06 > 0:13:09But at sea, in this age of discovery,
0:13:09 > 0:13:13sailors are starting to realise that accurate measurement of time
0:13:13 > 0:13:16is crucial to navigation,
0:13:16 > 0:13:20which means that the need for accurate clocks
0:13:20 > 0:13:23won't come from the calendar, it will come from the map.
0:13:28 > 0:13:30Navigators can figure out their latitude -
0:13:30 > 0:13:33how far north or south they are - by reading the sun.
0:13:35 > 0:13:39But to figure out longitude and how far east or west they're going,
0:13:39 > 0:13:40they need two things -
0:13:40 > 0:13:42the local time on the ship,
0:13:42 > 0:13:47and the exact time where they left port.
0:13:48 > 0:13:51Using the difference between these two times,
0:13:51 > 0:13:53they can calculate their exact position.
0:13:55 > 0:13:58But with no accurate clock on board,
0:13:58 > 0:14:00they soon end up completely lost.
0:14:02 > 0:14:04I have to get us back on course here.
0:14:11 > 0:14:14So this challenge, accompanied by a fat reward,
0:14:14 > 0:14:16is looking good to Galileo,
0:14:16 > 0:14:19who's now a father of three illegitimate children.
0:14:21 > 0:14:24The memory of the pendulum is yet to surface
0:14:24 > 0:14:28because by now, Galileo's completely obsessed by astronomy
0:14:28 > 0:14:31and the new invention of the telescope.
0:14:31 > 0:14:36In 1610, he discovers that Jupiter has its own orbiting moons
0:14:36 > 0:14:39which eclipse in a regular and predictable way.
0:14:42 > 0:14:45He proposes that sailors use these movements
0:14:45 > 0:14:47as a celestial time-keeper in the sky.
0:14:50 > 0:14:53Theoretically, it's a brilliant idea.
0:14:53 > 0:14:56But in practice, bobbing around in the middle of the ocean,
0:14:56 > 0:15:00it's almost impossible to make precise astronomical readings.
0:15:00 > 0:15:04I mean, I'm having a hard enough time just seeing that seagull over there,
0:15:04 > 0:15:07much less figuring out what's happening with the moons of Jupiter.
0:15:09 > 0:15:11OK, so that doesn't work.
0:15:12 > 0:15:16But it's this dead end which finally brings Galileo
0:15:16 > 0:15:21back to his original insight into the equal time of the pendulum.
0:15:23 > 0:15:28Staring at the heavens reminds him of gazing up inside the cathedral.
0:15:30 > 0:15:32Those swinging altar lamps.
0:15:33 > 0:15:36The pendulum experiment of equal time.
0:15:40 > 0:15:42The desperate need for an accurate time-keeper.
0:15:45 > 0:15:47And bingo!
0:15:47 > 0:15:49Galileo finally realises
0:15:49 > 0:15:52that a pendulum could be used to regulate clocks.
0:15:57 > 0:16:00So this is what he comes up with -
0:16:00 > 0:16:04a design for a perfect swinging pendulum.
0:16:04 > 0:16:05Its beats are equal
0:16:05 > 0:16:08and it can be used to control the hands of the clock.
0:16:11 > 0:16:14It's a revolutionary idea,
0:16:14 > 0:16:17but Galileo's now near the end of his life
0:16:17 > 0:16:20and doesn't get the chance to test it at sea.
0:16:22 > 0:16:25This is a classic case of someone failing to solve a problem,
0:16:25 > 0:16:29but, in failing, they hit upon an even more important idea.
0:16:29 > 0:16:32Galileo never wins any of the longitude prizes,
0:16:32 > 0:16:36but he does design one of the most important inventions of the age -
0:16:36 > 0:16:38the pendulum clock.
0:16:41 > 0:16:44This idea that's taken decades to come into focus
0:16:44 > 0:16:48is now going to have massive repercussions for the modern world.
0:16:50 > 0:16:54Within 15 years, Dutch astronomer Christiaan Huygens
0:16:54 > 0:16:57produces the first true pendulum clock.
0:16:58 > 0:17:03This technology is now 100 times more precise than previous clocks,
0:17:03 > 0:17:07with the loss or gain cut down to just one minute a week.
0:17:09 > 0:17:13More accurate clocks also mean better health care.
0:17:13 > 0:17:16Now able to record the passing of seconds,
0:17:16 > 0:17:20doctors start using clocks for the first time to measure our pulses.
0:17:22 > 0:17:25The craft of building accurate clocks has another payoff.
0:17:25 > 0:17:29Some 100 years later, Englishman John Harrison
0:17:29 > 0:17:31finally solves the longitude problem
0:17:31 > 0:17:34by inventing the marine chronometer,
0:17:34 > 0:17:37thanks to ever-evolving clock-making expertise.
0:17:40 > 0:17:41With better command of the seas,
0:17:41 > 0:17:44maritime trade and exploration now flourish.
0:17:46 > 0:17:49In 1831, a ship sails to the Galapagos Islands
0:17:49 > 0:17:56to fix the longitudes of foreign lands with the help 22 chronometers.
0:17:56 > 0:17:59On board is the young Charles Darwin,
0:17:59 > 0:18:02whose findings there form the basis of the Theory of Evolution.
0:18:05 > 0:18:08All this evolved thanks to the pendulum clock,
0:18:08 > 0:18:10first imagined by Galileo,
0:18:10 > 0:18:14which will continue to be our best way of measuring time
0:18:14 > 0:18:16until the early 20th century.
0:18:20 > 0:18:21Here in San Francisco,
0:18:21 > 0:18:26we have the largest wind-up-dialled mechanical clock in the world.
0:18:27 > 0:18:32It's housed inside the 73-metre tower of the iconic Ferry Building,
0:18:32 > 0:18:34and was built in 1898.
0:18:38 > 0:18:41Here's the pendulum itself. It's really cool to see this,
0:18:41 > 0:18:43this is really the first great breakthrough
0:18:43 > 0:18:45in the measurement of time.
0:18:46 > 0:18:51Dorian Clair has been repairing clocks since he was eight years old.
