Featured Research

from universities, journals, and other organizations

Physicists Determine Density Limit For Randomly Packed Spherical Materials

Date:
June 5, 2008
Source:
City College of New York
Summary:
The problem of how many identical-sized spheres can be randomly packed into a container has challenged mathematicians for centuries. A team of physicists has come up with a solution that could have implications for everything from processing granular materials to shipping fruit.

The problem of how many identical-sized spheres can be randomly packed into a container has challenged mathematicians for centuries.  A team of physicists at The City College of New York (CCNY) has come up with a solution that could have implications for everything from processing granular materials to shipping fruit.

Writing in the May 29 edition of “Nature,” they demonstrate that random packing of hard, i.e. non-crushable, spheres in three dimensions cannot exceed a density limit of 63.4 percent of the volume.  This upper limit is a consequence of a completely “jammed” state that occurs when the materials are at their lowest energy levels, i.e. as close to inert as possible.

“Theoretically, the jammed state would be achieved by lowering the temperature of the spheres to approach absolute zero, since this would cause them to contract,” explained Dr. Hernαn Makse, CCNY Associate Professor of Physics and principal investigator.  “In real life, however, it is attained by shaking the materials.”

The findings have potential applications for the manufacture of pharmaceuticals and cosmetics, where powders have to be mixed to a homogenous consistency, he said.  Currently, manufacturers must rely on empirical data, i.e. trial and error, to establish their formulas.  Professor Makse said his goal is to develop a theory of powders that could enable manufacturers to more efficiently develop new products. 

Two of Professor Makse’s Ph.D. students, Chaoming Song and Ping Wang, collaborated with him on the investigation.  Mr. Song completed his degree requirements in 2007.


Story Source:

The above story is based on materials provided by City College of New York. Note: Materials may be edited for content and length.


Cite This Page:

City College of New York. "Physicists Determine Density Limit For Randomly Packed Spherical Materials." ScienceDaily. ScienceDaily, 5 June 2008. <www.sciencedaily.com/releases/2008/06/080602114657.htm>.
City College of New York. (2008, June 5). Physicists Determine Density Limit For Randomly Packed Spherical Materials. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2008/06/080602114657.htm
City College of New York. "Physicists Determine Density Limit For Randomly Packed Spherical Materials." ScienceDaily. www.sciencedaily.com/releases/2008/06/080602114657.htm (accessed August 23, 2014).

Share This




More Matter & Energy News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is It a Plane? No, It's a Hoverbike

Is It a Plane? No, It's a Hoverbike

Reuters - Business Video Online (Aug. 22, 2014) — UK-based Malloy Aeronautics is preparing to test a manned quadcopter capable of out-manouvering a helicopter and presenting a new paradigm for aerial vehicles. A 1/3-sized scale model is already gaining popularity with drone enthusiasts around the world, with the full-sized manned model expected to take flight in the near future. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) — China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Newsy (Aug. 21, 2014) — Researchers found the scanners could be duped simply by placing a weapon off to the side of the body or encasing it under a plastic shield. Video provided by Newsy
Powered by NewsLook.com
Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) — Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins