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277 reviews for:
El universo elegante: Supercuerdas, dimensiones ocultas y la búsqueda de una teoría final
Brian Greene
4.03 AVERAGE
277 reviews for:
El universo elegante: Supercuerdas, dimensiones ocultas y la búsqueda de una teoría final
Brian Greene
4.03 AVERAGE
challenging
informative
slow-paced
‘The Elegant Universe’ by Brian Greene is a general introduction to cosmology and string theory. It is a beautifully written book! However, it is not for beginners. I think some classes in physics or cosmology, or a long-time subscription to a magazine like New Scientist or Science News would be a necessary educational background before reading this book. Or a genius-level understanding of mathematics. So. As far as I can tell, the book is a five-star read in clarity and expert knowledge.
From Wikipedia, I learned Greene is a genuine scientist. He attended Harvard and got his Ph.D. at Oxford. Greene joined the physics faculty at Cornell in 1990 and was appointed to a full professorship in 1995. He joined the staff of Columbia University as a full professor. At Columbia, Greene is co-director of the university's Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP) and is leading a research program applying superstring theory to cosmological questions. With co-investigators David Albert and Maulik Parikh he is a FQXi large-grant awardee for his project entitled "Arrow of Time in the Quantum Universe.
Greene does an amazing job of condensing a hundred years of cosmological science and physics into a few chapters. He describes in the first six chapters the most cogent and clear explanation of Einstein’s Special Relativity and General Relativity theories I have ever read. He also links past discoveries about electricity, magnetism, and gravity insofar as how such discoveries led to Einstein’s theories. These past discoveries about gravity and electricity also led to what were concurrent studies in Einstein’s lifetime by other scientists on quantum mechanics. Greene leads readers, gently, into how scientific experiments on quantum particles, especially photons and electrons, led to discoveries about the structures of atoms. These explorations have added hints about further mysteries yet to know surrounding the beginning and current state of the universe.
Around chapter five, Greene begins discussing string theories in depth. At first, I could follow. Clearly mathematics is the main source behind string theories (and physics), making real-world descriptions difficult. Green makes a heroic effort at avoiding direct mention of the maths (except in the Notes section at the back of the book). He includes drawings and word-picture analogies (using vivid visuals such as walnuts and donuts and trampolines and beach balls and floating astronauts moving about in space), to illustrate the theoretical conclusions derived from the mathematical view of the universe. I understand the necessity of alternative visual examples - how do you describe and show visually the concept of Time, or show how a Planck length of strings affects an invisible, to us, dimension’s dimensions!
Frankly, my history/literature brain burned out. This is an example of what killed neurons in my head:
“The particular calculation we were performing amounts, roughly speaking, to determining the mass of a certain particle species — a specific vibrational pattern of a string — when moving through a universe whose Calabi-Yau component we had spent all fall identifying. We hoped, in line with the strategy discussed earlier, that this mass would agree identically with a similar calculation done on the Calabi-Yau shape emerging from the space-tearing flop transition. The latter was the relatively easy calculation and we had completed it weeks before; the answer turned out to be 3, in the particular units we were using. Since we were now doing the purported mirror calculation numerically on a computer, we expected to get something extremely close to but not exactly 3, something like 3.000001 or 2.999999, with the tiny difference from rounding errors.” Page 277
Wtf does 3 mean to Greene? Confirmation of space-tearing flop transitions by a mirror mathematical version of normal physics mathematics, which proved part of the physics of string theory.
Got it?
Or this:
“Two related notions underlie these observable consequences; we will explain each in turn. First, as we have discussed, Strominger’s initial breakthrough was his realization that a three-dimensional sphere inside a Calabi-Yau space can collapse without an ensuing disaster, because a three-brane wrapped around it provides a perfect protective shield. But what does such a wrapped-brane configuration look like? The answer comes from Horowitz and Strominger, which showed that to persons such as ourselves who are directly cognizant only of the three extended spatial dimensions, the three-brane “”smeared”” around the three-dimensional sphere will set up a gravitational field that looks like a black hole. This is not obvious and becomes clear only from a detailed study of the equations governing the branes. Again, it’s hard to draw such higher-dimensional configurations accurately on a page, but figure 13.4 conveys the rough idea with a lower-dimensional analogy involving two-dimensional spheres.....Moreover, in Strominger’s 1995 breakthrough paper, he argued that the mass of the three-brane— the mass of a black hole, that is—is proportional to the volume of the three-dimensional sphere it wraps: The bigger the volume of the sphere, the bigger the three-brane must be in order to wrap around it, and the more massive it becomes. Similarly, the smaller the volume of the sphere, the smaller the mass of the three-brane that wraps it. As this sphere collapses, then, the three-brane that wraps around the sphere, which is perceived as a black hole, appears to become ever lighter. When the three-dimensional sphere has collapsed to a pinched point, the corresponding black hole—brace yourself—is massless.” Page 330
My brain vibrated feebly, then flopped, and collapsed into a massless black hole, gentle reader.
