wavelength right in this graph if you do your best try to focus as sharply as possible make this angle alpha 90 degrees your focus eyes will become wavelengths over - right that's how small you can focus this is called the diffraction limit so waves water fracked this year three of our colleagues working in our field were awarded the Nobel Prize in Chemistry actually for breaking through this limit so this limit has been come they can generate resolution smaller than the wavelength which is amazing achievement now we face even