Crisis in modern Physics

Physics is currently going through a crisis. It is of course true that Physics has faced crisis even in earlier times. For example, a hundred years ago one of the most baffling problems was the black body radiation problem. A black body is an object that absorbs all electromagnetic radiation that falls on it.

It was found experimentally that the radiation emitted by a black body did not agree with the classical Rayleigh-Jeans law. A second problem was the atom stability problem. An atom should be highly unstable according to the classical electromagnetic theory. These problems were solved by the introduction of the quantum theory.

The introduction of the quantum theory led to significant successes but also led to serious problems. In fact the current crisis in Physics is even worse than the one faced before. For example, there is the infamous cosmological constant problem. The cosmological constant is the energy of the vacuum. Before the introduction of the quantum theory, vacuum meant absolutely nothing. According to quantum theory, however, vacuum is boiling with energy of virtual particles.

Particles are called virtual because they pop out of vacuum and then vanish back into vacuum in very short time. When Physicists counted the energy of all the virtual particles, they found that the vacuum energy to be 10¹¹⁷ Joules/cc. Experiments give a value of 0.01 Joules/cc. This problem has not been solved in the last 40 years.

Then there is also the problem of testing the modern theories. The predictions of string theory which is the most prominent candidate can only be tested at energies close to big bang energy. At low energies its predictions match that
of the existing theories. It has been estimated that a straight forward test of string theory would need a collider that is 70 lightyears long. For comparison, the earth is only 8 light minutes away from the Sun. This means that there is no hope of a quick confirmation of string theory.

This crisis has resulted in a sharp drop in any major discovery in the last 30 years. I have given below a time line for major Physics discovery which shows that there has been no confirmation of any major theory since 1980.

Timeline of Fundamental Physics Discoveries Since 1780

Advances in our knowledge of the laws of nature consisting either of experimental discoveries or theoretical proposals that were confirmed experimentally.

Year ADVANCES IN PHYSICS

1782 Conservation of matter, Lavoisier

1785 Inverse square electricity confirmed, Coulomb

1801 Wave theory of light, Young

1803 Atomic theory of matter, Dalton

1806 Kinetic energy, Young

1814 Wave theory of light, interference, Fresnel

1820 Evidence for electro-magnetic interactions, Ampere, Biot, Savert

1824 Ideal gas cycle analysis, internal combustion engine, Sadi Carnot

1827 Resistance, etc., Ohm

1838 Lines of force, fields, Faraday

1838 Earth's magnetic field, Weber

1842-3 Conservation of energy, Julius Robert Mayer, William Thomson

1842 Doppler effect, Lord Kelvin

1845 Faraday rotation (light and electromagnetic)

1847 Conservation of energy 2, Joule, von Helmholtz

1850-1 Second law of thermodynamics, Rudolf Clausius, Kelvin

1857-9 Kinetic theory, Clausius, James Clerk Maxwell

1861 Black body, Kirchhoff

1863 Entropy, Clausius

1864 A dynamical theory of the electromagnetic field, Maxwell

1867 Dynamic theory of gases, Maxwell

1871-89 Statistical mechanics, Boltzmann, Gibbs

1884 Boltzmann derives Stefan radiation law

1887 Electromagnetic waves, Hertz

1893 Wein's radiation law

1895 X-rays, Roentgen

1897 Electron, Thompson

1900 Planck formula for radiation

1905 Special relativity, Einstein
Photoelectric effect, Einstein
Brownian motion, Einstein

1911 Equivalence Principle
Discovery of the nucleus
Superconductivity

1913 Bohr atom

1916 General relativity, Einstein

1919 Light bending confirmed

1922 Friedmann proposes expanding universe

1923 Stern-Gerlach experiment
Matter waves
Galaxies
Particle nature of photons confirmed

1925-7 Quantum mechanics

1925 Stellar structure understood

1927 Big Bang proposed by Lemaitre

1928 Antimatter predicted

1929 Hubble confirms expansion of universe

1932 Antimatter confirmed
Neutron discovered

1933 Dark matter found

1937 Muon discovered

1938 Superfluidity discovered
Energy production in stars understood

1939 Uranium fission discovered

1944 Theory of magnetism

1947 Pion discovered

1948 Quantum electrodynamics

1956 Electron neutrino discovered

1956-7 Parity violation found

1957 Superconductivity explained

1959-60 Role of topology in quantum physics, predicted and confirmed

1962 SU(3) theory of strong interactions
Muon neutrino found

1963 Quarks predicted

1967 Unification of weak and electromagnetic interactions
Solar neutrino problem found
Pulsars (neutron stars) discovered

1968 Experimental evidence for quarks found

1970-3 Standard model of elementary particles invented

1971 Helium 3 superfluidity

1974 Black hole radiation predicted
Renormalization group
Charmed quark found

1975 Tau lepton found

1977 Bottom quark found

1978 Dark matter found in galaxies

1980 Quantum Hall effect

1981 Theory of cosmic inflation proposed

1985 Bose-Einstein condensate found

1995 Top quark found

1998 Dark energy discovered

2003 WMAP observations of Cosmic microwave background

Timeline Source: American Physical Society