In Search of the Multiverse by John Gribbin

In Search of the Multiverse Reviews

• 
  Gendou

  This book takes the form of an essay, arguing for a multiverse using anthropic reasoning. It fails, miserably.
  
  The author brings up fine tuning, such as the Hoyle carbon coincidence, how cosmological constant almost 0, how gravity is weak, etc. I don't have a problem with very weak anthropic reasoning. For example, we might look to find a good explanation for a small, non-zero cosmological constant. When we estimate the value for the cosmological constant based on our current understanding, we come up with a fabulously wrong guess. This is a good area for study, but it isn't a "problem" to be "solved". We have no reason to demand that nature holds up to our expectations. Nor do we have any reason to expect that a correct theory be unique, or pleasing to our particular aesthetic sensibilities.
  
  Instead of defending anthropic reasoning, Gribbin plays on his readers ignorance with statements like "we still don’t know what electrons (or other quantum entities) are, nor how they do the things they do." This is really a mystical argument, that nature behaves in a way "feels" alien. It is no defense of anthropic reasoning.
  
  The biggest problem with strong anthropic reasoning, which Gribbin relies on, is its abuse of statistics. For example, it is stated that some constant has a fine tuning of 1%. This means that, if you change it's value by more than 1%, the universe will no longer look the way it does. This is a fallacious use of statistics, because there is no natural scale for the constants of nature. What justification is there for assuming that a cosmological constant of zero is any more natural than a non-zero value? Just because it happens to be close to zero, doesn't mean that zero is more natural. If it had been close to, but not exactly 137, would you feel differently? It's all a bunch of numerological quackery, unless you have a physical theory that predicts a certain value!
  
  Gribbin, like most anthropic goofballs, claims that "The very fact that we exist seems to be the best evidence available that we do indeed live in a Multiverse." But that is putting the cart before the horse. Their (unjustified) assumption is that the universe could have been different, and is different elsewhere. If that is true, than the existence of humans is indeed explained. But you could also use Occam's razor and just allow nature to be nature. Constants have their value because that's their value. It seems obvious that ours is only one of many possible ways that a universe could act. Maybe not, maybe there is only one self-consistent law. That just seems very unlikely.
  
  Gribbin makes the case for the Many Worlds Interpretation (MWI) of quantum mechanics, another form of multiverse. Gribbin starts by explaining how quantum computers work, in great detail, using the MWI. He then concluding that, because quantum computers work, the MWI must be correct, and that "it's difficult to doubt" the existence of the MWI multiverse. This is a logical fallacy, because other interpretations, like the Copenhagen Interpretation, can be used to predict the same outcomes! He's just playing favorites, which sure as hell isn't fooling me.
  
  Gribbin further proves himself insane by touting - I kid you not - a multiverse origin of "free will"! He calls upon Julian Barbour's idea of a "Big Heap"; a jumbled collection of snap-shots. Each is a different configuration state for the universe. In this view, time arises by creating a sort of flip book using these "moments". The observer creates their own history by putting them in an order. Gribbin proposes that "the quantum picture gives us back our free will". He's an idiot.
  
  Gribbin talks about wormholes. He explains how that can be used to travel backwards in time via causal loops. Then he proposes that, much like in Star Trek, parallel histories would arise from traveling back in time and changing the past. This alleviates the grandmother paradox. But it begs the question, how come the throat of a wormhole can spirit you away to another branch in the tree of the multiverse? It's a clever idea... if you've been smoking weed. But it doesn't hold up to the least bit of scrutiny. Very Gribbin.
  
  Gribbin introduces inflation and shows how it leads to a solution for the origin of the universe that avoids the Boltzmann Brain paradox. Then he concludes that inflation requires an infinite universe, which is not justified. He then suggests that other bubble universes are a type of multiverse, which is an argument over semantics. He then claims this type of multiverse supports his thesis about the MWI and fine tuning. It most certainly does not!
  
  He also talks about Lee Smolin's idea of black hole driven cosmic evolution. I think this idea is really cool, and I'm glad it was included in this book.
  
