BAS contacts

S1/S2 Science criticisms: 1. 'Standards and quality in secondary schools 1995-2000: The Sciences', Scottish Executive, 2000, ISBN 1 84268 417 5'

2. 'Improving science education: 5-14'

The Earth is a balloon
James H. Jamieson

I met an old friend at a conference recently and sitting beside him waiting for the afternoon session to begin I asked him what it had felt like to be upsidedown for several weeks. He had just come back from Australia. Taking a couple of moments for the allusion to sink in, I got given a withering look. The chairman was about to commence speaking so I quickly recast the question, "Surely you did notice that you were upsidedown?" "You must be joking!" was the reply.

I make a habit of asking these questions to anyone I meet who has recently travelled to the Antipodes. It doesn’t really matter whether the person so questioned, as at that recent conference, is a physicist, or a youngster having a gap year. The response is the same. Nothing was noticed. The Earth is round? We all believe it is. But ask anyone how he knows that it is round and you are most unlikely to get a convincing answer.

I emailed some scientists wintering on the Antarctic last southern winter with the same question and back came the answer, "Orion! It’s upsidedown here relative to how you view it from the UK." Great though it was to get an intelligent answer, it won’t do, supporting as it does the flat earth and round earth theories equally nicely. If that surprises you imagine modelling the flat earth with a large meeting hall. The Sistine Chapel will do, a place associated with the theory of geocentricity long after it was discounted in Britain. The Chapel floor models the flat earth while the vaulted ceiling with its Michelangelo panels represents the heavens. The central panel has the famous scene of the creation of Adam. The outstretched arm of God almost makes finger contact with a similar outstretched arm of Adam. It puzzled me that I couldn’t tell who was who until the thought occurred that if man was made in the image of God, then they would be indistinguishable.

Entering the Chapel as you do from an end, imagine gazing at this central panel with its two figures, X on the left, Y on the right. Now walk to the far end of the Chapel turn round and look back at the panel. The scene has been inverted. X is now on the right and Y is on the left. The Orion answer does not convince.

Whitehead warned against holding what he called "‘inert ideas’ – that is to say, ideas that are merely received into the mind without being utilized, or tested, or thrown into fresh combinations". The round earth idea is one such. Others may be the heliocentric model for the earth and planetary motion, that moonshine is reflected sunlight, the atomicity of matter, atomic elements, and gravity. Why gravity? Why not levity? Flames rise!

How many of us ask "how do we know …..? Why do we believe ….?" questions? How do we know the earth is round? It is a reasonable question to set a class? Be patient waiting for the theory to be confirmed. It may take days or weeks for evidence to be collected, mostly second hand, for inferences to be made and for false inferences to be rejected. The moonshine question is a good one because evidence to substantiate the idea that moonshine is reflected sunlight can be directly collected, night after night, over a period of a month. The recent Inspectorate report on science teaching is generally critical of S1/S2 science and an over-reliance on worksheets. Call forth these ‘inert ideas’ that everyone believes, but few can justify, and test them, one by one.


To reminisce a little further,
by the time I returned from my second Antarctic trip, I could recognize most of the constellations and major stars.
Studying the stars night by night on the long voyage home, I would see that the elevation of each had shifted by a discrete amount.
The ship’s speed was 10 knots and its course was almost due north from the Southern Ocean to the UK.
Thus each day we sailed about 240 miles north, or 4º of latitude.
The night before we crossed the Equator, the Plough stood low in the North, its Pointers pointing to an as yet invisible Polaris, hidden beneath the horizon.
Overhead stood Virgo and Leo. Behind us, the Southern Cross, low in the South.
On the following night, Polaris sat about 2º above the ocean; the Plough was 4º higher; Spica, in Virgo, had shifted to the south of the zenith; and the Southern Cross was 4º lower.
By noting changes like these, night after night, you come to realize that the Earth is round.

To finish with a coda, on one homeward voyage we first picked up the BBC home service broadcasts just north of Madeira and tuned into the Lunchtime Concert on the Third Programme to listen to Brahms' First Symphony.

Our receiving aerial was a vertical dipole and, because we were still sailing into the NE Trades, the ship was pitching in the swell causing the aerial to oscillate with a
10º amplitude and a 10 s period.
The cosine response of the radio signal strength superposed a
0.1 Hz signal on the music – the sound level strengthened and faded with the pitching of the ship.

The final movement of the First Symphony is a succession of rolling, rollicking phrases: to hear it in counterpoint to the ocean swell seemed the most perfect union of human artistry and nature.

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