Also: Perturbation Theory, Duality, Quantum chromodynamics, Symmetry, Spins, Supergravity, M-Theory, primordial nucleosynthesis, curled up dimensions (from nine to eleven - they don’t know how many exactly since the math is giving various answers to the question of multiverses, depending on the equation), Entropy, the Big Bang, the fabric of Space/Time, and my favorites, the uncertainty principle, spatial topology and reciprocals - not.
None of this is visible to the naked eye, gentle reader, and some of it not to the naked brain in any kind of brane. My bosons are weak, gentle reader, weak, by my gauge. The forces of my framework have been mechanically perturbed into a mass universe of simplified confusion. I am a flatland of one-dimensional fundamentals when it comes to ‘ordinary’ physics, much less possessing a particle of understanding the speculative kind of physics like string theories!
There is a Notes section which supposedly is in English, not that I could tell - a native English speaker - and an Index. Thankfully, there is a glossary of scientific terms, of which its pages I wore down to a Planck’s constant. However, maybe too many donuts (whether torus or spherical) and not enough broccoli in my life has annihilated the necessary electrons I needed to shine like an energetic photon. I am clearly reduced in mental energy to the lower spectrums, like ancient photonic microwaves spread out in a vast void of background noise, barely distinguished.
*sigh*
I found this, gentle reader - a PBS NOVA show about Brian’s Greene’s book. It’s easier.
https://www.pbs.org/wgbh/nova/video/the-elegant-universe-part-1/
From Wikipedia, I learned Greene is a genuine scientist. He attended Harvard and got his Ph.D. at Oxford. Greene joined the physics faculty at Cornell in 1990 and was appointed to a full professorship in 1995. He joined the staff of Columbia University as a full professor. At Columbia, Greene is co-director of the university's Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP) and is leading a research program applying superstring theory to cosmological questions. With co-investigators David Albert and Maulik Parikh he is a FQXi large-grant awardee for his project entitled "Arrow of Time in the Quantum Universe.
Greene does an amazing job of condensing a hundred years of cosmological science and physics into a few chapters. He describes in the first six chapters the most cogent and clear explanation of Einstein’s Special Relativity and General Relativity theories I have ever read. He also links past discoveries about electricity, magnetism, and gravity insofar as how such discoveries led to Einstein’s theories. These past discoveries about gravity and electricity also led to what were concurrent studies in Einstein’s lifetime by other scientists on quantum mechanics. Greene leads readers, gently, into how scientific experiments on quantum particles, especially photons and electrons, led to discoveries about the structures of atoms. These explorations have added hints about further mysteries yet to know surrounding the beginning and current state of the universe.
Around chapter five, Greene begins discussing string theories in depth. At first, I could follow. Clearly mathematics is the main source behind string theories (and physics), making real-world descriptions difficult. Green makes a heroic effort at avoiding direct mention of the maths (except in the Notes section at the back of the book). He includes drawings and word-picture analogies (using vivid visuals such as walnuts and donuts and trampolines and beach balls and floating astronauts moving about in space), to illustrate the theoretical conclusions derived from the mathematical view of the universe. I understand the necessity of alternative visual examples - how do you describe and show visually the concept of Time, or show how a Planck length of strings affects an invisible, to us, dimension’s dimensions!
Frankly, my history/literature brain burned out. This is an example of what killed neurons in my head:
“The particular calculation we were performing amounts, roughly speaking, to determining the mass of a certain particle species — a specific vibrational pattern of a string — when moving through a universe whose Calabi-Yau component we had spent all fall identifying. We hoped, in line with the strategy discussed earlier, that this mass would agree identically with a similar calculation done on the Calabi-Yau shape emerging from the space-tearing flop transition. The latter was the relatively easy calculation and we had completed it weeks before; the answer turned out to be 3, in the particular units we were using. Since we were now doing the purported mirror calculation numerically on a computer, we expected to get something extremely close to but not exactly 3, something like 3.000001 or 2.999999, with the tiny difference from rounding errors.” Page 277
Wtf does 3 mean to Greene? Confirmation of space-tearing flop transitions by a mirror mathematical version of normal physics mathematics, which proved part of the physics of string theory.
