The Universe: Leading Scientists Explore the Origin, Mysteries, and Future of the Cosmosby John Brockman Published 08 Jul 2014
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John Brockman brings together the world’s best-known physicists and science writers—including Brian Greene, Walter Isaacson, Nobel Prize-winners Murray Gell-Mann and Frank Wilczek, and Brian Cox—to explain the universe in all wondrous splendor.
In Universe, today’s most influential science writers explain the science behind our evolving understanding of the universe and everything in it, including the cutting edge research and discoveries that are shaping our knowledge.
Lee Smolin reveals how math and cosmology are helping us create a theory of the whole universe Brian Cox offers new dimensions on the Large Hadron and the existence of a Higgs-Boson particle Neil Turok analyzes the fundamental laws of nature, what came before the big bang, and the possibility of a unified theory.
Seth Lloyd investigates the impact of computational revolutions and the informational revolution Lawrence Krauss provides fresh insight into gravity, dark matter, and the energy of empty space Brian Greene and Walter Isaacson illuminate the genius who revolutionized modern science: Albert Einstein and much more.
Explore the Universe with some of today’s greatest minds: what it is, how it came into being, and what may happen next.
"The Universe: Leading Scientists Explore the Origin, Mysteries, and Future of the Cosmos" Reviews
It's said (several times in this book) that Cosmology is living a golden time. Indeed this collection of texts mentions huge ideas and changes that came out in the last 10 or 5 years. All this progresses do not point in the same direction though. On the contrary, there are many different theories and interpretations that describe all sorts of 'realities'. It might be that we live in the only universe it exists and had existed… or that multiple universes exist in parallel, or in cycles one after the other, or forming a sort of fractal, with bubbles inside bubbles (pockets) that astonishingly follow a type of evolution by selection akin to life on Earth. These descriptions are based on consequences from different theories, specially different variants of string theory, that is intensively debated in this book. with some of the authors pointing that it's the best and only possible path to continue doing physics in a deeper level, and other rejecting it completely. Two major sub-debates are important: 1.Will string theory someday contact experimental physics?, are string theory hypothesis, and some of their views, such as the 'landscape', verifiable and falsifiable? 2. Is the anthropic principle serious science? Not only theories are debated in this book but the very essence of science, of what constitutes a (valid) theory, and, very interestingly, how much philosophy can help on its progress (some authors here actually suggest that unless new philosophical ideas arrive, deep physics will get stuck).
I particularly enjoyed the chapter 14 in which Brian Greene and Paul Steinhardt have an intense discussion about the anthropic principle, string theory and the future of cosmology. They have opposite views in all these subjects, and the conversation feels like a chess game played by masters in which the lay person can only feel the intensity and grasp the boldest movements.
Written by several leading scientists.
- Alan Guth and Andrei Linde explain the Inflationary Universe theory.
- Lee Smolin discusses the nature of time.
- Lisa Randall and Neil Turok elaborate on the theory of branes, two-dimensional structures arising from string theory—whose existence is central to the cyclic universe.
- Seth Lloyd investigates how the universe behaves like a self-programming computer.
- Lawrence Krauss provides fresh insight into gravity, dark matter, and the energy of empty space.
- Brian Greene and Einstein biographer Walter Isaacson speculate on how Albert Einstein might view the theoretical physics of the twenty-first century.
- The late Benoit Mandelbrot looks back on a long career devoted to fractal geometry.
- Plus Nobel Prize winner Frank Wilczek, Astronomer Royal MaRtin Rees, Caltech physicist Sean Carroll, Stanford's Leonard Susskind, Oxford's David Deutsch, Cornell's Steven Strogatz, Albert Einstein Professor in Science at Princeton Paul Steinhardt, and more.
Interesting into. Many awesome names talking about interesting topics.
Chapter 1: A Golden Age of Cosmology by Alan Guth.
The uniformity of the background radiation best explained by Inflationary Universe. It is an addition to the Big Bang. The Big Bang was never really for the event itself but for what happened after it. Inflationary theory is about what made the universe bang. Almost certainly he right answer. Anti-gravity force that made the universe expand really rapidly.
Quantum fluctuations proposed by Hawking made the universe not completely uniform and so stars abd galaxies were able to form. Ripples on a uniform background. Can be see in the cosmic background radiation. 1 part in 100,000. Intensity of ripples varies with wavelengths.
