Quantum Scattering Amplitudes, or Amplitudes for short, has emerged
as a subfield of high-energy physics in the last two decades. It is
devoted to the calculation and application of scattering amplitudes
in relativistic quantum field theory. I give an overview of the
subfield and its connections to frontier areas of high-energy physics
and mathematics. I'll also review a number of topics within it,
including successes in applications to LHC physics, and the beginnings
of applications to gravitational-wave observations.