File:Geiger-engineerguy.ogv

Bill sings a song - with help from Doris Day - about the geiger counter. He shows that scientist Hans Geiger became an engineer when he designed the counter as a tool to make his life easier.

Transcript: [lip synching to Doris Day singing Tic, Tic, Tic music by Harry Warren, Lyrics by?]

Oh, give me your attention,

There's been a new invention;

It isn't any larger than an adding machine.

It's only fair to mention,

Though it's a new invention,

It's one that you have heard about, but few have ever seen.

It doesn't do division and it doesn't multiply,

It doesn't try to be a bird, it doesn't try to fly'

It came about because they made a big atomic bomb.

The new invention's clicking

And because of all its ticking,

I know where the idea came from;

With all due respect to Doris Day, the geiger counter came along long before the atomic bomb. And like all good inventions neccesity drove it. Hans Geiger engineered it to make his life easier.

He worked for Ernest Rutherford, a pioneer in nuclear physics. Rutherford assigned Geiger to measure the number of subatomic entities called "alpha particles" being emitted by radium. Amazingly, Geiger did this by eye!

Alpha particles are too small to be seen, but they produce a small flash if they hit a zinc sulphide screen. So, he sat for hours in a dark room, looking through a microscope counting these flashes.

He recalls his lab as a "gloomy cellar", in fact, he had to sit twenty minutes in the dark so his eyes could aclimate before he even made measurements. And his concentration was often broken by Lord Rutherford wandering through the lab singing "Onward Christian Solders." Myself, I also like singing.

[lip synching]

I tick, tick, tick,

Why do I tick, tick?

What amazing trick

Makes me tick, tick, tick?

I tick, tick, tick,

The amazing trick Geiger used to make his new counter tick is this: He filled a metal tube with gas. When alpha particle shoot throught the gas they knocks electron off the gas atoms - this ionization is, of course, exactly what make radiation so dangerous, but in this case Geiger haressed it to be useful. Those free electrons make a current flow, which his counter then multiplies to make those clicks so characteristic of a Geiger Counter.

[lip syncing]

You better listen to that Geiger Counter song,

And tick, tick all day long.

Tick, tick, tick, tick,

Tick, tick, tick, tick, tick, tick,

Tick, tick, tick, tick, tick, tick,