New research makes one wonder.
From New Scientist:
Despite tantalising early hints of a sighting, the most sensitive search yet for dark matter has come up empty. First results from the Large Underground Xenon (LUX) detector in South Dakota, announced today, failed to confirm previous potential sightings reported by other detectors. That may spell trouble for elegant recent theories of a shadow universe where myriad particles interact via their own dark forces.
Dark matter is the invisible stuff thought to make up about 80 per cent of the universe’s matter, and that gives away its presence only by exerting a gravitational tug on ordinary matter. The most popular dark matter candidates are weakly interacting massive particles (WIMPs). So far unseen, these would also interact with normal matter via the weak force, so should smack into it every so often in a way that can be detected. More.
So it is 80% of the universe’s matter, but we can’t find any?
Fox News: The dark matter search has come up empty:
The most advanced Earth-based search for the mysterious material that has mass but cannot be seen turned up “absolutely no signal” of dark matter, said Richard Gaitskell of Brown University, a scientist working on the Large Underground Xenon experiment, or LUX. A detector attached to the International Space Station has so far failed to find any dark matter either.
…
Essentially, scientists are searching for something they are fairly sure exists and is crucial to the entire universe. But they do not know what it looks like or where to find it. And they are not sure if it’s a bunch of light particles that weakly interact or if it is more like a black hole.
“It’s ghost-like matter,” McKinsey said.
Just in time for Hallowe’en.
Seriously, let’s give credit where credit is due. At least they are not pretending dark matter exists the way the UFO buffs use the Copernican Principle to pretend that They Are Out There.
See also Wired Science