  Gribbin ends the book by proposes that, if we can create a pocket universe in the lab, maybe our universe was created in the same way. From it's mention in the book, I decided to read Cosm by Gregory Benford. It was kind of neat. Very spooky. But this is just more anthropic reasoning, verging on theism.
  
• 
  Ints

  Laikā, kad vēl studēju ekonomikas un finanšu zinības, man tīri nejauši gadījās internetā uziet nelielu rakstiņu, kas bija veltīts daudzo pasauļu teorijai. Tā izrietēja no kvantu fizikas, saturēja gudrus vārdus – Visuma viļņfunkcija, viļņfunkcijas kolapss, nenoteiktības princips un Šrēdingera kaķis. Visu to saliekot kopā sanāca, ka katrā brīdī, kad notiek makroskopisks notikums ar noteiktu varbūtību, Visums sadalās tā, ka visas iespējamās varbūtības tiek realizētas. Globalizējot, mums līdzās pastāv milzīgs, bet galīgs visumu skaits, kuri daudz ko neatšķiras no šī, bet katrā no tiem pāris lietas ir nedaudz savādākas. Piemēram, vienā tu vakar esi vinnējis loterijā, bet citā tevi aizvakar ir nobraucis autobuss. Viss, kas vien ir jebkad varējis notikt, notiek. Skaidra lieta, ka šādas idejas mani pievērsa šim jautājumam.
  
  Grāmata apskata augstāk pieminēto Everett daudzo pasauļu teoriju, tiek apskatīta arī tā saucamā Kopenhāgenas interpretācija. Tomēr šīs skaitās samērā vecas idejas. Uzmanība tiek pievērsta arī jaunākajām fiziķu idejām, stringu un M-teorija tiek piesaukta vai ikkatrā lapaspusē. Smalki tiek apstāstīta Inflācijas teorija un tas, kā tās procesu ietekmē varētu rasties daudzi paralēlie visumi. Vārds „paralēls” gan te ir nevietā. Tiek apskatīta arī inflācijas teorijas modernā alternatīva – laiktelpa membrānas, kas laiku pa laikam, reizi triljons gados, ja gribam b��t precīzāki, saduras un rada mums lielā sprādziena iespaidu. Pārstartē mūsu Multiversu un cikls sākas no jauna. Vienu gan īsti nesapratu vai šīm membrānām ir jābūt tikai divām jeb tās arī ir milzīgs skaits.
  
  Laba ir arī nodaļa, kurā autors mums pastāsta, kādēļ kvantu datora esamība mums tieši norāda uz citu visumu eksistenci, jo rodas visai nopietns jautājums, kur notiek kvantu datora aprēķinu process. To, ka šāds dators ir realitāte, mēs jau zinām. Interesanta ir arī atbilde uz jautājumu, kas droši vien nomoka daudzus Matrix cienītājus – Vai mēs dzīvojam simulācijā? Loģiski spriežot sanāktu, ka varbūtība mums atrasties simulētā virtuālā pasaulē ir daudz lielāka, nekā gadījuma rezultātā evolucionēt kādā atsevišķā visumā. Galu galā mēs pat zinām mūsu pasaules pikseļa lielumu – Planka garums. Tomēr, ja tas tā būtu tad mēs varētu novērot pāris gļukus, kas mums par to tieši liecinātu.
  
  Ne visai interesanta man likās nodaļa veltīta visuma evolūcijai. Dabiskās atlases modelis tika ekstrapolēts uz visuma fizikas konstantēm un šo konstanšu ietekmei uz melno caurumu rašanās varbūtību. Tiek pieņemts, ka melnie caurumi aiz singularitātes ir citi visumi. Tālāk sākas teorijas, ka visums, kurš rada daudzus melnos caurumus, ir priekšrocība pret citiem visumiem. Tāds tad radīšot daudz vairāk citus visumus utt. Manuprāt šī nodaļa bija lieka.
  