0:18:51 > 0:18:55This would have been kind of state-of-the-art for a clock
0:18:55 > 0:18:57at the turn of the century back then?
0:18:57 > 0:18:59Actually, it's still state-of-the-art.
0:18:59 > 0:19:03There's no pendulums that have been invented that work better.
0:19:03 > 0:19:06How accurate do you think it was?
0:19:06 > 0:19:11When it was built, it was guaranteed to be within five seconds a week.
0:19:11 > 0:19:15Right. Do you think if Galileo could see this right now,
0:19:15 > 0:19:18he would instantly recognise what this was?
0:19:18 > 0:19:21Oh, he probably would come up with some improvement.
0:19:21 > 0:19:24- But it's been working... - He's so annoying that way!
0:19:24 > 0:19:26"I got a better idea how to do it!"
0:19:31 > 0:19:34The pendulum clock sets a new standard
0:19:34 > 0:19:37in the accurate measurement of time.
0:19:37 > 0:19:41But back then, unless you were a sailor, you didn't really have
0:19:41 > 0:19:44that much need for minute-by-minute accuracy in your clocks.
0:19:44 > 0:19:47I mean, most people were living pastoral lives.
0:19:47 > 0:19:49They didn't have office buildings with meetings
0:19:49 > 0:19:53or trains and ferries to catch and appointments all through the day.
0:19:54 > 0:19:57But then, in the middle of the 18th century,
0:19:57 > 0:20:00something very interesting begins to happen.
0:20:07 > 0:20:09By the 1760s, British clock-making
0:20:09 > 0:20:13is among the most technically advanced trades in the world.
0:20:15 > 0:20:17Craftsmen have devised tools
0:20:17 > 0:20:21to make tiny, precision-made parts of gears and screws.
0:20:22 > 0:20:25And this expertise is up-scaled to make much bigger,
0:20:25 > 0:20:30more sophisticated machines like steam engines and mechanical looms.
0:20:32 > 0:20:35All of which kick-starts what is perhaps
0:20:35 > 0:20:37the biggest social upheaval ever -
0:20:37 > 0:20:38the Industrial Revolution.
0:20:43 > 0:20:47Suddenly, our experience of time changes for ever.
0:20:48 > 0:20:51People leave the fields to work in new factories.
0:20:51 > 0:20:55They're no longer working by sunlight or paid by the task.
0:20:55 > 0:20:59Workers must clock in for the first time en masse for 14-hour shifts.
0:21:01 > 0:21:03They rebel by showing up late for work.
0:21:05 > 0:21:09Factories hire "wakers" to rouse them from their sleep on dark mornings.
0:21:13 > 0:21:16The disruption to our body clocks gives birth to a major new trade
0:21:16 > 0:21:20in the drugs of tea and coffee to help us stay awake.
0:21:22 > 0:21:25We're now working on artificial time,
0:21:25 > 0:21:28breaking away from a life that followed the sun.
0:21:36 > 0:21:42When we think about the technology that created the Industrial Age,
0:21:42 > 0:21:46we naturally think of thunderous engines and steam-powered looms.
0:21:46 > 0:21:50But imagine some alternate history where, for whatever reason,
0:21:50 > 0:21:52time-keeping technology lags behind
0:21:52 > 0:21:56the other machines that made the Industrial Age -
0:21:56 > 0:21:59would the Industrial Revolution have even happened?
0:21:59 > 0:22:03You can make a reasonably good case that the answer is no,
0:22:03 > 0:22:07because beneath the cacophony of the mills,
0:22:07 > 0:22:12another softer but equally important sound is everywhere -
0:22:12 > 0:22:16the steady ticking of pendulum clocks, quietly keeping time.
0:22:24 > 0:22:26Time in the early 1800s
0:22:26 > 0:22:30is still in the hands of those who can afford it,
0:22:30 > 0:22:33giving even more power to the powerful,
0:22:33 > 0:22:37to nation-builders, and mill-owners and aristocrats.
0:22:37 > 0:22:42And watches were exclusive status symbols for the privileged few.
0:22:42 > 0:22:46Common people had no hope of ever owning a watch,
0:22:46 > 0:22:51which made it so much harder for them to gain control over their own time.
0:22:58 > 0:23:01The story of how we all got to wear watches
0:23:01 > 0:23:05would have far-reaching and unexpected consequences
0:23:05 > 0:23:09and change everything from our moral values to the way we wage war.
0:23:11 > 0:23:14So, what are we looking at here?
0:23:14 > 0:23:17So, this is a very rare piece called the Minute Repeater.
0:23:17 > 0:23:20'I've come to meet Lawrence Pettinelli
0:23:20 > 0:23:22'at the traditional watchmaker Patek Philippe,
0:23:22 > 0:23:25'to shop for a watch 19th-century style.'
0:23:27 > 0:23:31Not to be too indelicate about this, but what does one of these go for?
0:23:31 > 0:23:33This particular piece in rose gold
0:23:33 > 0:23:36- is 739,000 Swiss francs. - OK, in dollars?
0:23:36 > 0:23:40In dollars, approximately 750,000 at the current exchange rate.
0:23:40 > 0:23:42750,000, that's worth more than my arm.
0:23:44 > 0:23:48That's impressive. OK, so, why is this so expensive?
0:23:48 > 0:23:51Well, first of all, it takes almost two years to produce,
0:23:51 > 0:23:56and you have very few watchmakers who can actually do this work.
0:24:00 > 0:24:03Just as in a 19th-century workshop,
0:24:03 > 0:24:06these watches are handmade with exquisite precision
0:24:06 > 0:24:09and they're still status symbols today.
0:24:09 > 0:24:13Look at all those tiny little intricate pieces down there.
0:24:13 > 0:24:16It's almost like a little city.
0:24:16 > 0:24:20Some of these components are as small as the breadth of a human hair.
0:24:21 > 0:24:24So, they're actually screwing these things in by hand?
0:24:24 > 0:24:27- They're screwing them in by hand. - It doesn't seem... I mean,
0:24:27 > 0:24:29it feels like you would have to train, like, fleas to actually,
0:24:29 > 0:24:32you know, put those screws in. That's extraordinary.
