A book about cosmology but mainly about anthropic cosmolgical principle,weak and strong,the book develops the importance of fine tuning of six,mainly A book about cosmology but mainly about anthropic cosmolgical principle,weak and strong,the book develops the importance of fine tuning of six,mainly of cosmic significance ,numbers. This numbers are: N the relation between the strenht of electrical with regard to the gavitational forcé.
Epsilon the los of mass or energetic efficiency in the nuclear fussion of protons.
Omega the mass density of our universe.
Lamda the value of cosmic repulsion that acelerates the universe expansión.
Q the ripples or asimetries imprinted in the Big-Bang.
D the number of spatial dimensions 3 of our universe.
The very precise fine tuning of the values of this numbers play a fundamental role in make a universe where complex long lived structures between them the life and inteligent life can exist.
In Font of this fact one can take two positions: First ,to think that this is not a chance instead it is the fruit of a inteligent design,this the anthropic cosmological principle strong versión. Second,following the latest ,yet speculative,theories of cosmic inflaction there are infinite inflactionary bubbles generating each one a different universe ,each one with differen phisical laws and constants and the universe we live is so because we are here to see it,this the weak versión of the anthropic cosmological principle. With regard to all this I Will type two textual paragraphs that I think are important in the philosofy of the book. "If evolution were rerun,the outcome would be different.Nothing seems to pre-ordain the emergence of inteligence;indeed some leading evolutionists believe that,even if simple life were widespread in the cosmos,inteligence could be exceedingly rare."
"Theorists may,some day,be able to write down fundamental equations governing physical reality.But physics can never explain what breathes fire into the equations,and actualices them in a real cosmos.The fundamental question of "Why is there something rather tan nothing?" remains the province of phylosofers.And even they may be wiser to respond,with Ludwig Wittgenstein,that"whereof one cannot speak,one must be silent.""
I now Will dare to make a ,personal surely fool ,reckoning about the limits of human attempt of answer the ultimate ask of Martin Rees.given that every thought or chain of thougths is a physical state or sucession of physical states of our brain and by that constrined to the basic physical laws of our cosmos it must be a autorefference problem,a sort of Godels theorem that prevents the explanation of the laws inside the laws or the game from inside the game,if so the ultimate ask will be ever unanswered and out of the human ,or other inteligent being inside the universe, reach.
A recomended book for all that would like to take a clear concise introduction to cosmology and its implications....more
There are two main streams of research in joining quantum mechanis and general relativity,the string theory that is background dependant,the space-timThere are two main streams of research in joining quantum mechanis and general relativity,the string theory that is background dependant,the space-time,and the loop quantum gravity that is not backgroun dependant as it is a quantum theory of the space-time,in this sense ,for me, this is a more fundamental theory. This is the first book I have read on loop quantum gravity and I have found it very clear ,accesible and easy to read in this difficult and technical subject,I also have found this theory beautiful and natural in the sense that it uses the same way to obtain a equation on the quantum dynamics of gravity as have used Schrödinger to obtain his equation on quantum dynamics of a particle,Schrodinger derived it from the classical mechanics equation of Hamilton-Jacobi and followig similar ways this theory derived it equation for the classic general relativity Hamilton-Jacobi equation of Wheeler-De Witt. After a brief histhory and fundamental concepts of quantum mechanics and general relativity where Aristóteles is subtly criticed and Democritus praised the book tells that the solutins of quanticed Wheeler-De Witt equation are spin networks where in the knots is the quanticed space vales and the relations with the next quanticed space knots are in the links where the spin resides and can have multiple of 1/2,I have found this razonable as the spin,a quantum magnitude that has not classic analoge, is related with the matrix unitarian representation in complex spaces of the Lorentz group,the group of lorentz transformations,a generalization of the space rotations and time translations of the galilean group, of the space-time in Special Relativity. In this theory the time dont appear in the equation,the time is relational,a ordered sucesión of events,macroscopically this order is given by the irreversibility the dynamics of the spin network is the spin foam and the quanta of gravity and space are the same in the new field named quantum covariant field. So far this is only a beautiful theory,but for me have several positive points : First-The Heisenberg incertidumbre principle for position momentun only give not absurd results if the space cant be shorter than Plancks length. Second-As the space have a minimun size,the infinites in the quantum field theory dont any more exist as the perturbative serie is finite and renormalization trick is not needed. Third-Inside the black hole the infinite density zero space point singularity dissapears.
