In physical cosmology , cosmic inflation , cosmological inflation , or just inflation , is a theory of exponential expansion of space in the early universe. Following the inflationary period, the universe continued to expand, but at a slower rate. Inflation theory was developed in the late s and early 80s, with notable contributions by several theoretical physicists , including Alexei Starobinsky at Landau Institute for Theoretical Physics , Alan Guth at Cornell University , and Andrei Linde at Lebedev Physical Institute. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe see galaxy formation and evolution and structure formation. The detailed particle physics mechanism responsible for inflation is unknown.
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Details if other :. Thanks for telling us about the problem. Return to Book Page. Get A Copy. Paperback , pages. Published March 18th by Basic Books first published More Details Original Title. Other Editions 6. Friend Reviews. To see what your friends thought of this book, please sign up. To ask other readers questions about The Inflationary Universe , please sign up.
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Rating details. More filters. Sort order. Jul 21, Manny rated it liked it Shelves: history-and-biography , science , science-fiction. It's why I gave up cosmology and went into nuclear physics! That's real science! How else are you going to make sense of the observational data? In fact, they didn't know. I wondered if they thought that would be a typical reaction, were I to ask other professional scientists. Would everyone say they didn't know, unless the question concerned the tiny area where they were an acknowledged world-class expert?
A thought about it. So, ah, to summarise, no one except a handful of experts understands our current theories about the origins of the universe well enough to say whether they make sense, but Alan Guth, the guy who kicked it off, has written a book about how we got here. I personally found it very helpful and feel I grasp the idea of "inflation" far better than I did a week ago: the brief summaries I'd seen elsewhere had left me cold, but seeing how the ideas developed over time put them into perspective and made them less outlandish.
Though I still have real trouble believing this stuff; it seems impossibly speculative, even if it does "explain" important things, in particular the flatness and uniformity of the universe, and the slight unevenness in the Cosmic Microwave Background Radiation CMBR that later turned into galaxies.
Guth describes his key insight from and the developments following on from it. You project the history of the universe backwards in time, and it gets hotter and denser the further back you go. But then, winding the clock forwards again, the universe cools down, and they split up into the three forces we see today.
In the process of doing so, there could have been an intermediate state, a "false vacuum", where the universe was filled with the enormous energy released by the splitting up of the three forces. This energy would have caused it to expand exponentially, making it uniform and flat; quantum fluctuations would account for the minor unevennesses we have found in the CMBR. This is indeed the standard story, but I am shocked to see how many assumptions you need in order to make it work. There is a bunch of "Grand Unified Theories" explaining how the three forces can be unified into one, but the energies needed to test them are over a billion times higher than anything we can create in our current accelerators.
The potential curve which determines how the energy level falls during the splitting of the forces needs to have a very specific shape in order to get results that match the data. Originally, the idea was that the field mediating the energy was going to be the Higgs field, which we know something about; but in fact the Higgs field turns out not to have the right properties, so a new field was required.
By the way, this seems to be why the Higgs is often called "the God Particle"; people thought for a while that it had created the universe, but they later changed their minds. The universe has to be locally flat enough before inflation started, which involves some kind of theory of quantum gravity. All these theories are speculative. I can't help being reminded of medieval cosmologies. Back then, astronomers tweaked systems of cycles and epicycles to make them fit the observed notions of the planets.
Now, they tweak the potential curves of the inflaton field to make it fit the patterns found in the CMBR. No one had ever seen a crystal sphere, and no one has ever seen an inflaton; perhaps they are equally mythical. But careful analysis of the crystal spheres eventually produced better theories, and I'm guessing the same thing will happen here, given time.
Why is there never a Newton around when you need one? It certainly seems to me that the result from Seeliger quoted by Norton completely invalidates Guth's argument, and in fact leaves him looking rather silly.
But see if you agree. It's amazing. View all 72 comments. Jul 03, Erin O'Quinn rated it it was amazing. In a nutshell, it is the time--billionths of a second in duration--when the first infinitesimal particle exploded and caused the entire universe to be created.
Almost overnight, Guth himself, like the universe he postulated, exploded from an unknown grad student to one of the superstars of astrophysics. But Guth took the theory a step further.
He postulated that not only did the universe begin in one incomprehensible fraction of a second--but the entire universe as it is now was created in that same time frame. He writes in an engaging, non-scientific style meant to reach out and grab readers such as I, people who have a hazy grasp of physics but who want a better notion of how our universe came to be. I would not be surprised if he were soon awarded a Nobel in Physics.
Read this book, and then sing along with Barenaked Ladies Mar 18, G. Reader rated it liked it. I've been trying to call Alan all day to congratulate him, but his phone seems to be permanently busy. Oh well, this will have to do. Alan, I'm big enough to admit you were right and I was wrong, and just let me know when you want that dinner at the Fat Duck. Kisses, G. Aug 20, Tomislav rated it it was amazing Shelves: science , auto-biography , 5-stars.
This book is presented chronologically, following his and his colleagues' work through problems and dead ends, and occasionally even events from his personal life. Even though it is math-less, it conveys the conceptual trade-offs and reasoning, beyond a mere description of the resulting theory to be taken on pure faith. As an engineer with detailed knowledge Alan Guth is not a science popularizer like Carl Sagan or Neil DeGrasse Tyson, but the actual scientist who originated Inflation cosmology.
As an engineer with detailed knowledge of physics only in those certain spots relevant to my career, I found this both challenging and rewarding to read, in my drive to broaden. Guth does not present all his work as a done deal in all particulars — although inflation certainly does seem necessary to address problems in the prior Big Bang model compatibility with GUTs, horizon problem, flatness problem, etc.
With the trade-off awareness gained, some brief summaries available online have a place to fit in. The reintroduction of cosmological constants to make timelines work out seems troubling to me. But as I have still not been through the math, and the math speculations precede observational data, I cannot claim to understand fully. My notes per chapter are below.
Hubble redshift ; mistaken age of universe. Heavier elements came from stars, later. Yang and Mills: quantum chromodynamics.
GUTs predict strengths of all known particle interactions. Spontaneous Symmetry Breaking are mechanisms for loss of high energy symmetry at lower energy. Minimum energy density on maps of multiple Higgs fields. Critical chapter; needs re-read! Spontaneous symmetry breaking is set at various Higgs values along the vacuum ring, arbitrarily during cooling after Big Bang. If changed, particle interactions would break out differently.
Vacuum energy in three-Higgs-field model. Second phase transition? Decay ultimately through quantum tunneling. False vacuum leads to temp reversal of certain properties, such as gravitation. Graceful Exit Problem.
ISBN 13: 9788483061787
The Inflationary Universe: The Quest for a New Theory of Cosmic Origins
El universo inflacionario