The most current estimates guess that there are 125 to 200 billion galaxies in the Universe, each of which has hundreds of billions of stars. A recent German supercomputer simulation put that number even higher: 500 billion. In other words, there could be a galaxy out there for every star in the Milky Way..
The Millennium Run simulation starts with the initial state of the Universe, where the Cosmic background radiation was created. Its properties are well known by satellite experiments and serve as the starting point for the corresponding matter distribution. Using the physical laws of the currently known cosmologies, the evolution of matter as galaxies and black holes is simulated and recorded.
This simulation was created and executed for the first time in 2005 by the Virgo consortium, an international group of astrophysicists from Germany, the UK, Canada, Japan and the USA.
PLEASE READ: I screwed up!
The Andromeda Galaxy is our closest: "spiral galaxy" (like our galaxy). Canis Major dwarf galaxy is the closest galaxy to the Milky Way.
The three nearest known stars are gravitationally bound in a system commonly called Alpha Centauri. The two larger stars, said to be Sun-like, are named Alpha Centauri A and B. The nearest to us is the littlest and is called Proxima Centauri. It is classified as a red dwarf and contains just a fraction of the mass of our Sun.
The three-star system is 4.36 light-years away, meaning light requires 4.36 years to travel from the stars to Earth, and so we see them as they existed 4.36 years ago.
Astronomers announced that Alpha Centauri A is now calculated to be 1,061,000 miles wide (1,708,000 kilometers), or 1.227 times the size of the Sun. The B-star is 748,100 miles across (1,204,000 kilometers), or 0.865 times the Sun's diameter. A parsec (symbol pc) is a unit of length used in astronomy. The length of the parsec is based on the method of trigonometric parallax, one of the oldest methods for measuring the distances to stars.
The name parsec stands for "parallax of one second of arc", and one parsec is defined to be the distance from the Earth to a star that has a parallax of 1 arcsecond. The actual length of a parsec is approximately 3.262 light-years.
Music by,
Pink Floyd: "Learning to Fly" is the second song on Pink Floyd's album A Momentary Lapse of Reason. The song is written largely by David Gilmour. It describes Gilmour's thoughts on flying, for which he has a passion, although some commentators have read it as a metaphor for Gilmour's feelings about striking out as the new leader of Pink Floyd after Roger Waters' departure which Gilmour confirmed on the Pink Floyd 25th Anniversary Special in May of 1992. Also an avid pilot, drummer Nick Mason's voice can be heard in the middle of the song. The song is the first CD-only single to be released on a global scale. "Learning to Fly" was included on Pink Floyd's greatest hits collection Echoes: The Best of Pink Floyd.
LEARNING TO FLY LYRICS:
Into the distance, a ribbon of black
Stretched to the point of no turning back
A flight of fancy on a windswept field
Standing alone my senses reeled
A fatal attraction is holding me fast
How can I escape this irresistible grasp?
Can't keep my eyes from the circling skies
Tongue-tied and twisted just an earthbound misfit, I
Ice is forming on the tips of my wings
Unheeded warnings, I thought I thought of everything
No navigator to find my way home
Unladen, empty and turned to stone
A soul in tension that's learning to fly
Condition grounded but determined to try
Can't keep my eyes from the circling skies
Tongue-tied and twisted just an earthbound misfit, I
Above the planet on a wing and a prayer,
My grubby halo, a vapour trail in the empty air
Across the clouds I see my shadow fly
Out of the corner of my watering eye
A dream unthreatened by the morning light
Could blow this soul right through the roof of the night
There's no sensation to compare with this
Suspended animation, a state of bliss
Can't keep my mind from the circling skies
Tongue-tied and twisted just an earthbound misfit, I
For more info:
http://www.mpa-garching.mpg.de/galform/press/
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