



Science says that the universe was created in a Big Bang 13.7 billion years ago. One of the most persistently asked questions has been: How was the universe created? Many once believed that the universe had no beginning or end and was truly infinite. Through the inception of the Big Bang theory however, no longer could the universe be considered infinite. The universe was forced to take on the properties of a finite phenomenon, possessing a history and a beginning. About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event all of the matter and energy of space was contained at one point. What existed prior to this event is completely unknown and is a matter of pure speculation. This occurrence was not a conventional explosion but rather an event filling all of space with all of the particles of the embryonic universe rushing away from each other. The Big Bang actually consisted of an explosion of space within itself unlike an explosion of a bomb were fragments are thrown outward. The galaxies were not all clumped together, but rather the Big Bang lay the foundations for the universe. The origin of the Big Bang theory can be credited to Edwin Hubble. Hubble made the observation that the universe is continuously expanding. He discovered that a galaxy's velocity is proportional to its distance. Galaxies that are twice as far from us move twice as fast. Another consequence is that the universe is expanding in every direction. This observation means that it has taken every galaxy the same amount of time to move from a common starting position to its current position. Just as the Big Bang provided for the foundation of the universe, Hubble's observations provided for the foundation of the Big Bang theory. The universe is at least 156 billion light-years wide. Astronomers estimate that there are 70 sextillion stars in the visible universe, or some 70 thousand million million million. That's a 7 followed by 22 zeros, or: 70,000,000,000,000,000,000,000 There are more stars in the universe than there are grains of sand on all of Earth's beaches.

Multiply our grains of sand by 10 and you still won't even come close to the actual number of stars in our universe. There are 100,000 times as many stars in the universe as sounds and words ever uttered by all humans who have ever lived. The Hubble Space Telescope (HST) site estimates there are hundreds of billions of galaxies in the universe. A recent German super-computer simulation estimates that the number may be as high as 500 billion! When telescopes are pointed at a galaxy that is, say, 10 billion light-years away, the light it detects left that galaxy 10 billion years ago. Light from the sun takes 8 minutes to reach you, thus you see the sun as it was 8 minutes ago. It might have blown up 4 minutes ago and you wouldn't know about it! The disk of our Milky Way galaxy is about 100,000 light years in diameter (one light year is nearly 6 trillion miles), but only about 1000 light years thick. If you could travel across our Galaxy from one side to the other at the speed of light (186,000 miles per second), it would take 100,000 years to make the trip. So, where are we located in our Galaxy? Earth is located in one of the spiral arms of the Milky Way (called the Orion Arm) which lies about two-thirds of the way out from the center of the Galaxy. Here we are part of the Solar System - a group of eight planets, as well as numerous comets and asteroids and dwarf planets which orbit the Sun.



