The Department of Chemistry and Physics concludes its Fall Seminar series. Details for this week’s talk are given below.
Friday, 12/1/2023
3-4pm Eastern
Grote 411
Stephan Schlamminger, PhD
National Institute of Standards and Technology
https://www.nist.gov/people/stephan-schlamminger
Why is it so difficult to measure small forces and torques accurately?
Standard advice to the young experimentalist is to convert the scientific experiment into either a frequency or a null measurement. The speaker of this colloquium has done neither and will share the trouble that he has gotten into in hopes of adding some additional weight to this advice.
In this undergraduate-friendly presentation, I will span the arc from the gravitational constant’s measurement to the kilogram’s redefinition. Both endeavors require precisely measuring forces traceable to an agreed unit system. Interestingly, it was possible to measure the mass of a kilogram with a relative uncertainty of 1 part in 108. However, the gravitational constant is only known with a relative uncertainty of three orders of magnitude higher. Curious why that is. Attend the presentation and gain a fascinating insight into the world of mechanical and electrical metrology.