I started thinking a few nights ago – not for the first time – about the greatest physicists in history. I pondered the fact that probably there are some truly great physicists whose work was or is unremittingly brilliant, but I’ve never heard of them because in addition to its brilliance, their work is relatively obscure.
An easier approach is to ask who have been history’s most influential physicists. I came up with this Top 10.
I tried to pick the physicists most influential in fulfilling the purpose of science, which I would roughly define as the activity which increases our understanding of the behavior of the universe and everything it contains. I also took account of the influence that their work had on other scientists.
Here are my picks – in historical order.
Anaximander is responsible for the idea that the earth needs nothing below it to support it. He said that the earth floats in the center of infinity, held in position because it is an equal distance from all the other parts of the universe. In doing so, he transformed humanity’s concept of our planet and how it relates to the rest of the universe.
The greatest scientist of ancient times, Archimedes pushed mathematics, physics, and engineering to new heights. He created the physical sciences of mechanics and hydrostatics, discovered the laws of levers and pulleys, and discovered one of the most important concepts in physics – the center of gravity. He applied advanced mathematics to the physical world and his surviving works inspired both Galileo Galilei and Isaac Newton to investigate the laws of motion.
Galileo was the first person to study the sky with a telescope. He was the first person to discover moons orbiting another planet, discovering Jupiter’s four largest moons. He discovered that Venus has phases like our moon – the first practical rather than mathematical evidence that the sun is at the center of the solar system. He also discovered that gravity accelerates all things equally, regardless of mass and that the acceleration of objects by gravity is proportional to the square of the time they have been falling. He stated the principle of inertia – in other words he discovered Newton’s First Law of Motion – and discovered the Law of the Pendulum.
Isaac Newton invented calculus, the mathematics of change, without which we could not understand the behavior of objects as tiny as electrons or as large as galaxies. His most famous work, Principia, is one of the most important scientific books ever written. In Principia Newton used mathematics to explain gravity and motion. Initially hardly anyone understood Newton’s new physics. When Newton walked past them one day, one student remarked to another:
“There goes a man who has written a book that neither he nor anybody else understands.”
Newton discovered the law of universal gravitation, proving that the moon orbits the earth for precisely the same reason that an apple falls from a tree. He formulated three laws of motion – Newton’s Laws – which lie at the heart of the science of movement. Furthermore, he proved that sunlight is made up of all of the colors of the rainbow and he built the world’s first working reflecting telescope.
Michael Faraday is arguably the greatest experimental physicist ever. By varying a magnetic field, he produced electric current in a wire, and so discovered electromagnetic induction, the means by which nearly all electricity is generated by power plants today. He discovered electromagnetic rotation – the forerunner of the electric motor – and he discovered that diamagnetism is a property of all materials. His laws of electrolysis lie at the heart of the science of electrochemistry, which he played a large part in founding. He invented the Faraday Cage, which on a large scale prevents lightning damaging anything within it and on a small scale allows electric and electronic experiments to be carried out without external interference. He was the first person to find that magnetism and light were somehow related when he discovered that a magnetic field rotates the plane of light polarization. He was the first person to demonstrate that gases can be liquified, and he also discovered the enormously important chemical compound benzene.
James Clerk Maxwell
James Clerk Maxwell’s work heralded a new epoch in physics – he unified the electric and magnetic forces, showing that they are fundamentally the same force. His equations showed that when electric charges accelerate they release waves of electromagnetism traveling at the speed of light, establishing that light itself is an electromagnetic phenomenon – in doing so he unified electricity, magnetism and optics. His kinetic theory of gases accurately explained the origin of temperature and he introduced probability theory into the physics of the very small, laying the foundation for quantum theory. He was the first person ever to produce a color photograph; and, with tremendous mathematical and physical intuition, he explained the behavior of Saturn’s rings over 100 years before the Voyager spacecraft confirmed that he was absolutely right.
Albert Einstein rewrote the laws of nature. He completely changed the way we understand the behavior of things as basic as light, gravity, and time. He proved that everyone, whatever their own speed relative to light, measures the speed of light to be 300 million meters per second in a vacuum. This led to the strange new reality that time passes more slowly for people traveling at very high speeds than for people moving more slowly. He discovered the iconic equation, E = mc2, which showed that energy and matter can be converted into one another. He rewrote Newton’s law of gravitation, which had been unchallenged since 1687. In his General Theory of Relativity, Einstein showed that matter causes space to curve, which produces gravity; he showed that the path of light follows the gravitational curve of space; and he showed that time passes more slowly when gravity becomes very strong. He also demonstrated the photoelectric effect, establishing that light can behave as both a wave and a particle.
Ernest Rutherford is the father of nuclear chemistry and nuclear physics. He discovered and named the atomic nucleus, the proton, the alpha particle, the beta particle, and he predicted the existence of the neutron. He discovered the concept of nuclear half-lives and achieved the first deliberate transformation of one element into another, fulfilling one of the ancient passions of the alchemists. An unusually large number of young scientists who spent time working with him went on to win Nobel Prizes, including James Chadwick, Cecil Powell, Niels Bohr, Otto Hahn, Frederick Soddy, John Cockcroft, Ernest Walton and Edward Appleton.
Niels Bohr completely transformed our view of the atom and of the world. Realizing that classical physics fails catastrophically when things are atom-sized or smaller, he remodeled the atom so electrons occupied ‘allowed’ orbits around the nucleus while all other orbits were forbidden. In doing so he founded quantum mechanics. Later, as a leading architect of the Copenhagen interpretation of quantum mechanics, he helped to completely reshape our understanding of how nature operates at the atomic-scale.
Werner Heisenberg played a crucial role in the creation of quantum mechanics, developing the matrix mechanics formulation, establishing that the behavior of atomic sized particles is very different from larger objects, sometimes with bizarre consequences at odds with common sense. Although Albert Einstein did not like it, Heisenberg showed that God continuously plays dice with the universe. Heisenberg’s uncertainty principle established that particles have paired properties that cannot both be known precisely. For example, if you know a particle’s position with high precision, you cannot know its momentum with high precision – there is always a level of uncertainty.
Okay, that does it – my personal Top 10. Before signing off, I’ll add honorable mentions for Johannes Kepler, Erwin Schrödinger, Paul Dirac, and Richard Feynman – all of whom I feel sorry about omitting from my list.
Feel free to offer your own thoughts and picks in the comments section below.
Author of this page: The Doc
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