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This topic is for Astronomical subjects (Texts and Articles) that you think they are interesting & You want to share them with others.
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Hi Dear Friends
This topic is for Astronomical subjects (Texts and Articles) that you think they are interesting & You want to share them with others.
Thank you
Top 10 Most Important Discoveries in Astronomy
Astronomy is the cool, sexy field of the scientific world. Sure, biologists and chemists are out there curing diseases or whatever, but they’re just so boring. Meanwhile, astronomers are busy showing us sweet pictures of distant planets and playing around with telescopes the size of buildings. How can you compete with that? You can’t, so here are the ten most important things astronomers throughout the ages have discovered:
10. The Movement of the Stars and Planets
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The Discovery
It’s tough to wade through a couple thousand years of ancient Babylonian, Egyptian, Greek, Indian, Chinese, Mayan and Persian astronomical history to pick out the highlights, so I’ going to cheat and roll all of their achievements up into one entry. Maybe if their civilisations hadn’t died out they would have got a better spot on this list, but because they couldn’t keep their empires together the ancient world gets stuck with the number ten spot. That’ll learn ‘em.
How Important Was It?
Many of their accomplishments form the basis of modern astronomy, but it’s the fact that they tracked the movement of the stars and planets that really got the whole ball rolling. The realisation that the stars in the sky follow fixed, predicable patterns, along with the discovery of planets that follow their own paths, are the two most basic, fundamental concepts of astronomy. And also astrology, an equally important field of study.
9. The Heliocentric Model
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The Discovery
Astronomers had speculated about heliocentrism (the idea that the Earth revolves around the sun, not the other way around) since ancient times, but in 1543 Copernicus was the first person to actually demonstrate the math behind the idea to prove it was a viable concept.
How Important Was It?
It took a while for Copernicus’ model to become universally accepted. (Get it? Astronomy puns are so easy.) Once it finally took hold it formed the basis of a scientific revolution. It eliminated many of the problems caused by the old geocentric model (it’s tough to make accurate calculations if you think the Earth isn’t moving), making it the first major shift in the field of astronomy since people realised the sun was a star and not an angry God. Also, his discovery made us feel stupid for once thinking we were the centre of the universe. Thanks a lot, Copernicus.
8. Kepler’s Laws
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The Discovery
In 1609, a German astronomer named Johannes Kepler told the world that planets moved around the sun on elliptical routes, not in perfect circles as was commonly believed. Yeah, you know science can be boring when ellipses instead of circles is one of its most important discoveries.
How Important Was It?
Elliptical movement means that the distance between the sun and any given planet changes over time, and that’s an important thing to recognise if you want to figure out how far away a planet is and how fast it’s moving (the closer it is to the sun, the faster it moves). Thanks to Kepler’s laws, astronomers were able to predict the motion of the planets with far greater accuracy than before.
7. The Moons of Jupiter
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The Discovery
Galileo, arguably the most important scientist ever, used a fancy telescope he half invented and half stole the idea for to discover four moons orbiting Jupiter in 1610. They were the first moons of another planet to be spotted, making them a landmark discovery. More importantly, we recently discovered that The Moons of Jupiter would make a sweet band name.
How Important Was It?
Remember when we said it took a while for heliocentrism to be accepted? Galileo’s discovery was the most important piece of evidence presented in support of Copernicus’ theory—the moons offered undeniable proof of celestial bodies that orbited something other than Earth. They also proved that planets other than Earth had moons, just in case it wasn’t already clear that we’re not special.
6. Herschel’s Map
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The Discovery
From 1780 to 1834, telescope maker William Herschel and his sister Caroline systematically mapped the heavens, charting thousands of stars and nebulae in the process. He also discovered Uranus, and if astronomers had stuck with his proposed name of Georgium Sidus (George’s Star) we would have been saved centuries of terrible jokes.
How Important Was It?
Making a map barely counts as a discovery; yet Herschel’s was extremely important, because when it was all finished it revealed the shape and size of the Milky Way galaxy. Not only was it much, much larger than had previously been estimated, but it turned out to be disc shaped, and our own sun was located nowhere near the centre. Herschel’s work cleared up a lot of misconceptions about our own little corner of the universe.
