When a skater glides on ice, his/her body weight is applied downward on a small area on the surface of the ice. The pressure generated is strong enough to make the ice melt at the point of contact. The friction between the skate and the ice is reduced. Ice skating is actually an act of sliding on a thin layer of water. This was thought to be the secret of skating, but a new study has it that the film offers a number of surprises. With a thickness measuring a few hundred nanometres to a micron (one hundredth the thickness of a strand of hair), it is much thinner than theoretical estimates had suggested. The film is not at all “simple water”. It consists of water that is as viscous as oil, with complex viscoelastic properties — properties of materials that exhibit both viscous and elastic characteristics. This unexpected behaviour suggests that surface ice does not completely turn into liquid water. Instead, it ends up in a mixed state similar to “snow cones” — a mix of ice water and crushed ice. The mystery of sliding on ice can therefore be found in the “viscous” nature of this film of water.
SNEAK PEEK
1. Contact with the ball
On a cricket bat, the ‘sweet spot’ is the point that makes the most effective contact with the ball. Turns out, something similar is at work when it comes to learning. Who called it the ‘zone of proximal difficulty’ and computed that it’s when failure occurs 15% of the time?
Ans: University of Arizona psychologist Robert Wilson
2. A life worth living
Possessing a high sense of purpose, or “usefulness to others” (akin to the Japanese concept of ikigai, or “a life worth living”) is linked to a lower risk of death or cardiovascular disease. Who found it in a seven-year study of 136,000 people with an average age of 67?
Ans: Dr. Randy Cohen with Alan Rozanski (Mt. Sinai St. Luke’s-Roosevelt Hospital)
3. Girls aren’t inferior
“Math class is hard’ was a phrase voiced by Teen Talk Barbie (a 1921 doll). It was attacked for being a pointer to the myth that girls are poor in maths. Who denied any gender difference in brain function or math ability and said that “science doesn’t align with folk beliefs”?
Ans: Jessica Cantlon (Carnegie Mellon University)
4. Many roads to Rome
There were at least two major migrations into Rome over the last few thousand years. The ancient world was perpetually in flux — in culture and in ancestry. Who traced this from DNA proof and concluded that Rome was “a melting pot of different cultures” even in antiquity?
Ans: Geneticist Jonathan Karl Pritchard (Stanford University)
5. They all made fire
Fire meant a means of cooking, light to work by, and warmth at the fingertips in our evolving years. But making it was not a domain of Homo sapiens. Who contended that early humans, including Neanderthals, not only controlled fire but also mastered the ability to make it?
Ans: University of Connecticut anthropologist Daniel Adler
6. Thinking about us
Activity patterns in our friends’ brains when they think about us may be remarkably similar to the activity patterns appearing in our brain when we think about ourselves. Who reached this incredible discovery despite the assumption that “it didn’t have to be that way”?
Ans: Psychologist Dylan Wagner (Ohio State University0
7. Virtually immersed
Virtual reality is not reality but it could influence some key parts of our inbuilt pain-fighting systems. In a study, 360 videos of Arctic scenes relieved patients of burning pain by immersing them in visuals of icebergs and sprawling icescapes. Who conducted the study?
Ans: Dr. Sam Hughes (MSk Lab at Imperial)
8. “Ghost” footprints
Does anyone look under fossilised footprints? The recent sighting of footprints hiding since the end of the last ice age called for it. Who realised that the sediment itself has a memory that records the effects of the animal’s weight and momentum “in a beautiful way”?
Ans: Daniel Adler (University of Connecticut)
9. Hyper-palatable
Hyper-palatable foods excite our brain-reward neural circuitry and overpower mechanisms that send a signal when we’ve eaten enough. They don’t come with any precise quantitative definition. Who offered specific metrics that might qualify foods as hyper-palatable?
Ans: University of Kansas psychologist Tera Fazzino
QUIZ No. 929
1. Who figured out that plants of the future will consume more water than they do today?
– Justin S. Mankin
– Elizabeth V. Volkenburgh
– Rolla Kent Beattie
1. Justin S. Mankin
2. Who sighted “the last necklace made by the Neanderthals” in the Iberian Peninsula?
– A. Rodríguez-Hidalgo
– Frank Hamilton Cushing
– Stanley Diamond
2. A. Rodríguez-Hidalgo
3. Who discovered that the dimensions of the human skull conform to the Golden Ratio?
– Phillip Harold Lewis
– Michael Atwood Mason
– Rafael Tamargo
3. Rafael Tamargo
4. Which Paralympian protested against inaction on climate change from atop a plane?
– James Brown
– Ekaterina Rumyantseva
– Lauren Woolstencroft
4. James Brown
5. Who once disguised herself to join a male-only mechanics pit crew at a race track?
– Bertha Benz
– Anne Louise Stevens
– Shirley Muldowney
5. Anne Louise Stevens