Demonstrating Uncertainty

Author
Teaser
Anyone using a modern camera is implementing an optical position measurement. In an active autofocus camera, a pulse of infrared light is emitted from the camera, and the time taken for it to be reflected back to the camera is used to compute the distance between the object and the image plane. Imagine how difficult it would be to operate such a system if the object recoiled every time the infrared pulse was reflected from it. Heisenberg suggested that this is precisely what would happen if light were used to determine the position of a quantum object as accurately as his famous uncertainty principle would allow. On page 801 of this issue, Purdy et al. (1) demonstrate this quantum back-action effect in an optical measurement of the position of a macroscopic mirror.
Title of Magazine or Source
Science
Year of Publication
2013
Volume
339
Issue
6121
Start Page or Article ID (correct)
770-771
Date Published
2013-02
Publisher
Science
DOI
10.1126/science.1234109
Link to online article
https://science.sciencemag.org/content/339/6121/770
JILA PI
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