jazzy_dave: (books n tea)
Brian Greene "Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe" (Penguin)









Brian Greene is a very smart fellow, with a deep understanding of physics, and a wide range of knowledge in other disciplines. He is at his best when explaining cosmology and theoretical physics, but less convincing towards the end of the book, when discussing consciousness and meaning.

The relentless increase in entropy is the major villain of this book, sending the universe towards a dark future without organized matter. Evolution has locally produced molecules, life, and temporary order, by using sources of low entropy energy, but in turn dissipating the heat produced by the processes producing the order into the surrounding universe. There comes a time when the universe has no more low entropy sources of energy.

I wish Greene hadn't come up with the term "entropy two-step" to describe this exchange and then proceed to use it every few pages as a shorthand. He is worried about extracting free will and philosophical meaning out of the idea that physical systems can be described, in theory, completely by the movement of their particles. I see this worry in many books about consciousness, and I think it is overstated.

The very readable narrative portion of the book is 326 pages, and the more exacting mathematical and physical details, index, and bibliography comprises another 102 pages.
jazzy_dave: (bookish)
Brian Greene "The Fabric of the Cosmos: Space, Time and the Texture of Reality (Penguin)




The Fabric of the Cosmos is a long, comprehensive overview of the nature of space and time. It begins with a short history of our view of time and space, moving quickly to Newton and then the precursors to relativity, before covering special and general relativity in detail, before carrying out the same treatment for quantum mechanics. The middle sections cover how relativity and quantum mechanics can start to explain what space and time actually are. Topics such as the big bang, and inflation, are described and brought in to further illuminate the latest scientific views of space and time. The final sections of the book are more speculative, first covering string theory, including branes, and then moving on to a very speculative final part, looking at whether time travel or teleportations are consistent with the current view of reality, and then about where physics might be going next in the coming decades. As is apparent from the above, the structure of the book is strong and very well-judged. I preferred it to The Elegant Universe for its broader remit, and because not so much of the book was describing ideas no one as yet has any evidence for.

In the end, I was left with an unsettling sense that the universe is utterly alien, compared with our everyday notions - that the real action is happening at scales so small even our most powerful particle accelerators don't have access to them. Even if they did, it could be that our entire sense of reality, of time and space, and the fabric of it all, might be a holographic illusion. It's as if we see a smooth 3D world in a holographic picture when what we're really receiving is just different pixels on a 2D surface.

There were just a couple of niggling issues: first, sometimes the explanations weren't precise or clear enough (for instance, special relativity was explained far better by Isaacson (not a physicist!) in his Einstein biography). This extended to the endnotes, which were meant to clarify, but the mathematical explanations seemed rushed to me - sometimes there more as a demonstration of his knowledge, rather than for pedagogical reasons. Second, this book is now a decade old, and it is calling out for either a second edition, or at least an update to the endnotes - when he speculates about what the LHC will discover and so on, this just seems so dated, and we really need a way for him to rewrite or add sections in the light of the latest developments.

But overall this was an incredibly fascinating, astonishing, thrilling, beguiling ride - and a fantastic achievement. I felt privileged to have read it.
jazzy_dave: (bookish)
John Brockman "The Universe" (Harper Perennial)




The matter originated in the Big Bang. Firstly as a soup of quarks, W's, Z's, electrons etc. As the new universe expanded and cooled, the quarks coalesced into particles like protons. As the expansion continued a point was reached where nuclei could trap electrons and make neutral atoms. This occurred about 380,000 years after the Big Bang. Once neutral atoms existed, the universe became transparent to photons, which we now see as the Cosmic Microwave Background. In our laboratories such as CERN, we can recreate the conditions that existed about 0.0000000001 seconds after the Big Bang and study the processes that would have been occurring at that time.
 

The offerings in this collection provide a look at what some of the worlds leading experts are working on and thinking about in the realm of theoretical physics. The quality of the writing varies widely, as one might expect from a collection of essays by multiple people. The prose ranges from childishly simple to quite technical. A few even exhibit some artistic flair with words. But all are interesting. One, perhaps untended, revelation is a glimpse of egos, and the (mostly) polite clash of egos in cases where scientists do not agree.

