Featured Research

from universities, journals, and other organizations

Slow Motion Melting Ice Crystals In A Computer Animation

Date:
January 10, 2008
Source:
Wiley-Blackwell
Summary:
An animated movie shows an ordered structure dissolving little by little into a disordered mess after a light pulse: Swedish researchers have used a computer to simulate ice melting after it is heated with a short light pulse.

The above still image from an animated movie shows an ordered structure dissolving little by little into a disordered mess after a light pulse.
Credit: Image courtesy of Uppsala University

An animated movie shows an ordered structure dissolving little by little into a disordered mess after a light pulse: Swedish researchers from the University of Uppsala have used a computer to simulate ice melting after it is heated with a short light pulse. The absorbed energy first causes the OH bonds to oscillate. After a few picoseconds (10-12 s) the energy is converted into rotational and translational energy, which causes the crystal to melt, though crystalline domains remain visible for quite a while.

The common form of ice crystals is known as hexagonal ice. In this form the oxygen atoms of the water molecules are arranged in a tetrahedral lattice. Each water molecule is bound to four neighboring molecules by means of bridging hydrogen bonds, leading to an average of two bridges per molecule. In water, there are, on average, only 1.75 bridging hydrogen bonds per molecule.

What happens in the process of melting" Carl Caleman and David van der Spoel have now successfully used a computer to simulate "snapshots" of melting ice crystals. These molecular dynamics simulations are ideal for gaining a better understanding of processes like melting or freezing because they make it possible to simultaneously describe both the structure and the dynamics of a system with atomic resolution and with a time resolution in the femtosecond (10-15 s) range.

The simulation demonstrated that the energy of the laser pulse initially causes the OH bonds in the water molecules to vibrate. Immediately after the pulse, the vibrational energy reaches a maximum. After about a picosecond, most of the vibrational energy has been transformed into rotational energy. The molecules begin to spin out of their positions within the crystal, breaking the bridging hydrogen bonds.

After about 3 to 6 picoseconds, the rotations diminish in favor of translational motion. The molecules are now able to move freely and the crystal structure collapses. This process starts out locally, at individual locations within the crystal. Once the symmetry of the structure is broken, the likelihood of melting processes occurring in the area immediately surrounding the crystal defect rises significantly. The melting process thus spreads out from this point little by little. At other locations the ice can maintain its crystalline structure a little longer.

A movie is available online at http://xray.bmc.uu.se/molbiophys/images/Movies/melt.mpg

Journal reference: David van der Spoel, Uppsala University (Sweden). Picosecond Melting of Ice by an Infrared Laser Pulse: A Simulation Study. Angewandte Chemie International Edition, doi: 10.1002/anie.200703987


Story Source:

The above story is based on materials provided by Wiley-Blackwell. Note: Materials may be edited for content and length.


Cite This Page:

Wiley-Blackwell. "Slow Motion Melting Ice Crystals In A Computer Animation." ScienceDaily. ScienceDaily, 10 January 2008. <www.sciencedaily.com/releases/2008/01/080107101005.htm>.
Wiley-Blackwell. (2008, January 10). Slow Motion Melting Ice Crystals In A Computer Animation. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2008/01/080107101005.htm
Wiley-Blackwell. "Slow Motion Melting Ice Crystals In A Computer Animation." ScienceDaily. www.sciencedaily.com/releases/2008/01/080107101005.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
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