*Published in 1998*

In order to remember Feynman on the 20th anniversary from his death, the students enrolled in the third year of physics of the University of Trieste organized a set of pedagogical lectures on topics dear to Feynman, or just encounters with people who had the fortune to meet and interact with Feynman. The schedule of lectures is indicated below.

And Feynman.com gives a big “hurray!” to the students and their professor, Ennio Gozzi, for their effort.

#### PATH-INTEGRALS FOR PEDESTRIANS

##### Ennio Gozzi Dept. of Theoretical Physics,University of Trieste.

Time: Monday March 3rd , 14 pm Place: Room A Dept. of Physics, University of Trieste. Via Valerio, Trieste ITALY

ABSTRACT: We will present a brief introduction of the main reasons that brought Feynman to the path-integral formulation of Quantum Mechanics. We will start from the little known work of Dirac on the use of the Lagrangian in quantum mechanics.

#### PATH-INTEGRALS FOR CYCLISTS

##### Ennio Gozzi

Wednesday March 5th Room A

ABSTRACT: We will start from the operatorial formulation of QM and, via a discretization of time, we will show how to obtain the path-integral formulation. We will in particular analyze the free particle, the harmonic oscillators and make a connection with the WKB methods.

#### MY MEMORIES OF FEYNMAN

##### DANIELE AMATI Sissa and Infn, Trieste

Time: Thursday March 13, at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

#### R.P.FEYNMAN, QUANTUM MECHANICS AND QUANTUM COMPUTATION

##### GianCarlo Ghirardi Department of Theoretical Physics, Univ. of Trieste and Infn, Trieste

Time: Thursday APRIL 3, at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

Abstract: We shall first stress the deep interest and insight of Feynman for the most subtle aspects of quantum mechanics by quoting several not-so-well-known sentences he wrote. Next, with reference to his suggestion of resorting directly to the use of microscopic systems in order to build elementary logical gates, we will briefly review the basic features and the recent progresses in quantum computation.

#### THERMODYNAMICS, COMPUTATION AND COMPLEXITY

##### FABIO BENATTI Department of Theoretical Physics, Univ. of Trieste and Infn, Trieste

Time: Thursday APRIL 10, at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

Abstract: As any physical process, computing asks for energy and usually dissipates it. I will briefly illustrates the path that, starting from Feynman’s analysis of the thermodynamic cost of computation, leads to Schumacher’s notation of Geodel’s friction.

#### Fulmini e saette (Inspired by Chapter 9, “Electricty in the atmosphere” of the Feynman Lectures note on Physics, Vol.2)

##### Guido Barbiellini Dipartimento di Fisica Università di Trieste E INFN, Trieste

Time: Thursday April 17th, at 18 PM. Place: Lecture Room A, Physics Dept. Univ. of Trieste, Via Valerio, Trieste.

Abstract: The astrophysical Mission AGILE is on a low equatorial orbit at 550 Km above sea level since April 23 2007 when was launched from the Indian base of Sriharicota close to Chennai (ancient Madras) in the south region of India. The instruments on board of AGILE are able to detect high energy photons coming from everywhere in the energy range from 0.1 to1000 Mev. This electromagnetic waves are usually denominated X and Gamma rays and due to very short wave length the interaction enhance their particles behavior . Many important astrophysical observations are already obtained in this first year of observation. During the time of earth observation, due to solar energy constrains, the AGILE telescope has detected gamma emission coming from below, very short (~1msec) and of high intensity ~ 100 counts on a surface of ~100 cm2 . The very same phenomenon has been observed in the 90 by the NASA Space mission dedicated to Compton (CGRO). This fast gamma flash (TGF) only recently (2006) has been related to lightning. A very precise time coincidence between the burst timing and an electromagnetic antenna sensible to the electromagnetic field originated by the discharge has proven the common source of the two phenomena. The electric field associated to the cloud of a thunderstorm or in to the different regions of our atmosphere are in general lower of the electric air breakdown so the lightning need a trigger . Recently has been suggested that the exstensive air showers initiated by the cosmic rays in the atmosphere can play this role. The fast ionization due to the EAS creates the free electrons seed for the discharge. The electrons have to reach in a short time a relativistic energy in order to minimize the energy losses in the air. The detection of energetic photons with an energy spectrum compatible with that of a bremsstrahlung from 30 Mev electrons ,is in agreement with the previous suggestion.The formation of the different kinds of lightnings is a very complex phenomenon that imply the contribution of many recent scientific discoveries not known to our ancestors that ascribed the lightning to the Zeus’s fury .From the sky Zeus was sending to earth burning arrows prepared in large series by Vulcano. This was a satisfactory possibility.

