KnowledgeCapsule: Super-Earths may have life-protecting magnetic shields
Super-Earths may have life-protecting magnetic shields
Super-Earths could have oceans of liquid metal and life-protecting magnetic shields, scientists say. Under the heat and pressure that exist inside super-Earths, magnesium oxide and other minerals commonly found in the rocky mantles of the terrestrial planets, transform into liquid metals, laboratory tests have shown, Discovery News reported.
Super-Earths are planets beyond the solar system that are bigger than Earth but smaller than gas giants like Neptune. The research has implications for understanding conditions on super-Earths, including whether they might be favourable for supporting life. Scientists zapped a piece of magnesium oxide with high-powered lasers to simulate the heat and pressure that would exist on planets roughly three to 10 times as massive as Earth. They discovered that the clear ceramic mineral first morphed into a solid with a new crystal structure, then completely transformed into a liquid metal. In that state, the liquid mineral may be able to sustain a physics phenomenon called a "dynamo" action, which is responsible for generating magnetic fields.
The discovery not only complicates models for understanding how planets form and evolve, but also blurs the distinction between a planet's core and its mantle.
"In the early history of planets like Earth, it is possible the entire planet was liquefied. Even today, some super-Earth planets may have these magma oceans," geophysicist Stewart McWilliams, with the Carnegie Institution and Howard University in Washington DC, said. The research was published in the journal Science.
Star trek desks: Classrooms for the next generation?
Scientists designing and testing what they hope might become the classroom of the future have found that Star Trek-style multi-touch, multi-user desks can boost children's maths skills. A three-year project with 400 eight to 10-year olds found that using interactive "smart" desks can have benefits over doing maths on paper, and that pupils are able to improve their fluency and flexibility in maths by working together. "Our aim was to encourage far higher levels of active student engagement," said Liz Burd of Britain's Durham University, who led the study. The research team, whose findings were published in the journal Learning and Instruction, designed software and desks that recognise multiple touches on a desktop using infrared light vision systems.The desks are built into furniture of the classroom to help encourage more collaboration, and are networked and linked to a main smartboard. A live feed of the desks goes directly to the teacher who can intervene quickly to help a pupil while allowing group work to continue. Burd's team found that 45 percent of pupils who used a maths programme on the smart desk system increased the number of unique mathematical expressions they created, compared with 16 per cent of those doing it on paper. Using the new desks helped children work together and solve problems using inventive solutions, the researchers said "We found our tables encouraged students to collaborate more effectively," said Burd.