NO, THIS isn鈥檛 a boiler room. This humble-looking machine in Seattle is searching for the universe鈥檚 missing ingredient: dark matter.
Dark matter is thought to account for 85 per cent of all the matter in the universe, but we don鈥檛 know what it is made of. The hunt for the front runners to explain its effects 鈥� weakly interacting massive particles (WIMPs) 鈥� has come up empty so far. So some physicists are searching for axions, a different type of particle, to explain the mysterious form of matter.
This detector, called the Axion Dark Matter Experiment (ADMX), takes advantage of a unique theorised property of axions: when they are exposed to a magnetic field, they can be converted into photons of light.
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The detector鈥檚 powerful magnet is designed to do just that, collecting the photons in a box that is kept at less than a tenth of a degree above absolute zero. So small is the expected photon signal that the detector has the most sensitive amplifiers in use in any scientific experiment, ones developed to read out subtle microwave signals in quantum computers.
Looking for traces of axions that have turned to light, the ADMX team slowly cycles through different frequencies, hoping for a ping. 鈥淲e鈥檙e listening for our favourite radio station, and we鈥檙e turning the dial really slowly so we don鈥檛 miss it,鈥� says ADMX operations manager Andrew Sonnenschein.
And if they find that station, they will solve one of the universe鈥檚 greatest mysteries.
Photographer
Tony Luong,
This article appeared in print under the headline 鈥淒etecting dark matter鈥�
