1. Five billion years ago
A spinning cloud of dust and gas collapsed under its own weight. As it did so, the centre began to heat up.
2. A star is born
As the cloud continued to spin, it flattened into a disc. At the centre of the spinning disc (our future Solar System) lay the embryo, our future Sun, which began to grow as it continued heating up.
3. Full ignition
When the temperature at the centre of the embryo star reached about 15 million celsius (27 million fahrenheit), nuclear reactions began turning hydrogen into helium, causing it to radiate heat and light.
4. Our Sun today
Energy generated in the core of the sun radiates to the surface in great churning currents. At the surface, the temperature is more than 5500 celsius (10 000 fahrenheit), and billions of ton of hot gas flare into space.
5. Tomorrow's Sun?
When the Sun has burnt up the fuel at its centre, it will start to expand rapidly and cool down, and it will become a red giant.
6. Star death
The Sun will eventually collapse, squeezing the last particles of fuel so tightly that it will reheat and glow bright white. At this stage, a star is known as a white dwarf.
Saturday, November 17, 2007
Making the Sun
The Universe is made up of countless clouds of gas and dust. Around 5 billion years ago. one of this swirling clouds formed a miiling - sized star - our Sun. The energy released by its burning gas provides the light and warmth necessary for life on Earth.
What makes the Sun shine?
Light from the Sun radiates through the entire Solar System. This light is generated in the core of the Sun, where temperatures reach around 15 million degree (27 million Fahrenheit), as hydrogen gas is converted into another gas, called helium, in a series of thermonuclear explosions, billion of times more powerful than the biggest nuclear bombs, are mere pinhead of these gases would be hot enough to ignite everything for 100 km (60 miles) around. The hot gases churn slowly towards the Sun's surface, where the burning solar gas shine for millions of miles into space.
The Universe is made up of countless clouds of gas and dust. Around 5 billion years ago. one of this swirling clouds formed a miiling - sized star - our Sun. The energy released by its burning gas provides the light and warmth necessary for life on Earth.
What makes the Sun shine?
Light from the Sun radiates through the entire Solar System. This light is generated in the core of the Sun, where temperatures reach around 15 million degree (27 million Fahrenheit), as hydrogen gas is converted into another gas, called helium, in a series of thermonuclear explosions, billion of times more powerful than the biggest nuclear bombs, are mere pinhead of these gases would be hot enough to ignite everything for 100 km (60 miles) around. The hot gases churn slowly towards the Sun's surface, where the burning solar gas shine for millions of miles into space.
Friday, November 16, 2007
STAR AND SUN
The Sun, a glowing globe of hot gas thousand of times bigger than the Earth, lies at the heart of our Solar System. Yet it is a pretty ordinary star. It is just one among 200 billion in our galaxy alone. Scientists estimate that it is about halfway through its life, having form, along with the Earth and the other planets, around 5 billion years ago. Although it is 1 392 000 km (865 000 miles) wide, it is middle weight in star terms and only medium brightness.
Why is the Sun Yellow?
The colour of a star depends on how it is and this, in turn, depends on its size and age. Our Sun is a star of medium size and brightness, with the surface temperature of about 5500 celsius (10 000 fahrenheit, whichmake it look yellow. As it gets older and uses up more of its energy, the surface temperature will drop to about 4000 celsius (7200 fahrenheit) and it will look red. When it has exhausted almost all of its energy, the Sun will collapse and heat up briefly in a white flare.
See how the Sun sattelite of distance (000 km) , radius (km) and mass (kg) at http://www.nineplanets.org/sol.html
Why is the Sun Yellow?
The colour of a star depends on how it is and this, in turn, depends on its size and age. Our Sun is a star of medium size and brightness, with the surface temperature of about 5500 celsius (10 000 fahrenheit, whichmake it look yellow. As it gets older and uses up more of its energy, the surface temperature will drop to about 4000 celsius (7200 fahrenheit) and it will look red. When it has exhausted almost all of its energy, the Sun will collapse and heat up briefly in a white flare.
See how the Sun sattelite of distance (000 km) , radius (km) and mass (kg) at http://www.nineplanets.org/sol.html
Our place in space
Less than 500 years ago, people thought that the Earth was the cenre of the Universe. It is only within the last few hundred years that we have learnt that the Earth is just one of nine planets revolving around the Sun.
