Ever since the existence of molecules was proven and
molecular reactions were predicted, humans have wanted to visually
observe how such events proceed. Such observations of
single-molecule reactions are highly important for the fundamental
understanding of chemical sciences, which would aid in the
development of novel catalysts, materials, or drugs, and help us
decipher the complex biochemical processes. However, this was not
possible for the longest time in modern chemistry, and so far the
information of dynamical processes on the nanometer scale was
obtained only from indirect methods because molecules were too
small to be visualized.
