0:00:34 > 0:00:36The walled city of Galway.
0:00:36 > 0:00:41There's nothing between here and North America, but sea...
0:00:41 > 0:00:42An ocean of sea.
0:00:42 > 0:00:47In the 19th century, wave upon wave of emigrants trusted their luck
0:00:47 > 0:00:51crossing the Atlantic, to flee poverty and famine in Ireland
0:00:51 > 0:00:54for a new life in a new world.
0:00:59 > 0:01:01But this special relationship with America
0:01:01 > 0:01:04goes back further than you might think.
0:01:05 > 0:01:0990 million years ago, what's now Ireland and North America
0:01:09 > 0:01:10were joined together.
0:01:13 > 0:01:16Then, they began to drift apart...
0:01:17 > 0:01:21..and the world's second biggest ocean emerged -
0:01:21 > 0:01:22the Atlantic.
0:01:30 > 0:01:32It dominates life on the Irish coast,
0:01:32 > 0:01:34yet the Atlantic remains full of mystery.
0:01:37 > 0:01:40We know more about Mars than we know about the oceans
0:01:40 > 0:01:43and the reason for that is the vastness of the oceans.
0:01:43 > 0:01:45They take up most of the planet.
0:01:45 > 0:01:49They're really deep. A huge body of water.
0:01:49 > 0:01:52I've joined James Ryan, from Galway's Marine Institute,
0:01:52 > 0:01:54and we're out here to check on this.
0:02:00 > 0:02:02It's a scientific buoy
0:02:02 > 0:02:06that's processing a constant stream of information about the ocean.
0:02:06 > 0:02:08Battered by the waves, occasionally,
0:02:08 > 0:02:12it requires a little loving attention.
0:02:12 > 0:02:13Oh, there we go.
0:02:13 > 0:02:16A more physical life than I imagined for most scientists.
0:02:16 > 0:02:18It is! This is the bit I really like -
0:02:18 > 0:02:20get away from the desk and the computer.
0:02:22 > 0:02:27Hanging below the buoy are data probes, to monitor temperature,
0:02:27 > 0:02:30salt content, wave motion, nutrients
0:02:30 > 0:02:34and even the dolphins' comings and goings.
0:02:34 > 0:02:37Wow, beautiful.
0:02:37 > 0:02:40So what do you have to do now that we're out here?
0:02:40 > 0:02:43I just want to raise up the sensors,
0:02:43 > 0:02:45- which are down at the bottom of this big pipe.- I see.
0:02:45 > 0:02:48In order for us to check them, we have to haul them up.
0:02:48 > 0:02:52'The underwater sensors need a clean to keep them working reliably.
0:02:55 > 0:02:57'It means scientists can now study the Atlantic
0:02:57 > 0:03:00'without ever leaving their desks.'
0:03:00 > 0:03:02So it's sending its information out?
0:03:02 > 0:03:06Sending the information, 24/7. It's sending data all the time.
0:03:06 > 0:03:10'There are plans to install a network of these buoys,
0:03:10 > 0:03:13'to track the progress of global warming.'
0:03:13 > 0:03:15This is one buoy here on the edge of Ireland.
0:03:15 > 0:03:18There are other equivalent buoys all around the world,
0:03:18 > 0:03:19all very new technology.
0:03:19 > 0:03:24They are, I suppose, like the heart monitor on a patient.
0:03:24 > 0:03:27We are checking the physiology of the oceans here and monitoring it
0:03:27 > 0:03:30at a time when it's really vital for the planet.
0:03:30 > 0:03:35We're finally learning to cherish this precious ocean,
0:03:35 > 0:03:39that previous generations saw as territory to be conquered.
0:03:57 > 0:04:01Past the Slyne Head Lighthouse, our journey continues on to Clifden.
0:04:09 > 0:04:16The first people to see this view from the air were the pioneering aviators, Alcock and Brown
0:04:16 > 0:04:23who completed the first non-stop trans-Atlantic flight, by landing here in 1919.