Got it?
Or this:
“Two related notions underlie these observable consequences; we will explain each in turn. First, as we have discussed, Strominger’s initial breakthrough was his realization that a three-dimensional sphere inside a Calabi-Yau space can collapse without an ensuing disaster, because a three-brane wrapped around it provides a perfect protective shield. But what does such a wrapped-brane configuration look like? The answer comes from Horowitz and Strominger, which showed that to persons such as ourselves who are directly cognizant only of the three extended spatial dimensions, the three-brane “”smeared”” around the three-dimensional sphere will set up a gravitational field that looks like a black hole. This is not obvious and becomes clear only from a detailed study of the equations governing the branes. Again, it’s hard to draw such higher-dimensional configurations accurately on a page, but figure 13.4 conveys the rough idea with a lower-dimensional analogy involving two-dimensional spheres.....Moreover, in Strominger’s 1995 breakthrough paper, he argued that the mass of the three-brane— the mass of a black hole, that is—is proportional to the volume of the three-dimensional sphere it wraps: The bigger the volume of the sphere, the bigger the three-brane must be in order to wrap around it, and the more massive it becomes. Similarly, the smaller the volume of the sphere, the smaller the mass of the three-brane that wraps it. As this sphere collapses, then, the three-brane that wraps around the sphere, which is perceived as a black hole, appears to become ever lighter. When the three-dimensional sphere has collapsed to a pinched point, the corresponding black hole—brace yourself—is massless.” Page 330
My brain vibrated feebly, then flopped, and collapsed into a massless black hole, gentle reader.
Also: Perturbation Theory, Duality, Quantum chromodynamics, Symmetry, Spins, Supergravity, M-Theory, primordial nucleosynthesis, curled up dimensions (from nine to eleven - they don’t know how many exactly since the math is giving various answers to the question of multiverses, depending on the equation), Entropy, the Big Bang, the fabric of Space/Time, and my favorites, the uncertainty principle, spatial topology and reciprocals - not.
None of this is visible to the naked eye, gentle reader, and some of it not to the naked brain in any kind of brane. My bosons are weak, gentle reader, weak, by my gauge. The forces of my framework have been mechanically perturbed into a mass universe of simplified confusion. I am a flatland of one-dimensional fundamentals when it comes to ‘ordinary’ physics, much less possessing a particle of understanding the speculative kind of physics like string theories!
There is a Notes section which supposedly is in English, not that I could tell - a native English speaker - and an Index. Thankfully, there is a glossary of scientific terms, of which its pages I wore down to a Planck’s constant. However, maybe too many donuts (whether torus or spherical) and not enough broccoli in my life has annihilated the necessary electrons I needed to shine like an energetic photon. I am clearly reduced in mental energy to the lower spectrums, like ancient photonic microwaves spread out in a vast void of background noise, barely distinguished.
*sigh*
I found this, gentle reader - a PBS NOVA show about Brian’s Greene’s book. It’s easier.
https://www.pbs.org/wgbh/nova/video/the-elegant-universe-part-1/
Not enough science and too much wildly imaginative suppositions. Every other topic was followed with, “unfortunately, we don’t have the knowledge or technology to substantiate this yet.” After a while, it felt like the author would have been a perfect stand-in for that guy with the crazy hair on Ancient Aliens. It was hard not to switch “string theorists believe” with “alien astronaut theorists believe.” I definitely came out of this having more questions than when I started, but not in a good way.
inspiring
slow-paced
This audiobook is amazing. To fall asleep too. I got in the habit of putting it on at night, with the timer set for 20 minutes. I never heard the timer stop. I did enjoy the book while it was being read, though. Some of the concepts are intensely thought provoking. Obviously, there are gaps in my comprehension, but I can honestly say that I see the universe differently now. Our three big spatial dimensions, which may have their genesis in some tidier string dimensions colliding and getting all busted up (which is the terminology used in the book). We might live in flatland. What is knowable?
Interesting but difficult read for me. Probably an easy read for someone with a science background.
adventurous
challenging
informative
inspiring
slow-paced
Did some of it go over my head? Yes. Do I want to weep at the elegance of the Universe? Also yes.
Excellent book for laymen to learn about general relativity and quantum mechanics. Got a little dry and overly-specific at times, but simple to read and I learned a lot from this book!
challenging
informative
slow-paced
“...things are the way they are in our universe because if they weren't, we wouldn't be here to notice.”