Generally, a very good overview.
jazzy_dave: (bookish)

Michael Brooks " 13 Things That Don't Make Sense" (Profile Books)




Brooks' exploration of science's current conundrums is provocative and at times satisfyingly eerie, examining the deadlocks we've reached, and positing that maybe these stumpers mean that we're on the brink of a revolution. 13 of today's bafflers, from dark energy to the placebo effect, are explained.

Brooks starts out in one of my favourite realms to consider: cosmology, with the hint of quantum. These areas are wonderful playthings for the dilettante. I like to skip the math, education, logic and levelheadedness and go straight for the wacky and fun. And Brooks lets me do that, lets me revisit my favourite pop pet theories. The first few chapters are the most fun, covering those big, fun, universe-sized physics topics.

The later paradoxes in the books, the ones involving biology and chemistry, lack the lustre of these first topics. Somehow the inexplicable success of homeopathy's quackery and a perplexing giant virus doesn't stand up to the hair-raising queerness of the Viking crafts' extra-solar system trajectory oddities, nor the notion that our fundamental constants may be inaccurate on cosmic scales or simply not constant at all. Shortly, it's clear that Brooks is a physicist, and that's where he shines.

A clear and entertaining read, unobtrusively constructed and well-researched.
jazzy_dave: (bookish)
John Gribbin "13.8" (Icon Books)








This is a lovely book for anyone interested in modern cosmology. It is not really watered down, but at the same time concepts and jargon are well enough explained that even readers with no physics background can probably follow along. This book also does a good job of covering the basics of the history of the science of cosmology, a very brief introduction of course, but sufficient to provide some detail of many of the key people involved in working out the age of the Universe, including several of the women involved in the early days of this research
jazzy_dave: (bookish)
Carlo Rovelli "Reality Is Not What It Seems: The Journey To Quantum Gravity" (Penguin)




Sometimes it's not what you understand or what you know for certain that really matters. It's acknowledging the limits of your understanding and still to be willing to press on. That, in fact, is close to what Carlo Rovelli identifies as the chief virtue of science. It's a point he makes in the final chapter of this fascinating journey from Anaximander past Copernicus and Newton, to Einstein, Dirac, and a host of other startlingly brilliant physicists, all of whom ventured forth from that initial point of ignorance. I feel like I'm in good company even though my ignorance may be clouding out my brilliance.


I must congratulate Prof. Rovelli because he was able to convey the gist of loop quantum gravity without diving deep down into the gory mathematical details. Of course, without even summarizing such details, one can only get a very fuzzy and intuitive grasp of the matter, but that's better than nothing.

I was also excited to learn about LISA (Laser Interferometer Space Antenna), a mission designed to detect and accurately measure gravitational waves from astronomical sources. According to Rovelli, what the famous LIGO did for detection of gravitational waves caused by black holes colliding, LISA will do for ancient black holes exploding, sort of a cosmic quantum gravitational background effect, similar to the famous cosmic microwave background radiation.

I also liked how Rovelli connected some of the scientific themes to literature and history, especially his references to "De rerum natura" and Dante, as well as establishing continuity with the great thinkers of ancient Greece.

I think the chapter regarding the concept of "information" and the role it plays in modern physics theories could be expanded and clarified more. Instead of trying to introduce quantum mechanics and relativity for which we have great popular accounts, he could've used those pages to explain his ideas about information in more depth.

I can recommend this book to people who'd like to have an intuitive overview of an important direction where modern physics research is headed to. And it's always nice and inspirational to read an Italian author who knows his history and literature so well.
jazzy_dave: (bookish)
Ian Stewart "Calculating The Cosmos" (Profile Books)







From space exploration to astronomy to astrophysics to cosmology these are unusual topics for prominent mathematics popularizer Stewart. However, it almost seems that his real purpose here is to express scepticism about dark matter, cosmological inflation, dark energy, the Big Bang itself, and "fine-tuning" arguments. Sure, he says a lot about the role of mathematics in the various topics, but almost entirely using words rather than symbols and equations. This does make the book more digestible and informative for many readers but is not rigorous for those like myself who prefer it chunkier with the equations thrown in. Personally, I would opt for the Roger Penrose book "The Road To Reality" to give me the real meat of the subject.  
jazzy_dave: (bookish)
Neil deGrasse Tyson "Welcome To The Universe" (Princetown University Press)