0:04:26 > 0:04:31But a few years before, this was home to another transatlantic breakthrough.
0:04:31 > 0:04:34Dick Strawbridge is searching for its remains.
0:04:37 > 0:04:42In its day, this was the world's biggest communications hub.
0:04:42 > 0:04:45The brainchild of an Italian entrepreneur.
0:04:45 > 0:04:46Just over 100 years ago,
0:04:46 > 0:04:48this man, Guglielmo Marconi,
0:04:48 > 0:04:51the pioneer of radio, brought his men here
0:04:51 > 0:04:55to set up the world's first wireless telegram service.
0:04:55 > 0:04:59We want to discover how Marconi did it. And why did he come here,
0:04:59 > 0:05:02to this isolated peat bog on the Irish coast?
0:05:06 > 0:05:09When Marconi arrived, his challenge was immense -
0:05:09 > 0:05:14build the most powerful transmitter the world had ever seen.
0:05:14 > 0:05:18Good to see you, sir. If you just want to swing around that way.
0:05:18 > 0:05:22'I've assembled a team of experts who'll try and generate a radio signal
0:05:22 > 0:05:26'with the same technology that Marconi pioneered here in Ireland.'
0:05:26 > 0:05:31You want to try and align those two insulators with these two vertical members here.
0:05:31 > 0:05:33'We've got electronics engineers from the Galway
0:05:33 > 0:05:37'and Mayo Institute of Technology, supported by radio experts from the Irish naval service,'
0:05:37 > 0:05:42and they're all here to unpick the puzzle that Marconi cracked in 1907.
0:05:43 > 0:05:46Just to confirm, we have arrived at the Clifden site
0:05:46 > 0:05:50and we're going to conduct the Marconi exercises, over.
0:05:50 > 0:05:54Clifden's one of the closest points between Ireland and North America.
0:05:55 > 0:05:59From here, Marconi planned to send and receive radio signals
0:05:59 > 0:06:04a staggering 1,900 miles across the Atlantic.
0:06:04 > 0:06:07He built a sister station at Glace Bay in Nova Scotia.
0:06:09 > 0:06:13This was years before it was possible to transmit voice messages.
0:06:13 > 0:06:18So he used Morse code, electronic pulses that correspond to letters of the alphabet.
0:06:20 > 0:06:26Marconi sent the first transatlantic radio message from Poldhu at Land's End.
0:06:26 > 0:06:31But six years later, to set up as a business, he uprooted to Ireland.
0:06:31 > 0:06:35Marconi proved radio communications at Land's End, didn't he?
0:06:35 > 0:06:37So why did he come to Ireland?
0:06:37 > 0:06:40Poldhu radio site for Marconi wasn't large enough
0:06:40 > 0:06:43for the type of antenna structure he was experimenting with.
0:06:46 > 0:06:48Marconi was building big.
0:06:48 > 0:06:55Here at Clifden, there was room for a huge antenna suspended on poles 200 feet high.
0:06:57 > 0:07:03All that's left of the mighty structure are dozens of concrete anchor blocks for the masts.
0:07:05 > 0:07:10To get some sense of the scale, I've asked our guys from the navy to act as markers.
0:07:10 > 0:07:13See the far lad there, he's only about a third of the way?
0:07:13 > 0:07:16Absolutely, that guy at the very top there of the hill,
0:07:16 > 0:07:20he's one third of the way of the entire antenna.
0:07:20 > 0:07:22This was a ginormous antenna.
0:07:22 > 0:07:27You could say, the biggest in the world at that particular time.
0:07:27 > 0:07:29Nothing like this had been seen before -
0:07:29 > 0:07:32an antenna over half a mile long.
0:07:34 > 0:07:40It would need up to 300,000 watts of power to send messages all the way across the Atlantic.
0:07:40 > 0:07:44So Marconi had to generate lots of energy on site.
