Episode 5

Image for Episode 5Not currently available on BBC iPlayer

Bang Goes the Theory, Series 4 Episode 5 of 8

Duration: 30 minutes

On the 50th anniversary of the invention of the laser, Jem Stansfield explains how they work and builds himself a homemade one. Dallas Campbell looks at the rise of Citizen Science and takes part in the research projects that need people power. And Dr Yan recreates a demonstration to calculate the speed of light. The programme is co-produced with the Open University. For more ways to put science to the test, go to www.bbc.co.uk/bang and follow the links to The Open University.


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    Bang LIVE rolls into Edinburgh on 15-17 April. Meet the presenters, watch the show and get hands-on with science in the interactive area.

    Bang LIVE locations and dates

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    Professor David Spiegelhalter and Dr Mike Aitken discuss the science of risk and why understanding uncertainty is vital for our society.

    Do some citizen science by taking the Big Risk Test
  • Weekly Web Pick

    Weekly Web Pick

    Lynne in Aberdeen asked: How do night-vision goggles work and why is everything green? So Dr Yan headed into the night to find out, using hi-tech specs and a thermal imaging device.

    Watch Dr Yan explain night-vision goggles
  • Dr Yan measures the speed of light

    Dr Yan measures the speed of light

    Find out how to measure lightspeed using some bread, butter and your microwave oven.

    Watch Dr Yan measure the speed of light - in his kitchen.
  • Dr Yan's lightspeed car

    Dr Yan's lightspeed car

    Dr Yan answers the intriguing question: What happens if I turn the headlights on in a car going at the speed of light?

    Watch Dr Yan use a toy car set to tackle the speed of light
  • Room with a view

    Room with a view

    The Royal Observatory's 'onion dome' was the location for Dallas' item on citizen science. The telescope dates from 1893, and is still the seventh largest of its kind in the world.

    The 28-inch Greenwich refracting telescope


Liz Bonnin
Dallas Campbell
Jem Stansfield
Series Producer
Paul King


The Open University

The Open University

If Bang stirs your interest in science then visit The Open University and discover more.

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