BOOMERANG and MAXIMA showed that the universe is geometrically flat, as predicted by Inflationary theory.
Some discrepancy 2 years ago, but more precise measurements later made made fit predictions. This theory is almost confirmed.
Dark energy 60% of matter energy. Similar to the anti-gravity force at the Big Bang. Could be vacuum energy. Dark matter only intetact throught gravity. 35% of matter. What we know is regular matter compromising 5% of matter. We have a lot deal to know. Out theories are surprisingly accurate.
Chapter 2: The Cyclic Universe by Paul Steinhardt
Today we know hell a lot about the universe and its history. Special time in human history. The Big Bang theory and Inflationary theories are our best theories (consensus model).
Development of an alternative theory. Unlike tje consensus model, in this one time doesn't have a beginning, but goes to infinity in past and future.
The cycle begings with dense hot universe to an empty one, taking trillions of years. Then the cycle repeats. History of this idea with Hindus, Neitsche and Edgar Alan Paul. Some scientists in early 20th century: Eisntein, Freidman, Lametre and Richard Tallman.
If the universe has a beginning, then you have to explain it. In a cyclic universe you don't have to do that as it is infinite.
Early models, Bug Bang to Big Crunch. Due to increasing entropy in each cycle, the cycles get longer and longer. This means in the past a cycle had time=0 which means a beginning. So you still have the same problem.
Overview of the consensus model. Complicated. Many assumptions. Inflation energy. Explains the evolution of universe, its deceleration and then acceleration (by Dark Energy).
In Newton gravity all matter is attractive, bit Einstein general relativity allows some forms of energy to be gravitationally self-repulsive.
The discovery is increasing acceleration of the universe is a huge discovery, a revolution and tells us that we live in a special time.
The Cyclic Model:
1. Bang maximum finite temperature (below plank energy scale)
2. Radiation dominated universe
3. Matter dominated universe
4. Dark energy dominated universe (central part of the theory and not merely added as in the consensus model). Accelerate the expansion of universe. With enough time it achieves the same inflation as in the beginning of universe. Leads the universe to a vacuum state. The universe is being made homogeneous, isotopic and geometrically flat. This doesn't go on forever.
5. Matter and energy are created [how?] and we begin a new cycle.
Barrows an idea from superstring theory. Membranes like two sides of a sandwich. We only see our brain. The two brains collide together every some trillion years. They are connected by a force like a spring which bring them together and after they collide another cycle begins. We can't observe the other brain directly.
[I heard about this idea first time in the wonderful Morgan Freedman documentary series Throught The Wormhole].
Only the fifth dimension contracts. Fits with current observational data. Gravitational waves around the time of the Big Bang would falsify this model, while confirming the Inflationary model. So each has different predictions.
Chapter 3: The Inflationary Universe by Alan Guth
Yet to be seen which model, this one or the previous one is right. 2 grounds for comparison: the cyclic model needs more development about what happens when the brains collide. Second, the observational evidence of gravitational waves.
Superstring theory. Strings and branes.
The Inflationary Theory. It explains the bang (what caused the universe to expand) in the big bang (aftermath of bang) and the origin of all matter in the universe. It's not an ultimate theory of origin/beginning since it starts with about a gram of matter. A repulsive kind of gravity, allowed by General Relativity. A negative pressuee causes a repulsive kind of gravity. Patticle physics tells us this negative pressure is possible.
[Many people wonder about what caused the Big Bang, this theory answers this question].
The Big Bang never explained why the universe is isotropic and homogeneous. These were only assumptions. Inflationary theory explains them.
The start is something a billion times smaller than size of a single proton. This is why all heat had time to uniform. Before discovering this, in the Big Bang for heat to be uniform energy had to travel 100 times faster than speed of light which is impossible.
Then rapid inflation takes place.
Inflation theiry also explains the flatness of the universe. Other possible geometrical shapres of universe, open and closed. During the Inflationary period the universe is rapidly driven towards flatness. During all the other times it's driven in another direction. This is why the universe is approximately flat atm. Period of inflation = 10^-34 second.
