I have a new story published in the 21 April edition of New Scientist. I co-wrote the story with New Scientist’s deputy features editor Valerie Jamieson.
AFTER 40 years of planning and hundreds of millions of dollars, NASA announced last week the first results from the Gravity Probe B experiment, which was designed to measure how Earth warps the fabric of space-time. The results may have been scooped, though, by astronomers bouncing lasers off the moon decades ago.
NASA launched Gravity Probe B (GPB) in April 2004. The satellite was equipped with precision-engineered gyroscopes to measure two effects predicted by Einstein's general theory of relativity. In one, called the geodetic effect, Earth's gravity dents space-time such that it should tilt each gyroscope by 0.0018 degrees over the course of a year. In a second, more subtle effect, called frame-dragging or gravitomagnetism, Earth drags space-time along with it as it rotates.
The GPB team only reported a measurement of the geodetic effect. Team leader Francis Everitt of Stanford University in California says that the team has seen…
The complete article is 637 words long and can be read on the web here but a subscription is required.