What do you think?
Rate this book
Nine Musings on Time: Science Fiction, Science Fact, and the Truth about Time Travel
Time travel is a familiar theme of science fiction, but is it really possible?
Surprisingly, time travel is not forbidden by the laws of physics - and John Gribbin argues that if it is not impossible then it must be possible.
Gribbin brilliantly illustrates the possibilities of time travel by comparing familiar themes from science fiction with their real-world scientific counterparts, including Einstein's theories of relativity, black holes, quantum physics, and the multiverse, illuminated by examples from the fictional tales of Robert Heinlein, Larry Niven, Carl Sagan and others.
The result is an entertaining guide to some deep mysteries of the Universe which may leave you wondering whether time actually passes at all, and if it does, whether we are moving forwards or backwards. A must-read for science fiction fans and anyone intrigued by deep science.
Surprisingly, time travel is not forbidden by the laws of physics - and John Gribbin argues that if it is not impossible then it must be possible.
Gribbin brilliantly illustrates the possibilities of time travel by comparing familiar themes from science fiction with their real-world scientific counterparts, including Einstein's theories of relativity, black holes, quantum physics, and the multiverse, illuminated by examples from the fictional tales of Robert Heinlein, Larry Niven, Carl Sagan and others.
The result is an entertaining guide to some deep mysteries of the Universe which may leave you wondering whether time actually passes at all, and if it does, whether we are moving forwards or backwards. A must-read for science fiction fans and anyone intrigued by deep science.
176 pages, Paperback
Published June 6, 2024
29 people are currently reading
206 people want to read
About the author
John Gribbin
385 books852 followersJohn R. Gribbin is a British science writer, an astrophysicist, and a visiting fellow in astronomy at the University of Sussex. His writings include quantum physics, human evolution, climate change, global warming, the origins of the universe, and biographies of famous scientists. He also writes science fiction.
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 19 of 19 reviews
November 1, 2022
I read John Gribbin’s “Simply Schroedinger” recently and really liked it. Cosmology is fascinating if complicated concepts can be outlined in an engaging way, and John Gribbin is really good at that (along with a few others such as Carlo Rovelli & Marcus Chown).
Time travel is not forbidden by the laws of physics, and that means it should be possible – at some point of time in some form says Gribbin. This book focuses on time theories with the aim of checking on implications for time travel. There is just enough background of fundamental particles, relativity, black holes to explore in what forms time travel can be possible. While in our minds we often picture devices which transport us across time periods, there are various natural formations in the universe which might help the cause. Quite often, as Gribbin points out – science fiction provides a train of thought which can be developed further. The book has many references to scientists’ papers, musings, stories and movies where various theories for time travel have been put forward.
That I was familiar with quite a bit of the theory helped, but more than that it was the writing which made it engrossing & fascinating. I also recommend Carlo Rovelli’s ‘The Order of Time’ for some interesting content on time, though that is not focused on time travel.
My rating: 4.5 / 5,
Thanks to Netgalley, Icon Books and the author for a free electronic review copy.
Time travel is not forbidden by the laws of physics, and that means it should be possible – at some point of time in some form says Gribbin. This book focuses on time theories with the aim of checking on implications for time travel. There is just enough background of fundamental particles, relativity, black holes to explore in what forms time travel can be possible. While in our minds we often picture devices which transport us across time periods, there are various natural formations in the universe which might help the cause. Quite often, as Gribbin points out – science fiction provides a train of thought which can be developed further. The book has many references to scientists’ papers, musings, stories and movies where various theories for time travel have been put forward.
That I was familiar with quite a bit of the theory helped, but more than that it was the writing which made it engrossing & fascinating. I also recommend Carlo Rovelli’s ‘The Order of Time’ for some interesting content on time, though that is not focused on time travel.
My rating: 4.5 / 5,
Thanks to Netgalley, Icon Books and the author for a free electronic review copy.
November 26, 2023
Fun and interesting perspective on the possibility (or inevitability) of time travel
September 1, 2022
I love John Gribbins books as he always finds a way to take a bunch and whole host of information and disseminate it in a cool and interesting way! This one (like the others in his series) is centred on a specific topic: time. Can we travel in time? What is time? Time in science fiction? I think we’re all intrigued by the concept and this book was definitely satisfy your curiosity!