2 tests for the theory:
1. Flatness: mass density should be that which makes the universe flat. Open curvature models of inflation failed. Flatness of the universe was not an accepted truth, it had to be measured. It appeared that all the matter available would only lead to 1% flatness. Dark energy comes to help, now we're up to 30%. Dark energy finally comes and proves the universe is flat.
2. Density perturbations. Inflation smoothes out anything before it (leading to a completely uniform picutre and therefore empty universe). Quantum fluctuations (at the 10^-35 of a second) saved the day as they led to some ripples necessary for formation of stars and galaxies. These were seen on the cosmic background radiation.
Observations are in agreement with Inflationary theory.
Inflation is not just a single theory, it is a class of theories. They get it closer to the answer. Paul's cyclic model is one form of an inflation theory.
Many versions of inflation. Saying inflation is right is not the end of story. Study of particle physics is essential for cosmological models.
Chapter 4: A balloon producing balloons producing balloons by Andrei Linde
Father of eternal chaotic inflation.
Main achievements in cosmology in the past 30 years. Creation of inflation theory.
The Cosmological Princple by Einstein says that the universe is homogeneous everywhere.
What happened before the universe emerged used to be considered meaningless or metaphysical until Alan Guth came with Inflationary theory.
As the universe grows, its total energy and mass grow even faster (2^3n) and become really large, enough to cause the big bang. Energy conservation breeched? How do you get a lot of energy from almost nothing? Total energy of matter increases, but total energy of matter + total energy of gravity is always zero (the total energy of the universe).
Alan Guth idea is how to start the inflation. Linde's idea is how to stop or continue it. If universe expanded really fast, then we are not able to see other parts of the universe with different properties. This is one version of inflation.
Inflationary multiverse. Laws of physics can differ in the multiverse just like phases of water (ice, liquid and gas). Quantum fluctuations lead to new inflations and therefore new regions within the multiverse.
Multiple equations of string theory fits nicely with the multiverse and anthropic principle.
This is against the aforementioned cosmic principle; the multiverse is not homogeneous.
In theory of chaotic inflation there are numbers up to 10^billion (the first inflation theory was 10^800) and even infinite.
The fluctuations in CMB confirmed the simplest form of inflation.
History of discovering inflation from a Russian perspective. Starobensky model. Alan Guth paper on inflation. Others in Russia reach the same discovery at about the same time. Linde improved the inflation theory.
Conference in Moskow. Stephen Hawking attends. Funny story and they become friends. Linde invited to a conference in Cambridge about cosmic inflation. Published a paper with a reply to Hawking criticisms.
In chaotic inflation the universe doesn't have to start hot. Due to quantum fluctuations inflation would go forever in some parts of the universe. 1986 internal chaotic inflation theory is born.
String theory landscape develops later.
1981. Quantum fluctuations give rise to galaxy formation.
Super gravity and string theory. History of a unified theiry. Eisntein work. No go theorums. Super symmetry. Super gravity. Superstrings. 10 dimensions. 6 compacted dimensions. Hallabiyaw space.
Dark energy. String theory 10^500 ways to make it; Susskinh called it string theory landscape. Fits with infinite chaotic inflation. Anthropic principle. Metaphysical questions help propel science further. We shouldn't be bounded by ideology.
The universe isn't a sphere it's a balloon giving.. etc.
Ultimate free lunch. Internal feist.
Chapter 5: theories of the brain by Lisa Randall
How do we go from string theory to particles and 4 dimentions? Masses of particles?
In string theory physics has gone ahead of mathematics. This is different from previous times when physicists used old math to solve their problems [it is actually similar to Newton who had to invent differential equations -calculus- in order to help his physics]. This made math and physics very close.
Why is gravity so weak? Branes.
This was a very complicated part and I hardy understood a thing.
Chapter 6: The Cyclic Universe by Neil Turok
It is unfortunate that many scientists interpret the Big Bang as if there was a beginning of time.
Inflationary theory has be supported by observations. However this theory doesn't deal with the beginning of the universe, it assumes there was Inflationary energy but doesn't explain it.
Work with Paul Steinhardt to answer how the universe began. String theory, strings and branes. Collison of the 2 branes.
Fits the observations. Predicts there were no gravitational waves at the big bang, unlike inflation theory.
Because the spaces in string theory can curled up in many forms, some have assumed it is random (anthropic principle). They don't have a theory of Big Bang or to pick one form or the other. This pedicts nothing. Postdiction. Not convinced of the landscape.