0:24:35 > 0:24:37We're used to it, now in the Electronics Age,
0:24:37 > 0:24:40that our world is populated by all these objects
0:24:40 > 0:24:44that have this meticulous, tiny, little mechanical universe to them
0:24:44 > 0:24:46that you can only see through a microscope.
0:24:46 > 0:24:48But in the middle of the 19th century,
0:24:48 > 0:24:52a watch like this would have been really the only object in our lives
0:24:52 > 0:24:55that would have that level of precision engineering to it.
0:24:55 > 0:24:58It would have been a real object of wonder.
0:25:00 > 0:25:03I've also carved my initials into this one. No-one will ever know.
0:25:09 > 0:25:13Today, you don't have to spend a fortune to buy a watch,
0:25:13 > 0:25:17you can pick one up on the street for a couple of bucks.
0:25:17 > 0:25:19But back in the mid-1800s,
0:25:19 > 0:25:23handcrafted luxury watches were the only kind on the market.
0:25:26 > 0:25:29The next leap forward in time and who could own it
0:25:29 > 0:25:33would come to us thanks to this guy - Aaron Dennison,
0:25:33 > 0:25:38a man so obsessed with his vision that he defied public opinion,
0:25:38 > 0:25:42earning himself a local reputation as a madman.
0:25:43 > 0:25:48But Dennison's no killer, nor is he insane - he's an ideas man.
0:25:49 > 0:25:52In 1826, the 14-year-old Dennison
0:25:52 > 0:25:55is working in his father's cobbler shop.
0:25:57 > 0:26:02And he sees his dad painstakingly custom-making leather soles
0:26:02 > 0:26:05for each individual, and so one day he says to his father,
0:26:05 > 0:26:12"Why don't we make a batch of leather soles all at once for popular sizes?"
0:26:12 > 0:26:15And this ends up saving his father a lot of time.
0:26:15 > 0:26:19But the usefulness of Dennison's idea won't end there.
0:26:22 > 0:26:26Dennison can't help but hatch new business ideas.
0:26:26 > 0:26:29Aged 27, he's got his own watch shop.
0:26:29 > 0:26:34He gets first-hand insight into this laborious boutique industry
0:26:34 > 0:26:37where many different people hand-produce many different parts
0:26:37 > 0:26:39to make a single watch.
0:26:39 > 0:26:43People are convinced this is the only way to do it.
0:26:43 > 0:26:48In 1840, he causes a storm of controversy by predicting
0:26:48 > 0:26:52that in ten years' time, watches will be made by machinery.
0:26:52 > 0:26:54The public pour scorn on the idea.
0:26:54 > 0:26:58One magazine goes so far as to call him the "lunatic of Boston".
0:27:02 > 0:27:04But as with Galileo,
0:27:04 > 0:27:09Dennison can't drive progress by simply accepting conventional wisdom.
0:27:09 > 0:27:13In the face of ridicule, he sticks to his vision.
0:27:15 > 0:27:19Visiting a nearby armoury in Springfield, Massachusetts,
0:27:19 > 0:27:23Dennison sees the weapons industry is making guns faster and cheaper
0:27:23 > 0:27:26by producing interchangeable parts -
0:27:26 > 0:27:30that is, identical parts made in batches by machines.
0:27:33 > 0:27:36Now, a hunch from his father's shoe shop
0:27:36 > 0:27:39and the experience of clock-makers
0:27:39 > 0:27:44and his observations of the rifle industry all start to morph together
0:27:44 > 0:27:47into the beginnings of a commercial plan.
0:27:47 > 0:27:49Dennison is going to make machines
0:27:49 > 0:27:52that can produce interchangeable parts
0:27:52 > 0:27:55so that he can mass-produce watches all under one roof.
0:27:58 > 0:28:01That's the thing about great innovations -
0:28:01 > 0:28:05they're often not stand-alone flashes of inspiration,
0:28:05 > 0:28:08but they're created by observing something in one field
0:28:08 > 0:28:10and bringing it over to another.
0:28:10 > 0:28:12Transferring the idea.
0:28:17 > 0:28:20For example, people think that Henry Ford invented the production line,
0:28:20 > 0:28:25but what he actually did was take the idea from Chicago's meat-packers,
0:28:25 > 0:28:28who removed cuts of beef from a carcass
0:28:28 > 0:28:31as it was passed along a trolley until nothing was left.
0:28:34 > 0:28:37Ford reversed this process for the production of his Model T,
0:28:37 > 0:28:42creating the assembly line and making cars affordable to the masses.
0:28:46 > 0:28:49Just like Ford, Dennison brings together innovative ideas
0:28:49 > 0:28:53to help millions afford something they could only dream of.
0:28:57 > 0:28:59After finding investors,
0:28:59 > 0:29:04Dennison builds this huge factory in Waltham, Massachusetts.
0:29:04 > 0:29:06It's a tremendous operation,
0:29:06 > 0:29:10it's filled with nearly 100 employees operating complex machinery.
0:29:10 > 0:29:14It's the first production line for manufacturing watches.
0:29:16 > 0:29:21Mass-producing the relatively large parts for guns is one thing,
0:29:21 > 0:29:25but it's completely new territory to mass-produce components
0:29:25 > 0:29:27the size of a flea for watches.
0:29:29 > 0:29:31New machines need to be invented to pull it off,
0:29:31 > 0:29:33and this doesn't come cheap.
0:29:35 > 0:29:36Despite glimmers of hope,
0:29:36 > 0:29:40Dennison and his team are constantly going back to the drawing board.
0:29:42 > 0:29:44But Dennison's like a dog with a bone.
0:29:44 > 0:29:48He's so obsessed with his idea that he runs out of money,
0:29:48 > 0:29:50has to sell his factory
0:29:50 > 0:29:53and suffer the indignity of returning as an employee.
0:29:54 > 0:29:59But ironically, Dennison's about to be rescued from his personal crisis
0:29:59 > 0:30:02by a crisis unfolding on the national level.
0:30:07 > 0:30:11The outbreak of the Civil War brings Dennison a new business idea.
0:30:14 > 0:30:18Despite being ordered by his new boss not to pursue any new projects,
0:30:18 > 0:30:20what does this crazy guy do?
