Subscription Center
Jun 24, 2009 | 7
Streams of falling water tend to clump into droplets as surface tension attracts globules of liquid in midair. Even though solid objects are presumed not to have surface tension, the same phenomenon has been observed with grains or sand or tiny beads. But so far, no one has been able to explain exactly what and how much force is at work drawing these objects together.
A new high-speed video outfit, designed by University of Chicago physics graduate student John Royer, has been able to capture these nanoscale forces for the first time, reports a paper published today in Nature (Scientific American is part of Nature Publishing Group).
Using an atomic force microscope, Royer and the research team were also able to measure the attracting force and found that even though the falling solids might look like tumbling liquid, surface tension that attracts the pieces is as much as 100,000 times less than liquid surface tension.
See what we're tweeting about
David_Bressan CBC podcast on old groundwater, early hunters, canine co-evolution http://t.co/FVT1mtN0tM
notscientific Hundreds of LED-equipped umbrellas will descend on MIT this Sunday night http://t.co/Cq6NOAD5yK notscientific #SciLogs Weekly Roundup: Science Seeker Awards, The Conversation UK, Endlings, Hopeful Monsters http://t.co/oIoprNGqRK
Deadline: Jul 25 2013
Reward: Varies
This challenge provides an opportunity for Solvers to build a web-based or mobile “app” to explore data relationships in scholarly conte
Deadline: Jun 29 2013
Reward: $7,000 USD
The Seeker for this Challenge desires proposals for chemical methods that could rapidly degrade a dilute aqueous solution
Powered By: 
YES! Send me a free issue of Scientific American with no obligation to continue the subscription. If I like it, I will be billed for the one-year subscription.
