Stellar evolution

                                 
                                                                  Stellar evolution



                           Stars make up almost fifty percent of our whole universe. Although they just seem like huge chunks of extraterrestrial material, they actually have a life cycle! They are not alive, but still have a cycle.

                            All stars start with huge clouds of dust particles. The force of gravity brings these particles together and forms denser clumps. In these clumps , hydrogen atoms start to fuse together and become heavier. This process is called nuclear fusion. Slowly, these small stars start to generate heat. Soon enough , they ignite and are in the main sequence of the star cycle.This is the stage that the sun is in. This is also the longest stage in the star cycle! This stage takes about 4 billion years to be completed! After this stage the star will take more energy and balloon up. This might burn a few planets to ash. this stage of the star is called the red giant. It is called the red giant because it glows red. Then the star will shed its outer layers, compressing itself. The outer layers form big clouds called the planetary nebula. Then the center of the nebula cools down and finally becomes a white dwarf. This is the route our sun will take as a star. Stars many times bigger than our sun with explode and will scatter stellar material far away. this will cause formation of new stars. This process is called a super nova.  These clouds of stellar material can form new clumps. these clumps may have protons and electrons which will be crushed into neutron stars. Another star that is 10 times bigger than the sun will shrink and form a tiny area of infinite density. this is called a singularity or black hole.

                           The cycle of stars is very ,very long. Sometimes a trillion years. These huge masses of rock that make up most of our universe are seeming like they are alive. They grow shrink and destroy other things in outer space.

What are fossils?

                Fossils are remains or prints of animals that lived long ago. 

What is SARS?

Severe acute respiratory syndrome.  It is a highly contagious disease caused by a virus.  A person infected by SARS experiences acute respiratory distress sometimes leading to death.

The disease first made its appearance in 2003.  Within six weeks of its discovery,  it had spread to thousands of people.  Since international travel was found to be a major factor in the spread of the disease,  it caused a global scare that affected national economies.

Lighting and Thunder

When there is a strom we often see dark fast moving colud masses which make rumbling noise.  The noise is generated by the lighting when it arcs across the sky.  The electro static discharge in the atmosphere causes the lighting effect.  It is very dangerous to be outside when there is a lighting strike.

Lighting bolts are mostly drawn by objects like lamp posts which are tall and  are good conductors of electricity.  Often tall buildings are deployed with lightning arrestors that help limit the effect of the lightning strikes. The cause of initial formation of lightning is still under debate.  Lightning can also occur during volcanic eruptions in the ash clouds.  Lighting aids in formation of nitric acid that is beneficial to plant life.

The study of lightning is called fulminology, and someone who studies lightning is called a fulminologist.

Marsupials

Kangaroo is a Marsupial.  The marsupials are mostly found in Australia.  The mother Kangaroo has a pouch attached to its body where it nurses the new born.  The new born kangaroos are very small in size.  the young ones of a Kangaroo is called a Joey.  Kangaroos have extremely strong back legs.  The hind legs help it to take giant leaps.  Kangaroos are herbivorous.  They are usually very timid in nature.  They usually attack with their hind legs.

Did you Know?

The Olympic torch weighs about 3 pounds only.

The biggest bug in the world is the Goliath beetle which can weigh up to 3.5 ounces to 4.5 inches long.

 Octopus and squid are the most intelligent vertebrates.

Largest Ocean - Pacific Ocean

The pacific ocean is the largest ocean in the world.  It covers nearly 1/3 of the earth's surface.  It is also the deepest ocean on the earth.  The pacific ocean lies between Asia and Australia on the west and North and South America on the East.  Pacific ocean is rich in natural resources and marine life. 
The Pacific's deepest parts are the ocean trenches.  These trenches are long,narrow, steep and very deep holes at the bottom of the ocean.  The deepest trench is the Mariana trench.  The deepth of this trench is more than the hight of Mt.Everest.
There are many islands in the Pacific ocean like Taiwan, Indonesia, Japan and New Zealand.  Other islands have risen from the floor of the ocean.  Some of them were from the volcanoes.  The islands were built over thousands of years by the lava that comes out of the volcanoes.  The Hawaiian islands are from volcanoes.

What are Glaciers?

In high mountains there are places that are packed with ice.  These ice packs are called 'Glaciers' these resemble gaint frozen rivers.  Many thousands of years ago most of the Earth's surface was covered with moving glaciers.
It takes a very long time to make a glacier.  First, snow falls on the mountains.  It collects year after year, until there is a thick layer called a snow field.
During summer months the snow field melts and sinks into the snow below it.  There it freezes and forms a layer of ice.  This happens year after year, until most of the snow field is converted to ice.  The snowfield is now a glacier.
The snow and ice ina glacier can become very thick and heavy.  The glacier then begins to actually move under its own weight and creeps down the mountain valley.  It has now become a valley glacier.
The valley glacier moves slowly but with enormous force.  As it moves, it scrapes the slides of the mountain and tears off pieces of it.  Sometimes it tears off chunks as big as a house.  As the glacier moves down warmer regions, the water melts and becomes source of water for rivers and lakes.