Yawning Article

The yawning is a reflex caused due to excess of carbon dioxide and lack of oxygen in the blood. The brain stem detects this and triggers the yawn reflex, through its non vital nuclei in medulla oblongata. Recently it has been suggested by some scientists that yawning is used for regulation of body temperature, too. The yawns are also caused by the same chemicals produced in human nervous system often called neurotransmitters like serotonin, dopamine, glutamic acid and nitric oxide. When their quantity is above their optimum level in the brain, it causes yawning.

My Face Recognition

I am a dream chaser. I have always had a great fascination for face recognition. This field has amazed me forever. Face recognition may seem an easy task for humans, and yet computerized face recognition system still can not achieve a completely reliable performance. The difficulties arise due to large variation in facial appearance, head size, orientation and change in environment conditions. Such difficulties make face recognition one of the fundamental problems in pattern analysis. In recent years there have been a growing interest in machine recognition of faces due to potential commercial application such as film processing, law enforcement, person identification, access control systems, etc. This field is growing at a very rapid pace in almost all fields of life. This has been mostly due to the increase in the crime these days. Such sophisticated technology can somehow help us in reducing the occurrence of such crimes.

Medium Star Article

Medium stars expand, as they grow old. Their core starts to run out of hydrogen and helium. Then the outer layer expands, cools, and it becomes less bright and it becomes a red giant. Now that the star is a red giant, the outer core of the star continues to expand. The helium in the core fuses together and form carbon atoms, which then release energy. Then the outer layers of the star start to drift away and form a planetary nebula.

The nebula starts to cool and shrink in size. Now the star becomes a white dwarf. It is a stable star with no nuclear fuel. The white dwarf radiates its leftover heat for billions of years until it all it has been used. Now it will become a black dwarf (A cold, dark dead star).

Read About Huge Stars

As huge stars grow old, they become red super giants. They become red super giants because their core fuses all its hydrogen into helium. Their core shrinks and becomes hotter and denser.

The core of the star collapses in an instant. The iron atoms are crushed together during the gravitational collapse. The temperature of the core reaches 100 billion degrees.

The electrical forces between the atoms' nuclei become greater than the gravitational forces, which cause a bright, short explosion called a supernova. The shock wave of the explosion blows away the outer layers of the star.

The star will become a neutron star or a black hole depending on its remaining mass. If its mass is 1.5 to 3 times the Sun's mass, (1.99 x 1030 kg) it will collapse and become a neutron star. Its mass is 1.4 times the Sun's, it has a strong magnetic field, and it spins rapidly.

If the mass of the star is more than 3 times the Sun's mass, it will become a black hole. A black hole has a gravitational field strong enough to keep light from escaping.