Reader’s Scigest 19-02-15

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Core Blimey!

By studying seismic waves, energetic shockwaves generated by earthquakes, to probe the internal structure of our planet, a team of scientists from the Universities of Illinois and Nanjing have discovered that the Earth’s inner core has a further unique region within it – a core of its own. They found that the alignment of iron crystals changed in direction from North-South in the very centre to approximately East-West when about halfway through the inner core, marking the boundary between two distinct sections. The findings could be vital to gaining further insight into the history and evolution of the Earth.

Popcorn Physics

Scientists have found the solution to a long-standing mystery – why popcorn makes a popping noise. Emmanuel Virot and Alexandre Ponomarenko investigated kernels using a microphone and a high-speed camera. They found that the distinctive sound is a result of moisture inside the kernel turning into water vapour and escaping rapidly as the pressure becomes too high, leading to a sudden pressure change that makes the cavities inside the popcorn vibrate, producing ‘pop’, much like when removing the cork from a champagne bottle. They also deduced that almost all (96%) of kernels will pop once they reach 180°C, regardless of the size and shape of the grain.

(Don’t) blame it on the boogie

It’s a question that many students have pondered: will listening to my favourite tunes while revising affect my ability to remember the material I have been reviewing? A study by the Georgia Institute of Technology has come to a comforting conclusion; when trying to remember names, young adults performed equally as well when listening to non-lyrical rock music or musical rain as when in a silent environment. However, older adults recalled ten percent fewer names with music when subject to the same test. The researchers attributed this to the decline of associative memory and the increasing difficulty of concentrating against background noise with age.

Photograph: Joelle Nebbe-Mornod on flickr

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