We need to understand the dynamics of the Big Bang (a mathematical model) and stop the useless anthropic reasoning.
2 parallel worlds separated by a gap. Dark energy is not stabel, it will revese at a certain time just like a ball going uphill will go downhill afterwards and when this haopens the two branes will start attracting each other and collide causing a big bang.
In inflation theory, dark energy plays no role in the inflation or big bang, in the cyclic model it does.
The old cyclic models were not infinite as explained above (with each bang we get more energy and matter, therefore the universe gets bigger, and the latter cycles last longer. If you trace into the past this means that there was a cycle where time was zero which implies a beginning of time). This one because with each bag matter and energy is diluted.
Chapter 7: Why does the universe looks the way it does by Sean Caroll
Dark energy. Prediction is 10^-8. Observation is 10^112. The difference is 10^120.
Why did the universe started in a state of low entropy. The anthropic principle is not enough. The answer is that our universe is part of a bigger system. We live in a multiverse.
We have 3 main theories:
1. General relativity
2. Standard model of particles (Quantum Field Theory).
3. The Big Bang.
They fit all the data we have. They can't be the final answer because they are inconsistent with each other. We need to move beyond them.
String theory could be true or false. Many questions about it.
We need to get to before the big bang and inflation. Inflation doesn't explain why it started. We need new models.
String theory and the poblems of observational evidence and falsifiablility.
The multiverse is not a theory, it is a result of the inflation theory and string theory.
Why did the universe had a low entropy? Inflation theory doesn't answer this. We don't know.
Chapter 8: In The Matrix by Martin Rees
Why is the universe the way it is?
Laws of nature are not independent of the universe?
Anthropic thinking. Our big bang and universe is just one of many just like our planet is one of many.
Firmer base for the multiverse. String theory. Landscape. Transfinite numbers (infinities of infinities).
"What we've traditionally called 'our universe' is just a tiny part of something which is infinite (..) What we have normally called the laws of nature are not universal laws—they're just parochial by-laws in our cosmic patch, no more than that, and a variety of quite different regimes prevail elsewhere in the ensemble."
Are we a simulation in a hyper computer?
Peaceful co-existence between religion and science.
50% set back for civilization. Risk of annihilation. We were very lucky in the 20th century. We have a lot of potential for the whole galaxy and therefore we should cherish our pale blue dot.
Dark matter the biggest challenge to String theory.
The Dark Ages and formation of galaxies. Exoplanets.
Human being size between that of an atom and a star.
Talks about discoveries in cosmology and other fields. Speculates on discovering the origin of life within 20 years. Life is more complex than physics.
Likes the public interest in origins questions and say it keep scientists aware of the big questions as they try to solve specific detailed ones.
Chatper 9: Think about nature by Lee Smolin
When thinking about the whole universe rsther than parts of it we run to questions about the laws of nature and why are they like this. What chooses among them.
Many questions are pushed to the question about the initial conditions at the Big Bang. Quantum field theory.
Cosmological natural selection.
Laws of nature outside time? This is a remnant of the idea of God. [Really?]
Nature has a memory about physical laws and develops habits about them. [Lol]
The ideas generated in theoritical and particle physics in the 1970s and 1980s have been confimed one time after another. But we didn't find super symmetry, any abnormality in Higgs boson, extra dimentions, new generation of quarcks etc. The standard model and inflation theory triumphed. The case is not closed.
Loop quantum gravity. String theory. Praises Paul Steinhardt and Neil Turok idea and explains his cosmological natural selection idea. We need a modelin which laws of nature evolve.
Boltzmann. Entropy. Direction of time. Riger Penrose. Initial conditions really improbable. Other laws are revesable in time. Why?
Chapter 10: The Landscape by Leonard Susskind
"For some people the universe is eternal, for me it's breaking news." John Brockman
"The beginning of the 21st century is a watershed in modern science, a time that will forever change our understanding of the universe. Something is happening which is far more than the discovery of new facts or new equations. This is one of those rare moments when our entire outlook, our framework for thinking, and the whole epistemology of physics and cosmology are suddenly undergoing real upheaval. The narrow 20th-century view of a unique universe, about ten billion years old and ten billion light years across with a unique set of physical laws, is giving way to something far bigger and pregnant with new possibilities. Gradually physicists and cosmologists are coming to see our ten billion light years as an infinitesimal pocket of a stupendous megaverse. At the same time theoretical physicists are proposing theories which demote our ordinary laws of nature to a tiny corner of a gigantic landscape of mathematical possibilities."
