Particle hunting in space, life in the urban jungle and more reader feedback
Space-based particle hunting
Physicist Sam Ting spent years lobbying to put a cosmic ray detector aboard the International Space Station. Now heâs using the Alpha Magnetic Spectrometer to collect particles that may shed light on the nature of dark matter, as Andrew Grant reported in âEyes on the invisible prizeâ (SN: 3/21/15, p. 22).
âThe Alpha Magnetic Spectrometer experiment can only capture particles that reach it,â wrote Irwin Tyler. If cosmic rays collide with particles on their way to Earth or stray from their original travel path, he writes, âthen there can be no accurate census of the kind Sam Ting is looking for. Should any sky survey find clustering of these particles, it would merely be an artifact created by these variations. Moreover, both counts and clustering would likely look very different if measured from a different position in our galaxy.â
Grant agrees that cosmic rays whizzing past the International Space Station arenât necessarily representative of particle populations elsewhere in the galaxy. âThe magnetic fields of Earth and the solar system warp the particlesâ trajectories. And little clumps of dark matter near Earth could theoretically send extra particles our way. Even so, cosmic rays remain a key tool for understanding the universe, and AMS is the best detector ever put in space to study them,â he says.
Wheat over water
Wheat came to the British Isles long before farming did. Scientists pulled wheat DNA from the soil of a site near the Isle of Wight. The site predates Englandâs agricultural lifestyle by about 2,000 years, wrote Bruce Bower in âWheat reached England before farmingâ (SN: 3/21/15, p. 17).
Reader Mark S. wanted to know how ancient hunter-gatherers schlepped the wheat all the way to England. âWheat is bulky. How would people, before the invention of the wheel, have transported it back then?â
Detecting lots of wheat DNA in the soil doesnât necessarily mean large quantities of wheat were present, says study coauthor Robin Allaby of the University of Warwick in England. Itâs more likely that hunter-gatherers only transported small quantities at a time, and that wheat wasnât a big part of their diet. âAs for the means of travel, we feel that it is most likely boat contact,â he adds. The site where the DNA was found was once a boat-building workshop. The nearest farmers, located along the west coast of France, were also skilled boaters.
Living in the urban jungle
In âWhen animals invade human spacesâ (SN: 3/21/15, p. 28), Nathan Seppa reviewed a book about the unexpected ways that animals adapt to city life.
Readers had plenty of stories about close encounters with wild animals. Mike Van Horn listed the menagerie of mammals that have passed through his neighborhood, including deer, coyotes, mountain lions and river otters. âWeâve also had migrations of large black and yellow spiders. Beautiful but a bit intimidating,â he wrote, adding that âtalk of humans invading animalsâ spaces fails to recognize that we also are animals. We are all invading each otherâs spaces. It is a shifting balance.â
Commenter RedCentipede pointed out that hunting may play a role in that shifting balance: âHere in eastern Massachusetts, deer are now so common in suburbia that theyâre a serious traffic menace, causing a couple of thousand crashes every year. Why so common in suburbia? Because hunting is prohibited within the populated parts of towns, so deer that move into the towns flourish and reproduce.â
Whatever the cause, some people donât mind sharing their living spaces. Marc Harris opined that animals are âfar more desirable neighbors than my human ones.â
Correction
âTeens have higher anaphylaxis risk than younger kidsâ (SN: 3/21/15, p. 15) should have said that pharmaceutical company Mylan markets, not makes, the epinephrine injector EpiPen.