That wonder molecule of life on Earth, DNA, is now being enlisted in the search for an exotic species zooming through the cosmos: dark matter.
As far back as the 1930s, astronomers watching distant galaxies saw that something was missing: There were not enough stars to account for the heavy gravity needed to whirl galaxies so quickly or smash them together so swiftly.
Something else must surround and suffuse every galaxy, some kind of gravitational glue.
Cosmologists dubbed it dark matter, as it sheds no light. And, they say, it far outweighs all the ordinary matter — stars and planets — that they can account for.
The leading candidate for this mystery substance: subatomic particles called WIMPs, or “weakly interacting massive particles.” They can’t be seen, but they should be nearly everywhere (at least in our galactic neighborhood). If true, every once in a great while, a zooming WIMP will by chance smack the nucleus of an atom like a well-struck cue against an eight ball.
For two decades, physicists have built detectors crammed with dense crystals and other heavy materials to try to catch WIMPs in this act. The results have been largely equivocal. There’s no smoking WIMP signal yet — although hints have appeared.
Proposals for the next generation of dark matter detectors run into the tens or hundreds of millions of dollars. One such project would require an empty mine filled with a cubic kilometer of gas.
Now, though, a group of big-name theoretical physicists and biologists has proposed a radical new type of detector that dangles DNA as dark-matter bait. At coffee-table size, it would be much less expensive than other proposed detectors, they say.
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