Waterdrop on grass

Waterdrop on grass

Description

Title:
Waterdrop on grass
Caption / Description:

A drop of water hangs from a blade grass.

From Wikipedia (http://en.wikipedia.org/wiki/Surface_tension):

The cohesive forces among the liquid molecules are responsible for this phenomenon of surface tension. In the bulk of the liquid, each molecule is pulled equally in every direction by neighboring liquid molecules, resulting in a net force of zero.The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. This attraction between molecules forms a surface "film" which makes it more difficult to move an object through the surface than to move it when it is completely submerged.

Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer, and absent other forces (including gravity), drops of virtually all liquids would be perfectly spherical. The spherical shape minimizes the necessary "wall tension" of the surface layer according to Laplace's law.

Another way to view it is that a molecule in contact with a neighbor is in a lower state of energy than if it was not in contact with a neighbor. The interior molecules all have as many neighbors as they can possibly have. But the boundary molecules have fewer neighbors than interior molecules and are therefore in a higher state of energy. For the liquid to minimize its energy state, it must minimize its number of boundary molecules and must therefore minimize its surface area.

As a result of surface area minimization, a surface will assume the smoothest shape it can (mathematical proof that "smooth" shapes minimize surface area relies on use of the Euler–Lagrange equation). Since any curvature in the surface shape results in greater area, a higher energy will also result. Consequently the surface will push back against any curvature in much the same way as a ball pushed uphill will push back to minimize its gravitational potential energy.

Tags / Keywords:
  • Grass
  • Droplet
  • Dew
  • Dewdrop
  • Drop
  • Rain
  • Surface tension
  • Water

Admin

Date Original Photo Taken:
Original File Name:
_MG_7853.CR2
Event:
Rating:
Date this image added/last updated on website:
Original File Dimensions:
4272px x 2848px
File Type:
JPEG
Color Mode:
RGB
Original Image Color Profile:
Adobe RGB (1998)

Location

Location Created:
Sublocation:
City:
Market Harborough
Province/State:
Leicestershire
Country:
United Kingdom
World Region:
Europe
Geo-location:

Rights

Copyright Status:
Copyrighted
Licensing Status:
Rights Managed
Available for Editorial Use:
Yes
Available for Commercial Use:
Yes
Copyright Notice:
© 2009 Dave Kennard

Camera Data

Date Digital Resource was created:
Shutter speed:
1200 s
Aperture:
f/8
Camera Model:
Canon EOS 450D
ISO:
100
Exposure Compensation:
0
Focal Length:
65mm
Focal Length (35mm equiv.):
Metering Mode:
Multi-segment
Flash:
On, Fired
Exposure Mode:
Manual
White Balance:
Manual
Light Source:
Exposure Program:
Manual

Additional shooting metadata

Lens:
Canon MP-E 65mm F2.8 1-5x Macro
Filters used:
Additional Optics used:
Setup:
Handheld
Canon MT-24EX Macro Twin Flash

Post Processing

Image Modified:
Software used:
  • Adobe Camera RAW
Post Processing: