Hubble Sees the Beautiful Side of Galaxy IC 335
Click the link to see a nice pic!!!
From NASA News Services.
Wednesday, December 31, 2014
Galaxies
My next post will be about galaxies guys. What is a galaxy? Well you might already know what IS a galaxy. ;) But I'm gonna speak about the types and some other little interesting facts about the beauties.
The Big Bang
Well guys this is a long post! But it's gonna be interesting........
How exactly was the universe created? Well, the answer is, we do not know an exact answer. But most astronomers now believe that the universe was created by the Big Bang. The Big Band theory was proposed by and astronomer known as Georges Lemaître.
Astronomers still do not know when this occurred. But astronomers have assumed that it occurred 13.8 billion years ago. The Big Bang Theory states that all matter in the universe began as a hot, dense and minute speck. This speck expanded and cooled down and the elements, stars, planets, galaxies and every other thing in the universe was created. The first elements in the universe were hydrogen and helium. Then eventually stars, galaxies, planets and other elements were created.
You might wonder where this Big Bang occurred? Well, there's no place where it occurred because, before the Big Bang length, width, height or the fourth dimension of time didn't exist. It sounds very interesting, isn't it? It was the Big Bang which brought space and time into life. Our universe is still expanding as it was before, so the galaxies and everything in it are moving further and further away from us.
In 1964, Arno Penzias and Robert Wilson discovered the cosmic microwave banckground radiation. It means, they discovered the whole universe was radiating microwaves. As the explosion of the Big Bang cooled down, these microwaves were left behind.
The Steady State Theory is the alternative for the Big Bang Theory. It says that the universe had no beginning or end, and it was ever expanding. Only few astronomers now believe in this theory.
So, if that's how the universe started, how will it end? Or will the universe actually end? There are also many theories proposed for this question.
The universe will stop its expansion if there's enough matter in the universe. The combined gravity of all those matter will halt the expansion and destroy everything in. This is known as the "Big Crunch". The Big Crunch sounds a bit thrilling and it will occur billions of years from now. But the alternative of this isn't much exciting and sounds a bit "dull". The stars in the universe will consume the hydrogen in the cosmos and eventually no new stars will be able to form and there will only be dead stars, black holes in a lifeless universe.
How exactly was the universe created? Well, the answer is, we do not know an exact answer. But most astronomers now believe that the universe was created by the Big Bang. The Big Band theory was proposed by and astronomer known as Georges Lemaître.
Astronomers still do not know when this occurred. But astronomers have assumed that it occurred 13.8 billion years ago. The Big Bang Theory states that all matter in the universe began as a hot, dense and minute speck. This speck expanded and cooled down and the elements, stars, planets, galaxies and every other thing in the universe was created. The first elements in the universe were hydrogen and helium. Then eventually stars, galaxies, planets and other elements were created.
You might wonder where this Big Bang occurred? Well, there's no place where it occurred because, before the Big Bang length, width, height or the fourth dimension of time didn't exist. It sounds very interesting, isn't it? It was the Big Bang which brought space and time into life. Our universe is still expanding as it was before, so the galaxies and everything in it are moving further and further away from us.
In 1964, Arno Penzias and Robert Wilson discovered the cosmic microwave banckground radiation. It means, they discovered the whole universe was radiating microwaves. As the explosion of the Big Bang cooled down, these microwaves were left behind.
The Steady State Theory is the alternative for the Big Bang Theory. It says that the universe had no beginning or end, and it was ever expanding. Only few astronomers now believe in this theory.
So, if that's how the universe started, how will it end? Or will the universe actually end? There are also many theories proposed for this question.
The universe will stop its expansion if there's enough matter in the universe. The combined gravity of all those matter will halt the expansion and destroy everything in. This is known as the "Big Crunch". The Big Crunch sounds a bit thrilling and it will occur billions of years from now. But the alternative of this isn't much exciting and sounds a bit "dull". The stars in the universe will consume the hydrogen in the cosmos and eventually no new stars will be able to form and there will only be dead stars, black holes in a lifeless universe.
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| The Big Bang |
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| Georges Lemaitre |
Sunday, December 28, 2014
Supernova! Highest temperature in the Universe - Space Week Special - Won...
One of my favourite videos! Nice explanation about a supernova.
Professor Brian Cox explains about the CERN supercollider and it's purpose
Friday, December 26, 2014
Telescopes
A telescope is an instrument which helps us to observe far away objects in the night sky. Hans Lippershey, a Dutch spectacle maker built the first telescope. Galileo Galilei heard about this telescope and made his own one in 1609. By using his new instrument, he observed the phases of planet Venus, moons of Jupiter (The Galilean Moons), sunspots and rings of Saturn. He also found that the moon has a rough surface.
The telescope Galileo constructed is known as a refractor. The lens which collect the star light is called the objective lens and the other lens is known as the eyepiece. Refractors use a large objective lens to have a good, clear image. But in reflectors, we do not need to use a large objective lens. Instead we use a concave mirror to focus the light on the magnifying eye piece. Reflectors tend to be more powerful than refractors as constructing a large mirror is easier than constructing a large lens.
Telescopes developed rapidly and became popular, and in 1668 Sir Isaac Newton constructed the first reflecting telescope.
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| Galileo Galilei observing the heavens with his telescope. |
Black Holes - Wonders of the Universe: Falling - BBC Two
Professor Brian Cox explains about black holes using the Victoria Falls in Zambia.
Early Astronomy
Astronomy is considered as the oldest natural science. Early cultures were amazed about celestial bodies and they believed that those objects were gods or spirits. They related those objects to various phenomena like rain, droughts and seasons. The first professional astronomers were priests. Ancient astronomy also played a part in religious matters.
Ancient structures like the Stonehenge in the Salisbury Plain in England were built according to precise astronomical alignments. It is an ancient place of Celtic worship which also seems to have been a sophisticated celestial observatory.
Egypt, China and Chaldea in Mesopotamia were the most important centres of ancient astronomy. The Egyptians built their pyramids by observing the stars. The Chinese observed important astronomical events such as eclipses and supernovae.
Unlike the other cultures, the Greeks tried to explain what they saw in a logical manner rather than merely observing it. Plato described his theory about a finite universe floating on an infinite space. His student Aristotle discovered that the Earth was spherical in nature by observing the curved shadow of the Earth on the moon's surface during a lunar eclipse.
Ptolemy who is best remembered for his book Almagest described Earth as the supreme centre of the universe, hence introducing the geocentric model. Aristarchus of Samos said that the Sun was the centre of the universe but his ideas were not accepted. This heliocentric model of Aristarchus was further established by the Polish astronomer, Sir Nicholas Copernicus. By using his naked eye observations of the five planets that were known to exist at that time, he revolutionised cosmology by placing the Sun at the centre of the Universe.
Ancient structures like the Stonehenge in the Salisbury Plain in England were built according to precise astronomical alignments. It is an ancient place of Celtic worship which also seems to have been a sophisticated celestial observatory.
Egypt, China and Chaldea in Mesopotamia were the most important centres of ancient astronomy. The Egyptians built their pyramids by observing the stars. The Chinese observed important astronomical events such as eclipses and supernovae.
- In 2136 BC they observed an eclipse of the sun.
- In 1054 AD they observed the supernova in the constellation of Taurus. Later astronomers discovered that the Crab Nebula is a remnant of this supernova.
Unlike the other cultures, the Greeks tried to explain what they saw in a logical manner rather than merely observing it. Plato described his theory about a finite universe floating on an infinite space. His student Aristotle discovered that the Earth was spherical in nature by observing the curved shadow of the Earth on the moon's surface during a lunar eclipse.
Ptolemy who is best remembered for his book Almagest described Earth as the supreme centre of the universe, hence introducing the geocentric model. Aristarchus of Samos said that the Sun was the centre of the universe but his ideas were not accepted. This heliocentric model of Aristarchus was further established by the Polish astronomer, Sir Nicholas Copernicus. By using his naked eye observations of the five planets that were known to exist at that time, he revolutionised cosmology by placing the Sun at the centre of the Universe.
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| Pyramids of Egypt |
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| Ptolemy |
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| Heliocentric model |
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| Stonehenge |
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