What's more, our Sun is just one of more than 200 billion stars in our galaxy, the Milky Way and the Milky Way is one of countless billions of unknown galaxies within the Universe.
Will the Universe ever come to an end?
At present, the Universe is still expanding as it has done ever since the Big Bang. Whether it will continue to do so is one of the big unanswered questions of astronomy, the science of the stars. There are two main theories about what will happen. The Big Chill idea suggest that the expansion will continue for ever with the galaxies, stars and planets growing ever farther apart, darker and colder, eventually even the stars will go out. Alternatively, some astronomers believe that the forced of gravity in the Universe is such that the galaxies will eventually begin to fall back on each other and that the Universe will collapse, in a superhot moment known as the Big Crunch.
Expanding space
The farther away a galaxy is, the faster it moves. This revelation led to the discovery that the Universe is expanding. It was made in 1929 by American Edwin Hubble. The Hubble Space Telescope is named after him.
Less than 500 years ago, people thought that the Earth was the cenre of the Universe. It is only within the last few hundred years that we have learnt that the Earth is just one of nine planets revolving around the Sun.
What's more, our Sun is just one of more than 200 billion stars in our galaxy, the Milky Way and the Milky Way is one of countless billions of unknown galaxies within the Universe.
Will the Universe ever come to an end?
At present, the Universe is still expanding as it has done ever since the Big Bang. Whether it will continue to do so is one of the big unanswered questions of astronomy, the science of the stars. There are two main theories about what will happen. The Big Chill idea suggest that the expansion will continue for ever with the galaxies, stars and planets growing ever farther apart, darker and colder, eventually even the stars will go out. Alternatively, some astronomers believe that the forced of gravity in the Universe is such that the galaxies will eventually begin to fall back on each other and that the Universe will collapse, in a superhot moment known as the Big Crunch.
Expanding space
The farther away a galaxy is, the faster it moves. This revelation led to the discovery that the Universe is expanding. It was made in 1929 by American Edwin Hubble. The Hubble Space Telescope is named after him.
Thursday, November 15, 2007
Groups of galaxies
Galaxies cluster in local groups. Our group has two subgroups centred on the biggest members, the Milky Way and the Andromeda
Milky Way
The Milky Way is a spiral, rather like a Catherine wheel, burning with the light of mire than 200 billion stars. Our Sun lies about two-thirds of the way out from the centre.
Sun
Our Sun, the central star of the Solar System, is a luminous ball of burning gas. Its massive gravity guides the nine planets, including the Earth, around the sky.
Earth in space
The Earth is a third closet planet to the Sun. It is unique in the Solar System in having vast oceans of liquid water and an oxygen-rich atmosphere.
Galaxies cluster in local groups. Our group has two subgroups centred on the biggest members, the Milky Way and the Andromeda
Milky Way
The Milky Way is a spiral, rather like a Catherine wheel, burning with the light of mire than 200 billion stars. Our Sun lies about two-thirds of the way out from the centre.
Sun
Our Sun, the central star of the Solar System, is a luminous ball of burning gas. Its massive gravity guides the nine planets, including the Earth, around the sky.
Earth in space
The Earth is a third closet planet to the Sun. It is unique in the Solar System in having vast oceans of liquid water and an oxygen-rich atmosphere.
Looking into the past
Like everything else, light takes time to travel across space. Light from the moon takes just over a second to reach us, and light from the Sun about eight minutes. When you look into the sky, then you are not seeing the present but the past - a wave of light that may have set out several thousand years ago. Our ability to look into the past is limited by our eyesight. But with modern telescopes, which can pick up not only light waves but also X-rays and radio wave, we can see even farther back - more than 10 billion years. In 1964, two American scientists detected a microwave 'hiss' coming from all directions of the sky. They realised that this hiss must be radiation released in the Big Bang still echoing throughout the Universe.
A mocrowave map of the sky, compiled from data gathered by satelite, glows with light created when the Universe began.
Universe now
Today, clusters of stars form different shaped galaxies. The heat of the Big Bang has dwindled to a faint background radiation.
Big Bang
During the Big Bang, the fireball flies apart, expanding rapidly and then cooling to form the first atoms - the simplest ones within three minutes, more complex ones taking 500 000 years.
