Latest SI base units Stories

2014-07-25 09:32:32

National Institute of Standards and Technology (NIST) To support the fair sale of gaseous hydrogen as a vehicle fuel, researchers at the National Institute of Standards and Technology (NIST) have developed a prototype field test standard to test the accuracy of hydrogen fuel dispensers. Once the standard is field tested, it will serve as a model for constructing similar devices for state weights and measures inspectors to use. Three automakers plan to begin selling hydrogen-fueled...

New U.S. Time Standard Launched By NIST
2014-04-04 13:21:23

[ Watch The Video: NIST-F2 Atomic Clock Sets The Time Standard ] NIST The U.S. Department of Commerce's National Institute of Standards and Technology (NIST) has officially launched a new atomic clock, called NIST-F2, to serve as a new US civilian time and frequency standard, along with the current NIST-F1 standard. NIST-F2 would neither gain nor lose one second in about 300 million years, making it about three times as accurate as NIST-F1, which has served as the standard...

Berkeley Physicist Uses Atomic Matter To Tell Time
2013-01-11 15:06:34

Brett Smith for redOrbit.com - Your Universe Online In a groundbreaking new study, physicists from the University of California, Berkeley have used atomic matter to measure time. According to a new report in the journal Science, Holger Müller and his Berkeley colleagues describe how to tell time using a cesium atom and the theory that matter can be both a particle and a wave. "When you make a grandfather clock, there is a pendulum and a clockwork that counts the...

The Kilogram Has Been Putting On Weight
2013-01-07 10:20:51

Brett Smith for redOrbit.com - Your Universe Online When getting on the bathroom scale after feasting at all the holiday parties, most of us have come to expect a larger number than usual — but scientists from University of Newcastle say that the kilogram itself has been bulking up over the years. The original weight standard for the kilogram (about 2.1 lbs.) is known as the International Prototype Kilogram (IPK), and the British researchers say the series of platinum-based...

2011-09-29 11:01:49

New research using graphene presents the most precise measurements of the quantum Hall effect ever made, 1 of the key steps in the process to redefine 2 SI units Groundbreaking research by the National Physical Laboratory's (NPL) Quantum Detection Group and an international team of collaborators is underpinning the biggest change in the Système Internationale d'unités (SI Units) since the system began 50 years ago. It has long been the goal of scientists to...

2011-07-20 13:13:59

The electromagnetic force has gotten a little stronger, gravity a little weaker, and the size of the smallest "quantum" of energy is now known a little better. The National Institute of Standards and Technology (NIST) has posted the latest internationally recommended values of the fundamental constants of nature. The constants, which range from relatively famous (the speed of light) to the fairly obscure (Wien frequency displacement law constant) are adjusted every four years in response to...

2011-02-10 07:49:08

Avogadro constant determined with enriched silicon-28 A milestone in the international Avogadro project coordinated by the Physikalisch-Technische Bundesanstalt (PTB) has been reached: With the aid of a single crystal of highly enriched 28Si, the Avogadro constant has now been measured as exactly as never before with a relative overall uncertainty of 3 "¢ 10-8. Within the scope of the redefinition of the kilogram, the value NA = 6.02214078(18) "¢ 1023 mol-1 permits the currently...

2011-01-24 09:35:00

Scientists are close to establishing a non-physical definition of the kilogram--the last remaining base unit in the International System of Units (SI) still defined by an existing object--after it was revealed that the prototype used to establish the measurement is shrinking. That prototype, which is a cylinder of platinum-iridium housed at the International Bureau of Measurements (BIPM) in France, has gotten approximately 50 micrograms (0.0000017 ounces) smaller over the past 100 or so...

2010-10-27 12:37:27

Taking the first steps of what would be a major historical advance in the science of measurement, the National Institute of Standards and Technology (NIST) is participating in a worldwide effort to recommend major revisions to the International System of Units (SI), the modern metric system that is the basis of global measurements in commerce, science and other aspects of everyday life. The new SI, which would be based on seven constants of nature, would enable researchers around the world to...

2010-02-05 13:22:06

Clock keeps time to 1 second in 3.7 billion years Physicists at the National Institute of Standards and Technology (NIST) have built an enhanced version of an experimental atomic clock based on a single aluminum atom that is now the world's most precise clock, more than twice as precise as the previous pacesetter based on a mercury atom. The new aluminum clock would neither gain nor lose one second in about 3.7 billion years, according to measurements to be reported in Physical Review...

Word of the Day
  • A small crescent-shaped structure or marking, especially the white area at the base of a fingernail that resembles a half-moon.
This word is a diminutive of the Latin 'luna,' moon.