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The Challenge: Make a Microscope



Why does glass work better than water at magnifying things?

Glass has a larger refractive index than water, so light travelling through a sphere of glass is bent much more than when light travels through a sphere of water of the same size. So it can magnify it better.

Why use a sphere?

A sphere has a highly curved surface, which makes for a very powerful lens. The diameter of the sphere determines the magnification — the smaller the diameter, the greater the magnification.

Screw for adjusting the height of the object being examinedA skewer to impale the object and rotate it The lens itself which was sphericalA metal plate serving as the body

Leeuwenhoek's microscope: move your mouse over the different parts for more information

Who invented the microscope?

Strong lenses have been used since antiquity to examine tiny objects. One of the earliest uses of a simple microscope was by Antony van Leeuwenhoek (1632-1723) in around 1680. Leeuwenhoek was a Dutch fabric merchant who used little "glass pearls" to examine the textiles in detail. Leeuwenhoek began to observe everything around him from saliva to pond water to beer. He discovered many micro-organisms and was the first person to describe bacteria, blood cells and sperm cells. To obtain ever-increasing magnifications, Leeuwenhoek worked on smaller and smaller lenses, finally reaching 1-2 mm (0.04-0.08 in.) diameter lenses. Such small and powerful lenses are difficult to handle and focus: you have to keep the instrument very close to your eye and look directly through the tiny lens.