What is the Difference Between Diffraction and Refraction?

The main difference between diffraction and refraction lies in the way light waves change direction when interacting with different media or obstacles:

• Refraction: This occurs when light waves pass from one medium to another, causing a change in their direction. Refraction is always accompanied by a wavelength and speed change. For example, when light passes from air into water, it slows down and changes direction slightly, causing the apparent position of the fish underwater to differ from its actual position.
• Diffraction: This is the bending of light waves as they pass through an opening or around an obstacle. Diffraction increases with increasing wavelength, and it can cause the spreading of light waves. For instance, waves can bend around corners, around obstacles, and through openings. Diffraction of light is not as obvious on a day-to-day basis, but it can be demonstrated in experiments like Young's double-slit experiment and using diffraction gratings.

In summary:

• Refraction involves the bending of light as it passes from one medium to another, always accompanied by a wavelength and speed change.
• Diffraction is the bending of light as it passes an obstacle or through an aperture, increasing with increasing wavelength.

Comparative Table: Diffraction vs Refraction

Here is a table summarizing the differences between diffraction and refraction:

In summary, diffraction is the bending of light waves around obstacles or through gaps, while refraction is the bending of light waves as they pass from one medium to another. Both processes involve changes in the direction of light waves, but they occur under different circumstances and are observable in various everyday examples.