0:30:22 > 0:30:25He waits until the boss is away on a honeymoon
0:30:25 > 0:30:31and orders work on another watch, a cheap model with a patriotic name
0:30:31 > 0:30:36that could be marketed to a captive audience with time on their hands.
0:30:39 > 0:30:42And this is what they produce.
0:30:42 > 0:30:46A simple, inexpensive watch, targeted at soldiers and named after
0:30:46 > 0:30:51one of the signers of the Declaration of Independence - William Ellery.
0:30:51 > 0:30:57It's a steal at 13, and a fraction of previous watch prices.
0:30:57 > 0:31:02The so-called "soldier's watch" accounts for 45% of Dennison's sales.
0:31:04 > 0:31:07The Ellery watch is a break-out hit -
0:31:07 > 0:31:12over 160,000 of them are sold, an unprecedented amount.
0:31:12 > 0:31:15Even Abraham Lincoln has one.
0:31:15 > 0:31:17Dennison has democratised time.
0:31:17 > 0:31:21In just two decades, watches become ten times cheaper,
0:31:21 > 0:31:24making them affordable to a mass market.
0:31:24 > 0:31:29The watch becomes the first must-have hi-tech gadget.
0:31:31 > 0:31:33Thanks to a crazy idea,
0:31:33 > 0:31:37a transformation of how we experience time now takes place.
0:31:38 > 0:31:41With more and more people carrying watches,
0:31:41 > 0:31:44we start to synchronise our actions.
0:31:45 > 0:31:48Before wide access to time-keepers,
0:31:48 > 0:31:51battles were started by the unreliable boom of a cannon.
0:31:53 > 0:31:57The Civil War Battle of Vicksburg in 1863
0:31:57 > 0:32:01is the first ever initiated by the synchronisation of watches.
0:32:02 > 0:32:04This forever changes the way we fight.
0:32:07 > 0:32:10Watch-ownership spurs an obsession with punctuality.
0:32:10 > 0:32:13It becomes a social virtue to keep good time,
0:32:13 > 0:32:15and people buy watches for their children
0:32:15 > 0:32:17to enhance their chances in life.
0:32:21 > 0:32:24Cookbooks evolve from never using time references
0:32:24 > 0:32:27to now offering recipes with timed instructions.
0:32:30 > 0:32:33Team sports start to form national leagues
0:32:33 > 0:32:36which run on much stricter schedules,
0:32:36 > 0:32:38allowing masses of people to attend at a fixed hour.
0:32:45 > 0:32:47Time gives us the power
0:32:47 > 0:32:51to organise and improve the efficiency of our lives.
0:32:51 > 0:32:53But there's a deep irony here
0:32:53 > 0:32:57because the more we start to own our own time,
0:32:57 > 0:33:00the more time starts to own us.
0:33:00 > 0:33:02We can finely tune our schedules,
0:33:02 > 0:33:04but we're constantly worrying about them
0:33:04 > 0:33:07and getting anxious about being late.
0:33:07 > 0:33:10So not only do watches liberate us,
0:33:10 > 0:33:12but they also start to enslave us.
0:33:16 > 0:33:18But 130 years ago,
0:33:18 > 0:33:22there were other consequences of us all owning watches.
0:33:23 > 0:33:26As more and more people in the 19th century
0:33:26 > 0:33:29can own a watch and synchronise their activities,
0:33:29 > 0:33:34it slowly dawns on society that it's not just groups of people
0:33:34 > 0:33:37but whole nations that need to get on the same clock.
0:33:41 > 0:33:43856 contact London on 118...
0:33:43 > 0:33:46..Charlie, hold short 27 left...
0:33:46 > 0:33:49Contact Tower, channel 11...
0:33:49 > 0:33:51This is Heathrow Airport,
0:33:51 > 0:33:54which transports more international passengers
0:33:54 > 0:33:56than any other airport in the world.
0:33:56 > 0:33:59Turn right onto taxiway alpha, holding point is Saturn...
0:33:59 > 0:34:02The people in the Air Traffic Control Centre coordinate
0:34:02 > 0:34:05over 1,300 flights a day
0:34:05 > 0:34:08with planes landing and taking off every 45 seconds.
0:34:11 > 0:34:15It's a miracle of scheduling, and now I'm going to have a go at it.
0:34:19 > 0:34:23Not for real, but in their simulator with trainer David Marshall.
0:34:25 > 0:34:26Just like in the real tower,
0:34:26 > 0:34:29the most important piece of equipment in the whole room
0:34:29 > 0:34:31is the simple, everyday clock.
0:34:33 > 0:34:35Every second counts as a departures controller.
0:34:35 > 0:34:37If you can save two seconds
0:34:37 > 0:34:39per airplane, per hour, it would mean
0:34:39 > 0:34:41an extra two or three departures an hour -
0:34:41 > 0:34:43that can be as many as a thousand people.
0:34:43 > 0:34:45So I probably shouldn't just check Facebook while I'm in the middle
0:34:45 > 0:34:48- of this?- No.- Just really stay focused on the job.
0:34:48 > 0:34:49OK. All right.
0:34:51 > 0:34:53He's already on the roll, he's already moving around the corner.
0:34:53 > 0:34:55So we can say, you're going to say it,
0:34:55 > 0:34:58"Turkish five hotel mike, line up."
0:35:01 > 0:35:03'OK, so I'm not a natural.'
0:35:03 > 0:35:05He's going out to the east.
0:35:05 > 0:35:07We've got this guy who's going to turn to the west,
0:35:07 > 0:35:09- there's our first landing. - I'm really confused.
0:35:09 > 0:35:12- If we look up...if we look out there...- Yeah, yeah, I can see,
0:35:12 > 0:35:13OK, that's pretty cool...
0:35:13 > 0:35:17'Every single landing and takeoff is recorded to the second.'
0:35:17 > 0:35:18When he gets airborne,
0:35:18 > 0:35:21as soon as his nose wheel comes up, you hit that button there.
0:35:21 > 0:35:26Planes are converging at Heathrow from 180 different destinations,
0:35:26 > 0:35:30so it's pretty important they're all using one standard time.
