Saturday, August 25, 2007

UNIVERSE

What is the universe at all?

People so often hear for this word, but a lot of them don’t know what its real meaning is. We could say that universe is never-ending space. But good definition is: Universe is totality of matters, energy and space. In universe stand everything that exist, and also we are now and always in universe. A word universe comes from Latin word universum which mean rotate as one.

Integral parts of universe are galaxies, stars, planets and all other space objects. It is supposing that in whole universe exist about 100 galaxies – and one of these is our galaxy – Milky Way.

The size of universe

When we look into the night sky, we actually look into the past. Namely, the light from the stars travel to the Earth some definite time. Real size of universe is very difficult to terminate. Every day we get proofs that universe is bigger than we thought.

One method how terminate the size of universe is light analysis. Henrietta Swan Leavitt found that we can notice the apparent brightness and determine oldness of light that came to Earth. It was base for discovering the galaxies.

Every star and every galaxy emit the light. The light from the nearest star, Proxima Centauri, to do Earth travels 4 years and 2 months. The light from Andromeda galaxy travels even 2.3 millions years. We can terminate that thanks to fact that light move always at velocity of 299 000 km/s. In the same way we can terminate the distance of some star or galaxy from the Earth. Lights of furthest galaxies to the Earth travel for 10 billions years and even longer.

Expansion of universe

Universe is in expansion all the time. That we can observe in distances among the galaxies. It’s notorious that galaxies get ahead between. But how prove that? The main way is by means of shift to red. Spectrograms can analyze the lights of stars and galaxies to various colors of specter – from red to violet. Various colors of specter have various wavelengths. Thus violet has short-waves, but red has beach combers.

Light fluctuates in the time. That’s the way we can terminate the distance among star or galaxy from the Earth. If waves shift to the red, that’s the sign that star or galaxy escape from the Earth.

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