  Atradu atbildi uz jautājumu, kā es varu zināt, ka es neesmu tikko radies kvantu fluktuācijas rezultātā ar visām atmiņām un pieredzi un tūlīt pat nepazudīšu. Var tak tā būt, ka tev aiz loga patiesībā nekā nav. Kopumā grāmatu vērtēju kā izcilu, dod reālu vielu pārdomām un ļauj saprast ka Multiverss nemaz tāda tukša pamuldēšana viss nav. Grāmatai lieku 10 no 10 ballēm. Cilvēkiem, kuriem jau Matrix ar savu simulēto vidi liekas uber ideja, ieteiktu te pasmelties vēl saistošākas lietas.
• 
  Nicky

  I don’t understand quantum physics or string theory, really — I couldn’t possibly explain them to someone, anyway. But I keep trying to, and this book has probably got the closest to making me really interested in the topic. It’s easy enough to follow, and doesn’t throw maths at you without explanation, and it helps that it’s focused on one of the important more interesting factors: quantum theory and string theory could require a multiverse. Gribbin has a look at all the reasons a multiverse seems likely, including the fact that quantum computing works at all, and takes you through anthropic reasoning, etc, etc.
  
  Overall, I still find parts of this difficult to get on with. We can’t know that we live in an average universe — even if there are an infinity of different universes, that doesn’t follow that universes which are suitable for life are more common. We could be living in a rare universe. We can’t see what the probabilities of anything are when we only have experience of one universe — nobody has ever convinced me we have the data to really judge.
  
  This is probably going to date badly when it comes to its explanations of string theory and a theory of everything, but for someone as lacking in knowledge as me, it works.
  
  
  Reviewed for The Bibliophibian.
• 
  RB

  This is definitely a Great read so far, but I must admit, that Chapter 4 is a wee bit too abstract/"floaty" to me, but again, I am not a physicist! Gribbin is doing a god job at explaining and visualising complex theories to a layman such as myself... Have to admit that it does give me more questions about the nature of our universe! :)
  Highly recommendable!
• 
  John Gribbin

  FYI I do not subscribe to ID but I do think the universe is probably an artefact. Read the book to find out what the difference is!
• 
  Riju Ganguly

  Nope. Not very good. Good, yes. But it doesn't have that special spark that makes a non-fiction unputdownable.
  Perhaps it would be better to stick to Micho Kaku's books, since they are a lot more lucid, and are more connectable courtesy all the pop-references.
• 
  Barry

  It never ceases to amaze me how hard some scientists work to explain away the need for a Creator. It's almost as if they are afraid of a Creator. In order to explain away the universe and everything it contains, they are wont to dream up fantastical theories that could be true, and therefore, with a leap in logic that is never explained but appears to be commonplace in theoretical physics, it must be true. Hence, we live inside of a black hole. That's right: the visible universe exists inside of a black hole. I'm pretty sure I'm being fair to Mr. Gribbin's writing here, but I might not be, because the train of thought bounces. Which is also what the universe has done, is doing, and will continue to do. For eternity. Which is possible, because some equation that is never explained allows that it could be possible, and therefore it must be true.
  
  At the end of the book, Mr. Gribbin explores the idea of intelligent design. Not at all meaning God, but other finite beings, much like us, who exist in other universes and have created this universe as an experiment or as entertainment. In other words, the creator that Mr. Gribbin envisions is finite, fallible, and definitely not eternal, yet has managed to create something that will last forever. This apparent paradox, one in which the multiverse is eternal and therefore had no creation, versus a multiverse that was created by other beings, is never resolved. But God most definitely was not involved, because it's silly to believe in a Creator who can create everything we see, yet is Himself unseen, but it's completely plausible to believe in a creator who can create everything we see, yet is himself unseen.
  
  In the grand analysis of this book, all sarcasm aside, there are some interesting ideas flung together in a book. I'm assuming the ideas are designed to flow together to present a case for a multiverse, much like ideas are typically woven together in a logical fashion to convince someone of something, but that thread of logic is desperately difficult to latch onto in this book. An idea is presented, with lots of fancy words and terms and numbers that don't mean anything to the reader, and then out pops a solid conclusion that therefore, this proves the multiverse exists. Then it's on to the next unrelated "fact", and we are told that if we still need for convincing, with the author dripping venomous insinuation that the reader would be a fool for still not believing, here it is. And then it's a string of blah blah blah and the obvious conclusion that is also conclusive evidence for the existence of the multiverse.
  
