Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Connecting the quantum and classical physics

02.04.2004


In this week’s issue of Science, a Dartmouth researcher comments about a new experiment that brings us closer to connecting the macroscopic and the microscopic worlds.



Miles Blencowe, a quantum theorist with the Physics and Astronomy Department at Dartmouth, wrote the article "Nanomechanical Quantum Limits" for the "Perspectives" section of the April 2 issue of Science. In it, he explains the problem of reconciling the inherent contradiction between the quantum or atomic world and the macroscopic word of trees, buildings and cars that we live in.

"The world we live in follows the principles of classical physics," says Blencowe. "We see objects in one place. In the microscopic world, the quantum world, things can be in two places at once. The Heisenberg Uncertainty Principle asserts that the more you try to localize an object the more you disturb it and it zooms away and then you don’t know where it is anymore. Somehow the atomic world becomes ours as we go to larger and larger systems. Scientists want to know how that crossover from quantum to classical occurs."


As a theorist, Blencowe and his colleagues propose experiments and hypothesize about the results. His commentary in Science discusses the findings of M.D. LaHaye and his collaborators, researchers with the Laboratory for Physical Sciences in Maryland. LaHaye’s group based their experiment on Blencowe’s theories.

"About three years ago, my colleagues and I proposed that we could see this quantum motion in the macroscopic realm with an extremely sensitive motion detector, called a single electron transistor. We came up with this idea to look at quantum effects in mechanical systems that are really tiny, but still much larger than a single atom."

The Maryland researchers cooled a tiny mechanical beam to close to absolute zero, and they measured its movement using a single electron transistor. As the beam is cooled, it slows down and the classical physics that normally dictate its movements are frozen out, leaving the quantum zero-point fluctuations, which is as close to still as you can get. Getting the beam to reveal its zero-point fluctuations, where quantum classical physics cross over to quantum physics, is the goal of the experiment, and LaHaye’s group comes close.

"It’s very exciting. They have achieved great sensitivity; they’ve come to within a factor of 10 of this zero point measurement," says Blencowe.

Blencowe is hopeful that the next generation of experiments will "reach the quantum limit for motion of mechanical systems well outside the microscopic domain," according to his article.

Sue Knapp | EurekAlert!
Further information:
http://www.dartmouth.edu/

More articles from Physics and Astronomy:

nachricht When helium behaves like a black hole
22.03.2017 | University of Vermont

nachricht Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars
22.03.2017 | International Centre for Radio Astronomy Research

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>