February 11, 2020
How we shape the Earth
Humans appear in the fossil record 200,000 years ago, began migrating out of Africa about 60,000 years ago, and reach the tip of South America about 1,000 years ago. In that time, we have completely reshaped the surface of the Earth, sometimes intentionally, but often inadvertently, through our actions to ensure survival and comfort. This presentation will discuss the many ways we have changed the Earth’s surface over the past several thousand years and how those changes continue to reshape the Earth today.
March 10, 2020
Do quantum tunneling times exist?
Abstract: Quantum tunneling is one of the most striking consequences of quantum mechanics. It is a generally well-understood phenomenon, with several applications. However, the question of how long it takes for a particle to tunnel has defied physicists since the early days of quantum mechanics. I will describe some of the difficulties plaguing the field, up to the current and heated debate in the literature, discuss the origin of the problem – namely, that time is not an observable in quantum mechanics – and describe some my group’s efforts to address the problem using quantum clocks.
April 14, 2020