Nigel 
May 11th,2010Have you ever caught yourself thinking something very very stupid?
I was reading about Marconi’s experiments to prove that radio could be used to send information a long way.
Clearly you can because we do,but in 1901 we knew less about the world. To most scientists it was obviously impossible to send meaningful radio waves across the Atlantic for the simple and very obvious reasons that the earth is a sphere but radio waves are a sort of light and only travel in straight lines. Here’s the kind of picture they might have drawn if they’d had computers –but even I know they didn’t.
Put the receiver far enough round the earth and obviously radio signals won't reach it - they don't travel through the planet you know!
Fortunately young Marconi was rich enough to indulge his fantasy. He set up a transmitter in Cornwall (most westerly point in mainland Britain) and then travelled to the nearest place across the Atlantic (Newfoundland) to try to receive the signal. His aerial was just a long wire. He tried lifting it with a balloon but bad weather ripped the balloon from its moorings. His team then tried a number of kites. How big is the aerial in your mobile phone? Marconi’s was five hundred feet long. That would be a big phone to carry around.
The signal being transmitted from Cornwall was just the letter S in Morse Code,three dots (say “dit dit dit”out loud to get the idea).
Now at first this puzzled me. Surely the scientific way to test the system was for Cornwall to send a signal he had to identify such as a random letter of the alphabet. But this was a pioneering experiment:he just wanted to know if it would work at all. Then he could focus on improving the signal. And at that stage it was hard enough to pick out from the static even something he was expecting as simple as three dots. Many people on hearing he’d succeeded assumed he was either mistaken or lying.
That was also a key reason for using Morse Code. In those days of messages being sent long distances by cable the technology was basic:even cable signals were filled with static,so a message needed to be encoded in some fairly foolproof way. By 1901 Morse Code was a worldwide standard,and probably tens of thousands of people could translate it as easily as they could read a book. Amusingly,in order to transmit high quality music without interference we now use digital radio which is for all practical purposes a very fast adaptation of Morse Code processed by computers.
So,I read,after hours of straining his ears Marconi got lucky. The atmospheric conditions improved long enough for him to make out the three evenly-spaced dots. Was he excited!
Wow,I thought. He needs to phone his team in Cornwall and tell them they can relax it’s worked.
Talking about fools …
…of course he couldn’t. He was inventing the technology which would make telephones possible. Couldn’t he bounce the signal off a satellite? Yeh,right,in 1901.
An existing system
Actually there was a transatlantic communications cable,but it only worked intermittently. Bit of history here you can skip:
The telegraph system of sending messages by Morse Code down electrical cables was introduced in 1839. Running a cable across the floor of the Atlantic was an immediate and obvious idea,but hard to put into practice. A working cable was run across the Channel from England to France in 1850,but that was a trivial distance compared with the Atlantic (a hundred times further under a far more violent stretch of water with much deeper sections). Cables laid across the Atlantic kept breaking. In 1857 one was successfully run and a signal received,and people were tremendously excited. Until that day messages could only be sent by ship which took days,and you had to wait for a ship. Mind you the first telegraph message was also slow by modern standards taking ten minutes per word to transmit. The first working cable broke within a few days. In 1866,despite attempts at sabotage,a new cable was laid. Other cables were laid over the next decades,and by 1901 the system was slow but reasonably reliable. It was of course still very expensive,and Marconi did not have access to it from his research base in Newfoundland.
Opposition to his announcement of success
The sources of opposition were money,power and image.
If he made a wireless system work it would probably replace the cables which had cost a lot of money to run. Actually the demand to communicate (part of which we call the Web) has grown so much that we still use cables. Of course now they’re fibre-optic ones,and far stronger.
If wireless took off then the controllers of the cables stood to loose influence and therefore power.
And many scientists had looked at the proposal,been unable to think of any way wireless signals could get past the horizon,and stated categorically that it was impossible.
They were right that Marconi’s initial experiment was not convincing,but he soon arranged for an independent test to confirm his result. Then,of course,began the long slog of improving the technology. For another example of the work required consider looking at my post:Thomas Edison,one of the greatest failures of all time.
So how did it work?
At the outer edges of our atmosphere is a layer called the ionosphere. In 1901 it was not known about,but was there able to partially reflect radio waves at some wavelengths which fortunately included the radio band Marconi used. Here’s a sketch to illustrate:
A radio signal being partly reflected by the ionosphere
Trigger for this article
Recently I was browsing the books at an Oxfam (charity) shop in Reigate and picked up a second hand copy of the Reader’s Digest book “When,Where,Why &How It Happened”. The first article I read was about Marconi’s 1901 experiment. Sadly as I understand Reader’s Digest are no longer trading. The book was first published in 1993.
I found myself partially in 1901,and yet suddenly realised how stupid my ingrained thinking could be when looking at fresh situations.
Perhaps this article should have been titled No line on the horizon. On the other hand U2′s latest album is in my view better 
