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30th July 2014, 02:40 PM
Dark Energy: Is It Merely An Illusion?
ScienceDaily Dark energy is at the heart of one of the greatest mysteries of modern physics, but it may be nothing more than an illusion, according physicists at Oxford University.
http://cph-theory.persiangig.com/2259-1.JPG
Changes in the rate of expansion since the universe's birth 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart at a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. (Credit: Image courtesy of NASA/STScI/Ann Feild)
The problem facing astrophysicists is that they have to explain why the universe appears to be expanding at an ever increasing rate. The most popular explanation is that some sort of force is pushing the accelerating the universe's expansion. That force is generally attributed to a mysterious dark energy.
Although dark energy may seem a bit contrived to some, the Oxford theorists are proposing an even more outrageous alternative. They point out that it's possible that we simply live in a very special place in the universe - specifically, we're in a huge void where the density of matter is particularly low. The suggestion flies in the face of the Copernican Principle, which is one of the most useful and widely held tenets in physics.
Copernicus was among the first scientists to argue that we're not in a special place in the universe, and that any theory that suggests that we're special is most likely wrong. The principle led directly to the replacement of the Earth-centered concept of the solar system with the more elegant sun-centered model.
Dark energy may seem like a stretch, but it's consistent with the venerable Copernican Principle. The proposal that we live in a special place in the universe, on the other hand, is likely to shock many scientists. The maverick physicists at Oxford conclude their paper by pointing out that forthcoming tests of the Copernican principle should help us sort out the mystery in the next few years.
انرژي تاريك يكي از بزرگ ترين رازهاي فيزيك مدرن است، اما شايد مطابق نظرات فيزيكدانان دانشگاه آكسفورد چيزي بيش از يك فريب نباشد.
مشكلي كه پيش روي متخصصان فيزيك نجومي است اين است كه آن ها بايد چرايي انبساط هميشگي جهان با سرعت فزاينده را شرح دهند.رايج ترين توضيح اين است كه نوعي نيرو وجود دارد كه تسريع انبساط جهان را موجب مي شود. اين نيرو عموماً به انرژي تاريك مرموز نسبت داده شده.
http://cph-theory.persiangig.com/2259-1.JPG
اگرچه انرژي تاريك مي تواند به چيزي تعبيه شود،نظريه پردازان آكسفورد حتي پيشنهاد عصباني كننده تري را مطرح مي كنند.آن ها خاطرنشان مي كنند كه ممكن است ما در مكان بسيار خاصي در جهان زندگي كنيم،ما در يك فضاي خالي بزرگ كه چگالي ماده در آن بسيار كم است هستيم.اين نظريه در برابر اصل كوپرنيكي پروبال گرفت كه يكي از مفيد ترين و ماندگارترين نظريه ها در فيزيك است.
كوپرنيك از جمله نخستين دانشمنداني بود كه درمورد اين كه ما در مكان خاصي در جهان نيستيم و اين كه هر نظريه اي كه اظهار كند ما استثنايي هستيم غلط است به بحث نشست.اين اصل مستقيماً ما را به سمت جايگزيني تصور كلي زمين-مركز با مدل ظريف خورشيد-مركز سوق داد.
انرژي تاريك ممكن است همچون انبساطي به نظر آيد،اما با اصل قابل احترام كوپرنيك سازگار است.از طرف ديگر اين طرح كه ما در مكان خاصي در جهان زندگي مي كنيم ضربه زدن به خيلي از دانشمندان است.فيزيكدانان مستقل در آكسفورد مقاله شان را با خاطرنشان كردن اين كه آزمايشات آينده اصل كوپرنيك،بايد به ما در يافتن ايراد اين معما كمك كند به پايان رساندند.
ترجمه : زهره مقدم
ScienceDaily Dark energy is at the heart of one of the greatest mysteries of modern physics, but it may be nothing more than an illusion, according physicists at Oxford University.
http://cph-theory.persiangig.com/2259-1.JPG
Changes in the rate of expansion since the universe's birth 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart at a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. (Credit: Image courtesy of NASA/STScI/Ann Feild)
The problem facing astrophysicists is that they have to explain why the universe appears to be expanding at an ever increasing rate. The most popular explanation is that some sort of force is pushing the accelerating the universe's expansion. That force is generally attributed to a mysterious dark energy.
Although dark energy may seem a bit contrived to some, the Oxford theorists are proposing an even more outrageous alternative. They point out that it's possible that we simply live in a very special place in the universe - specifically, we're in a huge void where the density of matter is particularly low. The suggestion flies in the face of the Copernican Principle, which is one of the most useful and widely held tenets in physics.
Copernicus was among the first scientists to argue that we're not in a special place in the universe, and that any theory that suggests that we're special is most likely wrong. The principle led directly to the replacement of the Earth-centered concept of the solar system with the more elegant sun-centered model.
Dark energy may seem like a stretch, but it's consistent with the venerable Copernican Principle. The proposal that we live in a special place in the universe, on the other hand, is likely to shock many scientists. The maverick physicists at Oxford conclude their paper by pointing out that forthcoming tests of the Copernican principle should help us sort out the mystery in the next few years.
انرژي تاريك يكي از بزرگ ترين رازهاي فيزيك مدرن است، اما شايد مطابق نظرات فيزيكدانان دانشگاه آكسفورد چيزي بيش از يك فريب نباشد.
مشكلي كه پيش روي متخصصان فيزيك نجومي است اين است كه آن ها بايد چرايي انبساط هميشگي جهان با سرعت فزاينده را شرح دهند.رايج ترين توضيح اين است كه نوعي نيرو وجود دارد كه تسريع انبساط جهان را موجب مي شود. اين نيرو عموماً به انرژي تاريك مرموز نسبت داده شده.
http://cph-theory.persiangig.com/2259-1.JPG
اگرچه انرژي تاريك مي تواند به چيزي تعبيه شود،نظريه پردازان آكسفورد حتي پيشنهاد عصباني كننده تري را مطرح مي كنند.آن ها خاطرنشان مي كنند كه ممكن است ما در مكان بسيار خاصي در جهان زندگي كنيم،ما در يك فضاي خالي بزرگ كه چگالي ماده در آن بسيار كم است هستيم.اين نظريه در برابر اصل كوپرنيكي پروبال گرفت كه يكي از مفيد ترين و ماندگارترين نظريه ها در فيزيك است.
كوپرنيك از جمله نخستين دانشمنداني بود كه درمورد اين كه ما در مكان خاصي در جهان نيستيم و اين كه هر نظريه اي كه اظهار كند ما استثنايي هستيم غلط است به بحث نشست.اين اصل مستقيماً ما را به سمت جايگزيني تصور كلي زمين-مركز با مدل ظريف خورشيد-مركز سوق داد.
انرژي تاريك ممكن است همچون انبساطي به نظر آيد،اما با اصل قابل احترام كوپرنيك سازگار است.از طرف ديگر اين طرح كه ما در مكان خاصي در جهان زندگي مي كنيم ضربه زدن به خيلي از دانشمندان است.فيزيكدانان مستقل در آكسفورد مقاله شان را با خاطرنشان كردن اين كه آزمايشات آينده اصل كوپرنيك،بايد به ما در يافتن ايراد اين معما كمك كند به پايان رساندند.
ترجمه : زهره مقدم