Who believed stones fall from the sky?

It’s often said that scientists long rejected the idea of meteorites, but the evidence for this assertion is far from convincing.

Pseudoscience constantly attempts to discredit science. One method is to complain that scientists have failed to accept facts that were both plain and obvious. Then, if science does not accept homeopathy, telepathy etc, this is to be expected and no reason to doubt the truthof these beliefs.

For many years scientists refused, against contrary evidence, to believe that stones could fall from the sky. True or false?

In 1807 a meteorite fell in Weston, Connecticut and was investigated by Professors Silliman and Kingsley of Yale (a fact). Thomas Jefferson, then President was informed and said, “Gentlemen, I would rather believe that those two Yankee Professors would lie than to believe that stones fell from heaven.”

Jefferson corresponded with the leading scientists of his time. According to Asimov he was “the closest approach to a scientist-in-office among all the Presidents of the US.” Did he really say this?

The story comes from a 1933 book by Harvey Harlow Nininger and has been quoted many times without question-even by Paul Kurtz in A Skeptic’s Handbook of Parapsychology and Asimov in his biographical sketch of Silliman. Nininger is something of a hero in the US, which is perhaps why this legend is so readily accepted, but he gave no early source for his story.

Proof needed

In the 18th century, science established that such things as fossils and stone artefacts had a terrestrial origin, though previously they were believed to have fallen to earth. Sceptical scientists began to question the idea of solid objects falling from the sky-some proof was needed. In the last decade of the 18th century two large falls of stones in Europe were observed by many people, and one of these followed the sighting of a large fireball that disappeared with a bang. The German physicist Ernst Florens Friedrick Chladni published a book translated as On the Origin of the Mass of Iron Discovered by Pallas and Others Similar to It. This carefully established a good case for the extra-terrestrial origin of meteorites.

Closer to the end of the century, Joseph Banks the president of the Royal Society, and the French mineralogist, Jackie-Louis Bournon then in England, obtained some pieces of rock, said to have fallen from the sky. These were analysed and found to be iron with a high percentage of nickel. This alloy had never been found in any rock that was definitely of earthly origin.These two scientists presented their theory to the Royal Society in London and the Institut de France in Paris respectively and it was well received by both. The latter heard also from Nicolas Louis Vauquelin who had reached similar conclusions. One of the remarkable features of this cooperation is that Britain and France were at war.

By a fortunate coincidence a shower of stones fell near L’Aigle in Normandy on April 26th 1803. Nearly 3000 were found and the incident was investigated by Jean Baptiste Biot. Analysis showed these objects had a similar composition to previous meteorites. All major French scientists and most others around the world were convinced and Chladni received belated honour.

Well perhaps not so belated. Chladni did not really have to wait very long; it took about 10 years for acceptance of his theory. The story that scientists would not believe his story, in spite of overwhelming evidence is about as far from the truth as is possible. Also it is most unlikely that Jefferson was not fully aware of these scientific discoveries.

Giant rocks

It did take longer to establish that huge rocks, large enough to make enormous craters, could also fall. These craters were often argued to be of volcanic origin because there was clear evidence that molten rock had flowed. It was only after the work of Joule in the middle of the 19th century that it became possible to understand the huge quantity of heat that would be released in such strikes. The rock in and around the crater would be melted by the release of energy.

In 1902 Daniel Moreau Barringer, a geologist and mining engineer, decided that the great crater in Arizona was caused by a meteor strike (though many thought it volcanic) and ought to contain a large and valuable amount of nickel/iron buried near its centre. He spent 30 years and a fortune without success, which gave some comfort to those who favoured the volcanic theory. But then in the 1950s Eugene Shoemaker showed by analysis of the data and further calculation, that most of the metal would have vaporised and this more or less settled the issue.

Years ago Fleur and I visited Meteor Crater, Arizona; I consider it one of the most dramatic natural features I have ever seen. Most geological phenomena have been produced slowly over millions of years. The idea of this one being produced in an instant is hard to comprehend. These days it is a major tourist attraction and it is not possible to explore the crater; one can only examine it from a viewing platform in company with a large number of other spectators.

We have also visited remote Wolfe Crater in WA, a much older feature on the edge of the true desert, which is gradually disappearing under wind-borne sand. This is not a tourist attraction; it is too far from tourist routes and reached via a track usable only by 4-wheel drive vehicles. We had the crater to ourselves and could wander at will. In a guide book we were amused to find the suggestion that it might be of volcanic origin. The idea that large stones cannot fall from the sky dies hard-at least among non-scientists.