Black Holes, Wormholes and Time Machines by Jim Al-Khalili

Black Holes, Wormholes and Time Machines Reviews

• 
  Maggie

  So exciting to read!! I read it in two days bc I was just so hyped about it. It’s an easy read. Even if you don’t understand anything about physics you’ll understand this book. Plus the author has a really funny way of explaining things so I absolutely loved it.
• 
  jack

  i read this book on and off throughout the year and i’ve never managed to grasp concepts quite like this book made me. khalili explains so many alternate perspectives in such simple ways. not sure i’ll ever look at the world in the same way again lol
• 
  Victoria

  opened my eyes on physics.
• 
  Silvio Curtis

  The title's pretty accurate. The book covers the standard popular-physics-book basics of relativity, then goes into more detail about the ways that relativity allows time travel, especially involving wormholes. It developed from a lecture that the author gave to high-schoolers to recruit them to study physics. At one point he says that it "was written with a teenage audience in mind," which could have put me off, but I'm glad it didn't. It is indeed a book that you could start without ever having heard of relativity, and it avoids math completely, but still manages to go into more detail than you might expect. It explains the difference between rotating (Kerr) black holes and non-rotating (Schwarzchild) ones, which I don't remember learning anywhere before. It was also interesting to read how Carl Sagan's request for help with Contact led to the discovery that macroscopic wormholes are theoretically possible.
• 
  William Schram

  Black Holes, Wormholes, and Time Machines by Jim Al-Khalili is a book popularizing some of the results of Einstein’s Relativity Equations. If you read about this sort of thing a lot as I do, this might not be anything new to you. This might especially be the case since the book was printed in 1999 so most of the work is current to 1998.
  
  The book itself describes the phenomena in question with skill and grace, remembering that this book is meant for laypeople and others unfamiliar with the subject. It describes the bending of spacetime being the cause of gravity, the experiments that proved Einstein to be correct and made him a household name and so on. The book talks about Olber’s Paradox, the Cosmic Background Radiation and other things related to the Big Bang and the expansion of the universe.
  
  As I mentioned, this book is meant for the common man or woman as the case may be. In that sense, the author avoids using too much scientific jargon and describes things in a manner that is easy to understand. With the “fabric” of reality and how it is warped by gravity, they use the rubber sheet analogy taking care to note that this is occurring in more dimensions than those occupied by a rubber sheet.
  
  It is somewhat amusing to me to read about people that don’t believe that the Speed of Light is as fast as anything can possibly go, but I suppose if you were never exposed to the equations I can’t really expect one to get it from everyday life. I mean, Special Relativity is only applicable when an object is going at an appreciable fraction of the Speed of Light. The fastest man-made vehicle is probably a rocket, but I doubt that many people will have the opportunity to even ride such a thing. Even in the case of a rocket, we are only talking about something barely capable of escaping Earth’s Gravity. Now 40,000 km/h or 25,000 mph might seem fast and it is. However, that is nothing to the Speed of Light. At an appreciable fraction of the speed of light time itself slows down. Due to the Mass-Energy Equivalence equation that Einstein is known for, you will begin to gain mass as you get closer to light-speed.
  
  In any case, this book was very good. It was a bit reminiscent of Paul Davies’ About Time which I think I still own somewhere. It covers a great deal of material in a thin package and has a bibliography if you are curious about any of the subjects and ideas covered.
• 
  Niklaus

  Come nel libro di Davis (Come costruire una macchina del tempo) il titolo su temi legati alla SF è in realtà un viatico per parlare di fisica seria pur disquisendo anche di tematiche (wormholes etc) che i fisici teorici puri considererebbero borderline. Ma del resto Kip Thorne se Stephen Hawking ci hanno insegnato che si può essere top e fare ospitate a The Big Bang Theory e fare da consulenti per film com Interstellar.
  Questo detto, il libro ci porta nel reame della Relatività e della Quantistica mentre si parla dei concetti pro e contro la fattibilità teorica di viaggiare nel tempo e di tutto quello che ne consegue (paradossi, etc). Un viaggio accessibile per chi ha una minima base scientifica; non semplicissimo ma accessibile a tutti.
  Il problema semmai è che avendo oramai quasi dieci anni, alcuni temi sono stati superati (ad esempio la teoria delle stringhe è meno in auge di un tempo) e l'esistenza delle onde gravitazionali provata.
  
