Why the sky appears blue?

Violet and blue light have short waves and are scattered then times more than red light waves by atmosphere. While the red light goes almost straight through the atmosphere, blue and violet are scattered by particles in the atmosphere. Thus we see a blue sky.

Sunsets appear reddish Why?

In the evening, the setting sun appears like a beautiful crimson red ball. But we all know it has not changed its color.
Sunlight contains all colors. But the atmosphere on, around and over the earth contains molecules of water, vapor, dust, air and other impurities. The sunlight which passes through these media gets scattered.
Our atmosphere scatters blue, violet and green colors much more than it does the red and yellow. Thus we can see more of red and yellow color and we have a crimson red sky in the evening. So when Sun sets it appears red to us.

How does the sea affect climates?

On hot days at the seaside, cool breezes blow inland from the sea. This is because land warms up faster that water. Hot air over the land rises, and cool air from the sea is sucked in. At night, the reversal happens, because the land cools faster than water. In this way, the sea moderates the climate of coast lands.
Ocean currents also play a part. Onshore winds are warmed or chilled by ocean currents, and the effects of these winds are felt some way inland
The effect of the oceans is slight in the hearts of continents. Central Asia and North America have extreme continental climates. Winters are far colder and summers hotter than coast lands in the same latitude

Where is the World's sunniest place?

We listen to weather forecasts to find out how warm and sunny, wet or windy the weather is likely to be. People in Sahara, in North Africa, don't have this problem. This is the world's sunniest place, with an average of over 4,300 hrs of sunshine a year - nearly 12 hrs a day!

How do icebergs form?

Icebergs are blocks of fresh-water ice that break off from glaciers and float out to sea. Glaciers are formed in polar regions where snowfall lasts for centuries, or even millennium, without entirely melting, and is eventually compressed into ice.
In the North Atlantic, most icebergs originate from the tidewater glaciers of Western Greenland. Compressed snow becomes firm, a granular snow, transformed eventually by pressure into dense ice. The weight of the icecap builds, causing the ice to flow as much as 60 feet a day through openings in the coastal mountains. Rising and falling tides causes slabs of ice to break off and form moving 'rivers of ice'.

Which bird works the hardest in formation like V-shaped alphabet during flight of birds and why?

The bird in the lead (at the forward point of the 'V' formation) works the hardest by being the first to 'break through' the air, which offers resistance to its flight. Just as a boat leaves a V-shaped wake of smoother water behind it, the lead bird leaves a V-shaped wake of 'smoother' air behind it (actually the lead bird creates a trail of air turbulence that helps lift along the V-shaped direction), and it is a bit easier for the birds to fly in the wake of the lead bird.

If you watch a V-formation carefully, you'll notice that the lead bird does not stay in that position for very long and will drop back into the formation, while another, not-as-tired bird takes the lead, breaking through the air first.

Why do people feel sleepy while reading?

Feeling sleepy while reading for many is due to the posture in which they read. While reading a person rarely moves, this lack of physical activity causes decreased blood flow to muscles, which results in accumulation of lactic acid (a product of incomplete combustion in the cells).

This lactic acid is a highly reducing or oxygen absorbing agent, which quickly reacts with oxygenated blood. This ensures lack of oxygenated blood flowing to the brain, which makes us feel sleepy.

To tackle this problem we must avoid reading in a single stretch, instead its better to take some breaks and indulge in physical activity at short intervals.

What is meant by Embryonic Stem Cells

The only way to cure the diabetes disease is by pancreas re-plantation. However, due to the shortage of organ donations and other factors there remains a greatly insufficient supply of organs. But this can be overcome by obtaining organs generated in the lab by culturing certain cells of our body, called 'Stem Cells'. The stem cells are capable of self-renewal and have the ability to divide and differentiate through a variety of stages to produce the mature tissues.

There are two types of stem cells in our body 1. Somatic Stem Cells, 2. Embryonic Stem Cells. The somatic stem cells are cells taken from mature tissues. The stem cells of bone marrow are an example. The bone marrow stem cells are pluripotent and give rise to progenitor cells, which differentiate to form which myeloid series are derived. The embryonic stem cells are cells taken from blastocyte, which is an embryo removed from the womb or brought from the fertility clinic.

The embryonic stem cells are more flexible the somatic stem cells. They can proliferate far more than stem cells from adults, producing far more descendant cells. This is important because many millions of cells are needed to repair organs. In addition the embryonic stem cells can differentiate into all the tissues of the body while a given type of adult stem cells seems to differentiate into only a small set of tissue types destined to them. The derivatives of embryonic stem cells can be optimised to produce differentiated growth. For, example, by adding and removing certain proteins these cells are directed to develop in the lab into new heart, bone, pancreas or other cells.