A Billion Tiny Pendulums Could Detect the Universe’s Missing Mass
Researchers at JQI and their colleagues have proposed a novel method for finding dark matter, the cosmos’s mystery material that has eluded detection for decades. Dark matter makes up about 27% of the universe; ordinary matter, such as the stuff that builds stars and planets, accounts for just 5% of the cosmos. (A mysterious entity called dark energy, accounts for the other 68%.)
Disappearing Light
Modern precision measurements are spectacular feats of engineering. An excellent example is determining the passage of time. Before John Harrison’s marine chronometer in the mid 18th century, ship clocks lost so much time that the sailors themselves often became lost as well. Today’s global positioning system (GPS) relies on rubidium and cesium atomic clocks aboard satellites. These clocks, precise to about one second per 30,000 years are far better than those used in the early days of navigation.