0:07:46 > 0:07:49That's why he built a power station in the middle of a bog.
0:07:51 > 0:07:55He had a lake, which he needed for water supply for his DC generators,
0:07:55 > 0:08:00which were right here beside us. That's the remnants of the DC generators over there.
0:08:00 > 0:08:07Amazingly, the generators were driven by a steam engines which burnt a traditional Irish fuel.
0:08:07 > 0:08:11Everywhere you look, what do see? Energy - turf peat.
0:08:11 > 0:08:13- They used peat for fuel?- Absolutely.
0:08:15 > 0:08:19But Marconi still needed a way of storing the electrical energy
0:08:19 > 0:08:23from his peat-fuelled generators - and releasing it rapidly.
0:08:23 > 0:08:28The solution was to construct a capacitor, or condenser.
0:08:28 > 0:08:32We're trying to build one like Marconi did, from steel plates.
0:08:34 > 0:08:40Adding plates increases the electrical energy a capacitor can store.
0:08:40 > 0:08:45Unlike a battery, it can be charged up quickly and discharged in a split second.
0:08:45 > 0:08:52This was the key component that enabled Morse code to be received loud and clear 1,900 miles away.
0:08:54 > 0:08:58- This is huge.- That may look huge today, but compared to Marconi,
0:08:58 > 0:09:01this condenser, this is minute!
0:09:01 > 0:09:04Look, have a look at that picture.
0:09:04 > 0:09:06Have you seen this?!
0:09:06 > 0:09:08This is a man here.
0:09:08 > 0:09:11We're talking about each panel being 12 times bigger than that?
0:09:11 > 0:09:15The panels at the bottom were about 12 feet, which would be
0:09:15 > 0:09:16about three of these sheets wide,
0:09:16 > 0:09:22and about 30 feet tall, which is between seven and eight times...
0:09:22 > 0:09:24- 25 times the size?- Absolutely.
0:09:24 > 0:09:30- And how many did he have?- You'll not believe this. He had 1,800 sheets.
0:09:30 > 0:09:35This condenser housing was 350 feet long and 75 feet wide!
0:09:38 > 0:09:44We've built a Marconi-style steel plate condenser, but what about generating the radio signal itself?
0:09:45 > 0:09:51The man with the biggest collection of early radio equipment in Britain is Bob Smallbone.
0:09:51 > 0:09:56He's arrived with a rare and crucial bit of kit, that dates right back to Marconi's time.
0:09:59 > 0:10:01That's cast iron, weighs a ton.
0:10:01 > 0:10:04- 1910 rotary spark gap. - We're ready to go.
0:10:04 > 0:10:06Get it connected, good man.
0:10:06 > 0:10:11In 1907, powering up such a rotary spark gap was no mean feat.
0:10:11 > 0:10:15Marconi's peat-powered steam engine drove his generators.
0:10:15 > 0:10:17We're using petrol power.
0:10:21 > 0:10:25We should be getting, what, about 230, 240 out, 230?
0:10:27 > 0:10:30But our generator's output is too low.
0:10:30 > 0:10:35- I should have been expecting 220. - Yep.- OK.
0:10:36 > 0:10:39After some tweaking, it's all systems go.
0:10:39 > 0:10:42- That's on top. - That's it. That's 220,
0:10:42 > 0:10:44So we're happy with that.
0:10:44 > 0:10:46Just one more part of the circuit to complete.
0:10:46 > 0:10:51- Bob's brought along a Morse key. - An absolute replica.
0:10:51 > 0:10:54- So that's exactly what they used 100 years ago?- Exactly.
0:10:54 > 0:10:56- Here in Clifden? - Here in Clifden.
0:10:56 > 0:11:01- There you go, no expense spared today. - Let's get it wired up.- Perfect.