  As interesting as the idea of a multiverse is, it seems that despite the protestations of Mr. Gribbin there is inconclusive evidence that more than one universe exists. Just because you can throw a half dozen theories against a wall does not mean that any of them will stick. I would love to read a book by an equally qualified author who pokes holes in the logical holes contained in this book, as one gets the impression while reading the book that there are many of them. Not an infinite number, mind you, but since an infinitesimally small number is still enormously larger than zero, therefore that conclusively proves that there are numerous logical holes in the book...
• 
  Andrew

  A reverential book on the quantum to standard model ideas on the universe, and how this poses the possibilities for the multiverse. The two paradigms are notoriously incompatible but Gribbin explores the common ground; from the collapse of the wave function - the smear of phenomena encoded with all possibilities appearing in a recognizable event - to the plurality of universes; some succeeding while others surviving briefly. It is these precarious margins - which allow our world and universe to be examined by our existence - that Gribbin conveys perfectly and gives a profound sense of awe.
  
  I would be very surprised if there is a more complete, reasonable or open-minded popular book on this subject.
• 
  Scott Holstad

  Not too bad. Interesting, but I thought it could have been better. It just felt like the author was sort of stretching a bit too much, a bit too hard at times, and while that's certainly understandable and while it's quite possible I've done something similar in some of my own research at some point (though am unaware of it), I just think the temptation to make connections to justify a point or assertion sometimes pushed the material not only past empirical but possibly past theoretical as well. Just a touch. Still a good read though, and recommended. I only hope to see a new edition come out one day that cleans up a few questionable areas...
• 
  Christine (AR)

  I don't think I really understood it. But my twelve year-old is reading it now. I give up forever.
• 
  Almodather Awad

  This book is another one of the Gribbin-miracle-books which break down the hardest, most abstract concepts and ideas of modern physics to the modern reader.
• 
  Kerem Cankocak

  
  Evrenimiz birçok evrenden sadece biri midir?
  Modern fiziğin en büyüleyici gizemleri bize bunu gösteriyor gibi. Diğer evrenlerin bizden önce geldiği, bizimkinin yanı sıra süzüldüğü veya bizimkini yansıttığı ne kadar imkansız gözükse de buna dair kanıt şaşırtıcı biçimde ikna edicidir.
  
  Şaşırtıcı ve karmaşık fikirleri en basit ifadelerle anlatmadaki yeteneğiyle bilinen ünlü bilim yazarı ve astrofizikçi John Gribbin, Çoklu Evren Arayışında kitabında okuyucuyu gerçekliğin sınırlarına doğru sıra dışı bir yolculuğa çıkartıyor. Kuantum fiziği, termodinamik, sicim teorisi ve Evren'in doğası hakkındaki en yeni araştırmaları ele alarak, güncel kozmolojiye yaptığı bu harikulade gezinti aynı zamanda yerleşik bilim dünyasının ötesine, teorik fizikçilerin daha henüz sormaya başladığı hayret verici sorulara doğru yol alıyor.
  Eğer evrenimiz üç boyutlu ve sonsuz ise, nasıl başka bir şeyin içinde olabilir? Bu alternatif evrenlerin birine seyahat etmek mümkün müdür? Parçacıklar oraya her an seyahat ediyorlar mıdır? Bilim adamları ona seyahat edemeden nasıl Çoklu Evren’in varlığını kanıtlayabiliyorlar?
  
  
  "Popüler bilim şahaseri."
  —Sunday Times (London)
  
  “Gribbin her şeyi çok sade bir üslupla anlatıyor, tek bir denklem kullanmadan.”
  —David Goodstein, The New York Times Book Review
  
  
  Çoklu evrenler ya da “Ba��ka Dünyalar”
  
  John Gribbin’in Çoklu Evrenler kitabı, bu zor konuyu hiç fizik veya kozmoloji bilgisi olmayanların anlayacağı bir açık anlatımla, bütün kapsamıyla sunuyor. Popüler deyimiyle “paralel evrenler”in varlığı henüz keşfedilmedi. Bizim gözlemlediğimiz evrenin dışında başka bir evrene ilişkin elimizde kanıt yok. Ama paralel evrenler (ya da Çoklu Evrenler) varsa bu birçok çözüm arayan soruya yanıt verecek.
  
