- 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.
- 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 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.
- Published on Tuesday, 23 April 2013 08:53
The expressionless gaze of the poker face. To win, it must be mastered, and master it is what the best poker players in the world do. And yet a new study is pointing out that to focus on the face alone is a mistake. In three studies naïve observers were able to judge the quality of poker players' hands by merely observing two second videos containing footage of the players' arms moving about. All they saw were the hands placing chips on a table, nothing more. What is shocking is that the footage shown was from the high-stakes poker world series - meaning these poker novices were, without knowing it, accurately guessing the hand quality of the best poker players in the world. Read on in my article in The Economist.
- Published on Monday, 08 April 2013 10:02
While it is nowhere near as problematic as arsenic and lead, caffeine is a pollutant. At high levels it messes up plant growth and can be highly destructive to both forests and agricultural lands. Thus, coffee factories cannot just dump all of their caffeinated waste just anywhere. They must pay to put it in specialised location where it cannot cause harm and then, they of course, pass this cost on to the consumer. Yet change is afoot as a team demonstrates that it might be possible to decaffeinate coffee factory waste quickly and easily using genetically modified bacteria. Read on in my article in The Economist.
- Published on Saturday, 13 April 2013 10:13
The giant squid isn't exactly easy to study. Live specimens are never seen at the surface and much of what we know of their behaviour comes from the sucker mark scars that they leave behind on sperm whales. Even so, a team collected genetic information from giant squid remains that have washed up all around the world and they made a rather shocking discovery, all giant squid on Earth are so closely related that they constitute just a single species. Perhaps more importantly their genetics indicate that they nearly went extinct in the not too distant past. Read on in my article in Nature.
- Published on Sunday, 17 March 2013 02:47