0:11:01 > 0:11:05Marconi was an astute entrepreneur. He wanted to make communications
0:11:05 > 0:11:07by wireless telegraph more accessible
0:11:07 > 0:11:11and create a big market for his ground-breaking service.
0:11:11 > 0:11:15- Here's an advert of the time, Dick. - The Marconi-gram!- Yep.
0:11:15 > 0:11:21'By making messages more compact, they'd use up less air time and so it'd be a lot cheaper.'
0:11:24 > 0:11:27Marconi's Wireless Telegraphic Code book.
0:11:27 > 0:11:32You just use one word and he gives you a whole sentence.
0:11:32 > 0:11:34- And those aren't real words? - No, they're not.
0:11:34 > 0:11:38- Abrotanoid?- Abrotanoid. - Cracking word! "Bankrupt stock will realise large amount".
0:11:38 > 0:11:41- That's a very long sentence for one word.- It is.
0:11:41 > 0:11:43- That would cost me eight pence?- 8p.
0:11:45 > 0:11:49We're getting a feel for the challenges Marconi faced here in 1907,
0:11:49 > 0:11:53trying to generate his revolutionary transatlantic radio messages.
0:11:53 > 0:11:56Now, the ultimate test...
0:11:56 > 0:12:00Frank has now got a live feed. Is anybody else worried?!
0:12:00 > 0:12:06If you touched the steel plates now, you'd become part of a 6,000-volt circuit and almost certainly die.
0:12:06 > 0:12:11The condenser's all wired up, which means we can store lots of energy.
0:12:11 > 0:12:13So we need to get everybody safe, flip the switch,
0:12:13 > 0:12:17and we'll be sending Morse a long way using our condenser.
0:12:17 > 0:12:21- Do you want to do a quick safety check for me please, sir? - Clear the danger area, please.
0:12:21 > 0:12:25- Can you confirm the danger area is clear?- Yes, clear. - Thank you. On my mark...
0:12:25 > 0:12:31Five, four, three, two, one, mark.
0:12:31 > 0:12:33You're in control.
0:12:34 > 0:12:35CRACKLING AND BUZZING
0:12:35 > 0:12:38Whoa! We like that! We like that!
0:12:38 > 0:12:40We're looking good.
0:12:40 > 0:12:43CRACKLING AND BUZZING
0:12:43 > 0:12:49The high voltage sparks are jumping across a tiny air gap between the stud contacts.
0:12:49 > 0:12:56When these rotating contacts line up and the Morse key is pressed, the spark creates a signal.
0:12:56 > 0:13:00Marconi's rotary spark gap was five feet in diameter and the sound
0:13:00 > 0:13:03of the sparks could be heard over half a mile away.
0:13:05 > 0:13:11As well as making audible sound waves, the sparks are also creating invisible radio waves.
0:13:11 > 0:13:15Even without connecting our scaled-down model to an antenna,
0:13:15 > 0:13:18it's so powerful, it's actually transmitting through the air.
0:13:18 > 0:13:20This is a radio that'll pick it up?
0:13:20 > 0:13:24Conventional radio, set to long wave. We should be able to pick it up.
0:13:24 > 0:13:30- If we head off, can you send us a message of some description? - I can indeed.- Excuse us.
0:13:30 > 0:13:34SIGNALS BUZZ ON RADIO Isn't that a beautiful clean spark!?
0:13:36 > 0:13:38We've got 100 watts in there.
0:13:38 > 0:13:40This is still going.
0:13:40 > 0:13:44- And there's no antenna?- Marconi had something like 100,000 watts.
0:13:46 > 0:13:51'Our signal could be picked up almost half a mile away.'
0:13:56 > 0:14:01Over a century ago, when Marconi launches his transatlantic wireless telegraph service,
0:14:01 > 0:14:06it heralded the dawn of a new era of high-speed communications.
0:14:06 > 0:14:10A big idea that made the world seem a little smaller.
0:14:15 > 0:14:18Subtitles by Red Bee Media Ltd