Phonons

Synopsis

The origins of modern quantum mechanics date back to 1900 and Max Planck’s hypothesis that oscillators, which classically would be allowed to have any energy, are allowed to have only discrete energies. This led Einstein to his conjecture that light was emitted in chunks or quanta characterised by the relation E=Hv, where E represents the energy of the quanta or photons, H is Planck’s constant and v the frequency. Discusses phonons which are quanta of sound rather than light and shows an experiment at Exeter University which purports to have demonstrated the existence of phonons in liquid helium using a secondary effect. This secondary effect is the acoustic analogue of the photo-electric effect; an interesting experiment but does it verify what it is intended to prove?*

Series

Physics of Matter, The: Course S272

Language

English

Country

Great Britain

Medium

Video; Videocassette. Standard formats. col. 24 min.

Year of production

1986

Availability

OUT OF DISTRIBUTION

Subjects

Physics

Keywords

matter; phonons; quantum mechanics

Credits

Producer

Ted Smith

Cast

Graham Farmelo
Stuart Freake

Production Company

Name

BBC Open University Productions

Distributor

Name

Open University Worldwide

Web

http://www.ouw.co.uk External site opens in new window

Phone

+44 (0) 1908 274066

Address

Walton Hall
Milton Keynes
MK7 6AA

Notes

NB. As of May 2016 Open University Worldwide are no longer distributing DVDs. They have posted this message on their website: ‘Unfortunately Open University Worldwide Limited has decided that product sales are no longer viable given the reduced funding to Higher Education institutions and diminishing demand for the products we have traditionally stocked. At present the Open University Students Association (OUSA) will continue to sell the "Good Study Guide", and we are in discussion with other possible distributors to continue to make The Open University’s products available for purchase. As soon as we have any information on other channels of distribution we will update this notice’. Some products are still available via second hand dealers on Amazon.co.uk