Magnification explained

Published on 05 November, 2024

Humans were using glasses for magnification in ancient Mediterranean and Middle East societies. Advances in magnifying glass led to microscopes and telescopes. Here is a simple explanation of how magnification works - on Earth and in Space.

Viewing a small bug through a magnification glass makes it appear big. Small details on the bug like its markings, patterns are clearly visible.

What is a magnifying glass ?

Magnifying glass is a convex glass that bulges out at the center. This glass converges or focusses light rays from the bug.

How magnifying glass works ?

Light rays bend as they pass through the glass because glass is thicker than air. Light cannot pass freely through closely packed glass particles. They are refracted or in simple words, bent as they pass through glass. This makes parallel rays converge or focus together.

The bent rays appear to be coming from a bug that is larger and.., farther behind the actual bug.

So, when looking through a magnification glass, you do not see the actual bug. Instead you see a reflection bigger in size or magnified.

Similar magnification happens in space too. Instead of a magnifying glass, there are cosmic objects like galaxies and nebulae with a lot of gas and dust. They magnifying objects that lie behind.

What is gravitational lensing ?

Objects like galaxies and stars are denser than the surrounding space. Its mass bends light rays coming from objects directly behind. Bent light rays make the reflection look bigger, magnifying details not previously seen.