A mirror is a smooth surface—typically made of glass with a metallic coating—that reflects light in a way that preserves the shape and detail of objects in front of it. Mirrors are a part of our daily lives: we use them when grooming, driving, decorating homes, and in high-tech applications like telescopes, lasers, and scientific instruments.
The most common mirrors are plane mirrors, which produce images that appear to be behind the surface at the same distance as the object in front of them.
How Mirrors Reflect Light
The key principle behind a mirror is the law of reflection: when light hits a smooth surface, it bounces off at the same angle as it arrived. This is why we can see a clear, sharp reflection rather than a blurry scatter of light.
Mirrors are typically made by:
- Polishing a glass surface until it is extremely smooth.
- Applying a thin metallic layer, usually aluminum or silver, to the back side of the glass to make it reflective.
The transparent glass protects the reflective metal and provides structural support.
Types of Mirrors
- Plane mirrors – Flat mirrors that reflect images in their actual size and orientation (but reversed left to right).
- Concave mirrors – Curved inward; used in shaving mirrors, headlights, and telescopes. They can magnify or focus light.
- Convex mirrors – Curved outward; used in vehicle side mirrors or security mirrors. They show a wider field of view but reduce the image size.
Everyday and Scientific Uses
Mirrors are used in:
- Personal care: bathrooms, dressing tables
- Automobiles: rear-view and side mirrors
- Architecture: creating the illusion of space
- Science: reflecting telescopes, microscopes, laser systems
- Solar energy: focusing sunlight in solar power plants
Some high-tech mirrors are coated with special materials to reflect only specific types of light—like ultraviolet or infrared.
Fun Facts About Mirrors
- Animals like dolphins and elephants can recognize themselves in a mirror—this is called mirror self-awareness.
- Mirrors don’t reverse top to bottom; they reverse front to back, which gives the illusion of left-right reversal.
- In space telescopes, ultra-precise mirrors are made using nanometer-level polishing.
Glossary
- Reflection – The bouncing of light off a surface.
- Law of reflection – States that the angle of incidence equals the angle of reflection.
- Plane mirror – A flat mirror that produces upright, reversed images.
- Concave mirror – A mirror curved inward that can focus or magnify images.
- Convex mirror – A mirror curved outward that provides a wide-angle view.