0:35:32 > 0:35:35Every air traffic clock is in Greenwich Mean Time.
0:35:35 > 0:35:37Every air traffic clock in the world?
0:35:37 > 0:35:39All over the world we're all working on the same time.
0:35:39 > 0:35:41OK, we've now wasted 20 seconds.
0:35:41 > 0:35:43- He could have been airborne 20 seconds ago.- Sorry!
0:35:47 > 0:35:51So how did we get to a global system of standardised time?
0:36:00 > 0:36:02Well, it was all thanks to
0:36:02 > 0:36:05an egomaniacal railroad clerk 150 years ago.
0:36:07 > 0:36:09A man who went head to head with public opinion
0:36:09 > 0:36:14to help launch a new dawn for telecommunications and broadcasting.
0:36:20 > 0:36:22In the middle of the 19th century,
0:36:22 > 0:36:25the railroad is transforming America.
0:36:25 > 0:36:30In just a few decades, over 100,000 miles of track are built,
0:36:30 > 0:36:33connecting the continent for the first time.
0:36:33 > 0:36:36It's a heroic chapter in American history,
0:36:36 > 0:36:38but it creates an unexpected problem.
0:36:41 > 0:36:42Here's the issue.
0:36:42 > 0:36:45The railroads are connecting all of these towns
0:36:45 > 0:36:48that have historically maintained their own individual time
0:36:48 > 0:36:51set by a local reading of the sun.
0:36:53 > 0:36:57In the 1880s, there were hundreds of towns, each using its own local time.
0:36:59 > 0:37:03Each differing not by the hour, but by the minute.
0:37:04 > 0:37:07There were 23 different times in Indiana,
0:37:07 > 0:37:0927 in Michigan
0:37:09 > 0:37:11and 38 across Wisconsin.
0:37:13 > 0:37:15What makes it even worse is that,
0:37:15 > 0:37:17in addition to each town having its own time,
0:37:17 > 0:37:19each railroad had its own time.
0:37:19 > 0:37:21And there were 50 different railroads!
0:37:28 > 0:37:33So back then, taking a journey by rail was something of an adventure
0:37:33 > 0:37:36which could leave you more than a little confused.
0:37:38 > 0:37:41So, you know what it's like taking a train ride today.
0:37:41 > 0:37:43You can kick back, read a book, listen to some music.
0:37:43 > 0:37:47But imagine what it would have been like in 1870 trying to take a train.
0:37:47 > 0:37:50Let's say we're travelling from New Haven to New York.
0:37:50 > 0:37:54And so I get on the train at 12 o'clock New Haven time
0:37:54 > 0:37:57and it takes us two hours to get to New York.
0:37:57 > 0:38:00So we should be arriving in New York at two o'clock.
0:38:00 > 0:38:04But in fact, in New York time, that's technically 1.55.
0:38:05 > 0:38:10But the train we're on is actually running on Boston time,
0:38:10 > 0:38:13so that means we're actually pulling into the station in New York
0:38:13 > 0:38:15on Boston time at 2.17.
0:38:16 > 0:38:20But then we're, like, making a connection to a train to Baltimore
0:38:20 > 0:38:22that's running on Baltimore time,
0:38:22 > 0:38:25so that train is actually leaving the station at 2.07,
0:38:25 > 0:38:27which seems to be in the past.
0:38:27 > 0:38:31I mean, you have to be a math major to figure out what time it is!
0:38:38 > 0:38:41If you think that was confusing for the individual passenger,
0:38:41 > 0:38:44imagine what it was like for this guy, William Allen,
0:38:44 > 0:38:47who was Secretary of the General Time Convention,
0:38:47 > 0:38:51which meant that he was in charge of reconciling the rail timetables
0:38:51 > 0:38:54for the entire US system.
0:38:56 > 0:39:00Most people would run away from this mathematical nightmare,
0:39:00 > 0:39:03but Allen seems mysteriously drawn to it.
0:39:06 > 0:39:11Professor Alexis McCrossen can shed some light on the matter.
0:39:11 > 0:39:13What really motivates Allen to get involved
0:39:13 > 0:39:16in the reinvention of time, basically?
0:39:16 > 0:39:19First and foremost, he is opportunistic.
0:39:19 > 0:39:20He's an egomaniac
0:39:20 > 0:39:24and this is his opportunity to make a name for himself.
0:39:24 > 0:39:28Allen realises that his path to greatness
0:39:28 > 0:39:32is in managing the schedules of all of these railroads
0:39:32 > 0:39:36that are proliferating like mushrooms after a rainstorm.
0:39:36 > 0:39:37I like that idea - the path to greatness
0:39:37 > 0:39:40being publishing railroad timetables.
0:39:40 > 0:39:43That's... "I'll be famous beyond imagination!"
0:39:43 > 0:39:45"Timetables, that's it!"
0:39:45 > 0:39:49But it's 1881, and Allen seizes the moment.
0:39:50 > 0:39:54And what he does is he introduces
0:39:54 > 0:39:57the idea of time zones,
0:39:57 > 0:39:59so not just of standardising the time,
0:39:59 > 0:40:02not just of creating one railroad time
0:40:02 > 0:40:05that all the railroads would follow,
0:40:05 > 0:40:08but of dividing the Standard Time in the United States
0:40:08 > 0:40:10into four zones.
0:40:10 > 0:40:14So this is the original map that Allen actually drew.
0:40:14 > 0:40:17I mean, this is kind of the blueprint for the time-zone system, right?
0:40:17 > 0:40:21- I mean, he actually hand-coloured these different divisions?- Yep. Yep.
0:40:21 > 0:40:24He figured out where to divide the time zones
0:40:24 > 0:40:26and he divided them at the basis
0:40:26 > 0:40:31of where different railroad lines ended, where they're terminated.
0:40:31 > 0:40:34And so he didn't exactly follow state lines,
0:40:34 > 0:40:36but he followed the geography of the railroad.
0:40:39 > 0:40:41Allen has a major fight on his hands
0:40:41 > 0:40:46because the proposal of Standard Time is a deeply controversial idea,
0:40:46 > 0:40:49and many Americans are afraid of it.