In a editorial world full of rather fancy physics books as those of Brian Green,Lisa Randal and others,this is a honest and fresh air book that gives a realistic alternative point As a anecdote,it seems that Greg Egan is a fan of this theory because in his novel Schids Lader the theory of everything is a quatum graph theory,the novel a really hard SF novel, begins textually so : "In the beginning was a graph,more like a diamond than graphite.Every node in this graph was tetravalent :connected by four edges to four other nodes.The edges has not length or shape,the nodes no position ;the graph consisted only of the fact that some nodes were conected to others.This pattern of connections,repeated endessly,was all there was "¡The world, pure geometry!...more
This book based on a BBC programme is one of the best popular science books I have read,it gives a very readable unified cosmic vission of almost all,This book based on a BBC programme is one of the best popular science books I have read,it gives a very readable unified cosmic vission of almost all,the universo,its origens,the fundamental laws of nature,the emergence of life,the emergence of inteligence,the fine tuning,if we are alone etc... The book explores,at least for me,two very interesting points :the fine tuning and the improbability of emergence of a technological civilization ,and so solving the Fermi Paradox,and I personally believe that it success in the explanations and reasonings It explains fine tuning as a result of the eternal inflaction that leads to a infinite inmortal universo growing fractal like withut end,there is not fine tuning problema,given the infinite multiverse,we are inevitable. As if we are alone,given the eucariotic and the oxigenic photosyntesis bottleneck the Galaxy could be teeming with life,,but it will be slime life,the emergence of complex multicelular not mentioning the emergence of the technological inteligence surely would be extremely improbable,we cannot comunícate with others because we are the first to emerge in the whole Galaxy,the Fermi paradox solved. We as example emerged because a asteroid colide with earth giving the rise of mammals,the dinosaurs dont give proofs of much improving inteligence despite their 150 milion years of kingdom,and we are here surely by a particular Earths orbit features that trought the Milankovich cicles give way to ice ages that trigered as a consecuence of strong climatic changes our emergence in the Rift valley.
One of the best books in giving advices and tricks for choosing telescopes,oculars,barlow lenses,finders,apertures,colimation of reflectors,places andOne of the best books in giving advices and tricks for choosing telescopes,oculars,barlow lenses,finders,apertures,colimation of reflectors,places and gear to a comfortable observation,teach how understand celestial coordenates and star hopping,astronomic software and many more. The authors are strongly in favor of a 10 inch dobsonian telescope as the best compromise in aperture , portability and easy of use, because in dark places allmost all interesting targets can be observed with this tube,yet also recomend as a cheap alternative ,over all for a beguiner ,a 6 inch dobsonian or for a grab and go a 90mm f11 refractor in altazimutal mount. Another imprescindible book in the library of a backyard astronomer...more
For me the best sky atlas for backyard astronomers,it has 80 detailed charts with the most interesting targets to observ,classified by right ascensionFor me the best sky atlas for backyard astronomers,it has 80 detailed charts with the most interesting targets to observ,classified by right ascension and dates and hours to better observation,has charts of both sky hemispheres and is also excelent for star hopping with the added value that is a relatively small pocket book. At the end of the book have close up charts of the Pleiades,Orions Sword,Virgo Galaxy Cluster and Large Magellanic Cloud A imprescindible tool book...more
A sort of a Nearly a Histhory of Everything but foccused mainly on astrophysics,writen as a series of articles touching diverse subjects.
A very entertA sort of a Nearly a Histhory of Everything but foccused mainly on astrophysics,writen as a series of articles touching diverse subjects.
A very entertaining,easy to read popular science book with, unusual in this sort of books, a touch of fine and at times acid humor.
It has two very interesting final chapters where the author makes a disgression of the relations between people,science and religion,and makes clear his position in regard to the inteligent design hypotesis with yhe following textual phrase :"Science is a philosofy of discovery.Inteligent design is a philosophy of ignorance.
A interesting,entertaining and easy summer read...more
There are many books devoted to the standard model,the Higgs field and Higgs boson,each one with its own personality.
This book is foccused in the concThere are many books devoted to the standard model,the Higgs field and Higgs boson,each one with its own personality.
This book is foccused in the concept of void,and is in some way a more philosofical book.
Begins with the concept of void by greek philosofers and tells the history of the concet till the absolute space time of Newton,the space permeated by the ether inth Maxwell electomagnetism,the defeat of the ether by Einstein and the revival of the idea as now the void is a geometry filled with quantum fields and swarms of virtual particles as the Casimir effect has proved,but this is a relativistic concept of ther ether.
The book ends with cosmological questions.The universe created as a quantum fluctuation of near zero energy,balance between kinetic and gavitational negative potential energy, and by that with a long lasting as the uncertainty principle says(this is the idea of the book "A Universe fron Nothing" by Krauss),the phase transition and forcé decoupling by Higgs field,the mas as the interaction of particles with this field,the possibility of existence of infinite universes in the spontaneous simetry breaking as a pencil that can falls in any direction,each universo with its own hierarchy of forces and fundamental constants (we have the luck of live in the one fitted for us ,this could explain the fine tuning and the inteligent design),but where is the fluctuating field coming from?,or what is the ultimate cause of that field?.
The autor is honest insaying that the asking of who or what is before big bang is a nonsense question in the physics realm as the time was created in the big bang.This is for me a metaphysical question beyond science,if we trespass this limit enter in the realm of methaphysics of a infinite starcaise of causes or accept the concept of incaused cause.
Also there is the hypotesis by Hawking that the universe is a four dimensional surface of a fifth dimensional sphere and by that the time unlimited and circular without begining nor end,a sort of revival of steady state cosmology,that of Hoyle, and so our universe simply is, (here the tomist idea of God ,the existence is the esence,or in spanish-yo soy el que soy-i dont know the english translation) .But the fundamental question remains.
A easy to read book ,clarly explained and that present deep questions.
By the way the book has a humoristic anonimous quote:"Why dont the big bang happened before"....more