The Wave, Particle, and Mechanical Properties of Light

The Wave, Particle, and Mechanical Properties of Light

Prof. Jack Sankey (McGill U.)

Sept. 1, 2016 19:00


Every day, all day long, we are continuously bathed in light, even when we think it is dark. Light is everywhere, it comes in all colors (even invisible), and without a second thought, we use it to navigate the world around us: we naturally detect visible light with our eyes or invisible light (radiated heat) with our skin, and we often use technology to detect more exotic forms of light (e.g. x-rays) to learn more about what is inside us or in the universe around us.

But what is light? How does it really behave, and what else can we do with it? In this talk I will discuss the some of the strange and surprising properties of light that I have managed to learn about – and sometimes observe firsthand – over the past 37 years. Of particular interest, light seems to behave fundamentally differently when observed under different conditions: sometimes it seems wave-like, sometimes it seems particle-like. Sometimes it can exert a measurable force on objects large enough to hold in our hands or see in the night sky. Under the right conditions, light can even be used to levitate tiny objects or cool them down like a refrigerator (freeze ray?). I will discuss these and some of the other exciting advances in the field of “optomechanics”, wherein the forces exerted by light have become a powerful tool in controlling the motion of macroscopic solid objects.

See the slides form this lecture