0:40:50 > 0:40:53Allen starts an enormous lobbying campaign,
0:40:53 > 0:40:57writing nearly 600 letters and countless circulars
0:40:57 > 0:40:59to mayors and city councils
0:40:59 > 0:41:02to try and cajole and arm-twist them into signing up.
0:41:05 > 0:41:08But there's fierce opposition to the prospect of change.
0:41:10 > 0:41:13A paper in Cincinnati writes, "It's simply preposterous.
0:41:13 > 0:41:16"Let the people of Cincinnati stick to the truth
0:41:16 > 0:41:19"as it is written by the sun, moon and stars."
0:41:22 > 0:41:25And these are all the original circulars that he sent out.
0:41:25 > 0:41:29- Look at how many of them there are. - Oh, hundreds.- It's amazing.
0:41:29 > 0:41:32"Are you in favour of the hour system of time standards
0:41:32 > 0:41:34"as illustrated by the accompanying map?"
0:41:34 > 0:41:37And we've got this great kind of 19th century, "YES!"
0:41:37 > 0:41:42But some people, this guy, he answers, "I think not."
0:41:42 > 0:41:46That's right. And check this out. Then he writes on the back. "Why?"
0:41:46 > 0:41:49He says, "Dear sir, the reason why I say no
0:41:49 > 0:41:52"to the questions on the other side of the sheet
0:41:52 > 0:41:56"is because it would be an entire revolution in our time."
0:41:56 > 0:41:58I mean, that's it, it's a revolution in our time.
0:41:58 > 0:42:00That's what he's trying to put in motion.
0:42:05 > 0:42:10After an epic seven-month battle to wrestle America's chaos of times
0:42:10 > 0:42:15into a simple system, Allen finally triumphs.
0:42:18 > 0:42:21All of which leads to one of the strangest days
0:42:21 > 0:42:26in the history of time - November 18th, 1883.
0:42:26 > 0:42:28The day of two noons.
0:42:32 > 0:42:37The first noon rings out at St Paul's in the New York local time.
0:42:39 > 0:42:44And then, four minutes later, there's another noon.
0:42:44 > 0:42:48The first ever 12pm Eastern Standard Time,
0:42:48 > 0:42:50announced by the bells of Trinity Church.
0:42:52 > 0:42:53BELLS TOLL
0:43:02 > 0:43:03As the bells ring out,
0:43:03 > 0:43:07the new Standard Time is sent down the telegraph lines
0:43:07 > 0:43:10for all the railroad stations to set their clocks to.
0:43:12 > 0:43:15America goes from hundreds of times to just four.
0:43:17 > 0:43:20And rail travel becomes a hell of a lot easier.
0:43:23 > 0:43:27Just a few weeks after his time system is implemented,
0:43:27 > 0:43:29Allen writes in a letter,
0:43:29 > 0:43:33"The adoption of the Standard Time system is an event
0:43:33 > 0:43:39"which is likely to be noted in the history of the world, for all time."
0:43:39 > 0:43:42I mean, OK, it may sound like he was a little full of himself,
0:43:42 > 0:43:45but, actually, he might have had a point
0:43:45 > 0:43:48because when you think about it, it's not just railroads.
0:43:48 > 0:43:51Any time you take a flight somewhere or schedule a phone call
0:43:51 > 0:43:53with someone living in another city,
0:43:53 > 0:43:56you're living inside of standardised time.
0:43:59 > 0:44:01Thanks to Allen's dogged crusade,
0:44:01 > 0:44:07America becomes a modern nation by embracing one single system of time.
0:44:12 > 0:44:14The very next year,
0:44:14 > 0:44:17Greenwich Mean Time is set up as the international meridian
0:44:17 > 0:44:20and the whole world is divided up into time zones.
0:44:22 > 0:44:25With this new web of time wrapped around the world,
0:44:25 > 0:44:28we are now more closely connected to foreign countries
0:44:28 > 0:44:33through improved trade, travel and communications.
0:44:33 > 0:44:39We also become closer to our fellow citizens through broadcasting.
0:44:39 > 0:44:41Now, for the first time ever,
0:44:41 > 0:44:44millions of us could sit down to a show at exactly the same moment.
0:44:44 > 0:44:47- RADIO:- 'In the deciding game of the Eastern League Baseball...'
0:44:49 > 0:44:53The story of time in the 20th century is all about clocks
0:44:53 > 0:44:56shaving the second down to smaller and smaller increments.
0:44:56 > 0:44:58And some of these tiny clocks
0:44:58 > 0:45:01are inside our laptops and our cellphones.
0:45:01 > 0:45:03It turns out you can't make a computer
0:45:03 > 0:45:05without a super-accurate clock.
0:45:05 > 0:45:10And all of these devices together combine to speed up our lives
0:45:10 > 0:45:12in a thousand different ways.
0:45:12 > 0:45:15And that's the funny thing about modern clocks.
0:45:15 > 0:45:20The better we get at measuring time, the less we seem to have of it.
0:45:20 > 0:45:24But the most important change in our measurement of time would come
0:45:24 > 0:45:28from a scientific breakthrough that had both catastrophic
0:45:28 > 0:45:31and transformative consequences for the entire world.
0:45:40 > 0:45:45Atomic physics brings us man's most destructive weapon,
0:45:45 > 0:45:48but it also provides us with a platform,
0:45:48 > 0:45:53an environment that encourages people to think big,
0:45:53 > 0:45:56bringing revolutionary ideas to energy and medicine.
0:45:59 > 0:46:05This pioneering work in physics will transform our relationship to time,
0:46:05 > 0:46:08revealing secrets about our ancient past
0:46:08 > 0:46:10and also helping us predict our future.
0:46:12 > 0:46:18In October of 1967, a group of scientists gathered in Paris
0:46:18 > 0:46:21and changed the very definition of time itself.
0:46:21 > 0:46:25They decided that the astronomical time that humans had used
0:46:25 > 0:46:29for all of history simply wasn't accurate enough any more,
0:46:29 > 0:46:33and they decided to trade the largest object in the solar system
0:46:33 > 0:46:35for one of the smallest.