  Gözlemlediğimiz evrenin 13,7 milyar yıl yaşında olduğunu ve Büyük Patlamayla başladığını biliyoruz. Ancak bu “her şeyin” Büyük Patlamayla başladığı anlamına gelmiyor. Gözlemleyemediğimiz evrenler olabilir, evrenimiz döngüsel olabilir (Büyük Patlama ve Büyük Çöküşler arasında gidip gelen bir evren gibi) ya da hiper uzay içinde sonsuz evrenlerden birisi olabiliriz.
  
  Mutlak kesinlikle bildiğimiz tek şey var: Gözlemlediğimiz Evren sürekli genişliyor, dolayısıyla çok uzun bir zaman önce (tam olarak 13.7 milyar yıl önce) çok küçük bir noktadaydı (bir atomdan daha küçüktü). Yapılan hesaplamalar, sıfır zamandan sonraki saniyenin çok küçük bir kesirinde, bugün gördüğümüz evrenin tüm içeriğinin atom çekirdeği yoğunluğunda sıcak bir madde yığınına sıkıştığını gösteriyor. Ama bu noktada şimdiki fizik kuramlarımız işlemez oluyor. Henüz daha geriye giden, tutarlı ve diğer her şeyi açıklayan bir kuram çıkmadı ortaya. Yani günümüz fiziği “başlangıcı” ispatlayamıyor. Çok sayıda kuram var elbette. Örneğin sicim kuramlarına dayanan bir kuantum kütleçekim kuramı ispatlanabilirse, zamanın doğuşundaki tekillik sorunu çözülebilir. Çünkü kuantum fiziği bize, zamanın diğer her şey gibi öbekli olduğunu söylüyor. Bu zamanın bölünemeyen en küçük olası bir biriminin olduğu ve dolayısıyla evrenin sıfır zamanda sonsuz yoğunluktaki bir tekillikten değil, çok yüksek bir yoğunluk durumundan, 10-43 saniye yaşıyla başladığı anlamına geliyor.
  
  
  İşte bu gibi sorular ve özellikle de Büyük Patlama kuramı, evrenin milyarlarca yıl önce durup dururken ortaya çıkıp kendi kendine genişlemeye başlaması savı, birçok fizikçiyi tedirgin etmekte. İnsanlar doğal olarak Büyük Patlamadan önce neler olduğunu öğrenmek istiyor. Paralel Evrenler hipotezi bunlara da bir yanıt sunuyor. Ayrıca başka bir problem de yanıt sunuyor: Kuantum fiziğindeki “ölçüm problemi”ne. Kuantum fiziğinde temel gizem (Feynman’a göre tek gizem), bir elektronun iki delikten aynı anda geçmesidir (diğer bir deyişle Schrödinger’in kedisi paradoksu). Hangi delikten geçtiğine baktığınızda, elektronlar ekranda girişim deseni oluşturmaz, belli bir duruma ‘çökerler’, bakmadığınızda ise iki delikten birden geçerler (kedi hem ölü hem canlıdır – ya ölü ya da canlı değil).
  
  
  Kopenhag yorumuna göre elektron gibi kuantum varlıklarının siz onlara bakmıyorken ne yaptıklarını sormak anlamsızdır. Bu yoruma göre, uzaydaki bir noktada, örneğin iki delikten birinde, gerçek gözlemden bağımsız olarak, elektronun nesnel varlığına verilebilecek herhangi bir anlam yoktur. Elektron sadece biz onu gözlemlediğimizde varlığa kavuşur gibi görünür...
  Ancak kuantum fiziğinin tek yorumu bu değildir. 1957 yılında Everett’le başlayıp, DeWitt’le devam eden ve en son Deutsch’un toparladığı bir diğer yoruma göre, elektronun nerede olduğuna baktığınızda, dalga fonksiyonu çökmez ama gözlemci de dahil tüm evren bölünür.
  