The landscape of possibilities. Megaverse and pocket universes. Defends Anthropic principle strongly. This part is a mine for quotes.
More and more scientists are accepting the multiverse for two reasons:
1. Eternal inflation
2. String theory.
Quote "22nd century.."
Hadrons: protons neutron and mesons.
History of string theory and his role in it. Personal story with Mary-Gulmann. String theory helps with black holes.
Chapter 11: Susskind vs Smolin about anthropic principle.
Susskind vs Lee Smolin [I have already read this discussion on the website few months ago. I was more sympathetic to Smolin back then. This shows that are more sympathetic to ideas we learn more about or read more recently.]
Susskind lays the case for anthropic principle as done on Edge.org. 4 points. Falsifiablility. Quarcks, inflation and evolution all were accused of being unfalsifiable.
Takes on Smolin's idea. Explains and praises it then criticize it [same style of argument adopted by Dan Dennet]. Our pocket universe is not dominated by black holes and black holes do not lose any information.
Lee Smolin's final letter.
Vacuum energy. Internal inflation. 2 problems. The method is logically flawed. Can only explain the vacuum energy.
Explains his theory of CNS. Explains a lot and is falsifiable. Information is not lost in black hole; it is available in the new universe. Background dependent and independent theories.
Chapter 11: Susskind vs Smolin about anthropic principle. This chapter order was wrong. The last letter was put before the original email exchange.
Smolin anthropic principle unfalsifiable and makes no predictions therefore not part of science. Suggests scientific alternatives to it. CNS is so far the only falsifiable scientific theory for the multiverse. A large neutron star would falsify it.
John Brockman has perhaps the coolest gig in the world. He finds some of the smartest people on earth, most of them scientists and some of them artists, and talks to them about what questions they're asking themselves lately. This is not to say that he has an easy job, of course; Brockman is apparently supremely good at what he does, because he manages to get some of the most interesting thinkers on earth to talk to him and each other for our benefit, and if that were easy to do I would be doing it myself. Fortunately, Brockman shares their conversations and essays with the rest of us, both on his website (edge.org) and in a series of books which collect their essays together.
In this one, he brings to us the reflections, recollections, musings, and predictions of those whose job it is to think about the Big Picture. Not trifling little matters like the Meaning of Life, but rather the very Big Picture, about the Universe. It is somewhat surprising to me whenever I am reminded that the theory of the Big Bang is less than a century old. That is, even when Albert Einstein was first developing the Theory of Relativity, he had no knowledge of the idea that the Universe had such a "beginning".
In the 90 years since the Big Bang was first postulated, physics has gone on a wild ride. In fact, so wild, that I think perhaps it has gotten too far ahead of the rest of human knowledge. The last few decades has seen physics (at least the universe-spanning kind of physics we are concerned with here) in the awkward position of having to generate new theories without much in the way of new experiments. The supercollider in Europe was a long time coming, and the last few years it has for the most part just confirmed what was already suspected. New physics comes from new and unexplained data to explain, and when that is missing, it is like a person undergoing sensory deprivation.
The main theoretical push in recent decades has been string theory. It is a matter of opinion as to whether or not string theory amounts to a person's hallucinations in response to sensory deprivation. In this book, you hear a few different takes on this question. This, really, is the most important difference between this book, and most books on astrophysics; it concentrates not on what is known or even suspected, but rather on what there is disagreement about.
And there is quite a lot of disagreement. If a theory requires 11 (or maybe 12) dimensions instead of the 3-dimensinal world we appear to inhabit, is that absurd? If the physical laws of our universe seem to be fine-tuned to a great deal of precision to allow for life, is that a coincidence need explaining? Is the value of universal constants really even an "event" that could be in need of explaining? This is not a book for people who like to think only about questions they can put their hands on. It's also not a book for people who want a single, unequivocal version of the truth; there is a lot of disagreement in this book, and often just after reading what one really smart physicist says, we read an essay by another equally smart physicist explaining why the first one is all wrong.