Our Galaxy is estimated to contain at least 200 billion stars and possibly up to 400 billion stars. If each star in our galaxy were the size of a grain of salt it would make a pile four feet across and four feet high. If there is intelligent life for one in every million stars, our galaxy has over 200,000 extraterrestrial civilizations. So what exactly is a Galaxy? Galaxies are large systems of stars, dust and gas bound together by gravitational force. Most galaxies are tens of thousands of light years in diameter, and contain billions of stars. Galaxies come in three primary shapes; spiral galaxies are thin disks, with spiral arms surrounding a central hub; elliptical galaxies are uniform, oval-shaped agglomerations; and irregular galaxies have little or no definite structure. When you watch the night sky, you notice that all of the objects in the night sky appear to be moving across the sky very slowly from east to west. The apparent speed and motion of everything is due to the rotational speed of the earth. The earth rotates on its axis at about 1,000 miles/hr. Stars twinkle because the light we see coming from the stars travels through the atmosphere around the earth and there is turbulence in the Earth's atmosphere. How long would it take to travel to the nearest star? Using the kinds of propulsion systems we have, and taking advantage of a 'gravitational slingshot' from Jupiter, we could probably get up to 150,000 miles per hour. The nearest star is Proxima Centauri at a distance of 4.2 light years. At a speed of 150,000 miles per hour from a passive slingshot maneuver, it would take about 17,900 years to reach this star. Super-fast space travel would kill you in minutes. Everyone thinks it would be cool to travel at the speed of light, which is why scientists devote their lives to working out if it would be possible and NASA is trying to develop its own warp drive. But it turns out super-fast space travel would be fatal. A paper published in Natural Science brings some boring common sense to the speed-of-light-travel table. In order to travel huge distances, people need to travel close to the speed of light. In so doing, travelers cover extremely large distances very quickly and, thanks to the quirks of relativity, would feel like it took mere minutes because of an effect known as time dilation, which squashes perceived time. Trouble is, traveling close to the speed of light brings about other effects, too. In Natural Science, Edelstein and Edelstein point out that hydrogen in any craft cable of traveling at the speed of light would also prevent it from traveling at the speed of light. They explain: Unfortunately, as spaceship velocities approach the speed of light, interstellar hydrogen H, although only present at a density of approximately 1.8 atoms/cm3, turns into intense radiation that would quickly kill passengers and destroy electronic instrumentation. In addition, the energy loss of ionizing radiation passing through the ship's hull represents an increasing heat load that necessitates large expenditures of energy to cool the ship. In other words, travel close to the speed of light and you'll be bombarded with so much radiation that you kick the bucket. The knock-on effect is that even if it's possible to create a craft capable of traveling close the speed of light, it wouldn't be able to transport people. Instead, there's a natural speed limit imposed by safe levels of radiation due to hydrogen, which means humans couldn't travel faster than half the speed of light unless they were willing to die almost immediately. Only 55% of all Americans know that the Sun is a star. Q. Why does the moon fit almost exactly over the sun during an eclipse? A. The Sun is roughly 400 times bigger than the Moon and it is 400 times further away. The sun is over 300,000 times heavier than earth. If our sun were the size of the dot over this letter "i", the nearest star would be the same sized dot but 10 miles away. Every square yard of the sun's surface sends out energy equal to the power of 700 automobiles. Only about one two-billionth of this energy actually reaches us. If a piece of the sun the size of a pinhead were to be placed on Earth, you could not safely stand within 90 miles of it! A neutron star has such density that a teaspoonful of its matter would weigh more than all the people on Earth. Ever wonder how our planet Earth stacks up against the other planets in our solar system? The planets compared to the size of our Sun: Our Sun compared to other well known Suns beyond our Solar System: And some real giants:

Antares is the 15th brightest star in the sky. It is more than 1000 light years away. The pistol star might be the most luminous star known, producing 4 million times as much power as our Sun. VV Cephei is so huge, that if we replaced our own sun with it, it would occupy a space that would extend way past Jupiter’s orbit. T he largest known star known to man is VY Canis Majoris, a red hypergiant star located about 5,000 light-years from Earth.

