The empty space between my hands:
	Not only is it full of air,
	It contains hundreds of television channels.


Think of all the things you can pick up with a radio receiver of some
kind. All the TV channels you can pick up - including the endless
hundreds of satellite channels. All the public broadcast radio
stations - AM, FM, and DAB. The private radio channels used by
emergency services and taxi companies, and the military. The channels
used for aircraft to contact air traffic control. The ones used at
sea. CB and amateur radio. The mobile phone networks, carrying
Internet traffic as well as phone calls. Wireless Internet access
points. Then moving beyond the man-made, radio waves emitted by stars
near and far, including exotic objects like pulsars.

People can spend their lives exploring the radio waves that just fall
on an antenna set up in their back yard, with equipment that can only
pick up a limited section of the radio spectrum.

But even without the equipment to pick it up, the radio spectrum is
still there. Just hold your hands flat, a comfortable distance apart,
and look at the empty space between - and try to grasp just how much
amazing stuff is in it.