YouTube video by nature video, October 2015

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Video: Fluorescence is a State of Mind
Stefan Hell explains super-resolved fluorescence microscopy
Historically, light microscopy has been limited in its ability to resolve closely spaced objects, with the best microscopes only able to resolve objects separated by 200 nm or more. This limit is known as the diffraction limit.
How to break this fundamental law of physics and win a Nobel Prize to boot: In this nature video, Stefan Hell explains super-resolved fluorescence microscopy for which he shared the 2014 Nobel Prize in chemistry.