How long do astronomers get to search for something that has no direct evidence?
Dark Matter News
The Universe Is Expanding Surprisingly Fast (Mike Wall on Space.com). Nobody knows what dark matter is; even less what dark energy is. Astronomers are feverishly looking for the mysterious unknown stuff, which they must find to maintain the consensus cosmology. Yet the properties of the stuff, detected indirectly by its effects (if it exists), is changing as they observe: “it’s possible that dark energy — the mysterious force that’s thought to be driving the universe’s accelerating expansion — has grown in strength over the eons,” Wall writes.
No sign of seasonal dark matter after four years of searching (New Scientist). “Dark matter has just suffered another blow. Only one experiment claims to have seen signs of the mysterious stuff, and now the massive XENON100 experiment has failed to find any evidence for that signal,”Jennifer Ouellette reports. “This may put the controversial signal to rest once and for all – but some say it’s not that simple.” What’s it going to take to falsify this dark hypothesis? The skepticism is justified, she admits. “So does this mean it’s all over but the crying for the controversial claim? Not necessarily.”
New evidence in favor of dark matter: The bars in galaxies are spinning more slowly than we thought (Science Daily). Hope springs eternal to find dark matter. This story is not about detecting it, but inferring it from the motions of barred spirals.
Searching for axion dark matter with a new detection device (Phys.org). The “axion” sounds like something real, but it’s just a place-holder for ignorance. It’s just a name for a proposed particle to constitute dark matter, ever since evidence for WIMPs and MACHOs have been disappointing. Jim Shelton talks about Yale’s attempt to build a detector for the mysterious particle (if it exists). Will this turn out to be an elaborate search for ghosts?
Next-gen dark matter detector in a race to finish line (Phys.org). In this article, Glenn Roberts Jr. reports on South Dakota’s team trying to improve the sensitivity of their LUX detector, ever since the previous tests didn’t find the stuff. This story is red meat for sociologists of science. Groups around the world are racing to detect dark matter, perhaps for fame or fortune of a Nobel Prize. But what if there isn’t any? “It’s a friendly and healthy competition, with a major discovery possibly at stake,” one researcher says. Maybe it keeps mad scientists out of trouble.
Stanford physicist suggests looking for dark matter in unusual places (Phys.org). Amy Adams interviews physicist Peter Graham about his ideas about where axions might be hiding.
Can dark matter vanquish controversial rival theory? (Science Magazine). Adrian Cho wonders if the continued non-detection of dark matter will lend credibility to MOND theory (Modified Newtonian Dynamics).
Astroparticle physics: Dark matter remains elusive (Nature). Xiangdong Ji writes about the failure of the XENON detector to find dark matter. Searchers find it hard to quit. They just think they need to increase the sensitivity of their detectors.
Sometimes increasing the sensitivity of instruments works; solar neutrinos were found that way, and so were fluctuations in the cosmic microwave background. At some point, though, it will become ridiculous to keep pressing the case. We wonder if changing the assumptions about the age of the universe would solve the problem.