Wednesday, July 2, 2008

The Fascinating Force of Gravity

Subscribe in a Reader

DON'T FORGET TO COMMENT ON THIS ARTICLE

by apple1165

ISAAC NEWTON, about 300 years ago, theorized how gravity works. He imagined a man throwing an object from the top of an unusually high mountain. If simply dropped, the object would fall, as would an apple, downward to the ground.

If, however, it was thrown forward, it would follow a curved path in falling to the ground. Newton then reasoned that if thrown fast enough, it would circle the earth in an orbit.

From this theorizing, the link between gravity and the movements of the moon and the planets became apparent to him: the moon bound in an orbit around the earth because of the pull of earth's gravity and the planets kept in their orbits by the sun's gravity.

A Universal Law

After careful study, Newton formulated a precise mathematical description of this universal law. Simply stated, Newton's equations said that all objects, small or large, exert a pull on one another, the strength of that pull being dependent on how massive the objects are and on the distance between them.

With some refinements, scientists still use Newton's basic formulas describing gravity, particularly in planning such space ventures as sending a space probe to encounter Halley's comet in 1985. In fact, English astronomer Edmond Halley, a colleague of Newton, used Newton's theories to predict the year when that comet would next appear.

Newton's discoveries about gravity gave him a glimpse of the order manifest in the universe, an orderliness that arises through intelligent design. But his work was by no means the final word on the subject. At the beginning of this century, scientists came to realize that some aspects of Newton's theories were inadequate, even inconsistent.

Einstein and Gravity

In 1916 Albert Einstein put forward his general theory of relativity. His amazing discovery was that gravity not only shapes the universe but also governs the way we see and measure it. Why, gravity even affects the way time is measured!

Again, an illustration helps clarify matters. Imagine space to be like a boundless rubber sheet. Now, placing an object on this flexible mat will cause a dimple, or depression. According to Einstein's description, the earth, the sun, and the stars are like objects on a flexible mat, causing space to curve. If you roll another object onto the rubber sheet, it will be deflected into a curved path by the depressed area around the first object.

Similarly, the earth, the planets, and the stars move along curved paths, following the natural "depressions" in space. Even a beam of light is deflected when passing near massive objects in the universe. Furthermore, Einstein's equations predicted that light traveling against gravity would lose some of its energy, as noted by a slight shift in color toward the red end of the spectrum. Physicists call this phenomenon gravitational redshift.

Thus, besides clearing up the discrepancies arising from Newton's discoveries, Einstein's theory revealed new secrets of how gravity works in the universe.

Fascinating Effects

The ability of gravity to affect the way light travels gives rise to some astonishing consequences that astronomers have observed.

Desert travelers have long been familiar with mirages optical illusions that have the appearance of water shimmering on the ground. Now, astronomers have photographed cosmic "mirages." How is this?

Light from a distant object, believed to be the active nucleus of a galaxy and called a quasar (or, quasi-stellar object), passes intervening galaxies in the line of sight from the earth. As the light passes the galaxies, it is bent by gravitational forces. The bending of the light forms two or more images of the one quasar. An observer on earth, thinking that light has come straight toward him, concludes that he is seeing more than one object.

Another fascinating aspect arising from Einstein's work concerns black holes. What are they, and what is their connection with gravity? A simple experiment serves to answer.

Try throwing an object above your head. You will notice that it rises to a certain height, stops momentarily, and then falls back to the ground. With light it is different. A beam of light can escape from earth's gravity because it travels fast enough.

Suppose now that the force of gravity was much stronger, strong enough to prevent even light from escaping. From such an object, nothing could escape. The object itself would be invisible because no light could escape its gravity and reach the eyes of an outside observer, hence the name black hole.

The German astronomer Karl Schwarzschild was the first to demonstrate the possibility, in theory, of black holes. Although there is, as yet, no unequivocal proof that black holes really do exist in the universe, astronomers have identified a number of possible candidates. Black holes may also be the hidden powerhouses of quasars.

Gravity Waves

On the basis of Einstein's work, we can also picture gravity as an invisible web, linking everything and holding the universe together. What happens when that web is disturbed?

Consider again the illustration of the rubber sheet, and suppose that an object on the sheet is suddenly jostled to and fro. The vibrations generated in the sheet will disturb nearby objects. Similarly, if a star were violently "jostled," ripples in space, or gravity waves, might be generated. Planets, stars, or galaxies caught in the path of a gravity wave would experience space itself contracting and expanding like a rubber sheet vibrating.

