Biophysics is the branch of physics that applies the principles and methods of physics to study biological systems. 

Biophysics is rapidly becoming one of the most important frontiers of basic research and already has an enormous impact on our daily lives and on the environment.

Biophysics bridges two seemingly unrelated fields: biology and physics. Whereas biology deals with the studying of life with a primary focus on its variety and complexity, physicists look for mathematical laws of nature and make detailed predictions about the forces that drive these systems. Spanning the distance between the complexity of life and the simplicity of physical laws is the challenge of biophysics. Studying the patterns in life by using state-of-the-art physical measurements and complex computational models is the most powerful way to find out how life works at the fundamental level.

What Do Biophysicists Study?
Biophysicists study life at every level, from the molecular scale to cells, whole organisms and even ecosystems. The ultimate goal is to find out how biological systems work on the most detailed level. This involves developing new experimental and computational tools to understand at a fundamental level the structure, interactions, dynamics, and ultimately the function of biological systems. The biological questions of interest to biophysics are as diverse as the organisms of biology and the properties of all their components, for example:

• How does the brain process and store information?
• How does the heart pump blood?
• How do viruses invade cells?
• How do plants harness sunlight to make food?
• How are genes switched on and off?
• How do nature's nano-machines (like motor proteins and enzymes) move to do their work?

What are the applications?
Biophysics is a source of innovation and instrumentation for any high-tech economy. The applications of biophysics depend on needs on many levels. In the 20th century, great progress was made in treating disease. Biophysics helped create powerful vaccines against infectious diseases. It described and controlled diseases of metabolism, such as diabetes. Biophysics provided both the tools and the understanding for treating the diseases of growth known as cancers. Today rapid progress is being made in understanding how diseases work at a fundamental level. Moreover, numerous environmental problems of our planet are being addressed.

Biophysical methods are increasingly used to serve everyday needs, from forensic science to bioremediation. It provides the life-saving treatment methods of kidney dialysis, radiation therapy, cardiac defibrillators, and pacemakers. Biophysicists invented instruments for detecting, purifying, imaging, and manipulating chemicals and materials.

Why is biophysics important right now?
Society is facing physical and biological problems of global proportions. How will we continue to get sufficient energy? How can we feed the world's population? How do we remediate global warming? How do we preserve biological diversity? How do we secure clean and plentiful water? These are crises that require scientific insight and innovation. Based on the principles of physics and the mechanisms of biology, biophysics provides valuable insight and technologies for meeting these challenges.

Biophysics discovers how to modify micro-organisms for producing biofuel (replacing gasoline and diesel fuel) and bio-electricity (replacing petroleum products and coal for producing electricity). It discovers the biological cycles of heat, light, water, carbon, nitrogen, oxygen and the organisms involved throughout our planet. Biophysics harnesses micro-organisms to clean our water and to produce lifesaving drugs.

The main tools of biophysics are:

• Spectroscopy
• Microscopy & Imaging
• Crystallography
• Force manipulation techniques, e.g. optical tweezers

A myriad of other physical techniques are also used in isolation or in combination with these main tools. To obtain a complete picture, the experimental approaches generally go hand-in-hand with computational modelling.

_{(Information adapted from the Biophysical Society)}