  
  Üst üste binme durumları aslında ‘Çoklu Evrenler’dir. Böylece meşhur Schrödinger’in kedisi paradoksu da çözlümüş olur. Yani kedinin hem ölü hem canlı olma durumu (üst üste binmiş durumlar) yerine, bir evrende canlı diğerinde ölü olması durumu gelir. Kuantum durumundaki fark, asıl bölünenin Evren veya gözlemci olmadığı, ama ortalama dalga fonksiyonunun, üst üste binme durumlarının ölçüm veya gözlem yapıldığı an kendi içinde bir dallanma oluşturduğudur. Everett’in büyük başarısı bunu eksiksiz bir matematik diliyle ifade etmesi ve bu yorumun Bohr’un kuantum fiziği versiyonu olan Kopenhag yorumuyla karşılaştırılabilecek her yönden özdeş olduğunu kanıtlamasıydı.
  Kuantum gizeminin farklı bir yorumunu getirmesi dışında, Çoklu Evrenler kuramı “Evrenin başlangıcındaki enerji nereden geliyor?” sorusuna da bir yanıt veriyor. Einstein’ın 1905’de ortaya koyduğu özel görelilik kuramına göre E=mc2 (Enerji eşittir kütle çarpı ışık hızının karesi) ile uyumlu olarak enerji madde, parçacık ve alanlar arasında değiş tokuş yapabilir. Alanda yeteri kadar uygun enerji varsa, kendini bir çift parçacığa dönüştürebilir (bir parçacık ve onun karşı-parçacığına) ve bu varlıklar, enerjileri başka bir çeşit alan enerjisine dönüştükçe, yok olarak etkileşebilirler. Kuantum belirsizliği, elektron gibi bir nesnenin kesin bir enerjiye sahip olmasının imkânsız olduğunu söyler. Ama kuantum belirsizliği, bize aynı zamanda, boş uzayın bile enerjisinin kesin bir değere sahip olmasının imkânsız olduğunu hatırlatır. Oysa sıfır, kesin bir değerdir, dolayısıyla kuantum fiziğine göre, boş uzay, yani vakum olarak düşündüğümüz şey, aslında bu şekilde oluşmuş kısa ömürlü varlıkların kaynaştığı bir alandır. Durum böyleyse, belki de evren bir kuantum dalgalanmasından başka bir şey değildir. Üstelik evrenin toplam enerjisi de sıfırdır: Yani negatif kütleçekim, maddenin pozitif enerjisine eşittir. Dolayısıyla başlangıçta büyük bir enerji patlaması olmamış, bir kuantum dalgalanması olmuştur.
  
  Eğer bu kuram doğruysa, bazıları bir diğeri üzerine binen, diğerleri tamamen birbirinden ayrı olan; ama uzay ve zamanın aynı Evren’ini işgal eden bu kabarcıklardan sonsuz sayıda olabilir, ama hiçbir gözlemci hepsini aynı anda algılayamaz. Öte yandan Evren gerçekten bizim onun sadece sonlu bir hacmini görmemize rağmen sonsuz olabilir. Kozmologlar atomdan küçük bir enerji ateş topu merkezli bir Evren’den bahsettiklerinde, tüm gözlemlenebilir Evren’i kastederler. Asıl süper-yoğun durumun kendisi sonsuz büyüklükte olabilir ve bizim görünür Evren’imiz bu sonsuz bölgenin şişerek çok daha büyük bir boyuta ulaşan küçük bir parçasını temsil ediyor olabilir.
  
  Eğer sonsuz sayıda Çoklu Evrenler varsa, bunlardan bazılarında bizim yaşadığımız dünyanın bir benzeri olma olasılığı çok yüksektir. Ancak bu erişemeyeceğimiz kadar uzakta veya başka bir boyuttaki bir evrende var olmaktadır. Ancak bu benzer dünyada varolan “biz” aslında biz değiliz, bizim benzerimizdir. Olası başka bir dünyadan sözediyoruz. Bir varlık olarak biz değiliz orda olan, ama bize benzeyen bir başka varlıktır diğer evrende varolan “biz”. Şüphesiz diğer evrenlerde bize benzeyen insanların tercihleri ve hayatları tamamen farklı olacaktır. Tekrar elektron örneğine dönersek, elektron iki delikten geçerken gözlem yaptığımızda onu hangi delikte gözlemlersek o duruma çökmüş oluyor. Başka bir evrende farklı deliğe çökmüş olabilir. Bunun gibi, dün sabah evden çıktığımızda sola döndüğümüzü varsayalım. Başka bir evrende bizim benzerimiz sağa dönmüş olabilir ve böylece farklı bir “yaşam dallanması” meydana gelmiş olabilir.
  