Since these waves have not as yet been detected, what proof do scientists have that Einstein's theory is correct? One of the best indications comes from a star system known as a binary pulsar. This consists of two neutron stars in orbit about a common center, with an orbital period of about eight hours. One of these stars is also a pulsar it emits a radio pulse as it rotates, like the sweeping light beam from a lighthouse. Thanks to the precise timing of the pulsar, astronomers can map the orbit of the two stars with great precision. They find that the time of orbit is slowly diminishing in exact agreement with Einstein's theory that gravity waves are being emitted.

On the earth, the effects of these waves are infinitesimal. To illustrate: On February 24, 1987, astronomers spotted a supernova a star undergoing a spectacular transformation, blazing forth with the brilliance of millions of suns as it blew off its outer layers. Gravity waves produced by the supernova would cause, on the earth, a shiver in dimension of only a millionth of the diameter of a hydrogen atom. Why so small a change? Because the energy would be spread out over a vast distance by the time the waves reached the earth.

Baffling

In spite of great advances in knowledge, certain fundamental aspects of gravity still baffle scientists. It has long been assumed that there are basically four forces the electromagnetic force responsible for electricity and magnetism, the weak and the strong forces acting within the nucleus of the atom, and gravity. But why are there four? Could it be that all four are manifestations of a single fundamental force?

Recently it was established that the electromagnetic force and the weak force are manifestations of an underlying phenomenon the electroweak interaction and theories seek to unify the strong force with these two. Gravity, however, is the odd one out it does not seem to fit in with the others.

Scientists hope that clues may come from recent experiments performed in the Greenland ice sheet. Measurements made down a one-and-a-quarter-mile-deep [2,000 m] hole bored in the ice seemed to indicate that the force of gravity differed from what was expected. Previous experiments, performed down mine shafts and up television towers, likewise indicated that something mysterious was causing deviations from the predictions of the Newtonian description of gravity. Meanwhile, some theoreticians are trying to develop a new mathematical approach, the "superstring theory," in order to unify the forces of nature.

Gravity Vital for Life

The discoveries of both Newton and Einstein demonstrate that laws govern the movements of heavenly bodies and that gravity acts as a bond holding the universe together. A professor of physics, writing in New Scientist, drew attention to the evidence of design in these laws and said: "The most minute change in the relative strengths of gravitational and electromagnetic forces would turn stars like the Sun into blue giants or red dwarfs. All around us, we seem to see evidence that nature got it just right."

Without gravity we simply could not exist. Just consider: Gravity holds our sun together, sustaining its nuclear reactions, which supply our needed heat and light. Gravity keeps our spinning earth in orbit around the sun making day and night and seasons and prevents us from being thrown off like mud from a spinning wheel. Earth's atmosphere is held in place by gravity, while the pull of gravity from the moon and the sun generates regular tides that help circulate the waters of our oceans.

Using a tiny organ of our inner ear (otolith), we sense gravity and learn to take it into account from infancy when walking, running, or jumping. How much more difficult it is for astronauts when they have to cope with zero-gravity conditions in spaceflight!

Yes, gravity contributes to making life on earth normal for us. It is, indeed, a fascinating example of our Creator's "wonderful works." Job 37:14, 16.

Did you find this article useful? For more useful tips, hints, points to ponder and keep in mind, do please browse for more information at our websites. http://www.marvelsofcreation.com and http://www.adsflick.com

Don't forget to download Indocquent's free social bookmark utility at http://www.indocquent.com/social_bookmark/social_bookmark_landingpage.html.

43 comments:

lettyrburrage said...

累死了…來去看看文章轉換心情~..................................................

連絡 said...

Fancy may kill or cure...................................................

籃球 said...

與其爭取不可能得到的東西,不如善自珍惜運用自己所擁有的........................................

踢人 said...

此處是值得一探究竟的好部落格!! ........................................

ya said...

你的文章讓我有種特別的感覺,請加油哦~~........................................

于名于名 said...

When everything is coming your way, you are in the wrong lane.............................................

伯怡建銘君臻 said...

adult成人情色激情成人聊天網情色影片色情俱樂部性愛影片情趣淫水影音情色限制級照片live show女生自慰影片超屌成人情色留言板淫亂女自慰免費視訊辣妹巨乳鹹濕色情影音聊天自拍走光照片免費情色av圖片亞洲情色論壇淫慾免費裸女圖片裙底風光台灣色情論壇一夜正妹淫娃網情色下載a圖片全裸淫蕩女人情色影音聊天高潮自慰色情圖片成人自拍女生自慰亞洲成人色情dvd舔乳頭女生自慰影片台灣色情網站台灣性樂園sex story情色影音激情聊天室嘿咻情色自拍

RickyLeadbetter0421嘉容 said...

I do like ur article~!!!...................................................

YoungW21087 said...

路過--你好嗎..很棒的BLOG.........................................

