Feynman was also widely known outside the physics community as an exceptional teacher and colorful, unconventional character.

This is closely tied to the functional integral formulation of quantum mechanics, also invented by Feynman – see path integral formulation.

Feynman diagram and path integral methods are also used in statistical mechanics.

There was also a version of this talk, with the same name, that Feynman gave to high school students.

Feynman was also known for his talks in low level science classes.

Richard Feynman also ascribed to it: " We never are definitely right, we can only be sure we are wrong.

Although Richard Feynman noted that a simplistic interpretation of the relativistic Dirac equation runs into problems with electron orbitals at Z > 1 / α = 137, suggesting that neutral atoms cannot exist beyond untriseptium, and that a periodic table of elements based on electron orbitals therefore breaks down at this point, a more rigorous analysis calculates the limit to be Z ≈ 173, but also that this limit would not actually spell the end of the periodic table.

He also introduced knot invariants defined by complicated integrals analogous to Feynman integrals.

It also forms the basis for the rigorous path integral formulation of quantum mechanics ( by the Feynman – Kac formula, a solution to the Schrödinger equation can be represented in terms of the Wiener process ) and the study of eternal inflation in physical cosmology.

The Feynman diagram for this is also called a penguin diagram due to its shape remotely resembling a penguin ( with the initial and final state electrons as the arms and legs, the second photon as the body and the first looping photon as the head ).

In 1965 Richard Feynman examined the Fatio / Lesage mechanism, primarily as an example of an attempt to explain a " complicated " physical law ( in this case, Newton's inverse-square law of gravity ) in terms of simpler primitive operations without the use of complex mathematics, and also as an example of a failed theory.

In modern theoretical physics, Green's functions are also usually used as propagators in Feynman diagrams ( and the phrase Green's function is often used for any correlation function ).

Feynman's suspicions were corroborated by General Kutyna, also on the commission, who cunningly provided Feynman with a broad hint by asking about the effect of cold on O-ring seals after mentioning that the temperature on the day of the launch was far lower than had been the case with previous launches: below freezing at 28 or 29 Fahrenheit (− 2. 2 to − 1. 6 ° C ); previously, the coldest launch had been at 53 ° F ( 12 ° C ).

Youssef also cites the work of Richard Feynman, P. A. M. Dirac, Stanley Gudder and S. K. Srinivasan as relevant to exotic probability theories.

The Feynman – Kac formula can also be interpreted as a method for evaluating functional integrals of a certain form.

Feynman had never formalized the bet because he couldn't define his terms sufficiently and precisely, but paid up anyway ; Feynman is also on record as saying that he was disappointed with the outcome because he had hoped his reward would stimulate some new fabrication technology, but McLellan's motor used only existing techniques.

This approach is related to state-sum models of statistical mechanics and topological quantum field theory such as the Turaeev-Viro model of 3D quantum gravity, and also to the Regge calculus approach to calculate the Feynman path integral of general relativity by discretizing spacetime.

Nobel-prize winning physicist Richard Feynman also met Nick the Greek, according to the autobiographical Surely You're Joking, Mr. Feynman !.

One can then make an expansion in powers of the coupling parameters and truncate the higher-order terms ( also known as higher loop contributions, due to the number of loops in the corresponding Feynman graphs ).

To quote Richard Feynman "... there is also an amplitude for light to go faster ( or slower ) than the conventional speed of light.

Feynman also pays homage to Isaac Newton's struggles to come to terms with the nature of light.

It also introduces his famous " Feynman diagrams " and how quantum electrodynamics describes the interactions of subatomic particles.

The technique of renormalization, suggested by Ernst Stueckelberg and Hans Bethe and implemented by Dyson, Feynman, Schwinger, and Tomonaga compensates for this effect and eliminates the troublesome infinities.

This was first suggested theoretically by Richard Feynman in 1955, and was soon found experimentally.

The idea that a form of turbulence might be possible in a superfluid via the quantized vortex lines was first suggested by Richard Feynman.

