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Science (mostly history, and mostly gravity)

Chasing the history of the gravity method sometimes took me down side-tracks that did not quite fit the theme, and so never made it into ‘The Hunt’. Also, and inevitably, there were stories that should have been in ‘The Hunt’ but which I missed. Here are some of them, and bits of new Earth Science are sometimes included!

Climate of suspicion

Scepticism is great, and vitally important in any science, but when science itself is under attack, anyone who claims to be a scientist needs to stand up and defend it.

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Extreme gravity

Extremes are now again fashionable in many areas of life. But – extreme gravity? Is there anything to be gained by searching for those points on the Earth’s surface where gravity is highest, lowest, steepest?

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Pendulum gravity on Guam

In 1819 Louis de Freycinet measured gravity on Guam using four pendulums, and in 1828 Fyodor Litke did the same thing, with just one pendulum. How well did they do?

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Pulau Anso: another missed opportunity

The astronomer John Goldingham makes an appearance in ‘The Hunt for Earth Gravity’ on account of pendulum measurements he made in his observatory in Madras (modern Chennai), but he has another claim to fame. He was responsible the first gravity measurements made in Sumatra or, rather, on one of its offshore islands.

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The magnetics of DC power

For magnetic surveys, power lines are a nuisance. Normal AC lines can interfere with magnetometer electronics if you get too close. But what about DC lines? Just forget about working anywhere near them.

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Pendulums and geology’s strongest gravity effect

There has to be a point on the Earth’s surface where the effect of geology on gravity is greatest. With the sea-covered areas unlikely settings because of the low density of sea water and almost all land areas now covered to some extent by gravity surveys, it is possible to say, with a fair degree of confidence, where that place is. It is on the largest of the Bonin (or Ogasawara) Islands, Chichi-jima,

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Thoughts on the Lairg gravity low

In 2008 Ken Amor and a group of his colleagues from Oxford and Aberdeen universities published a reinterpretation of the Stac Fada member of the Stoer Group sediments that outcrop on Stoer beach and in some other similar localities in the northwest of...

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“Mea culpa” on Myanmar gravity

I imagine that anyone trying to write a history of anything is all too aware of the probability (near certainty) that something important will have been left out. Sometimes new documents will emerge after the book or paper has been finalised, sometimes...

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The scandal of Henry Browne

In 1823 Basil Hall, a British naval officer who became the first person to measure gravity in the Galapagos Islands, advised anyone who might imitate him by taking gravity pendulums overseas to recognise the “….advantage which … would arise from having the whole experiment performed in England, by the person who is afterwards to repeat it abroad, not under the hospitable roof of Mr. BROWNE … but in the fields, and with no advantages save those he could carry with him…”

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