#### FEYNMAN’S PARTON MODEL

##### DANIELE TRELEANI Dept. of Theoretical Physics, University of Trieste And INFN.

Time: Wednesday, April 23rd, Time 18 PM. Place: Room A, Physics Dept. Via Valerio

ABSTRACT According to Ne’eman, the parton model represents one of the greatest contributions of Feynman to the development of last century’s physics. Indeed our present description of high energy reactions in terms of elementary degrees of freedom is, to a large extent, built on the Feynman’s parton model idea. The basic elements of the parton model will be reviewed while its developments and its actual implementation in the standard model will be briefly outlined.

#### NANO-PHYSICS “There is plenty of room at the bottom”, Feynman 29-12-1959

##### Silvio Modesti Dept. of Physics, University of Trieste Tasc INFM , Trieste

Time: Tuesday , April 29th , at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

ABSTRACT: “What would the properties of materials be if we could really arrange the atoms the way we want them? They would be very interesting to investigate theoretically. I can’t see exactly what would happen, but I can hardly doubt that when we have some control of the arrangement of things on a small scale we will get an enormously greater range of possible properties that substances can have, and of different things that we can do.” R. P. Feynman, APS Meeting 29-12-1959 Yes, now we can arrange the atoms the way we want, and measure the properties of each atom. Nanomanipulation is one of the methods. I will present some examples of the surprising properties of the materials obtained in this way. For example you can “easily build” materials where the electrons behave like ultra-relativistic particles with zero rest mass and address QED phenomena in a new way, or where “normal” non-magnetic atoms acquire strange magnetic properties.

#### TOPOLOGICAL QUANTUM COMPUTATION

##### G.MUSSARDO SISSA AND INFN-Trieste

Time: May 8th, 18 PM ; Place: Room A, Dipartimento di Fisica,Via Valerio.

ABSTRACT: Tolopogical Quantum Computation has recently emerged as one of the most exciting approaches to constructing a fault-tolerant quantum computer. The proposal relies on the existence of topological states of matter whose excitations are neither bosons nor fermions, but are particle that obey fractional statistics. The search for a large-scale, error free, quantum computer is reaching an intellectual junction at which knot theory, quantum Hall effect and field theory are all coming together to produce quantum immunity.

#### Quantum liquids

##### Gaetano Senatore Dipartimento di Fisica Teorica, Università di Trieste and Democritos INFM-CNR

Time: Thursday , MAY 15th , at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

ABSTRACT: In the mid-fifties, Feynman’s interests concentrated on condensed matter problems, mostly on liquid helium, with seminal contributions that I shall briefly review. I shall then illustrate as some of Feynman ideas still constitute the basis of modern theories and computations on quantum liquids.

#### Feynman’s biophysical adventures

##### EDOARDO MILOTTI Department of Physics, Univ. of Trieste and INFN-Sezione di Trieste

Time: Thursday MAY 22, at 18 PM Place: Lecture Room A, Physics Dept. ,Univ. of Trieste, Via Valerio, Trieste

Abstract: Feynman’s curiosity led him to probe the extremes of human physiology and the inner workings of the fly’s eye. He also contributed some important statistical concepts that have made their way in biophysics. In this seminar I discuss Feynman’s notion of molecular motor and I describe the evolution of the concept in modern biophysics.