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Messed up mirrors manipulate light
David Ellifrit/Center for Whale Research
in Brief Moths remember their first time
Orca oracles lead pods through troubled waters CALL them oracles of the orca world. Female killer whales may live beyond the menopause so that they can use their experience and wisdom to ensure the survival of the entire pod, especially during food shortages. Female orcas often live into their 90s, even though they typically stop breeding at 40. As far as we know, the only other species to go through a menopause and live so long without reproducing are humans and short-finned pilot whales. So why orcas? To try and figure it out, Darren Croft of the University of Exeter, UK, and his team analysed 750 hours of video
of more than 100 orcas filmed in the coastal Pacific waters off British Columbia and Washington since 1976. They found that post-menopausal females were 32 per cent more likely to lead the group than nonmenopausal adult females and 57 per cent more likely than adult males. They were also more likely to be in charge in years when their staple food – chinook salmon – was in short supply (Current Biology, doi.org/2mx). “Post-menopausal orca females act as repositories for important knowledge. They essentially store important survival information,” says Croft. “Anyone who fishes for migratory trout or salmon will tell you that timing is key, that the fish return in particular cycles of tides and times of the year. Post-menopausal females probably get to know where to look and when.”
Too much praise makes Jack a vain boy YOU’RE so vain, you probably had overpraising parents. One of the first extended studies of childhood narcissism suggests that heaping praise on your kids could make them more prone to being selfish and vain. There are two competing theories of how narcissism can arise in children. One is that they may be compensating for having cold, unloving parents. The other 16 | NewScientist | 14 March 2015
is that their parents praise them too much, giving them an inflated sense of self-worth. Eddie Brummelman at the University of Amsterdam in the Netherlands and his colleagues tested these ideas by studying 565 children aged 7 to 12, a period in which narcissistic traits can emerge. Over 18 months, the children and their parents answered regular questionnaires
designed to measure narcissistic traits and parental behaviour. The team found no correlation between parental coldness and narcissism in the children, but did find a clear link between how much parents praised their children and how narcissistic the kids were six months later (PNAS, DOI: 10.1073/pnas.1420870112). However, the effect was small, so other factors may also make people self-centred – perhaps genetics, says Brummelman.
SOMETIMES it pays to be sentimental. Where African cotton leafworm moths mates for the first time helps decide the location of future liaisons, and where they lay their eggs. Although the moths have a large number of host plants, they innately prefer some, like cotton over cabbage. But Magali Proffit of the Swedish University of Agricultural Sciences in Alnarp and her colleagues found that if the first time the moths mated was on cabbage, they showed an increased preference for it. And mating had to be involved: moths didn’t just favour plants they were familiar with, even those sprayed with a sex pheromone (Ecology Letters, doi.org/2m4). Such behaviour could one day result in groups of the moth diverging into different specialist species, says Peter Roessingh of the University of Amsterdam, the Netherlands.
Messed up mirrors manipulate light FUNHOUSE mirrors just got a lot wackier. Reflective surfaces built using artificial materials could bounce certain kinds of light at strange angles, or make a mirror that turns into a window. A normal mirror reflects light back at the same angle it hits, but this is not true of “metamirrors” – so called because they are made of metamaterials, whose complex structure lets them manipulate light. The only one made so far sends face-on microwaves back at a 45 degree angle (Physical Review Letters, doi.org/2pn). Because metamirrors are tuned to work at a certain wavelength, and are transparent to all others, a surface could be made that is, say, mirrored under red light but see-through for other colours.
in Brief Moths remember their first time
Orca oracles lead pods through troubled waters CALL them oracles of the orca world. Female killer whales may live beyond the menopause so that they can use their experience and wisdom to ensure the survival of the entire pod, especially during food shortages. Female orcas often live into their 90s, even though they typically stop breeding at 40. As far as we know, the only other species to go through a menopause and live so long without reproducing are humans and short-finned pilot whales. So why orcas? To try and figure it out, Darren Croft of the University of Exeter, UK, and his team analysed 750 hours of video
of more than 100 orcas filmed in the coastal Pacific waters off British Columbia and Washington since 1976. They found that post-menopausal females were 32 per cent more likely to lead the group than nonmenopausal adult females and 57 per cent more likely than adult males. They were also more likely to be in charge in years when their staple food – chinook salmon – was in short supply (Current Biology, doi.org/2mx). “Post-menopausal orca females act as repositories for important knowledge. They essentially store important survival information,” says Croft. “Anyone who fishes for migratory trout or salmon will tell you that timing is key, that the fish return in particular cycles of tides and times of the year. Post-menopausal females probably get to know where to look and when.”
Too much praise makes Jack a vain boy YOU’RE so vain, you probably had overpraising parents. One of the first extended studies of childhood narcissism suggests that heaping praise on your kids could make them more prone to being selfish and vain. There are two competing theories of how narcissism can arise in children. One is that they may be compensating for having cold, unloving parents. The other 16 | NewScientist | 14 March 2015
is that their parents praise them too much, giving them an inflated sense of self-worth. Eddie Brummelman at the University of Amsterdam in the Netherlands and his colleagues tested these ideas by studying 565 children aged 7 to 12, a period in which narcissistic traits can emerge. Over 18 months, the children and their parents answered regular questionnaires
designed to measure narcissistic traits and parental behaviour. The team found no correlation between parental coldness and narcissism in the children, but did find a clear link between how much parents praised their children and how narcissistic the kids were six months later (PNAS, DOI: 10.1073/pnas.1420870112). However, the effect was small, so other factors may also make people self-centred – perhaps genetics, says Brummelman.
SOMETIMES it pays to be sentimental. Where African cotton leafworm moths mates for the first time helps decide the location of future liaisons, and where they lay their eggs. Although the moths have a large number of host plants, they innately prefer some, like cotton over cabbage. But Magali Proffit of the Swedish University of Agricultural Sciences in Alnarp and her colleagues found that if the first time the moths mated was on cabbage, they showed an increased preference for it. And mating had to be involved: moths didn’t just favour plants they were familiar with, even those sprayed with a sex pheromone (Ecology Letters, doi.org/2m4). Such behaviour could one day result in groups of the moth diverging into different specialist species, says Peter Roessingh of the University of Amsterdam, the Netherlands.
Messed up mirrors manipulate light FUNHOUSE mirrors just got a lot wackier. Reflective surfaces built using artificial materials could bounce certain kinds of light at strange angles, or make a mirror that turns into a window. A normal mirror reflects light back at the same angle it hits, but this is not true of “metamirrors” – so called because they are made of metamaterials, whose complex structure lets them manipulate light. The only one made so far sends face-on microwaves back at a 45 degree angle (Physical Review Letters, doi.org/2pn). Because metamirrors are tuned to work at a certain wavelength, and are transparent to all others, a surface could be made that is, say, mirrored under red light but see-through for other colours.