  Una frase salvata dal libro riassume bene la necessità di apertura mentale ma tenendo sempre a portata di meno il sano giudizio critico
  “Allarga le tue vedute, ma non tanto da lasciar scappare il cervello".
  James Chrisley
• 
  Ionuț Leonte

  O lectura introductiva asupra gaurilor negre, gaurile de vierme, calatoriile in timp ( trecut - viitor), teoria relativitatii a lui Einstein (generala si speciala), teoria gravitationala a lui Newton, mecanica cuantica, Big Bang, viteza sunetului, unde, expansiunea universului, dimensiuni, multivers, bosonul Higgs („particula Dumnezeu”, 2013), a carui descoperire este anticipata de autor la CERN (Geneva), prin acceleratorul de particule (un tunel de 23 km cu particule ale caror viteze sunt apropiate de viteza luminii) etc. Autorul a incercat sa stocheze foarte sumar cat mai multe notiuni despre univers, intr-un limbaj simplificat, comun, insa nu mi se pare edificator in explicatii. Acesta subliniaza ca stiinta progreseaza intr-un ritm accelerat, insa raman anumite enigme: daca acest univers e inchis/deschis, daca exista multivers, cum poate fi combinata mecanica cuantica cu teoria relativitatii, cum se poate construi o masina a timpului, cum sa depasesti viteza luminii etc. Nu se stie daca vor putea fi demonstrate empiric aceste teorii.
  
  Einstein, in 1915, prin faimoasa ecuatie E = mc², a schimbat si revolutionat intelegerea noastra despre univers, iar autorul, prin aceasta carte, nu ezita sa-i elogieze meritele.
  
  Sa afli ca suntem doar niste entitati organice microscopice in acest univers, un punct in marele plan cosmic, o magaldeata in oceanul infinit, ca exista si altceva in afara acestei planete... Te invata sa apreciezi mai mult acest patos energetic al vietii, ca nimic nu e garantat, ca egocentrismul nostru este insignifiant si lamentabil in fata universului necrutator. As fi vrut ca aceste notiuni sa fie predate in scoli, ca curiozitatea elevilor sa fie stimulata prin misterele nebanuite ale universului.
• 
  Maj

  This is my first non-all-out-space physics book. I love Prof Al-Khalili's TV programmes and have bought a few of his books in ebook form (well, apart from this one which is hugely expensive, instead got a PDF of it from Academia.edu). Definitely looking forward to reading the others but thought starting with the first one was as good a place as any.
  Not gonna pretend everything in this book lodged itself in my brain, (after all, at school I got Cs from physics and Cs and Ds in maths...and have since forgotten everything), but it pretty much gave me what I expected from it. And hopefully some of the basics are finally gonna stick from now on. (Like that there are two theories of relativity which I either never knew or have forgotten. See, that's my level of idiot right here.)
  It's obvious that even 20 years ago Prof. Al-Khalili already had a knack for relating science to idiots. And I actually enjoyed the "attempts at humour", thank you very much.
• 
  Azzurra

  Lettura molto interessante anche per chi, come me, ha solo una scarsa infarinatura della matematica o della fisica. Alcuni capitoli risultano più impegnativi da comprendere ed è necessaria una maggiore attenzione, ma Al-Khalili riesce nel suo intento di rendere comprensibile una tematica tanto affascinante quanto complessa con il suo brillante umorismo da scienziato.
  Decisamente consigliato!
• 
  Sehar

  Never has physics felt more understandable! Through all the stephen hawking I've ever read and not retained an iota of, this is the book i was waiting for.
  I cant say i understood a 100% but atleast 70%. Ok fine, 60%🤦‍♀️. 50 atleast.
• 
  Alex Rondón Reggio