  
  Bir başka fizik problemi ise, kütleçekim kuvvetinin çok zayıf oluşudur. Çoklu Evrenler kavramı bu probleme de bir çözüm sunar: Eğer kütleçekimden sorumlu olan gravitonlar Evren’imizden içeri de sızabiliyorlarsa o zaman kütleçekimin neden bu kadar zayıf olduğu bir açıklama kazanabilir. Sicim kuramlarındaki çok boyutlu zar modellerinde, birçok 3 boyutlu zar dünyası daha yüksek boyutlu uzayda yan yana durabilir, tıpkı masanın üzerindeki bir kağıt yığını gibi. Kimi fizikçiler, kapı komşusu evrenin belki de bize on birinci boyutta mikroskobik derecede yakın olduğunu ve onun bazı gravitonlarının bizim evrenimize sızarak kütleçekimi meydana getirdiklerini savlıyorlar.
  Son olarak, Witten’ın M-teorisi ise titreşen sicimler yerine, titreşen zarları koyan bazı fizikçiler, Büyük Patlamaya değişik bir açıklama getirmekteler. Bu kurama göre bir nokta bir 0-zar’dır, bir çizgi (veya sicim) bir 1-zar’dır, bir tabaka bir 2-zar’dır, ve görsellemesi zor olsa da, daha yüksek boyutlarda özdeş yapılar bulunmaktadır: 3-zar, 4-zar, vs. Ovrut, Steinhardt ve Turok bu kuramı evrenin başlangıç soruna bir çözüm olarak kullanıyorlar ve Büyük Patlamanın birbirine çarpan zar evrenler ile başlamış olabileceğini öneriyorlar. Ayrıntılarına bu yazıda giremeyeceğimiz bu kuramın detaylarını Çoklu Evren’lerde okuyabilirsiniz.
• 
  Brian C Melton

  Generally good descriptions of the basic perspectives with equally good explanations. Falls prey to much of the same circular reasoning and question begging prevalent in the field. The argument for the multiverse is like many others: a swarm of vaguely defined and often mutually exclusive possibilities, in the midst of which we are "assured" we'll find some kind of multiverse.
• 
  Beth

  I'm deeply skeptical about multiple universes and especially the many-worlds interpretation of quantum physics, which is a weird beast. There's a great deal of theory but very little solid evidence. I can't claim to understand all the science and math, but it's a fascinating topic.
• 
  Retrobot

  Tonnes of interesting information in the first few chapters.
  Became a bit too heavy towards the end and full-on ridiculous when talking about a creator and that's where I stopped. No thanks.
• 
  Paige McLoughlin

  very short and a little dismissive I have read better on this topic.
• 
  Sacamo

  The book was totally excellent.
• 
  Sajith Kumar

  Coming from the lair of one of the greatest writers of popular science, the book commands attention not only for its title, but in layout too. Cosmology and astrophysics are exciting subjects of the genre, finding wholehearted support from all classes of readers. Questions on the origin of the universe and time has been raised from prehistoric times, but physics explains it with a flourish. This book is all about a fundamentally new idea gaining ground in academic circles where the feasibility of multiples universes existing side by side is accepted. Each of these worlds might be slightly different from ours, with different histories which will not affect us in any way. With this convenient postulate, Gribbin answers the confusing problem of the cosmic parameters so fine-tuned for life. After all, if there is an infinite array of possible universes, it is natural that some of them would be conducive to life and hence we are here! The question of verifying the postulates does not arise, since the technology is not yet ripe for generating the tremendous quantum of energy required for the test run. In fact, some of the arguments may never be tested. Then, what is the sanctity of this concept as a scientific principle, which assumes testability and falsifiability as sacrosanct touchstones of reason? Astrophysicists are not concerned with this paradox and they continue to churn out theories and predictions which shuts commonsense out of the loop. In one part, Gribbin calls in the arguments of Richard Dawkins regarding evolution in the biological world caused by natural selection as the basis for the creation of multiple universes which differ slightly among one another. The idea of multiple universes is so tentative that we, the readers are under no obligation to accord the level of respect we bequeath to scientific theories. With this preface firmly in mind, a reader might find the book inspiring by granting a glimpse on the state of thinking in the global physics community. We would be amazed by the range of ideas and speculations that are produced by analyzing quantum mechanics and general relativity. Moreover, Gribbin sums up the work performed and results obtained during the first decade of the present century. The book is essential reading just for this reason.
  