It is, though, a great book for stretching your mind a bit, and zooming out to the Biggest of the Big Pictures. If you are ready for that, Brockman is here to give you the opportunity.
Who would have thought a series of essays written by multiple scientific experts could have been as spell tingling as this book was? I know I didn't expect to enjoy this book as much as I did. Part of the reason this book works so well is because none of the essays are that recent. We've learned a lot in the past two years for which the authors with their wild speculations at the time were not aware of.
Two things the current reader should be aware of before listening to these essays. 1) The Higgs Boson is real and is at 125 Giga Electron Volts which is half way between the string theorist wanted (115 GeV) and what the multi-universe supporters expected (144 GeV), and 2) Gravitational waves have probably been found and if that is true Inflation Theory has more support than the authors of the essays realized at the time.
For most of the essayists, I've read their books for which they are going to write or have written at the time they wrote the essays. The essays cover the subject matter of their books fairly well, and you can save yourself from reading 25 or so books by listening to these essays. (The one exception is the essay by David Deutsch. He's talking about something beyond anything in his books
I highly recommend this book. It goes through various theories on the origin and nature of the universe explained in a simplified (not that simple but still) way. This book is absolutely mind-blowing. Although I am rereading some chapters to grasp the concepts because science, but I'm completely mesmerized.
This is a solid book but not necessarily one that I would recommend. I chose it because I've read books about cosmology and astrophysics for the laywoman and have enjoyed them. I thought this book would give me a good overview of current ideas in the fields, and I recognized at least one name on the cover of the book.
The book does deliver in providing an overview of what's going on in physics and cosmology relatively recently. It did get published before the Large Hadron Collider was fully up, so it's already outdated in that sense, but as most of the writers note, physics has sort of slowed down recently, and I don't think the major ideas are outdated.
What are the major ideas? String theory, of course, inflation, cosmological natural selection, and the cyclic universe. The various essays shed light on each of these concepts to varying degrees. String theory is the least defined being the oldest concept. The others are spelled out a little more clearly, especially inflation and the cyclic universe. My favorite essays are the ones in the middle, "Think about Nature" by Lee Smolin, "The Landscape" by Leonard Susskind, "Smolin vs. Susskind: The Anthropic Principle" (my favorite, favorite), "Science is not about Certainty" by Carlo Rovelli, "The Energy of Empty Space that Isn't Zero," by Lawrence Krauss, "Einstein: An Edge Symposium" (my second favorite, being the transcript of a conversation between Brian Greene, Walter Isaacson, and Paul Steinhardt about Einstein and string theory), and "Einstein and Poincaré," my third favorite, by Peter Galison. Oh, I really enjoyed "Who Cares about Fireflies?" by Steven Strogatz, a later essay about synchronicity and simultaneity.
I enjoyed that these essays were collected by Brockman from contributors to his website, Edge.org. There's a camaraderie between the (mostly) men, who share a common ground and who respect each other. The tone of most of the essays is conversational. There are some arrogance and condescension, but overall, the goal is to educate people and to encourage the search for further knowledge and understanding. What I got out of the book is mostly additional knowledge and some (minor) entertainment, particularly from my favorites mentioned above. So, why wouldn't I recommend it?
This collection is not particularly enlightening. You could find the information elsewhere in a more thorough way. I also don't like the organization of the book. The last few essays seem to have little connection to cosmology and to the universe as a whole. They obviously relate to things in the universe (what book doesn't?), but they just don't fit thematically with the other essays. I don't know why Brockman included them and especially why he placed them last. It sounds weird to say about this type of book, but the structure feels anticlimactic.
The thing I do like about the book is that it gives a cross section. You're not reading a book by one person with one agenda. You're reading a collection of essays by people who defined and support string theory, who disagree with or have difficulty with string theory, people who see more evidence for an inflationary universe, people who see more evidence for a cyclic universe, physicists, mathematicians, historians, etc. You get a variety of viewpoints all in one, and you can decide whose side you're on. For that, the book is useful. Still, I could also use it as a reference and read the books by the authors that I really enjoyed and get a fuller understanding of their ideas because I don't get that here.
All in all, it's a good book but not something I'm likely to remember (like A Brief History of Time, Black Holes and Baby Universes, and The Elegant Universe).