  A crash course into astrophysics, particles physics, quantum mechanics and of course black holes, wormholes and time machines.
• 
  Massis

  Amazing!
• 
  Ο χρήστης τάδε

  Aπο τα καλύτερα βιβλία για το συγκεκριμένο θέμα!
• 
  Paññādhammika Bhikkhu

  Good for beginners. Quite a lot packed in.
• 
  Iolanda Ciobanu

  Do you believe time travel is possible, but do not understand the physics of it? Detailed information is provided and there are presented all options.
• 
  smarandul

  I enjoyed this a lot.
• 
  Alina Grigore

  Very interesting but at times hard to understand without a proper background..
• 
  Joseph

  Standard physics book. Educational.
  Neutral in explaining how time travel is possible with equal counterpoints on why it's impossible, which I liked.
  Could have cut down on the attempted humor, but otherwise a good book.
• 
  Gaggle

  Explained so well even I understood it. An enjoyable scientific book if you are interested in that area of science.
• 
  Alisa Kester

  This was quite an amazing book, even though he actually doesn't believe in the possibility of time travel (he thinks the only way it would work was if the past, present, and future existed all together as one moment, and he believes that would negate free will. Which it doesn't, of course, so he and I disagree there). But overall, I enjoyed it and learned enough to make my brain buzz with all my newly acquired knowledge and ideas.
  
  I particularly loved this section, on quantum particles:
  
  "If we measure a certain property of an electron...then quantum mechanics will tell us what we are likely to find. However, it tells us nothing about what the electron is doing when it is not observed. This would not be a problem if we could trust electrons (and all other particles) to behave sensibly, but they don't. They will disappear from the place they were last seen and spontaneously reappear somewhere else that should, by rights, be inaccessible to them. They exist in two places at once, they tunnel through impenetrable barriers, travel in two different directions simultaneously, and even have several conflicting properties simultaneously. But the moment you look to see what is going on, the electron will suddenly start behaving itself again and nothing will look out of sorts. However, the unavoidable conclusions we have to draw from the results of our observations is that the electron was most definitely doing something very strange indeed when we weren't looking."
• 
  Frostling

  Excellent book whose purpose is to familiarize the reader with the universe, how it was created, what it is made of, and how time affects everything.
  
  In order to explain how time travel could be possible (At least in theory), we are treated to a history of science, form the precursors of Newton, to the successors of Einstein.
  
  Despite the fact that this book is now 11 years old, it remains a good and compact introduction to physics, astronomy and cosmology.
  
  I particularly appreciated the description of how a 2D world would cope with 3 dimensions. All sorts of weird things would stat happening. It is an interesting analogy when we consider what happens in our 3D world when scientists focus on quantum mechanics.
• 
  Claire Stamper

  Intriguing read. Al-Khalili keeps his use scientific jargon on the down low and thoroughly explains unfamiliar terms and concepts, presents scientific evidence from a relatively objective viewpoint, and isn't dry and boring like so many other authors of the nonfiction science genre. I would recommend his book to anyone interested in understanding the possibility of black holes, wormholes, multiple dimensions, and time travel in our fascinating universe.
• 
  Katerina

  I´m very into this topic. But. I´m used to use my imagination. Fourth, fifth etc. dimension, parallel universes and space-curving is little bit above my othervise very colorful imagination (deformed by sci-fi series). What i can´t imagine, that i don´t get. I will definitely give a chance to this book again.
• 
  Eric

  Interesting, if somewhat condescending. The author seems to be a rather conservative physicist, which makes me wonder why he wrote the book at all. Nevertheless, it's loaded with facts about high-energy physics and easy-to-grok explanations.
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  Alexandra Anne

  
  I am so grateful to this book for helping me visualize a fourth dimension. I've used the 2D world + 3D sphere analogy many times with remarkable success in helping people visualize it too. I recommend this book to anyone and everyone.