notes of everyday science

[oxon]

THE UNIVERSE

The Big Bang theory

According to big band theory, The Universe came into existence 15 to 20 billion years ago when a cataclysmic explosion took place. The Echo of this big bang can still be heard in the form of microwave radio signal from the space. This is also called 3K microwave background radiation first detected by Arno Penzias and Robert Wilson for which they were awarded the Nobel Prize. Before the birth of our Universe, there was no time, no matter and no space. All the energy and matter of the future cosmos were concentrated in a single point of energy. All the forces were unified in this single point and were in perfect harmony. By someway way this harmony was disturbed and a catastrophic explosion happened and it filled our space with every particle of matter hurled away from everywhere particle. Thus, this is how our universe exploded into life, and matter, space and time came into existence.

[oxon]

Galaxies

Galaxy is a fundamental unit of the Universe. It consists of several hundred thousands of stars together with interstellar gas and dust. Thousands of million of galaxies stretch out to the limits of the observable Universe. They fall into four categories in shape; spiral, spherical, elliptical and irregular. Our galaxy is spiral, contains 100000000000 stars with a diameter of 100000 light years and it is called the Milky Way. According to Greek legend, the pearly band of the milky way stretching across the sky is milk split from the breast of the goddess Juno. The nearest spiral galaxy to the milky way is Andromeda Galaxy; it is 2,200,000 light years away from us. This is our galactic neighbor along with Large Magellanic Cloud which is 170,000 light years away. The arms of the spiral galaxy are called the galactic arms. A collection of galaxies is called cluster.

[oxon]

The Future of the Universe; Open or Closed


There are two main theories of the Universe; Open Universe or Closed Universe. Some physicists believe that our Universe will expand forever. Other are convinced that expansion of our Universe will slow down and finally start contraction ultimately resulting in the Big Crash or Crunch. If there is sufficient matter in the Universe, gravity will eventually win and begin pulling the galaxies together again, causing the Universe to experience a reverse of the big bang the big crunch. After this a new Universe may come into being with totally different laws of nature; this is the cyclic theory.

[oxon]

Solar System

1- consists of sun and all objects revolving/traveling/circling around it.

2- Earth and other 8 planet part of solar system.

3- Includes Asteroids, meteoroids, comets also.


Mercury

Distance from Sun............................. 0.387 Astronomical unit
Diameter is........................................4880 KM
one revolution around sun in ...............88 days
how many moon it has........................no moon
second smallest
closest to sun

Venus:

Distance from Sun............................. 0.723 Astronomical unit
Diameter is........................................12104 KM
one revolution around sun in ...............723 days
how many moon it has........................no moon

its hottest
wrapped in thick clouds of carbon dioxide


EARTH

Distance from Sun............................. 1 Astronomical unit
Diameter is........................................12756 KM
one revolution around sun in ...............365 1/4days
how many moon it has........................one moon

beautiful ball of colors
blue ocean, white clouds, brown continents


MARS

Distance from Sun............................. 1524Astronomical unit
Diameter is........................................6787 KM
one revolution around sun in ...............687 days
how many moon it has........................2 moon (Phobos and Deimos)

mars is Barren
covered with red dust
called red planet