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 July 26, 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 July 26, 2014).

Share This




More Matter & Energy News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) — Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) — TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) — When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
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