1. Galileo Galilei.
Galileo Galilei (1564-1642) was the first person to turn a telescope on the moon, the planets, and the stars, discovering four of Jupiter’s moons.
2. Isaac Newton.
Isaac Newton (1642-1727) is one of the most famous scientists who ever lived. He invented calculus (see Leibniz), formulated the laws of motion, and proposed the new idea of universal gravitation.
3. Gottfried Leibniz
Gottfried Leibniz (1646-1716) invented calculus independently of Isaac Newton, though Newton and is more widely credited as the field’s founder. It’s Leibniz’s notation we use today, though.
4. Johannes Kepler.
Johannes Kepler (1571-1630) was a mathematician and astronomer, best known for discovering three rules that describe the orbits of planets. His second law states that a line joining a planet and the Sun sweeps out equal areas during equal intervals of time.
5. Joseph Fourier.
Joseph Fourier (1768-1830) was a pioneer in theories of heat and vibration. The technique he invented for this work – representing complex waves by adding together simpler waves – is now used everywhere in science and engineering.
6. Thomas Young.
Thomas Young (1773-1829) pioneered the “double-slit” experiment that showed the dual wave-particle nature of light by shining a light through two narrow slits, producing a interference pattern.
7. Michael Faraday.
Michael Faraday (1791-1867) proposed the idea of electromagnetic fields extending through space – at the time a radical notion – after conducting research into the relationships between electricity and magnetism.
8. Nikola Tesla.
Nikola Tesla (1856-1943) was a physicist, electrical engineer, and inventor who designed the modern AC electrical supply system as well as a method to send electricity wirelessly through the air through the use of Tesla coils that produced giant lightning bolts.
9. Max Planck.
Max Planck (1858-1947) showed that light could only come in packets of certain sizes. It was the first step on the road to quantum mechanics.
10. William Henry and William Lawrence Bragg.
William Henry Bragg (1862-1942) and William Lawrence Bragg (1890-1971) were the father-son team behind Bragg’s law, which describes how X-rays diffract inside crystals.
11. Marie Curie.
Marie Skłodowska-Curie (1867-1934) developed the theory of radioactivity (a term that she coined), learned to isolate radioactive isotopes, and discovered two new elements, radium and polonium.
12. Niels Bohr.
Niels Bohr (1885-1962) laid the groundwork for developing subatomic physics and quantum mechanics. His Bohr model of the atom was the first to place a large atomic nucleus at the centre and the small electrons around it.
13. Ernest Rutherford.
Ernest Rutherford (1871-1937) theorized that atoms have their charge concentrated in a very small nucleus. By bombarding atoms with high energy particles and mapping how they bounced back, or didn’t, he discovered (and named) the proton.
14. Albert Einstein.
Albert Einstein (1879-1955) came up with relativity, one of the pillars of modern physics (alongside quantum mechanics).
15. Erwin Schrödinger.
Erwin Schrödinger (1887-1961) famously proposed a thought experiment, now known as Schrödinger’s Cat, to point out the apparent paradox of the Copenhagen interpretation of quantum mechanics: if a particle can really be in two states at once, what of a cat whose fate depends on the particle’s state?
16. James Clerk Maxwell.
James Clerk Maxwell (1831-1879) formulated the equations that describe electricity, magnetism, and optics as manifestations of the same phenomenon – the electromagnetic field. He’s also the namesake of Maxwell’s demon, a thought experiment in which a hypothetical demon violates the Second Law of Thermodynamics.
17. Louis de Broglie.
Louis de Broglie (1892-1987) suggested that all matter also has wave-like properties. This concept is known as wave-particle duality, or the de Broglie hypothesis, and became central to quantum mechanics.
18. Richard Feynman.
Richard Feynman (1918-1988) made ground-breaking contributions to many branches of physics. He’s lives on in Feynman diagrams, a visual system for figuring out what happens when particles interact. Feynman painted them on his van.
19. Rosalind Franklin.
Rosalind Franklin (1920-1958) was a biophysicist who used X-ray diffraction data to determine the structures of complex minerals and living tissues, including – famously – DNA.
20. Peter Higgs.
Peter Higgs (born 1929) was one of several physicists to propose that elementary particles acquire mass by interacting with a new kind of field, now known as the Higgs field. In 2012 the Cern particle physics lab announced they had discovered a Higgs boson, confirming the existence of Higgs’ field.