Category Archives: Electricity

60-Second Hilarious Adventures in Astronomy

A slide picture from 60 seconds in Astronomy, showing English astronomer on holiday. Image: The Open University
12 Short Videos about the Physics of the Cosmos

The Open University has teamed up with “geek chic” comedian David Mitchell to release a series of 12 short animated YouTube videos about the Physics of the Cosmos: “60-Second Adventures in Astronomy”.  A real treat.  And it’s educational!  If you have only 60 seconds, you can now learn everything we know about matter, energy, life, the Universe and everything…

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Lightning and the Earth’s Electric Field

A photograph showing some spectacular lightning bolts above a city skyline at night.
Earth’s Electric Field

The Earth has an electric field.  On average, this field points vertically downwards and it has a magnitude of about 100 N C-1 (Newtons per Coulomb).  It exists because the Earth’s surface carries a negative charge of – 5 x 10C, while the upper atmosphere carries a compensating positive charge.  An average of 400,000 thunderstorms a day sustain a relatively constant electric field.

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Let There Be Light…

A photograph showing the sun reflecting over the waters at Loch Kathrine through a curtain of trees. Low sun. Image: NaturPhilosophie
Fiat Lux…

Light.  Most of us take it for granted during the day.  And at night, we have learned to domesticate it.  Light, the natural agent that stimulates our sense of sight and makes things around us visible. 

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