Mangroves

Mangroves have some interesting adaptations that help them survive in estuaries.

They grow in muddy soil that does not contain much oxygen. To get air, some mangroves give out special roots called breathing roots. Breathing roots are lined with special cells ( called lenticels) that absorb air. Mangroves are surrounded by salty water, which is harmful to most plants. A special membrane covering their roots helps mangroves to filter out most of the salt. Some mangroves are also able to excrete salt through their leaves.

First Woman in Space

Valentina Tereshkova ( Russian ; born 6 March 1937 ) is the first woman in space, now a retired Soviet cosmonaut. Out of more than four hundred applicants and then out of five finalists, she was selected to pilot Vostok 6 on 16 June 1963 and became the first woman to fly on space.

Before being recruited as a cosmonaut, Tereshkova was a textile - factory assembly worker and an amateur parachutist. After the famale cosmonaut groups dissolved in 1969, she became a prominent member the Communist Party of the Soviet Union, holding various political offices.

After the collapse of the Soviet Union, she retired from politics but remained revered as a hero in Russia.

Aerogel

Aerogel , created by Steve Kistler in 1931 is a material with very interesting properties . Also known as frozen smoke , it contains 99.8% air. It is the best known insulator and can support 2000 times its own weight. To the touch areogel is a dry, rigid material .

The brick shown in the picture is kept on an aerogel.

Eclipse

The Moon plays an important part in the formation of eclipses.

When light falls on an opaque object its shadow is formed. The Earth and the Moon are also opaque objects. When the Sun's light falls on the Earth and the Moon , their shadows are formed and they cause eclipses. At the time of the eclipse the Sun, the Earth and the Moon are in a straight line.

There are two types of eclipses : a) Solar Eclipse b) Lunar Eclipse

* A Solar Eclipse occurs when the Moon comes between the Sun and the Earth .

* A Lunar Eclipse occurs when the Earth comes between the Sun and the Moon .

Formation of the Universe

The method of the formation of the universe is best explained by the Big Bang Theory.

At some point, a massive "explosion" of "material" occurred. This material was composed of the superforce. It was all tightly compacted in a small space.Then, it all exploded. As it expanded creating space and time as it went, the energy density decreased. Eventually as the universe became sufficiently large with the expansion of spacetime, matter formed.Matter, as in substance, behaving as it does, created stars, and galaxies formed. Expansion continued until we see the universe as we do today, and the "echo" or "aftershock" of the Big Bang is seen as cosmic background microwave radiation.

Water on the Moon

Three different spacecraft have confirmed there is water on the moon.

A favorite theory is that water, either as water by itself or as its components of hydrogen and oxygen, was deposited on Earth during its early history–mostly during a period of "late heavy bombardment" 3.9 billion years ago–by the impacts of comets and asteroids.
Because the Moon shares the same area of space as Earth, it should have received its share of water as well. However, since it has only a tiny fraction of Earth's gravity, most of the Moon's water supply should have evaporated and drifted off into space long ago. Most, but perhaps not all.