5. The Theory of Relativity
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The Discovery
Albert Einstein, a German scientist you may have heard of, proposed his theory of relativity in 1915.
Summed up, the theory states that mass can warp both space and time, which allows large masses like stars to bend light. It’s trippy stuff.
How Important Was It?
To understand the true significance of relativity you’d need to listen to someone who has a deeper knowledge of physics than some guy who writes lists for the Internet. Put as simply as possible, relativity replaced Newton’s theory of mechanics, which had been the basis of astronomy for the previous 200 years. Einstein argued that motion was relative, and that the concept of time depended on velocity. This new way of thinking was used to explain various astronomical problems that had been impossible to solve using Newton’s old-timey methods, and gave astronomers new ways of theorising about how the universe worked.
4. The Expanding Universe
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The Discovery
Edwin Hubble gave the astronomy world a one-two punch of knowledge between 1924 and 1929.
Not only was he the first to discover other galaxies, but by tracking their movement he learned that they are moving away from us (and the ones farther away are moving faster), which was the first evidence we had to suggest that the universe is expanding.
How Important Was It?
Hubble’s first discovery changed our conception of the size of the universe. It was the first proof we had that space was really, really, really big. His second discovery offered major support for the Big Bang theory, which is the best idea we’ve got as to how the universe was born. See, that’s the kind of stuff that gets a giant space telescope named after you.
3. Radio Astronomy
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The Discovery
Remember when radio was all the rage in the entertainment world? Of course you don’t, you’re not 80 years old. But in the world of astronomy radio is still important today, thanks to a discovery by Karl Jansky in 1931. His experiments with radio waves led him to find signals coming from the centre of the galaxy, and he’s considered the founding father of radio astronomy as a result.
How Important Was It?
Scientists that followed up on Jansky’s discovery found that there are all sorts of radio waves coming at us from space, and the sources of most of them are celestial objects that can’t be seen with other methods. Radio astronomy soon turned into a huge field that’s been responsible for the discovery of many stars and galaxies, as well as brand new classes of objects like quasars and pulsars. I don’t really know what those are, but they sound badass so this discovery must be important.
2. Cosmic Microwave Background Radiation
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The Discovery
It was a pair of radio astronomers, Arno Penzias and Robert Wilson, who discovered cosmic microwave background radiation in 1964. CMBR is a type of radiation that’s present in very small quantities (hence the term background) all throughout space, and is believed to be leftover from when the universe was in a very early stage of growth.
How Important Was It?
CMBR offered further evidence in support of the Big Bang theory. The idea is that this radiation has been present since the Big Bang, and has spread out as the universe expands (see number four on the list). Its discovery was enough to turn the idea of the Big Bang from a contested concept into the predominant explanation of our origins. Penzias and Wilson won the Nobel Prize for their work; and we all know nobody ever gets a Nobel Prize unless they’ve really earned it.
1. Extrasolar Planets
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The Discovery
An extrasolar planet is one that’s outside of our solar system, and astronomers believed in their existence for a long, long time. Yet, it wasn’t until recently that the tools to actually spot one became available; it was only in 1995 when Swiss astronomers Didier Queloz and Michel Mayor discovered a planet in the constellation Pegasus they dubbed 51 Pegasi b. Yeah, astronomers may be great at discovering things but they’re not great at naming them.
How Important Was It?
Not only did Queloz and Mayor finally prove that extrasolar planets are out there, but the method they used has been repeated to find many more. Nearly 500 extrasolar planets are now known to exist, and that’s just the beginning (right now astronomers can only spot ones that are massive). As more and more planets are found, it’s only a matter of time until the most important astronomical discovery in history is made: a planet full of benevolent and sexy aliens. Hurry it up, science!
From: http://www.toptenz.net
Space Firsts - Basics
From Nick Greene, former About.com Guide
The first Earthling in space:
Laika, a dog, was launched into space on the Sputnik 2 in 1957. She survived the launch and for a time in space, but after a week, the air ran out and Laika died. The following year, as its orbit deteriorated, the craft exited space and re-entered the Earth's atmosphere and, without heat shields, burned up along with Laika's body.
