Albert Einstein said in 1936: "The eternal mystery of the world is its comprehensibility". Universe is easily understood as it is governed by a small set of very simple rules – be it the rise of water when one steps into it; or the dropping of light/heavy objects from a tower; or seeing an apple hit the ground and not fly upwards from a tree. Physicists try to find patterns and principles that describe why the physical world behaves the way it does. Physics is the most fundamental of the sciences as it deals most directly with the simple rules that govern the universe and the simple particles that everything in the universe is made of.
We experience many interesting phenomena in the world around us – colours of a rainbow, the flight of birds, ice floating on water, lightning and the thunder that follows it in a storm, the beautiful hexagonal symmetry of small snowflakes and many more. These can be explained with the understanding of physical principles and processes that cause the phenomena we observe in daily life. The observation and exploration of the world around us helps us in identifying the underlying order or pattern in what we find. Physics is that part of science which deals primarily with the inanimate world, trying to identify the most fundamental and unifying principles. The phenomena of nature are roughly divided into classes like mechanics, acoustics, heat, electricity, magnetism, light, quantum mechanics and nuclear physics.