Jonathan and I have
done something like this once before in Cariacou - we
made a radio transmitter and receiver that meant we
could communicate across a distance of a whole 15 metres.
That is an easily shoutable distance. So we needed to
do better than that, really!
To communicate across space it's just not possible
to use sound waves. Sound relies on air as a medium
so, since space is effectively a vacuum, no sounds can
be heard. We can only hear on Earth because we exist
in an atmosphere with air. So light is the obvious thing
to use to try carrying a message, since it can travel
across a vacuum without any problem. But we still need
to capture the sound of a voice somehow on the light
We had a small laser pointer, but frankly light from
the sun here is so intense that it makes more sense
to try and capture that somehow. Jonathan gets cannibalising
an old radio to get hold of the transistors. They're
sensitive to light, usefully. I make a load of light
reflectors. Since we're not sure what we need or what
will be most effective, I make lots to try out. Really
have no idea which will work best.
It's a lovely idea - light carrying the vibrations
of a voice, so you can pick it up somewhere else. Just
detect the changes in the light, turn it all into an
electrical signal, amplify then feed it to a loudspeaker.
Sounds simple - perhaps too simple.