popular science

YEAR:

1665

IMAGE:

Cross section of cork (50x)

Physicist Robert Hooke figured out how to block stray light rays, but he also focused illumination: He passed the glow from an oil lamp through a flask of water to diffuse the beam. This made blurry but bright images, revealing something wild in a slice of the bark of a cork oak tree: empty spaces. Hooke dubbed them “cells.” YEAR:

1677

IMAGE:

Microbial creatures (300x)

When Antony van Leeuwenhoek’s expertly ground glass lenses revealed single-celled organisms 10 times smaller than plant cells, his colleagues could hardly believe it. They spent three years looking for their own “animalcules.” After Hooke and others repeated the experiments, scientific study got a lot smaller. YEAR:

1903

IMAGE

: Gold nanoparticles (10,000x)

Richard Zsigmondy and Henry Siedentopf used their ultramicroscope on colloids, mixtures containing super-teeny particles. They sent a beam through the slurry at right angles, then used a compound scope to see how the light scattered.Their first blingyfind: the4-nanometre-wide bits that colour glass.YEAR:

1939

IMAGE:

Tobacco mosaic virus (500,000x)

Max Knoll and Ernst Ruska created the tool that, eightyears later, would first spot viruses: the transmissionelectron microscope. Scientists took samples of cellsand shot electrons through instead of light. As theyhit, theyformed an image, which viewers could projectonto a fluorescent screen and magnify.

ILLUSTRATIONS BY SINELAB

5

7

6

8

YEAR:

2015

IMAGE:

A single atom (20,000,000x)

YEAR: The UK’s SuperSTEM lab sees objects a million times thinner than a hair. Electrons zip through magnets that focus them toward the sample, then pass through a set of lenses. The scope sees which ones lose energy on the way, translating that data into an image—and revealing the intricate structures of individual atoms.

1955

IMAGE:

Tungsten atoms (1,000,000x)

Erwin Müller found a way to visualise the atoms on the end of a needle with his field ion scope: Put the poker in a vacuum chamber and shock it. The needle emits electrons that ionise surrounding gas. As the ions fly away, they collide with a special screen, creating a magnified image of the kaleidoscope-like atom lattice.

POPSCI.COM.AU 25