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Lines to celebrate the electromagnetic spectrum Rodney Dale — 2 May 2002
The spectrum electromagnetic I celebrate here in this song As I press right ahead with my epic I just hope it won’t come out too long.
At one end of the spectrum is wireless; At the other, the fine gamma rays, For the spectrum eternal is tireless To the end of the cosmos’s days.
If you multiply wavelength and frequency It’s always just 300k — That’s velocity in metres per second, And that’s where it’s destined to stay.
The longest of waves are at one end Exciting your wireless set; But even the radio’s shortest Are some of the longest you’ll get.
A frequency 1 kiloHertz has A wavelength of 10 to the 5 (Times three metres in case you’ve forgotten) Which is where longwave radios thrive.
When the wavelength gets down to a metre You’re now in the realms of FM And TV’s to be found on such wavelengths And NMRI uses them.
Next up are the waves centimetric Produced by the magnetron’s cavity; There’s one in your microwave oven For fast food — that modern depravity.
And the waves getting shorter and shorter And the frequency higher and higher We’re into the far infrared now That radiates out of the fire.
There is infrared middle and near, too, With a frequency ratio of three; And a host of benign applications Medicine, process and astronomy.
It’s amazing that one little window Is an octave of visible light Producing a spectrum of colour For that most useful attribute — sight.
The wavelength’s at 10 t’minus 7 Times 7.8 for the red And 3.8 times for the violet, And the eye’s rods and cones are so bred
That the rods act in dim lumination (And their vision is so-called scotopic) And the cones are descriers of colour (And their vision is so-called photopic).
And the waves getting shorter and shorter Ultraviolet is next on the line; We know that some insects can see it So if you’re an insect — that’s fine.
Wilhelm Röntgen discovered the X-rays Whose wavelength is e’en shorter still; They’re essential for pinpointing fractures And perhaps finding out why you’re ill.
They are used in the treatment of cancer When they’re focused on cancerous cell You can go in with all sorts of illness And come out comparatively well.
And finally, gamma radiation ... Which is surely most harmful of all For nuclear reactors emit it, And the atom bomb — when it’s let fall.
So quantum electrodynamics Is really a wonderful thing A keystone of general physics Where its unifying spectrum is king.
(84 lines; 426 words; 2'50")
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