It is so big that it would take over 7,000,000,000 (7 Billion) Suns or 7,000,000,000,000,000 (7 Quadrillion) Earths to fill VY Canis Majoris. Feeling smaller? According to some estimates, approximately 19,000 meteorites weighing about 3.5 ounces each shower the Earth every day, but only about 10 are recovered each year. The star "Lucy" in constellation Centaurus is actually a huge cosmic diamond of 10 billion trillion trillion carats. The cosmic diamond is a chunk of crystallized carbon, 2,500 miles across, some 50 light-years from the Earth in the constellation Centaurus. Astronomers have decided to call the star "Lucy" after the Beatles song, Lucy in the Sky with Diamonds. The Kuiper Belt Beyond the orbit of Neptune lies the Kuiper belt. It extends outward an additional three billion kilometers away from the Sun. The belt contains different-sized lumps of icy mixtures. These lumps are called Kuiper belt objects. The biggest are called minor planets or dwarf planets. The Kuiper belt may have formed when the gravity of the young planet Jupiter hurled the objects out to where they are now. The Kuiper belt is named after Gerard Kuiper (rhymes with "viper"), one of several astronomers who hypothesized about a field of small objects beyond Neptune. Since the Kuiper Belt was discovered in 1992, the number of known Kuiper belt objects (KBOs) has increased to over a thousand, and more than 70,000 KBOs over 100 km (62 mi) in diameter are believed to exist Among the Kuiper Belt objects is Eris, is the largest known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly. It is approximately 2,500 kilometers in diameter and 27% more massive than Pluto. Originally nicknamed Xena by its discoverers, this dwarf planet, discovered in 2005, has been officially named Eris by the International Astronomical Union. The name was proposed by Mike Brown, a member of the team that made its discovery, and the name was accepted by the committee. Magnifying The Universe This interactive infographic accurately illustrates the scale of over 100 items within the observable universe ranging from galaxies to insects, nebulae and stars to molecules and atoms. Numerous hot points along the zoom slider allow for direct access to planets, animals, the hydrogen atom and more. As you scroll, a handy dial spins to show you your present magnification level. While other sites have tried to magnify the universe, no one else has done so with real photographs and 3D renderings. To fully capture the awe of the vastly different sizes of the Pillars of Creation, Andromeda, the sun, elephants and HIV, you really need to see images, not just illustrations of these items. Stunningly enough, the Cat's Eye Nebula is surprising similar to coated vesicles, showing that even though the nebula is more than 40,000,000,000,000,000,000,000 times larger, many things are similar in our universe. Each time you zoom in a depth, you're magnifying the universe 10x ... and every time you zoom out, the bigger objects are 1/10th of their prior size. If you zoom from the biggest object, The Observable Universe (8.8 x 10E26 ... or 880,000,000,000,000,000,000,000,000m across), all the way down to the hydrogen atom's proton nucleus (1.7 x 10E-15 ... or 0.0000000000000017m across), you will have zoomed in over 100,000,000,000,000,000,000,000,000,000,000,000,000,000x! Our universe really is immensely massive and surprisingly small. (Click icon in upper-right of graphic for full screen view.)



Copyright 2012. Magnifying the Universe by Number Sleuth. How Big Is The International Space Station? The International Space Station (ISS) is a habitable artificial satellite in low Earth orbit. It follows the Salyut, Almaz, Skylab and Mir stations as the ninth space station to be inhabited. The ISS is a modular structure whose first component was launched in 1998. Now the largest artificial body in orbit, it can often be seen at the appropriate time with the naked eye from Earth. The ISS consists of pressurized modules, external trusses, solar arrays and other components. ISS components have been launched by American Space Shuttles as well as Russian Proton and Soyuz rockets. Budget constraints led to the merger of three space station projects with the Japanese Kibō module and Canadian robotics. In 1993 the partially built components for a Soviet/Russian space station Mir-2, the proposed American Freedom, and the proposed European Columbus merged into a single multinational program. The ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology and other fields. The station is suited for the testing of spacecraft systems and equipment required for missions to the Moon and Mars. The station has been continuously occupied for 12 years and 136 days, having exceeded the previous record of almost 10 years (or 3,634 days) held by Mir, in 2010. The station is serviced by Soyuz spacecraft, Progress spacecraft, the Automated Transfer Vehicle, the H-II Transfer Vehicle, and the Dragon spacecraft. It has been visited by astronauts and cosmonauts from 15 different nations. The ISS program is a joint project between five participating space agencies: NASA, the Russian Federal Space Agency, JAXA, ESA, and CSA. The ownership and use of the space station is established by intergovernmental treaties and agreements. The station is divided into two sections, the Russian orbital segment (ROS) and the United States orbital segment (USOS), which is shared by many nations. The ISS is maintained at an orbital altitude of between 330 km (205 mi) and 410 km (255 mi). It completes 15.7 orbits per day. The ISS is funded until 2020, and may operate until 2028. The Russian Federal Space Agency (RSA/RKA) has proposed using ISS to commission modules for a new space station, called OPSEK, before the remainder of the ISS is de-orbited. (Click on each image to enlarge) Why do we see North star at the same place throughout the year? Earth is spinning on its own axis and the imaginary projection of this axis into space lies close very to the North star, hence you see the North star in the same position. Imagine there is a spinning wheel on the floor and a lamp which is exactly above the center of the wheel. If you sit in the center in the wheel, you will not see any shift in the position of lamp since the wheel axis and the lamp axis coincide. On the contrary, if you sit on the rim of the wheel and started looking at the lamp, you can experience the movement of lamp. This is what is happening in case of Earth spinning and North Star.