Who was the greatest scientist of all time and why?

Answer 1

Albert Einstein was.

Albert Einstein -- Scientific Career

Einstein had always been convinced that Atoms existed and were of minute nonzero size, as against the popular belief that these are a delusion only. A hundred years back, another scientist Antoine Lavoisier also supported this idea by chemical experiments. Ludwig Boltzmann, an atomist physicist projected theories on atoms but could not radically demonstrate a universal position of state of the atoms at all temperatures. The solids and gases confirmed of atoms, their velocities and the specific heat generated, but all these assumptions filed at zero temperatures. The same fate met Maxwell's work.

Einstein believed that if atom is a reality then one consistent theory should explain aspects of observations. He undertook real hard efforts that finally led him to thermodynamics and then to statistical physics. He concluded his work the theory of specific heats of solids.

The leading German journal Annalen der Physik published Einstein's four papers (Annus Mirabilis Papers), in 1905 calling it Einstein's 'Miracle Year'.

Special Relativity

In 1905 his papers discussed the radical theory of special relativity observing that independence of speed of light required fundamental changes to notion of simultaneity. This reflected on time space frame of a moving body slowing down relative to the observer. Similarly in the paper on mass-energy equivalence were then considered as separate concepts, Einstein concluded by equations of special relativity. This summed up that small mass could be converted into huge amounts of energy. This finding proved a prediction on nuclear power.

Protons

In 1905 Einstein projected another theory that light itself was made up of localized particles (quanta). This was rejected by almost all scientists. However, Robert Millikan completed his experiments on photoelectric effect and measured Crompton scattering in 1919. This confirmed the light particles idea of Einstein. He was motivated and led to it by thermodynamic considerations and had nothing to do with photoelectric effects. His entropy defined detailed equations on light wavelengths and frequency differences within the same light, which were later accepted as realistic conclusions.

Atomic Vibrations (quantized)

The specific heat anomaly in solids was concluded and ratified by applying the quantum theory in 1906. Einstein based his working on the notion that each atom oscillates independently and not joined to others, as was usually thought. By detailed demonstrations he proved the motion of atoms, their velocities, the quantized motion and specific heat calculations even at zero temperatures match those deducted by other scientists, earlier and the present. Further work by others reconfirmed the correct application. This work of Einstein laid the foundation of condensed matter physics.

Adiabatic Principle and action-angle variable

Ernest Rutherford discovered the nucleus of the atom stated that electrons orbit it like planets. Niels Bohr proved that the quantum mechanical postulates of Planck and developed by Einstein, explain the discrete motion of electrons in atoms and further described adiabatic principle and adiabatic invariant.

Wave-Particle Duality

Einstein elaborated on the Max Planck's energy quanta to possess momentum and should act as independent particles. This 1909 paper projected photon concept and wave-particle duality in quantum mechanics.

Critical Opalescence

Einstein refers to Raleigh scattering and explains that light of all wave lengths is scattered and the fluid looks milky white. This also depends on density and some other factors.

Energy at Zero Point

Einstein noted that oscillator energies by Planck had incorrect zero point. This view was made in 1913 stating that according to thermodynamics a molecule with two atoms can split into two free atoms. For this he proposed a new formula.

Equivalence Principal

Einstein had his 'happiest thought'. He figured that gravity of one matter has effects on the other according to gravitational fields. He visualized that when clocks are placed at different heights, the lower one will move slower as more force acts on it than the one that is placed higher. He confidently stated the earlier theory on gravity by Gunnar Nordstrom was incorrect. These findings led him to publish a paper from Prague announcing the effects of gravity on light, specifically gravitational redshift and deflection of light. He proposed some thought experiments on general relativity.

General Relativity

Einstein published a paper on the general theory of relativity in 1915, as it is still today. He terms gravitation as a distortion of the structure of spacetime by matter, affecting the inertial motion of the other matter. The worldwide astronomers set to prove him wrong, took to observatories view the 'redshift'. In 1917 and 1918 no signs showed up. In 1919 the British astronomer, Arthur Stanley confirmed Einstein's prediction of gravitational deflection of star light by the sun, while photographing a solar eclipse in Brazil. Einstein was praised and received the best comments "the great feat of human thinking about nature" and "the greatest discovery ever made". This fact finding illustrates the deep intuition of the Great Scientist.

Einstein continued his work on various other subjects. Much was still in the pipe line nearing completion when he died in 1955. His colleagues and fellow scientists are continuing his experiments further confidently. He stood his ground against strong difference of opinion and was often proved convincingly right. He had his weak points also. In the course of unknown exploration of the natures secrets one has to take lead by assumptions, side-tracking and often retreating back in the absence of positive signals. The achievements create history and he has a lot many in his account. Only that matters while the rest of criticism is probably jealousy.

He also had the most famous equation nowadays which is E = mc2.