Sort of an informal version of a comprehensive textbook for an introductory astronomy course, with Tyson (helped by Strauss) covering stars and planets, Strauss covering galaxies, and Gott covering relativity and cosmology. Handsomely produced, colourfully illustrated, written with verve, *and* quite meaty. Mathematics is present, but it is high-school level and does not dominate. There's no evidence that Gott or the other authors have any sympathy with those who nowadays question inflation or other aspects of the concordance model of cosmology.


I suppose i could read textbooks rather than pop-science books which this book generally comes under(albeit much more slowly, and with a pad and pencil in hand for figuring things out), but I don't want to read a physics textbook, well not since i studied it as an Open University course way back in the late seventies. AS such, this is still a very comprehensive overview , and if you want to dig deeper,and have a very good handle on the mathematics,then go for a textbook on the subject. Meanwhile, this will suffice.

jazzy_dave: (bookish)
John D. Barrow "The Book Of Nothing" (Vintage)






He may use flowery language to convey his thesis on the aspect of nothing and that to some he tried to cover so much stuff that it never lingered anywhere but when you are dealing with the vacuum of space in a non technical way to lay readers then you have to take time (in both senses of it as well as spactime) to convey such complex cosmological information. It may be heavy going at times but i did enjoy this book.

Perhaps not the best book to describe such things as the vacuum state,inflation, black body radiation , the cassimir effect or the value of the cosmological constant (lambda), so with this caveat i would suggest other books to read first.
jazzy_dave: (Default)
These are the few limits on our ability to know.

http://nautil.us/issue/40/learning/how-much-more-can-we-learn-about-the-universe


Krauss_BR-2


COLLIDING GALAXIES: Such cosmic commotion will one day cease to occur, and observers in the distant future may never realize how dynamic our universe once was.
jazzy_dave: (Default)
Well we sure are having an Indian summer with temperatures unbelievably  high for this time of the year. Even now approaching eleven at night we are still in the low twenties.

Whilst in Faversham i sold some paperbacks and used the local library. Did a few hours of sunbathing just outside said library in spurts of thirty minutes each,as the sweat was pouring off me.

I arrived back in the Bourne and had the second shower of the day.Listened to a Cd compilation of the songs of Burt Bacharach by various artists, watched a fee episodes of Charmed, had some more coffee vodka bevvies and chilled out.

I also watched another Horizon documentary - How Big Is The Universe.

It is vast.The Milky Way alone is 100 thousand light years across.The universe is around 46 billion light years and expanding rapidly due to dark energy. The thing is we as yet do not know exactly what dark energy is but that it takes up around 70 per cent of the universe and defies the pulling force of gravity and dark matter. In a sense the universe is infinite. That is rather sobering.
jazzy_dave: (Default)
Roger Penrose "The Emperor's New Mind : Concerning Computers, Minds and the Laws of Physics" (Verso)






Roger Penrose isn't just any old boffin: he is the Emeritus Rouse Ball Professor of Mathematics at Oxford University and has been knighted for his services to Science. The Emperor's New Mind is his attempt to crack that perennial philosophical chestnut, the Consciousness/Artificial Intelligence problem. Penrose's view is that Strong AI is simply wrong and that a computer could never replicate (functionally or actually) what we know as "consciousness".

Originlly published in 1991 this was a long, grueling read. I won't say I clearly understood (or even dimly understood) all this book. At times my eyes glazed over, and my comprehension phased out only to resume later usually after long passages of mathematical symbols ,though the math in this book was relatively simple, and i had encountered Hamiltonians and vector spaces in an O.U. second level pure mathematics course.



It helpd that I'd read other things about artificial intelligence, computers, relativity, cosmology, and quantam physics. By his own admission, Penrose finds it difficult to explain mathematical things verbally and his arguments often go on and on without tying them into the central question of the book - is algorithmically based AI possible? In the end I think they all show to be relevant.

