When talking about dark matter (DM), there's a standard line that gets used from popular talks through to journal papers: we only know about its gravitational interactions. That is, we've measured its existence and abundance from how it affects galaxy rotation curves, or the structure of the cosmic microwave background; but we have no direct information about any other types of coupling it might have to the ordinary stuff we are made of1.
Of course, there are a lot of searches of various types looking for those interactions. One of the most basic is direct detection, building a very sensitive and low-background experiment and looking for dark matter scattering off the atoms in your apparatus. It is here that one of the more enticing, puzzling and long-standing mysteries of dark matter is to be found; the fact that several experiments claim signals, that seem to be ruled out by other searches that found nothing2.
My attention was drawn by the publication on the arXiv today of another paper in the signal column.
Wednesday, 15 January 2014
Tuesday, 7 January 2014
My brother came to visit over the holiday season, so I missed the exciting announcement of the release of Angband 3.5.0 on Christmas Eve! It apparently has the longest changelist in the history of the game, and marks the end of the current lead and the start of a new one.
Monday, 6 January 2014
I should really know better: when trying to work, don't read news that isn't sport. I'll just find something that makes me rage too much to concentrate.
It seems the Senator also likes to criticise Islam, for reasons I'm sure are completely intellectual and not xenophobic.The prime minister, Tony Abbott, has distanced himself from the South Australian Liberal senator Cory Bernardi, who described abortion advocates as "pro-death" and suggested children raised by single parents were more likely to be promiscuous and law breakers.Bernardi’s new book, The Conservative Revolution, also argues against other "non-traditional" families including step families and same-sex families, and says the “understanding that children come into families as gifts, not commodities” is missing in the push for in-vitro fertilisation (IVF) and surrogacy.
The Christmas season is generally a quiet time in terms of new research papers. The reason's pretty obvious; with so many people taking time off, anything you put out won't be read as much. And that's assuming you haven't dashed off somewhere yourself. Still, things don't drop to a complete halt, and you get odd little papers like this one on the Higgs decay.