View Full Version here: : Time, Einstein & the coolest stuff in the Universe lecture
Lecture: "Time, Einstein and the coolest stuff in the universe"
Presenter: Dr William D. Phillips, National Institute of Standards and Technology
and the University of Maryland. Winner of the 1997 Nobel Prize in Physics (http://nobelprize.org/nobel_prizes/physics/laureates/1997/phillips.html)
Date and time: Wednesday 4 August 2010, 6.30pm
Venue: The Seymour Centre, University of Sydney
Cost: $20 Adults / $15 Concession. Free for Sydney University staff, students and Alumni upon presentation of Uni ID or Alumni card)
Link including booking details: http://sydney.edu.au/sydney_ideas/lectures/2010/professor_william_d_phillips.shtml
renormalised
30-07-2010, 12:36 PM
That would be great to go to...bad luck I live too far away.
Mai and I have booked. Looking forward to it and hopefully we will bump
into some fellow IIS members at the coffee cart.
Nobel laureate, William D Phillips, delivered an entertaining presentation
here in Sydney tonight.
Building upon Einstein's insight that "time is what clocks measure", Phillips
explained by slowing down a Cesium atom in an atomic clock, one
could measure time with higher precision. He explained the easiest
way to slow down an atom is by cooling it.
Building upon an idea of Bose in the 1920's, Einstein had predicted that at temperatures
close to absolute zero, matter would enter a new state known as the Einstein-Bose
condensate or BEC. It was not until 1995 that researchers at NIST produced BEC
for the first time, reaching a temperature of around 170 nanokelvin (nK), winning
workers there a Nobel prize.
However, to their surprise, experimentalists discovered that temperatures significantly
lower than originally predicted by the existing theory were being reached.
In their quest to reach even lower temperatures, Phillips and his colleagues at NIST
developed a technique of cooling matter using lasers, reaching incredibly low
temperatures measuring picokelvin (pK). This work won Phillips and his
colleagues the Nobel.
Confining the laser cooled matter in a magnetic field container has then formed
the heart of the most state of the art clocks available today.
Phillips talked about clocks such as the "atomic fountain" design
at NIST that had an accuracy of about 1 part in 10 to the 14th power per day.
As Phiilips joked, NIST being a US Govt body, such clocks are
"suitable for government use".
Such is their precision that relativistic effects could be observed when the
clock was raised a few centimeters. Phillips mentioned that the current time
standard does not specify knowing where a clock is located, but that practitioners
in the field are already using a mean sea level reference. At the NIST
facility in Boulder, Colorado, apart from the altitude, the gravitational field
of the Rocky Mountains alters the timekeeping of theses clocks compared
to the same clocks elsewhere.
Phillips said a forthcoming generation of clocks should achieve accuracies
of about 1 second in 3 billion years.
Phillips said such timepieces might be used to help prove whether some of the
fundamental constants of nature are in fact constant at all and that work in this
area has already begun.
wavelandscott
05-08-2010, 03:36 AM
Sounds like it was an interesting talk! Thanks for sharing...
psyche101
10-08-2010, 09:58 AM
Thanks for the run down Gary, this sounds like it was a very interesting night. Anyone else go?
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