Earth viewed from space

                                      EARTH FROM SPACE

Viewed from space, the most striking feature of our planet is the water. In both liquid and frozen form, it covers 75% of the Earth’s surface. It fills the sky with clouds. Water is practically everywhere on Earth, from inside the planet's rocky crust to inside the cells of the human body.

This detailed, photo-like view of Earth is based  largely  on observations from MODIS,                            Earth from space               

the Moderate Resolution Imaging

Spectroradiometer, on NASA's Terra satellite.

It is one of many images of our watery world

featured in a new story examining water in

all of its forms and functions.
 

Diffraction of light

              Diffraction of Light

When the light rays meet some obstacle in their path they will bend and travel. This process is called Diffraction of Light. Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665.

Wonders of Diffraction of light

1.        Solar glory at the steam from hot springs. A glory is an optical phenomenon produced by light backscattered (a combination of diffraction, reflection and refraction) towards its source by a cloud of uniformly-sized water droplets.

2.        Colors seen in a spider web are partially due to diffraction, according to some analyses.

3.        Different colors appear on C.D surfaces due to diffraction of light.

4.   When seen from far different colors appear near holes due to diffraction.

5.        Streaks appear behind hills during sunrise and sunset due to diffraction.

6.        When we see a lamp with half open eyes different colors appear due to diffraction of light.

Interference of light.

                   Interference of light

When two or more light rays overlap, their wavelengths and phases are changed.This is called Interference of Light. This is discovered by Thomas young

In physics, interference is the addition of two or more waves that result in a new wave pattern. Interference usually refers to the interaction of waves that are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency.

The term interference has a different meaning in radio communications.

Wonders of interference of light

1. Different colors appear when oil falls on the water.

2. Soap bubbles exhibit different colours