These days scientists can see way down to the molecular level; they can observe living nerve cells at work and proteins interacting. But this ability wasn't guaranteed: For years, researchers believed there was a physical limit to how small a person could see using a microscope.
Today, three researchers won the Nobel Prize in Chemistry for their work in bypassing that limit. Eric Betzig, Stefan Hell, and William Moerner will share the award.
According to the , scientist Ernst Abbe has postulated in 1873 that the maximum resolution anyone would be able to achieve with a microscope would be half the wavelength of light—about 0.2 micrometers. That would allow researchers to see a cell or bacterium, but a virus or a protein would be too small to view.
In 2000, Hell worked around the "Abbe diffraction limit" by inventing stimulated emission depletion (STED) microscopy, a way to make a fluorescent molecule glow. Betzig and Moerner created a separate, similar solution called single-molecule microscopy, which Betzig used for the first time in 2006.