The first human in space:
Yuri Gagarin, a cosmonaut from the USSR, launched into space on April 12, 1961 aboard the Vostok 1. His flight lasted one hour and forty-five minutes, orbiting the Earth one time. Describing the view of the Earth from space, Gagarin radioed, "It has a very beautiful sort of halo, a rainbow."
The first American in space:
Alan Sheppard was launched into space aboard Mercury 3 on May 5, 1961 to become the first American in space. His craft did not achieve orbit, but rose to a height of 116 miles and traveled 303 miles before safely parachuting into the Atlantic Ocean.
The first American to orbit the Earth:
On February 20, 1962, the Friendship 7 capsule carried astronaut John Glenn around the Earth 3 times on a 5 hour space flight. He was the first American to orbit the earth.
The first woman in space:
Valentina Tereshkova flew in space aboard the Vostok 6 on June 16, 1963.
The first American woman in space:
On June 18, 1983, the space shuttle Challenger lifted off with Sally Ride aboard. She was the first American woman in space.
The youngest American in space:
Besides being the first American woman in space, Sally Ride was also the youngest American when she rode the Challenger in 1983.
The first person to make a second trip into space:
Gemini 3, the first piloted Gemini flight, included Virgil "Gus" Grissom among its crew as it lifted off in March of 1965. He had previously flown in space in July, 1961 aboard the second suborbital Mercury mission.
The first African American in space:
August 30, 1983, the space shuttle Challenger lifted off with Guion "Guy" Bluford, Jr., the first African American in space.
The first African American woman in space:
Mae Jemison lifted off in the space shuttle Endeavour on September 12, 1992, first African American woman in space.
The first space walk:
Alexei Leonov, a Soviet cosmonaut, was the first person to step outside of his spacecraft while in Outer Space, on March 18, 1965. He spent 12 minutes as he floated as far as 17.5 feet from his Voskhod 2 craft, enjoying the first space walk ever.
The first American to walk in space:
During the Gemini 4 mission, Ed White made a 21 minute EVA (Extra-Vehicular Activity), also known as a space walk.
The first American woman to pilot a spacecraft:
Eileen Collins piloted the space shuttle Discovery in 1995.
The first man on the moon:
With his famous words, "That's one small step for man, one giant leap for mankind." Neil Armstrong, on the Apollo 11 mission, stepped onto the Lunar surface on July 20, 1969, becoming the first man on the Moon.
The second human to step on the moon:
Armstrong's Apollo 11 crewmate, Buzz Aldrin, was the second person to step on the moon, also on July 20, 1969.
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Future of Our Galaxy Galactic Milleniumنقل قول:
Astronomy Essays and Papers
Future of Our Galaxy Galactic Millenium What Does the Future Hold. (adopted from an article by Greg Laughlin and Fred Adams, "Celebrating the Galactic Millennium", Astronomy November 2001) Not too long ago, we were looking forward to the New Millennium. To many of us, this was an important event of our lives. On a larger scale, however, the New Millennium looks insignificant. "If we adopt an astronomical perspective, however, a much larger and more distant celebration remains on the schedule-the Galactic Millennium," write Greg Laughlin and Fred Adam in their article Celebrating the Galactic Millennium. Laughlin and Adam speculate about the proposed changes to the Universe in the future and the coming of the Galactic Millennium
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The Purpose of Stonehenge is Still Unknown
Although nobody knows what Stonehenge was intended for or how it was created, there are many contradiction beliefs about who designed it, how Stonehenge was built and the purpose of the ancient group of standing stones on Salisbury Plain. Stonehenge seems to have been in continuous human use from about 3100BC to 1100BC. The name Stonehenge was recorded in literature from the 12th century and is thought to relate to the idea of stones hanging in the air
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Masters Of The Universe
One of the few remaining mysteries of science is the black hole. When a star runs out of fuel to keep it burning, it explodes into a supernova(Intro. to Black Holes 1) After a supernova, some of the matter that was blown off leaves in pockets to different places in space. These pockets contract to from a pulsar, or new born star. The rest of the matter left from the massive explosion of the supernova comes back together forming a neutron star. If the dead star was too massive, the neutron star will be so large that its own gravity will crush it (Intro.To Black Holes 1).
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http://www.123helpme.com/view.asp?id=76532
