Browsing: Physics

Right now, scientists all over the world are trying to understand how we get injured when our bodies are subjected to strong, dynamic loads – a hard body-check on the hockey rink, a tackle on the football field, a car crash, or even a bomb blast. Fortunately, I haven’t had any experience with bomb blasts, and I like to think I’m a great driver (don’t we all!), so I haven’t been in any car crashes (so far!), but what I do know something about is hockey. I grew up in Buffalo, New York. We Buffalonians love hockey, so it should come as no surprise that I’ve been playing hockey ever since I could skate under the crossbar. Like any good…

It was Monday, April 25, 2016, and I was going to meet mass experts Pat Abbott and Eddie Mulhern of NIST’s Mass and Force group as part of my frantic preparations for a 5:21 p.m. flight to Paris. Pat and Eddie were the appointed custodians of the four 1 kilogram masses that I was to transport to the Bureau International des Poids et Mesures (BIPM) (that’s French for “International Bureau of Weights and Measures”) as part of the world’s first comparison among masses calibrated entirely in terms of fundamental constants of the universe. That’s right. These kilograms were calibrated in terms of fundamental constants of the universe and not in terms of some piece of metal enshrined in a vault…

This article was written in response to the March 14, 2016, death of John Cahn, one of the world’s foremost materials scientists, who worked at NIST from 1977 to 2006. Cahn received the National Medal of Science in 1998 and the Kyoto Prize in Advanced Technology in 2011. I first met John Cahn in the late 1960s when he visited our department of metallurgy at the Technion — Israel Institute of Technology. Already a famous thermodynamics-of-materials scholar, John was our most important visiting scientist at the time. During that period I was studying for my master’s and then Ph.D. degrees, and John and I were talking science. John was interested in my work and in particular in the microstructure of…

Have you ever wondered what might happen if we run out of fossil fuels? How do you think we will be able to survive without the resources we need to heat and cool our homes and buildings or the raw materials we use to create all the plastics that make up our modern world? Indeed, if we continue to use up these energy sources up at alarming rates, I think the consequences will be devastating to humanity’s future. As a 17-year-old with a brand new driver’s license back in 1973 during the OPEC Middle East oil embargo, I found myself pondering these serious questions as I sat in line for hours waiting my turn with the family cars to “fill…

Happy Pi Day! No, not pie day, Pi Day. That Greek character pi, π, that you’ve heard of but aren’t quite sure what the big deal is. Pi is the ratio of a circle’s circumference to its diameter. As yawn-inducing as that may sound, it’s an important ratio because pi is the same no matter the size of the circle. This magical ratio, pi, is true for the circle describing the tire of an automobile or a circle going around the entire Earth. We can use pi to calculate a diameter. If the circumference of the Earth at the equator is 40,075 kilometers, which it is, then the diameter of the Earth is equal to the circumference divided by pi,…