0:46:35 > 0:46:39And we entered the age of atomic time.
0:46:42 > 0:46:47You could say that time as we know it is largely thanks to this place -
0:46:47 > 0:46:50the US Naval Observatory in Washington DC.
0:46:53 > 0:46:54This building has a name
0:46:54 > 0:46:57that sounds like something out of a George Orwell novel -
0:46:57 > 0:47:00the Directorate of Time.
0:47:00 > 0:47:02These are some of the most accurate clocks
0:47:02 > 0:47:05- that human beings have ever designed?- Yes.
0:47:05 > 0:47:07You might think that the clocks we use
0:47:07 > 0:47:10are still ultimately set by the rotation of the Earth.
0:47:12 > 0:47:16But in fact, today we measure time by tracking the behaviour of atoms,
0:47:16 > 0:47:18using atomic clocks like these.
0:47:20 > 0:47:23The man in charge here is "time lord" Dr Demetrios Matsakis.
0:47:25 > 0:47:28He's got some insane statistics.
0:47:29 > 0:47:31How do we define a second now?
0:47:31 > 0:47:37A second is defined as 9,192,631,770
0:47:37 > 0:47:40periods of oscillation of an undisturbed caesium atom.
0:47:42 > 0:47:45I hope all the schoolkids have memorised that.
0:47:48 > 0:47:49Just like a pendulum,
0:47:49 > 0:47:53atoms can be used to measure equal intervals of time
0:47:53 > 0:47:56by reading the regular pulses of energy they emit.
0:47:58 > 0:48:02These are the most accurate measurement systems
0:48:02 > 0:48:05ever made operationally by mankind.
0:48:05 > 0:48:08- In terms of measuring anything. - Of measuring anything.
0:48:08 > 0:48:11A good caesium clock on a bad day
0:48:11 > 0:48:14will differ by about five nanoseconds in its time
0:48:14 > 0:48:15from what we thought it would be.
0:48:15 > 0:48:18- So a nanosecond is one... - A billionth of a second.
0:48:18 > 0:48:19"A billionth of a second"...
0:48:19 > 0:48:23The thing is, when the first atomic clocks were built in the 1950s,
0:48:23 > 0:48:27their formidable power to break down the second
0:48:27 > 0:48:30confirmed something extraordinary.
0:48:30 > 0:48:33The Earth's rotation is slowing down.
0:48:36 > 0:48:38Back when T Rex roamed the world,
0:48:38 > 0:48:40a day was only 23 hours long.
0:48:42 > 0:48:46And ever since, the solar day has been slowly increasing in length.
0:48:48 > 0:48:50Not only that, atomic time also showed us
0:48:50 > 0:48:54that the Earth's rotation is not always consistent.
0:48:54 > 0:48:58To compensate, a leap second was added to the clock.
0:48:59 > 0:49:03But this intervention into time has been a little controversial.
0:49:05 > 0:49:07The leap-second argument is that some people think
0:49:07 > 0:49:10- we don't need this extra second. - That's right.
0:49:10 > 0:49:13They think that adding, including that second is too disruptive.
0:49:13 > 0:49:16There are many stories about web pages going down,
0:49:16 > 0:49:19airlines having to shut down because their computers went offline
0:49:19 > 0:49:23when they detected a one-second jump and didn't know it was coming.
0:49:23 > 0:49:27That shows you how dependent the world has become
0:49:27 > 0:49:30on this level of accuracy in time-keeping.
0:49:30 > 0:49:33You tell a computer, "Oh, there's an extra second in this day,"
0:49:33 > 0:49:35and an entire airline system goes down.
0:49:35 > 0:49:37Yes, that could happen.
0:49:37 > 0:49:40You probably won't have noticed,
0:49:40 > 0:49:45but since 1972, 25 leap seconds have been added to our lives.
0:49:47 > 0:49:50Once these clocks have ordained what time it is,
0:49:50 > 0:49:54an intelligent average - the universal Standard Time -
0:49:54 > 0:49:56is then distributed by this monster clock.
0:49:58 > 0:50:04This is where US Standard Time is broadcast out to the entire country.
0:50:04 > 0:50:08Every time you, you know, check your phone to see what time it is,
0:50:08 > 0:50:10you're ultimately getting that information
0:50:10 > 0:50:12from this clock in this room.
0:50:12 > 0:50:15I mean, it's actually kind of bizarre that I'm standing right next to it.
0:50:15 > 0:50:17I feel like I could fiddle with some of these buttons
0:50:17 > 0:50:20and, like, the entire country would be late for work!
0:50:22 > 0:50:25Atomic clocks are now so accurate
0:50:25 > 0:50:30that we can measure time with a drift of just a single second every -
0:50:30 > 0:50:33wait for it - five billion years!
0:50:35 > 0:50:38And increasingly, these clocks are important,
0:50:38 > 0:50:41not just for finding out what time it is,
0:50:41 > 0:50:44but for finding out where we are.
0:50:46 > 0:50:49That's because every time you look at your smartphone
0:50:49 > 0:50:55to assess your location, you're calling on ultra-precise atomic time.
0:50:56 > 0:50:58So, let's say I'm in a big city
0:50:58 > 0:51:02and I want to find out where the nearest coffee shop is.
0:51:02 > 0:51:07I take out my phone and up above me there are 24 GPS satellites.
0:51:07 > 0:51:09They're effectively giant clocks in orbit,
0:51:09 > 0:51:14only they're accurate to a billionth of a second.
0:51:14 > 0:51:16My phone gets a signal from four of them,
0:51:16 > 0:51:18they're basically just sending a time-stamp.
0:51:18 > 0:51:22Only there's a slight difference between each of the signals.
0:51:23 > 0:51:26Using those differences in time,
0:51:26 > 0:51:29my phone can calculate its exact distance
0:51:29 > 0:51:30from each of the satellites,
0:51:30 > 0:51:35enabling it to fix its location with pinpoint accuracy.
0:51:37 > 0:51:41But GPS satellites do way more than get us from A to B.
0:51:41 > 0:51:45For starters, their clocks coordinate the system used by cash machines
0:51:45 > 0:51:47and other financial transactions.