According to Richard Feynman, it was his former graduate student and collaborator Albert Hibbs who originally suggested to him ( circa 1959 ) the idea of a medical use for Feynman's theoretical micromachines ( see nanotechnology ).

Hibbs suggested that certain repair machines might one day be reduced in size to the point that it would, in theory, be possible to ( as Feynman put it ) " swallow the doctor ".

However, in 2006 Dyson himself confirmed that the diagrams should be called Feynman diagrams because " he taught us how to use them ".

This means that for a brief period of time, the total momentum of the two charges are not conserved, implying that the difference should be accounted for by momentum in the fields, as speculated by Richard P. Feynman.

However, Feynman soon found that, while he respected the intellects of his fellow Commission members, they universally finished their criticisms of NASA with clear affirmations that the Challenger disaster should be addressed by NASA internally, but that there was no need for NASA to suspend its operations or to receive less funding.

Feynman felt that the Commission's conclusions misrepresented its findings, and he could not in good conscience recommend that such a deeply flawed organization as NASA should continue without a suspension of operations and a major overhaul.

Later in the Chapel Hill conference, Richard Feynman — who had insisted on registering under a pseudonym to express his disdain for the contemporary state of gravitational physics — used Pirani's description to point out that a passing gravitational wave should in principle cause a bead on a stick ( oriented parallel to the direction of propagation of the wave ) to slide back and forth, thus heating the bead and the stick by friction.

In quantum electrodynamics, electromagnetic interactions between charged particles can be calculated using the method of Feynman diagrams, in which we picture messenger particles called virtual photons being exchanged between charged particles.

The interaction of sub-atomic particles can be complex and difficult to understand intuitively, and the Feynman diagrams allow for a simple visualization of what would otherwise be a rather arcane and abstract formula.

These integrals do, however, have a regular structure, and may be represented graphically as Feynman diagrams.

The Dyson series can be alternately rewritten as a sum over Feynman diagrams, where at each interaction vertex both the energy and momentum are conserved, but where the length of the energy momentum four vector is not equal to the mass.

For the QED interaction Lagrangian,, describing the interaction of a fermionic field with a bosonic gauge field, the Feynman rules can be formulated in coordinate space as follows:

When describing graviton interactions, the classical theory ( i. e., the tree diagrams ) and semiclassical corrections ( one-loop diagrams ) behave normally, but Feynman diagrams with two ( or more ) loops lead to ultraviolet divergences ; that is, infinite results that cannot be removed because the quantized general relativity is not renormalizable, unlike quantum electrodynamics.

In any event, as Richard Feynman once said, " It is scientific only to say what's more likely or less likely, and not to be proving all the time what's possible or impossible.

) Later on this will be corrected to include specifically quantum mathematics, following Feynman.

To calculate the probability of any interactive process between electrons and photons it is a matter of first noting, with Feynman diagrams, all the possible ways in which the process can be constructed from the three basic elements.

( These must not be confused with the arrows of Feynman diagrams which are actually simplified representations in two dimensions of a relationship between points in three dimensions of space and one of time.

Using Wick theorem on the terms of the Dyson series, all the terms of the S-matrix for quantum electrodynamics can be computed through the technique of Feynman diagrams.

As Feynman noted, an idea or theory "... could never be proved right, because tomorrow's experiment might succeed in proving wrong what you thought was right.

These probability amplitudes can be represented as a complex number or equivalent vector — or, as Richard Feynman simply calls them in his book on QED, " arrows ".

Feynman cautioned that to avoid becoming cargo cult scientists, researchers must first of all avoid fooling themselves, be willing to question and doubt their own theories and their own results, and investigate possible flaws in a theory or an experiment.

In the middle of the 20th century, Richard Feynman realized that the perturbative expansion could be given a dramatic and beautiful graphical representation in terms of what are now called Feynman diagrams.

In topological field theory, he introduced the moduli space of stable maps, which may be considered a mathematically rigorous formulation of the Feynman integral for topological string theory.

This particle viewpoint is especially helpful when there are a large number of complicated quantum corrections to the calculation since these corrections can be visualized as Feynman diagrams containing additional virtual particles.