I love the fact that in the week we’re celebrating the moon landings, we may also cast a shadow over the theory that got us there.
To land a spacecraft on the moon requires a close understanding of gravity. Gravity is something of an obsession of mine – I discussed what we still don’t understand about it in this New Scientist feature recently. What’s fascinating to me (and not discussed in my article) is that solar eclipses seem to show up an anomaly in gravity.
It’s described in more detail here, but essentially, the story is this. Way back in 1954, someone noticed a pendulum swings oddly during a total eclipse. Does that mean gravity is altered when the moon, sun and Earth align? If so, there’s no explanation for it.
The phenomenon has been observed on more than 20 other occasions too, but no one has screened out all the other possible explanations, such as the sudden change in temperature, atmospheric pressure and even light levels associated with an eclipse. Today, however, Chinese scientists are going to do just that.
The solar eclipse occurring over southern China today will be the longest eclipse of this century, and gives an unprecedented chance to find out whether the theory that got us to the moon still needs a little tweak. The results will be out in a few months, apparently. Watch this space.
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