Biophysics, or Biological Physics, encompasses a wide variety of phenomena, ranging from fundamental quantum-mechanical simulations of biological reactions, to experimental and computational determination of macromolecular (proteins, DNA, membrane) structure and dynamics, to subcellular biological self-assembly and cell organization, to biological molecular machines, to biomedical applications, to biomimetics, the design and engineering of useful artificial devices based on observed biological structures. Biophysics employs most modern devices and methods invented to study the invisible world: X ray scattering, nuclear magnetic resonance (MRI), laser spectroscopy and imaging, atomic force microscopy, large-scale computer simulations, and many more. The Biophysicist seeks to understand how the biological world functions, based on fundamental physical principles.  Biophysics is highly multidisciplinary, demanding expertise in physics, chemistry, biology and nanotechnology, as will be seen from the links below.