MARIE SKLODOWSKA CURIE
(1867-1934) opened up the science of radioactivity. She is
best known as the discoverer of the radioactive elements
polonium and radium and as the first person to win two Nobel
prizes. For scientists and the public, her radium was a key to
a basic change in our understanding of matter and energy. Her
work not only influenced the development of fundamental
science but also ushered in a new era in medical research and
A simple example of exponential decay in physics is radioactive decay.
Exactly when a particular radioactive nuclei will decay cannot be predicted, but
for a given material we can say that an individual nuclei has a probability
λ (called the decay constant) of decaying in unit time.