0:51:51 > 0:51:55GPS gives us cheaper food thanks to robotic farming.
0:51:58 > 0:52:02Not to mention all the GPS apps that help us peer around the corner
0:52:02 > 0:52:05to hail a taxi or figure out when the next bus is coming,
0:52:05 > 0:52:08or even to find the nearest coffee shop.
0:52:14 > 0:52:15It's incredible to think about it,
0:52:15 > 0:52:19but all this GPS technology is ultimately dependent
0:52:19 > 0:52:21on electrons dancing around an atom.
0:52:23 > 0:52:25But atomic physics would usher in
0:52:25 > 0:52:29another revolution in our measurement of time.
0:52:29 > 0:52:31And this one wouldn't tell us where we need to go,
0:52:31 > 0:52:34but instead, where we've come from.
0:52:56 > 0:53:02This is about as far from the modern world of time as you can get.
0:53:02 > 0:53:05I'm in California's Anza-Borrego Desert.
0:53:05 > 0:53:09And looking out here, I can't see any sign of civilisation.
0:53:10 > 0:53:13And the whole contemporary rhythm of split-seconds,
0:53:13 > 0:53:14it's just almost impossible to imagine.
0:53:14 > 0:53:18Here, you're living on geologic time.
0:53:21 > 0:53:23This is where, millions of years ago,
0:53:23 > 0:53:28the notorious San Andreas Fault was created in Southern California.
0:53:29 > 0:53:32It's a barren and beautiful landscape
0:53:32 > 0:53:36but before this, it was a lush savanna with rivers and lakes,
0:53:36 > 0:53:38populated by exotic animals,
0:53:38 > 0:53:41sabre-tooth cats and mammoths.
0:53:41 > 0:53:45And before that, it was a vast ocean teeming with aquatic life.
0:53:47 > 0:53:49So how do we know this story?
0:53:49 > 0:53:54Well, in part because we invented a very different kind of clock.
0:53:56 > 0:53:57For centuries,
0:53:57 > 0:54:03we had no idea exactly when the first humans spread across the globe...
0:54:03 > 0:54:07or exactly how to date the rich source of fossils
0:54:07 > 0:54:09scattered all over the desert floor.
0:54:12 > 0:54:17That is, until this brilliant woman, came along - Marie Curie.
0:54:19 > 0:54:21In the 1890s,
0:54:21 > 0:54:24she made history by studying the new field of radioactivity.
0:54:28 > 0:54:31She and her husband Pierre showed the world
0:54:31 > 0:54:34that radioactive atoms decay at constant rates.
0:54:36 > 0:54:38Carbon 14, for example,
0:54:38 > 0:54:42decays by 50% every 5,730 years.
0:54:43 > 0:54:46Other elements have wildly different rates of decay,
0:54:46 > 0:54:48but each one is regular and predictable.
0:54:50 > 0:54:53Once again, science had delivered the crucial concept
0:54:53 > 0:54:56of equal intervals of time,
0:54:56 > 0:55:00and the idea dawned that rocks could be clocks.
0:55:04 > 0:55:06Clocks that don't tick by the second,
0:55:06 > 0:55:11but on the scale of centuries or millennia, and deep into the past.
0:55:12 > 0:55:16So, there was a...basically, above a certain point here,
0:55:16 > 0:55:19- there was an ocean.- Yes, about 6.25 million years ago.
0:55:19 > 0:55:21Palaeontologist Lyndon Murray
0:55:21 > 0:55:25uses radiometric dating to read the landscape.
0:55:25 > 0:55:27It has an error margin of just 2-5%.
0:55:29 > 0:55:31And so is this process going to continue,
0:55:31 > 0:55:34are we just going to get ever more precise?
0:55:34 > 0:55:35Every rock will have its birthday?
0:55:35 > 0:55:38Well, you have a goal, and that's the goal.
0:55:38 > 0:55:41I guess this is a basic question, why do we do this?
0:55:41 > 0:55:44The geology and dating of what happened here
0:55:44 > 0:55:49can help in determining a record of past climate,
0:55:49 > 0:55:52of eight million years, actually.
0:55:52 > 0:55:54So we can see a sequence of events that happens,
0:55:54 > 0:55:59and how and perhaps why the climate changes.
0:55:59 > 0:56:03So in a way, all these technologies that let us look back in the past
0:56:03 > 0:56:07with such precision are actually also enabling us to predict the future?
0:56:07 > 0:56:09Yeah, yeah, I've always thought that.
0:56:13 > 0:56:18Radiometric clocks have given us this amazing time machine.
0:56:18 > 0:56:20I mean, they've helped us pinpoint exactly when humans
0:56:20 > 0:56:25first crossed the Siberian land bridge into the Americas.
0:56:25 > 0:56:28But they've also helped us predict the future.
0:56:28 > 0:56:30And in doing that, they may help us tackle
0:56:30 > 0:56:33one of the 21st century's most important problems -
0:56:33 > 0:56:34how to solve climate change.
0:56:35 > 0:56:39So in a way, clocks aren't just about measuring time,
0:56:39 > 0:56:44they can also help us understand where we came from
0:56:44 > 0:56:45and where we're headed.
0:56:52 > 0:56:55In the 400 years that have passed
0:56:55 > 0:56:59since Galileo first started tinkering with the equal time of the pendulum,
0:56:59 > 0:57:04clocks have transformed just about every facet of modern life.
0:57:06 > 0:57:09And there are those who say that our modern, accelerated,
0:57:09 > 0:57:12sped-up world is too frenetic,
0:57:12 > 0:57:18and they long for the slower pace of a pastoral life
0:57:18 > 0:57:22when our clocks were set by the rising and the setting of the sun.
0:57:24 > 0:57:26But the thing about the modern clock
0:57:26 > 0:57:29is that it's never just been about time.
0:57:29 > 0:57:32In a very real sense, our ability to measure time
0:57:32 > 0:57:34in increasingly small increments
0:57:34 > 0:57:39has made the world a smaller and more connected place.
0:57:41 > 0:57:44As to what the clocks of the future will bring us -
0:57:44 > 0:57:47for that, only time will tell.