Physics is the study of how the universe works, and it is divided into two main branches: classical physics and modern physics.

What is Classical Physics?

Classical physics describes the world we see around us every day. It works perfectly for objects that move at normal speeds and are large enough to see. This branch is based on laws discovered before the year 1900. Sir Isaac Newton is the most famous figure here, as he defined the laws of motion and gravity. For example, when you throw a ball, classical physics calculates exactly where it will land based on its speed and height.

• Mechanics: Study of motion, like a moving car or a falling apple.
• Thermodynamics: Study of heat and how it changes into energy.
• Optics: Study of light, like how mirrors and lenses work.

The Rise of Modern Physics

Modern physics began at the start of the 20th century when scientists discovered things that classical laws could not explain. It deals with extremely small objects, like atoms, or things moving at incredibly high speeds, close to the speed of light. Albert Einstein and Max Planck were pioneers in this field. They realized that energy and matter behave in very strange ways at these tiny scales.

Key Differences Explained

The main difference lies in the scale of what is being studied. Classical physics is deterministic, meaning if you know the starting conditions, you can perfectly predict the future outcome. Modern physics, especially Quantum Mechanics, is probabilistic. It tells us that we cannot know exactly where an electron is; we can only calculate the probability or chance of finding it in a certain place.

Real-World Impact

We use both branches every day. When a civil engineer builds a bridge, they use classical physics to ensure it stays standing. When you use your smartphone, you are using modern physics. The microchips inside your phone rely on our knowledge of how electrons move through silicon, a concept that only makes sense through the lens of modern quantum physics.