  For more, see
  http://sapientiasemita.blogspot.in
• 
  Matty

  John Gribbin has been hailed as the patron of popular science writing and when reading his book 'In Search of the Multiverse' you can come to appreciate why. Gribbin takes you on a journey to explain why the Multiverse Theory is the most appropriate and justified theory thus far and while this may not be the opinion of all physicists, the theory satisfies all the tests of quantum mechanics and general relativity and provides a few explanations that previous theories such as the Copenhagen Interpretation could not.
  
  Gribbin is aware that indeed there are still a few problems with the theory (in fact several theories are introduced, all variations on the theme) and it will take some time and a few revisions to clean up the rough edges as it were, but that's no reason for something that may seem so illogical to be written off; especially when you consider the subject matter, quantum mechanics requiring you to check your logic at the door in most cases.
  
  In short the Mutiverse Theory suggests that at the quantum level every possibility is realised (not in the same way that certain personal development books have hijacked the idea to mean thinking about something will make it happen, this is naïve and frankly offensive to the real science), multiple universes that share the same outcome collapse back into one and those that differ diverge and never interact again. There are many reasons offered by Gribbin that support this, most notable for me was the reasoning why gravity is such a weak force compared with the other three forces (strong nuclear, weak nuclear and electromagnetism) and could be a step in the right direction for the discovery of a uniform theory of the forces.
  
  Whether you agree with Gribbin or not, 'In Search of the Multiverse' is an enlightening read and a clear voice in the often baffling banter of cosmology (I finally understand how the universe could have been created from a quantum fluctuation, from literally nothing!).
• 
  Alex Telander

  John Gribbin, an acclaimed science writer and astrophysicist, tackles a number of subjects in his new book, In Search of the Multiverse. People are often sent running for the hills when they hear terms like quantum mechanics, string theory, and not to mention the important differences between general and special relativity. The key with Gribbin is that he doesn’t hold back in throwing the reader into the thick of all this scientific thought and theory and then leave them there, but acts as a life-saving guide, taking them along step by step, explaining terms and ideas in their simplest form and in a way that any reader can appreciate and understand; along with numerous examples with normal everyday settings. He also fully admits that there are areas of the above mentioned terms that no one fully understands, at least not yet. Quantum mechanics for one: the idea that every possibility in a particular situation can be achieved in an instant to the point where possibilities in other dimensions are reached. It all sounds like science fiction, and yet results have somehow been achieved. Gribbin takes you through, thoroughly, so in the end – at least for a little while – you are able to grasp what’s going on. The other key to In Search of the Universe is that it’s not a 600-800 page tome, but a relatively short 200 pages, with concise chapters, making it all the more easier for the reader to get through these complex subjects at a decent pace and to reread if necessary. And how many parallel universes are there out there? Well, you’ll just have to read the book to find out.
  
  Originally written on December 21, 2010 ©Alex C. Telander.
  
  For over 500 book reviews, and over 40 exclusive author interviews (both audio and written), visit
  BookBanter.
• 
  Rei ⭐ [TrulyBooked]

  I was surprised to see pro-intelligent design arguments come up at the very end of the book. While Gribbin distances himself from the people who are against natural selection (and all that jazz), I don't know if I can subscribe to the idea that the universe is designed. But then again, we see strange things all the time. Who is to say that there isn't someone out there watching us Truman Show style?
  
  The book tries really hard to be accessible and stumbles toward the middle. When I found myself rereading pages over and over again, it got frustrating. I'd like to think that it's not my comprehension that was suffering (since I've read many other cosmology books), but the density of the text. Either way, it's an interesting read.