Featured Research

from universities, journals, and other organizations

Physicists Show Way To Count Sweets In A Jar -- From Inside The Jar

Date:
July 30, 2009
Source:
New York University
Summary:
The question of how many sweets are in a jar depends on the shapes and sizes of the sweets, the size of the jar, and how it is filled. Guessing the number of sweets in the jar is difficult because the sweets located at the center of the jar are hidden from view and can't be counted. Researchers have now determined how sweets pack from inside the jar, making it easier to more accurately count them.

How many sweets fit into a jar?
Credit: Photo Credit - Top Images: Brujic Lab; Bottom Images: Martin Lacasse

How many sweets fit into a jar? This question depends on the shapes and sizes of the sweets, the size of the jar, and how it is filled. Surprisingly, this ancient question remains unanswered because of the complex geometry of the packing of the sweets. Moreover, as any contestant knows, guessing the number of sweets in the jar is difficult because the sweets located at the center of the jar are hidden from view and can't be counted.

Researchers at New York University have now determined how sweets pack from inside the jar, making it easier to more accurately count them.

To answer the question of how particles pack in general, the NYU team made a transparent, fluorescent packing of oil droplets in water, which allowed it to record three-dimensional images and examine the local geometry of each member of the pack. In other words, what does a packing look like from the point of view of a grain within—i.e., a "granocentric" view?

Their findings, which appear in the latest issue of the journal Nature, show that packing strongly depends on the size distribution—larger particles pack with more neighbors than do smaller ones. Nevertheless, the average number of contacts per particle always stays the same to preserve mechanical stability.

These experimental clues led the researchers to develop a model that successfully captures the geometry, connectivity, and density of the observed sphere packings. This means that starting from a set of particles of known sizes, the density of packing can be determined, making it possible to guess the number of sweets in the jar. Indeed, the model was able to also predict experimentally observed trends in density for mixtures of particles of two different sizes with varying ratios.

Packing problems are important in technological settings as well, ranging from oil extraction through porous rocks to grain storage in silos to the compaction of pharmaceutical powders into tablets. The ability to predict the packing of polydisperse particles—a range of sizes in a single system—has significant impact on these and related technologies.

The research was conducted by the group led by Jasna Brujic, an assistant professor in NYU's Department of Physics, consisting of post-doctoral researchers Maxime Clusel and Eric Corwin and junior research scientist Alexander Siemens.


Story Source:

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


Cite This Page:

New York University. "Physicists Show Way To Count Sweets In A Jar -- From Inside The Jar." ScienceDaily. ScienceDaily, 30 July 2009. <www.sciencedaily.com/releases/2009/07/090729132105.htm>.
New York University. (2009, July 30). Physicists Show Way To Count Sweets In A Jar -- From Inside The Jar. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/07/090729132105.htm
New York University. "Physicists Show Way To Count Sweets In A Jar -- From Inside The Jar." ScienceDaily. www.sciencedaily.com/releases/2009/07/090729132105.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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