Science
Thin, Active Invisibility Cloak Demonstrated for First Time
JK Rowling may not have realised just how close Harry Potter's invisibility cloak was to becoming a reality when she introduced it in the first book of her best-selling fictional series in 1998.
Professor George Eleftheriades and PhD student Michael Selvanayagam in The Edward S Rogers Sr Department of Electrical and Computer Engineering have designed and tested a new approach to cloaking – by surrounding an object with small antennae that collectively radiate an electromagnetic field. The radiated field cancels out any waves scattering off the cloaked object.
Picture a mailbox sitting on the street. When light hits the mailbox and bounces back into your eyes, you see the mailbox. When radio waves hit the mailbox and bounce back to your radar detector, you detect the mailbox. Eleftheriades and Selvanyagam's system wraps the mailbox in a layer of tiny antennae that radiate a field away from the box, cancelling out any waves that would bounce back. In this way, the mailbox becomes undetectable to radar.
Beyond obvious applications, such as hiding military vehicles or conducting surveillance operations, this cloaking technology could eliminate obstacles – for example, structures interrupting signals from cellular base stations could be cloaked to allow signals to pass by freely. The system can also alter the signature of a cloaked object, making it appear bigger, smaller, or even shifting it in space.
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Weight Loss Not Always Beneficial for Romantic Relationships
Losing weight is generally beneficial for human health, but when one partner in a romantic relationship loses weight, it doesn't always have a positive effect on the relationship. According to new research from North Carolina State University and the University of Texas at Austin, there can be a "dark side" to weight loss, if both partners are not on board with enacting healthy changes.
For the study, researchers surveyed 21 couples – 42 adults – from across the country. One partner in each couple had lost 30 or more pounds in less than two years, with an average weight loss of about 60 pounds.
The researchers found that, after weight loss, the couples' communication generally changed for the good. The partner who lost weight was more likely to talk about healthy behaviours and inspire his/her partner to maintain or enact a healthy lifestyle.
However, in some cases, weight loss resulted in negative communication. Some partners who lost weight nagged their significant other to follow their lead, which caused tension in the relationship. Other partners who hadn't lost weight reported feeling threatened and insecure by their partner's weight loss. These participants were resistant to change in their relationships. They would make critical comments toward their significant other, be less interested in sex, or try to sabotage their partner with unhealthy food in order to derail their partner's efforts and prevent the partner – and the relationship – from changing.
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New Links Between Social Status, Brain Activity
New studies released today reveal links between social status and specific brain structures and activity, particularly in the context of social stress. Using human and animal models, these studies may help explain why position in social hierarchies strongly influences decision-making, motivation, and altruism, as well as physical and mental health. Understanding social decision-making and social ladders may also aid strategies to enhance cooperation and could be applied to everyday situations from the classroom to the boardroom.
The new findings show that
! Adult rats living in disrupted environments produce fewer new brain cells than rats in stable societies, supporting theories that unstable conditions impair mental health and cognition
! People who have many friends have certain brain regions that are bigger and better connected than those with fewer friends. It's unknown whether their brains were predisposed to social engagement or whether larger social networks prompted brain development
! In situations where monkeys can potentially cooperate to improve their mutual reward, certain groups of brain cells work to accurately predict the responses of other monkeys
! Following extreme social stress, enhancing brain changes associated with depression can have an anti-depressant effect in mice.
Other recent findings discussed show that
! Defeats heighten sensitivity to social hierarchies and may exacerbate brain activity related to social anxiety
"Social subordination and social instability have been associated with an increased incidence of mental illness in humans," said press conference moderator Larry Young, PhD, of Emory University, an expert in brain functions involved with social behavior. "We now have a better picture of how these situations impact the brain. While this information could lead to new treatments, it also calls on us to evaluate how we construct social hierarchies – whether in the workplace or school – and their impacts on human well-being.
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How Our Taste in Music Changes
We would perhaps be reluctant to admit that our taste in music alters – softens even – as we get older.
A new study suggests that – while our engagement with music may decline – music stays important to us as we get older, but the music we like adapts to the particular 'life challenges' we face at different stages of our lives.
Using data gathered from more than a quarter of a million people over a ten year period, researchers divided musical genres into five broad, "empirically derived" categories they call the MUSIC model – mellow, unpretentious, sophisticated, intense, contemporary – and plotted the patterns of preference across age-groups.
The study led by Arielle Bonneville-Roussy from Cambridge's Department of Psychology found that, unsurprisingly, the first great musical age is adolescence – defined by a short, sharp burst of 'intense' and the start of a steady climb of 'contemporary'. 'Intense' music – such as punk and metal – peaks in adolescence and declines in early adulthood, while 'contemporary' music – such as pop and rap – begins a rise that plateaus until early middle age.
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