Penrose ventures into widely speculative ground by saying he believes consciousness will be better understood when quantum mechanics and relativity are joined, probably, he believes, by quantum gravity. He makes the startling the proposal that the brain is a quantum computer computing numerous quantum possibilities until gravitational collapsing the quantum wave-function and realizing one quantum reality.

Penrose concludes with some intriguing paradoxes in time perception. Do we really, as certain experiments suggest, experience everything two seconds behind and are limited by a half-second delay before conscious action is realized? Penrose doubts it, but it's intriguing. Penrose isn't afraid to consider philosophical questions which most scientists shy away from and firmly grounds, unlike most philosophers, human behavior and consciousness in the physical world and its laws. Some of Penrose's approaches were different than the usual treatment his topics get, particularly de-emphasizing quantum mechanics' indeterminism and imprecision as others do, but, rather, the precision and predictions the theory does allow.length to explain, and their relevance, without having to get your head around every complicated equation.

I think that some of his theories are enticing, and altogether this was a good read, but perhaps could have benefited from a more decisive outcome. The ending comes an an anti-climax, but getting there is worth the whole trip.



Multiverse

Sep. 2nd, 2015 09:46 pm
jazzy_dave: (Default)
Just watched Horizon on BBC2. A mind boggling look into the multiverse , from the inflationary period of the Big Bang to multiple bifurcations of quantum universes, in which every universe is parallel to our own, to the extraordinary concept of every universe including our to be the physical reality of mathematical processes. Totally fascinating.
jazzy_dave: (Default)
A couple of brain expanding short science clips from TED -

What Happened To Antimatter>



Dark Matter and Dark Energy

jazzy_dave: (Default)
After watching the film on Sky this evening of The Theory Of Everything i might now tackle the book i have in my collection The Road to Reality: A Complete Guide to the Laws of the Universe, which happens to be a 1,099-page book aimed at giving a comprehensive guide to the laws of physics. Phew!





Or his other one i have, The Emperor's New Mind , in which he argues that known laws of physics are inadequate to explain the phenomenon of consciousness. He proposes the characteristics that this new physics may have and specifies the requirements for a bridge between classical and quantum mechanics (what he calls correct quantum gravity). Penrose uses a variant of Turing's halting theorem to demonstrate that a system can be deterministic without being algorithmic.



(For example, imagine a system with only two states, ON and OFF. If the system's state is ON when a given Turing machine halts and OFF when the Turing machine does not halt, then the system's state is completely determined by the machine; nevertheless, there is no algorithmic way to determine whether the Turing machine stops.)

Penrose believes that such deterministic yet non-algorithmic processes may come into play in the quantum mechanical wave function reduction, and may be harnessed by the brain. He argues that the present computer is unable to have intelligence because it is an algorithmically deterministic system. He argues against the viewpoint that the rational processes of the mind are completely algorithmic and can thus be duplicated by a sufficiently complex computer. This contrasts with supporters of strong artificial intelligence, who contend that thought can be simulated algorithmically. He bases this on claims that consciousness transcends formal logic because things such as the insolubility of the halting problem and Gödel's incompleteness theorem prevent an algorithmically based system of logic from reproducing such traits of human intelligence as mathematical insight.
jazzy_dave: (Default)
I have a feeling that my bro will want to pick my brains on aspects of cosmology today. He has been trudging through the Stephen Hawkings book, A Brief History Of Time. In particular is the slippery subject of the Uncertainty Principle, and that includes the thought experiments of Erwin Schrodinger's Cat in a Box , and the opposing Copenhagen interpretation vs. The Many Worlds interpretation of quantum theory.

(Note - the Copenhagen interpretation is the one in which all particles are in a state of quantum flux, known as a superposition state,  until the observation of ithis flux forces it to collapse to one state.)


The other areas he will want too idscuss will be black holes, and the backbone to all quantum physics, Planck's Consatnt , which is defined as  about 6.62606×10−34 joule sec.

(Extra note - i wish there was devices to plug into our brains to make us instant experts lol)

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