GenovevaPer32669 said...

Well done!........................................

DennyMa said...

來逛逛blog~~跟您打聲招呼..................................................

Glennie9654 said...

「不可能」這個字詞,在聰明人的字典中是找不到的。

GusF_Finkbeiner1209 said...

想像力的力量比知識更加巨大。

韋于倫成 said...

百尺竿頭,更進一步..................................................

葉淑芬 said...

成人影貼 彩虹視訊聊天室 聊天影音 85cc歐美 免費影片欣賞 同志交友 女優寫真貼圖 色情性感遊戲 影片h 偷拍熟女露點照 視訊美女聊天室 可愛 情趣網 微風18 少女圖片 成人影城 免費線上觀賞a片 情色貼貼 免費線上看色情片 徵一夜情人 av383影音 完美女人幫 寫真 色美女貼圖 辣妹爆乳 人妻-免費線上 熟女 a片下載 空姐影片 a片a圖a漫 巨乳女寫真 85cc論壇 微風人成 aa片試看 777成人 人之初貼圖 援交留言 嘟嘟情色網 鋼管秀奶 av片線上看 洪爺影片欣賞 國中大奶正妹 sex情色貼片 線上下載av 巨乳人妻 夫妻性愛貼圖 後宮無碼a片 限制級小說 0204成人 國中生性愛 美女走光

佳慧 said...

錢,給你帶來歡愉的日子,但不給你帶來和平與幸福........................................

彥安彥安 said...

辣妹貼圖0401影音視訊bonbonsex日本avdvd光碟f 罩杯美女圖片情色a片免費無碼a片小魔女影片交流成人 影片sex明星露點鏡頭日本戀愛卡通日本成人聊天視訊dxlive日本成人遊戲日本成人遊戲節目日本成人部落格日本成人電影免費日本成人電影下載日本成人視訊聊天室日本成人AV視訊 辣妹視訊 辣妹0401線上影城視訊交友cleansing18禁成人影片嘿咻kiss168z6成人色站杜雷斯正妹牆成人論壇ss369成人色網38ga成人台灣kiss倩色網18成人影城919sex色片直播網5278成人色論免費線上影片觀看最新卡通a片最新加勒比 潮吹教學講座最新av女優排名最新av女優介紹最新無碼av

宥妃 said...

Better say nothing than nothing to the purpose...................................................

家賢 said...

A good medicine tastes bitter. ..................................................

彥安 said...

上班好累哦,看看部落格轉換心情~~~先謝謝啦!! .................................................................

洪筱婷 said...

初次造訪,安安^^

江婷 said...

死亡是悲哀的,但活得不快樂更悲哀。......................................................................

志穎志穎 said...

Quality is better than quantity.................................................................

于庭 said...

所有的資產,在不被諒解時,都成了負債............................................................

戴昀德 said...

向著星球長驅直進的人,反比踟躕在峽路上的人,更容易達到目的。............................................................

明中明中 said...

蛛絲馬跡皆學問、落花水面皆文章............................................................

慧娟 said...

這個時代,不缺乏感傷,但缺乏反思~~希望能多看到值得思考的文章!............................................................

吳婷婷 said...

不能記住往事的,人注定要重蹈覆轍。.......................................................

江淑如 said...

要保持更新呦,加油!!!期待你的新文章!!!..................................................................

青卉 said...

生存乃是不斷地在內心與靈魂交戰;寫作是坐著審判自己。. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

思恬 said...

超棒的,給予最大支持。(* ̄△ ̄*)............................................................

許紋奇 said...

Of two evils choose the least.............................................................

魏智偉魏智偉 said...

Learning makes a good man better and ill man worse.............................................................

劉黃志宇建娥 said...

做些小善事,說些愛的字句,世界更快樂。..................................................

亦奈美妮 said...

所有的資產,在不被諒解時,都成了負債..................................................................

佳陳容 said...

良言一句三冬暖,惡語傷人六月寒。............................................................

宜明文潔 said...

一棵樹除非在春天開了花,否則難望在秋天結果。..................................................

文王廷 said...

與人相處不妨多用眼睛說話,多用嘴巴思考. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

秋協盛協盛昀 said...

你怎麼能經過一片海,而忘記它的藍?......................................................................

48684 said...

要持續更新下去喲!!期待~~............................................................

于庭吳 said...

新手上路哦~請大家多支持(・ˍ・*) ............................................................

黃英吳思潔吳思潔邦 said...

原來天鵝嫁給癩蛤蟆就會生出醜小鴨。。。

宜DimpleHollow欣 said...

愛情是一種發明,需要不斷改良。只是,這種發明和其他發明不一樣,它沒有專利權,隨時會被人搶走。.................................................................