Three New Myths

Three big ideas went to the wall last week, good examples of how science works by trying to disprove theories.

One involved the analysis of DNA in the 400,000 year old femur of a fossil human from a cave in Spain. That in itself was a surprise: that such old DNA retains its chemical identity.

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The theory was that Neanderthal Man was there in Spain then, but the DNA turned out to be more like that from a different population of early humans, Denisovan Man only known in Siberia. The theory was based on evidence from bone structure (which was also the source of these unreliable facial reconstructions) while the DNA evidence was very detailed and measurable.

The second falsification concerned the Moon, and the theory from the 1980s that some planet-sized object hit the very early Earth. Although the object was thought to have passed on, a ring of  debris from the crash coalesced into the Moon.

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Now, it seems, the angular momentum of the Moon’s orbits is not consistent with the Earth’s 24 hour day, as you would expect if they were from the same source. Furthermore, the chemical composition of the Earth’s crust is very similar to the surface samples retrieved from the Moon: there’s no sign of other chemicals expected from some foreign object. See go.nature.com/hndjnq. (M Meyer et al Nature 504, 16-17, Dec 5th)

Thirdly, John Eliot Gardiner, musicologist, conductor and author of Bach: Music in the Castle of Heaven, has dispelled the idea that JS Bach was a conforming man of uneventful routine. This reputation came from the regularity of his frequent church compositions and from the lack of evidence about the other parts of his life.

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Gardiner has got to know Bach as well as anyone over the last three hundred years, especially on the 300th birthday pilgrimage to play most of the choral works across Europe and elsewhere. In his new book, Gardiner presents evidence that Bach was a “natural dissident” who had a congenital problem with authority. Why else would he have hit on the brilliant idea that the soprano performer of the motet “Furchte Dich Nicht” should enter by standing up in the gallery, hidden from the orchestra and congregation?

Crater Creators

It seems that about 4,000 million years ago the entire Solar System was bombarded by impacts from rocks and debris, stray material that had formed during the Sun’s birth (Nature Geoscience July 2013). Some of the “artist’s impressions” may not be entirely make-believe.

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Analysis of rocks and data obtained by the Apollo missions suggest the stray rocky bodies that fell on the Moon were left behind when the planets were forming.

These intense cataclysms formed the largest impact basins on the Moon, the six below being up to 1,000 kms in diameter with hundreds of craters.

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Their age is being assessed from analysis of the rock that melted from the force of the impacts, and ranges from 3,900 to 4,200 million years have been suggested. The magnitude and length of the bombardment is still being worked out, but things seem to have quietened down after this period. Other evidence from Mercury, Mars, Earth and even the gaseous Jupiter and Saturn shows remains from the same bombardment during this same time interval.

Is it coincidence that the earliest signs of life on Earth are from rocks that date to the end of this bombardment interval? After all, links between early life and extraterrestrial organic molecules have long been suspected. Or is that very question another kind of make-believe: “art” for the scientists, “science” for the creationists? Or is the very suggestion mere grist to the mill for research funding?

With their 2001-A Space Odyssey, Stanley Kubrick and Arthur C Clarke were very sceptical.

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