From Washington Post on 5 Feb. 90 via Dallas News Paper
Scientist’ experiments focus on making better microscope
Scientists have achieved the first step toward the invention
of an entirely new kind of microscope that they predict could be
able to see objects as small as the individual molecules in a
While the electron microscope can see molecules, it will not
work on living subjects at normal temperatures and pressures.
The new procedure, called “molecular exciton microscopy,”
promises to do this because it uses a modified form of ordinary
light. The smallest object visible with a light microscope is
roughly the size of the shortest wavelength of visible light,
which is blue and measures about 400 nanometers (a nanometer is a
billionth of a meter).
This is small, but still so big that a single ray
illuminates manymolecules at one time, masking differences. The
new method, reported in the Journal of Science by Aaron Lewis of
Hebrew University in Jerusalem and Raoul Kopelman of the
University of Michigan and their colleagues, squeezes light waves
into far smaller dimensions.
They did it by shining light through a funnel with an
extremely tiny tip. When photons, particles of light, reach the
tip, they are absorbed by a crystal of anthracene. Inside the
crystal, the photons become excitons (a combination of an
electron and a “hole,” an electrically charged void). Excitons
are far, far smaller than an atom. As they emerge from the tip
of the funnel, they are reborn as photons.
contributed by Ron Moore