No wild goose chase
- Published on Wednesday, 26 June 2013 08:57
Polar bears feed on seals and as sea ice melts, many researchers have assumed that they are really rather screwed. Even so, there is debate over just how screwed they really are. A few teams have pointed out that polar bears have a long history of hunting geese during summer months in areas where sea ice has always melted away. Other teams have countered that there is no way for polar bears to get enough calories from a goose for the chase to even be worth it. Now a team has analysed a number of real goose hunts that they filmed in the wild, calculated the kinematics of these activites and is pointing out that they may not be as useless as they seem. Read on in my article in The Economist.
The broken biological clocks of city birds
- Published on Sunday, 16 June 2013 09:17
Just as city slickers have faster and more frenetic lives than country folk, so too do urban birds, compared with their forest-dwelling cousins. City birds literally get up earlier and stay up later than their country-living kin. Moreover, when birds from the cities and forests were put inside enclosures where the only light they had was dim artificial illumination, the city birds very quickly lost their daily rhythms while the country birds did not. Whether this is a trait that helps the birds survive in cities remains to be determined, but it is a fascinating find just the same. Read on in my article in Nature.
Sopping it up
- Published on Thursday, 06 June 2013 08:50
Getting oil out of water, an infuriating task under the best conditions, is getting ever more attention as oil spills cause more and more environmental damage. There is a dire need for cheap, sustainable and biodegradable materials that can absorb the stuff. Materials like barley straw and wool have been studied, but nothing fantastic has been found yet. Keen to find a silver bullet, a team noticed that cotton had not been given much attention so they decided to run an experiment with crappy unprocessed cotton that had poor commercial value. They really didn't expect to find much, but discovered that each pound of the material had the ability to sop up more than 30 pounds of crude oil. Read on in my article in The Economist.
- Published on Sunday, 26 May 2013 11:00
Darwin was amongst the first to describe the act of nectar robbing by bumblebees, the extensive removal of nectar from a flower by creating a hole in the side of the corolla. These holes can then be used to extract newly formed nectar by other bumblebees of the same or different species (known as secondary nectar robbery). Darwin was long fascinated by this and speculated in his later days that nectar robbery might be subject to social learning. Now a new study is proving him right, but in more ways then anyone imagined. The new study reveals that not only do bumblebees learn how to engage in nectar robbery, but the learning that is taking place is occurring across species boundaries, with different bumblebee species learning from one another. Read on in my article in The Economist.
Blackmail in the wild
- Published on Thursday, 09 May 2013 10:49
A team studying birds in the African desert are making a bold proposal: that young pied babblers are throwing themselves in harm's way to force their parents into feeding them more. The team noted that youngsters were fed more food and more often when they stuck themselves away from the nest and into areas where predators were likely to be present. Feeding increased even further when members of the social species started making alarm calls indicating that a predator was approaching. The team has a long way to go to prove that this is, indeed, the youngsters blackmailing their parents, but that is certainly what it looks like. Read on in my article in Nature.
- Published on Thursday, 16 May 2013 10:57
Unlike light and sound, which can readily be aimed and manibulated by lenses and mirrors, heat is a difficult beast to tame, yet a team of engineers is now tinkering with materials that do precisely this. The new approach relies on nanostructured semiconductor alloy crystals. The spacing of tiny gaps in these crystals is tuned to match the wavelength of heat phonons. These crystals then channel heat in a specific direction.
However, to make heat function as an electromagnetic wave that can actually be bounced around, the frequency of heat phonons had to be reduced significantly. The reason is down to the distance that high frequency waves can travel. Sound waves can travel for kilometers because they are often very low in frequency, but heat waves have terahertz frequencies that allow them to travel for mere nanometers. To deal with the this, the crystals were made with nanoparticles of germanium in a particular size range that had the effect of lowering overall frequency.
Following transmission through these crystals, the team found that more than 40 percent of the total heat flow was concentrated within a hypersonic range of 100 to 300 gigahertz. Moreover, most of the phonons aligned in a narrow beam, instead of moving in chaotic directions. As a result, this beam of narrow-frequency phonons can be manipulated much like a ray of light. Read on in my article in The Economist.
That which does not kill us, screws us up long term
- Published on Monday, 29 April 2013 09:03
It is a huge psychological question... do daily unpleasant emotional experiences wear us down over time or do these experiences make us stronger, inoculating against later distress?Using data from two national surveys, a team examined the relationship between daily negative emotions and mental health outcomes ten years later. Shockingly, overall levels of daily negative emotions predicted clinical diagnosis of disorders like anxiety and depression a full decade after the emotions were initially measured. The study needs to be repeated for anyone to be certain that the findings are true, but at this stage it certainly looks like chronically experiencing negative emotions in response to daily stressors takes a serious toll in the long run. Read on in my article in The Economist.