Physicists looking at anomalies in Earth's gravity have turned to a garden gnome that has been shipped around the globe to have itself weighed at locations as remote as the South Pole.
The experiment is a twist on the 'travelling gnome' prank, in which a garden ornament is mysteriously stolen, photographed at various locations - with the pictures posted on the Internet - and then returned home.
The project promotes the wares of a German maker of hi-tech scales, but also has a serious application, by measuring differences in Earth's gravity that also affect weight.
"Most people don't realise Earth's gravity actually varies slightly," says experiment coordinator Tommy Fimpel.
"One of the main causes is variations in the shape of the planet. Believe it or not, the Earth is actually potato-shaped, so you'll weigh up to 0.5 per cent more or less, depending on where you go. We thought our Gnome Experiment would be a fun way to measure the phenomenon."
Scientists who take part in the project receive a flight case that comprises of a gnome named Kern, of which only one has been made, plus a set of precision scales.
So far he has weighed most - 309.82 grams - at the Amundsen-Scott Research Station in Antarctica, where the inertial pull produced by Earth's rotation is strong.
His weight in Sydney came in at 307.8 grams.
Andre Wyzenbeek, general manager of John Morris Scientific in Sydney, says great care was taken in measuring the gnome.
"You would generally weigh him on multiple occasions to make sure the reading was stable. I believe between three and five readings were taken," says Wyzenbeek.
He says Kern spent about a week in Sydney.
"He spent a fair amount of time with our team, but unfortunately he didn't have the opportunity to have a beer. He's a very precious little gnome and we didn't want him to get him scratched or have him interact with the local wildlife."
Kern's next stops include Snolab, a Canadian particle physics facility two kilometres below the surface of the Earth that is the deepest laboratory in the Earth, and the underground Large Hadron Collider, the famous particle smasher at CERN in Switzerland.