Session Q1: Plenary Session II

The Kavli Foundation Lectureship: The Double Pulsar: A Unique Gravity Laboratory

Ever since their discovery, pulsars have been used as precise cosmic clocks. Their observations in binary systems takes us beyond the weak-field regime of the solar-system in the study of theories of gravity. Their contribution is crucial as no test should be considered as complete without probing the strong-field realm of gravitational physics by finding and timing pulsars. This is particularly highlighted by the discovery of the first double pulsar system which is unique in that both neutron stars are detectable as radio pulsars. This, combined with significantly higher mean orbital velocities and accelerations when compared to other binary pulsars, provides the best available testbed for general relativity and alternative theories of gravity in the strong-field regime to date. This review presents the plethora of relativistic phenomena observable in this fascinating system and gives an up-to-date report on its exploitation as a gravity lab.   

Dark Matter in the Cosmos and in the Laboratory

80\% of the matter in the universe is ``dark matter,'' a neutral, diffuse, and weakly-interacting material made of an unknown elementary particle. In this colloquium, I will explain how we know this, and how we might try to directly observe dark matter particles in the galaxy. I will then examine dark matter from a particle physicist's viewpoint and explain how we will use data from high-energy particle colliders to discover and identify the dark matter particle.   

High Temperature Superconductivity 20 Years Later: Achievements, Promises and Challenges

The discovery of high temperature superconductivity (HTS) 20 years ago has been hailed as one of the major advancements in modern science with great promises. In this presentation, I shall first briefly recall the seminal observation of superconductivity at 35 K in early 1986 and several episodes leading to the discovery of superconductivity at 93 K in early 1987. I shall then summarize the progress that has been made in the ensuing 20 years in the areas of HTS science, materials, and applications. Finally, challenges to realize the full promises of HTS technology will be discussed and steps to meet the challenges proposed.