Star birth
In the first billion years or so, clouds of atoms of hydrogen and helium gas thicken into the beginnings of galaxies and stars.
Like everything else, light takes time to travel across space. Light from the moon takes just over a second to reach us, and light from the Sun about eight minutes. When you look into the sky, then you are not seeing the present but the past - a wave of light that may have set out several thousand years ago. Our ability to look into the past is limited by our eyesight. But with modern telescopes, which can pick up not only light waves but also X-rays and radio wave, we can see even farther back - more than 10 billion years. In 1964, two American scientists detected a microwave 'hiss' coming from all directions of the sky. They realised that this hiss must be radiation released in the Big Bang still echoing throughout the Universe.
A mocrowave map of the sky, compiled from data gathered by satelite, glows with light created when the Universe began.
Universe now
Today, clusters of stars form different shaped galaxies. The heat of the Big Bang has dwindled to a faint background radiation.
Big Bang
During the Big Bang, the fireball flies apart, expanding rapidly and then cooling to form the first atoms - the simplest ones within three minutes, more complex ones taking 500 000 years.
Star birth
In the first billion years or so, clouds of atoms of hydrogen and helium gas thicken into the beginnings of galaxies and stars.
Wednesday, November 14, 2007
THE MAKING OF UNIVERSE
How did the Universe begin?
Around 15 billion years ago, all the matter from which our Universe is made was packed into a superhot, superdance fireball less than 1 cm (1/2in) wide. This fireball flew apart in a violent explosion known as the 'Bing Bang', and within a millionth of a second, it had grown to some 16 billion km (10 billion miles) across. It continued to expand, but as it did so it cooled - just as steam rising from a kettle cools as it expands.
Atoms, the building blocks of our Universe, began to form. Over the course of the next few billion years, the force of gravity drew matter together into clumps to form galaxies and stars.
If you look into the sky, what you see is the Universe or at least part of it. The groups of stars known as galaxies, the planet and their moons, the floating lumps of rock, called asteroids, even the cold empty space between them, were formed as many as 15 billion years ago in a sudden flash known as the 'Big Bang'.
The story of the Universe is a remarkable one. It all began 15 billion years ago with a flash and a bang, called the 'Big Bang'. A fireball blew apart, cooled and then clumped together as galaxies and stars, including eventually our own, the Sun.
Around 15 billion years ago, all the matter from which our Universe is made was packed into a superhot, superdance fireball less than 1 cm (1/2in) wide. This fireball flew apart in a violent explosion known as the 'Bing Bang', and within a millionth of a second, it had grown to some 16 billion km (10 billion miles) across. It continued to expand, but as it did so it cooled - just as steam rising from a kettle cools as it expands.
Atoms, the building blocks of our Universe, began to form. Over the course of the next few billion years, the force of gravity drew matter together into clumps to form galaxies and stars.
If you look into the sky, what you see is the Universe or at least part of it. The groups of stars known as galaxies, the planet and their moons, the floating lumps of rock, called asteroids, even the cold empty space between them, were formed as many as 15 billion years ago in a sudden flash known as the 'Big Bang'.
The story of the Universe is a remarkable one. It all began 15 billion years ago with a flash and a bang, called the 'Big Bang'. A fireball blew apart, cooled and then clumped together as galaxies and stars, including eventually our own, the Sun.
INTRODUCTION
The world is a proper noun for the planet Earth envisioned from an anthropocentric or human worldview, as a place inhabited by human beings. It is often used to signify the sum of human experience and history, or the 'human condition' in general.
Well, below is a main title for the this knowledge of planet earth :
Well, below is a main title for the this knowledge of planet earth :
- The making of Universe
- Star and Sun
- The birth of the Planets
- Man on the Moon
- Comets, meteors and asteroids
- Spinning Earth
- Inside the Earth
- Volcanoes and Earthquakes
- The Earth’s atmosphere
- Weather and climate
- Mountains and mountain ranges
- Rivers and lakes
- Oceans and seas
- Around the coast
- Grasslands
- Forests
- Deserts
- Polar regions
- Rocks and minerals
- Gems and precious metals
- Fossil fuels
The other info that you can know :
- The night sky
- Planets
- Exploration of space
- Geological timescale
- Landscapes
- Seas and oceans
- Zones of living
- Global Energy
- Natural disasters
Subscribe to:
Posts (Atom)