This work was instrumental in convincing scientific sceptics of the reality of atoms. He proposed a means to measure both the size and average speed of the atoms. Einstein accounted for this motion by stating that minute atoms move randomly in a liquid and collide with the pollen grains. This motion was subsequently termed Brownian motion defied attempts by scientists to satisfactorily explain it until 1905. In 1827 the Scottish botanist Robert Brown observed and described the random motion of tiny grains of pollen under a microscope.

Brownian motion and the size of atoms.

It was for his work on this topic and not relativity that Einstein was awarded the Nobel Prize in Physics in 1921. Light therefore was quantised, with the energy of a photon being proportional to its frequency. Attempts to explain this effect, in which ultraviolet or blue light knocked electrons off a metal plate when even high levels of red light could not, using classical physics had all failed.īy considering light to behave as discrete particles called photons rather than as a wave Einstein was able to successfully account for the observations.

Einstein applied the concept of the discrete package of energy, the quantum, discovered by the German physicist Max Planck to explain the photoelectric effect. The photoelectric effect and the photon.2005 was celebrated as the World Year of Physics to commemorate the centenary of the papers he wrote in 1905 on three key topics in Physics: It contains Einstein’s analysis of simultaneity, probably the most celebrated conceptual analysis of the century.Albert Einstein is probably the most recongnisable and famous scientist in the world today even though he died six decades ago. The theory is arresting enough to demand serious reflection and, unlike quantum theory and general relativity, its essential content can be grasped fully by someone merely with a command of simple algebra. It is the first port of call for philosophers and other thinkers, seeking to understand what Einstein did and why it changed everything. It has also received considerable attention outside physics. As the first of the modern theories, it provides the foundation for particle physics and for Einstein’s general theory of relativity and it is the last point of agreement between them. This special theory of relativity has a central place in modern physics.

Only then does Einstein get down to the business of space and time and lay out a new theory in which rapidly moving rods shrink and clocks slow and the speed of light becomes an impassable barrier. Even its first paragraph just calls to mind an elementary experimental result due to Faraday concerning the interaction of a magnet and conductor. Its title, “On the electrodynamics of moving bodies,” gives no inkling that it will develop an account of space and time that will topple Newton’s system.

Modern readers turning to Einstein’s famous 1905 paper on special relativity may not find what they expect.

Relativity by einstein