MEASUREMENTS

Gaithersburg, Maryland - November 09, 2018: Dr. Savelas Rabb, research chemist at the National Institute of Standards and Technology holds NIST's version of a 1 kg single-crystal silicon sphere -- one of the roundest man-made objects in the world -- which is used to measure the Avogadro Constant, which will redefine the mole, the measures substance. And because mass is part of the mole equation, it can also prove the Planck Constant's definition of a kilogram.

Scientists at the National Institute of Standards and Technology have helped improved methods for definitively measuring a kilogram. Representatives from 57 countries will vote at the General Conference on Weights and Measures in Versailles, France to redefine four basic units of measurement November 16, 2018.

CREDIT: Matt Roth for The New York Times
Assignment ID: 30226894A

Add to Lightbox Download

Filename: 181109_NIST_255.JPG
Copyright: 2018, Matt Roth
Image Size: 8256x5504 / 3.8MB; mattrothphoto.com; National Institute of Standards and Technology Gaithersburg Maryland NYTimes New York Times NYTs Scientists NIST N.I.S.T. General Conference on Weights and Measures kilogram Kibble Balance Plank Constant pure Silicon sphere
Contained in galleries

Gaithersburg, Maryland - November 09, 2018: Dr. Savelas Rabb, research chemist at the National Institute of Standards and Technology holds NIST's version of a 1 kg single-crystal silicon sphere -- one of the roundest man-made objects in the world -- which is used to measure the Avogadro Constant, which will redefine the mole, the measures substance. And because mass is part of the mole equation, it can also prove the Planck Constant's definition of a kilogram. <br />
<br />
Scientists at the National Institute of Standards and Technology have helped improved methods for definitively measuring a kilogram. Representatives from 57 countries will vote at the General Conference on Weights and Measures in Versailles, France to redefine four basic units of measurement November 16, 2018. <br />
<br />
CREDIT: Matt Roth for The New York Times<br />
Assignment ID: 30226894A