Earlier today, parts of Asia – including India and China – were treated to the longest total solar eclipse of this century. Apart from offering spectacular visuals – both in the sky, on the ground and in between – the event also offered the perfect opportunity to test a controversial theory: that gravity varies slightly during a total eclipse.
The debate over this anomaly began in 1954 when French economist and physicist Maurice Allais noticed erratic behaviour in a swinging pendulum when an eclipse passed over Paris. Allais reported that the pendulum’s swing direction changed abruptly at the time of the eclipse. However, subsequent tests have seen both positive and negative results, and so it remains a debatable phenomenon. Allais probably didn’t do himself any favours by reintroducing the concept of the aether to explain the anomaly, but it’s good to see that many scientists remain open to testing the phenomenon further.
As mentioned in the news briefs though, the alleged anomaly came under close scrutiny today in China:
Chinese researchers have prepared eight gravimeters and two pendulums spread across six monitoring sites. The team hopes that the vast distance between the sites (roughly 3000 kilometres (1864 miles) between the most easterly and westerly stations), as well as the number and diversity of instruments used, will eliminate the chance of instrument error or local atmospheric disturbances.
“If our equipment operates correctly, I believe we have a chance to say the anomaly is true beyond all doubt,” says Tang Keyun, a geophysicist at the Chinese Academy of Sciences.
The opportunity won’t come again soon. At over five minutes, the event will be the longest total solar eclipse predicted for this century. What’s more, the event will occur when the sun is high in the sky; a time when, according to Tang, any potential gravitational anomaly should be greatest.
Stay tuned…
Previously on TDG:
