9 of 12 people found the following review helpful
Einstein daemon awakens!,
By A Customer
This review is from: The Extravagant Universe: Exploding Stars, Dark Energy, and the Accelerating Cosmos (Princeton Science Library) (Hardcover)We could very well start presenting this book as a piece of work that will reveal to you the immense strangeness that lies in our Universe. It is generally known that Einstein considered the Cosmological Constant introduced in the General Relativity field equations as his greatest blunder after Hubble have shown the expansion of the Universe. Well, even if this story is much of an anecdote and that probably no one ever heard or seen it written by Einstein, as Kirshner also reveals in his book, it summarizes very well the feelings most physicists have regarding that constant. We were used to consider our Universe as a place full of matter and energy that is expanding, and because of gravitational attraction between the mass bodies it gradually slows down. Two major possibilities arise for the ultimate fate of the Universe, either it expands forever, or reverses the cycle and starts contracting ending in what is called the Big Crunch, depending on its density. This is what was frequently taught about 10 to 15 years ago. Now, you can start forgetting all that. In the last years a series of observations have shown increasing pieces of evidence that have no place in such a conceptual model. Therefore, astrophysicists and cosmologists started to rewrite that story. One of the pieces of evidence is that, contrary to common belief, the Universe is not slowing down its expansion, is actually accelerating it! Isn't gravity an attractive force, always?! Well, yes… so the answer seems to be to consider a non-zero value for the Einsteins's cosmological constant. And what does that constant mean? Physicists consider it as a measure of the energy of the vacuum, and contrary to gravity it acts as a repulsive force! And where does that come from? Actually nobody knows! Besides, dark matter, a yet unknown form of matter that appears to exist in our Universe (we feel it but do not see it!) seems to be a potential candidate. Thrilled? Then the best thing to do is to pick up this book and read it. There, Robert Kirshner will delight you with the description of these marvellous discoveries, especially the efforts his group and others have put into the analysis of high redshift supernova (far away supernova stars) that allowed them to demonstrate that the Universe is expanding at an ever increasing rate in the past billion years. My statement may be risky but, in the same way relativity theory and quantum mechanics have signalled the major scientific revolutions in the 20th century, also cosmology will revolutionize science for the 21st century. That is the feeling one gets reading about these exciting discoveries. Do not miss the next developments!
The Extravagant Universe: Exploding Stars, Dark Energy, and the Accelerating Cosmos (Princeton Science Library)(3 customer reviews)
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