It’s split into nine different musings, drawing on scientific facts and what we know as inferred from physics and experimental evidence. It’s written for every kind of reader, whether you don’t know science at all or are a long term lover; it’s for everyone.
It’s brilliantly written as always and succinct and to the point without being too brief. I learnt from it and found it to be a great recap to some things I already knew. Each chapter was really insightful and informative and it’s full of intrigue and interesting information to keep you reading. Another great addition to his outstanding series of books!
Thank you to the author and publish for this book on NetGalley in return for my honest thoughts and review.
It’s split into nine different musings, drawing on scientific facts and what we know as inferred from physics and experimental evidence. It’s written for every kind of reader, whether you don’t know science at all or are a long term lover; it’s for everyone.
It’s brilliantly written as always and succinct and to the point without being too brief. I learnt from it and found it to be a great recap to some things I already knew. Each chapter was really insightful and informative and it’s full of intrigue and interesting information to keep you reading. Another great addition to his outstanding series of books!
Thank you to the author and publish for this book on NetGalley in return for my honest thoughts and review.
February 10, 2023
واحد من كتب جون جريبين لتبسيط العلوم، وتلك المرة يتحدث الكتاب عن فكرة من أهم أفكار الخيال العلمي ألا وهي فكرة السفر عبر الزمن، وكيف تناولها علماء الفيزياء، وهل يمكن حقا تحقيقها؟!
عبر صفحات الكتاب نستكشف أن قوانين الفيزياء النظرية لا ترفض فكرة السفر عبر الزمن، بل على العكس، تقول إن هناك إمكانية لتحقيق ذلك الأمر في وقت ما، ويستعرض الكتاب في ذلك الموضوع نظرية النسبية لأينشتاين، والثقوب السوداء، وفيزياء الكم، وفكرة الأكوان المتعددة، وآراء العديد من الفيزيائيين مثل "كارل ساجان"، و"روبرت هينلاين"، وغيرهما.
كتاب لطيف يحث على التفكير بشكل مختلف، ويفتح مجالات متعددة لقراءات متنوعة.
عبر صفحات الكتاب نستكشف أن قوانين الفيزياء النظرية لا ترفض فكرة السفر عبر الزمن، بل على العكس، تقول إن هناك إمكانية لتحقيق ذلك الأمر في وقت ما، ويستعرض الكتاب في ذلك الموضوع نظرية النسبية لأينشتاين، والثقوب السوداء، وفيزياء الكم، وفكرة الأكوان المتعددة، وآراء العديد من الفيزيائيين مثل "كارل ساجان"، و"روبرت هينلاين"، وغيرهما.
كتاب لطيف يحث على التفكير بشكل مختلف، ويفتح مجالات متعددة لقراءات متنوعة.
December 20, 2025
Kitap zaman yolculuğunu bilimsel düşünce uzerinden 9 başlıkta inceliyor.
1.Dusunce de özel ve genel gorelilik teorileriyle zamanin nasıl 4. boyut oldugundan ve kütle cekimin nasıl uzay - zaman dokusunu büktüğünden bahsediliyor. Burada özel gorelilik kuramı, uzay icersinde sabit giden seylere ne olduğunu tarif ediyorken, genel gorelilik buna ek olarak hizlanan seylere neler oldugunu ve bu seyleri kutlecekimin nasıl etkilediğini de tarif ediyor. Isik hızına yakin hızlarda 50% de biraz (%13); 90% de çok daha fazla (86%), hareket eden objeler icin zaman yavaşlarken, mesafede kısalarak uzay ve zamandaki bozulmalar birbirini tam olarak dengeliyor. Goreleligin sadece teoride kalmayıp navigation icin denklemlerinin aktif kullanildigi da bu bölümden ilginc bir nottu.
2.Dusunce zaman algisinin nasıl termodinamiğin 2. Kuralı olan entropinin artis egilimiyle uyumlu olduğu ve zamanin okunun bu yonde aktigi (algısı) isleniyor.
3.ve 4. Dusuncelerde kuantum un bu konuyla alakasına giriliyor ve kuantum tunelleme ile parcacik/dalgalarin nasıl bir trajektuar uzerinde hareket etmek yerine ihtimaller doğrultusunda farklı yerlerde gözükmesi fikrine bağlı olarak isik hızı olan c nin 4.5 katına kadar ulasan hızlarda deneyler yapildigindan bahsediliyor. Burada isik hizinin bir bariyer olduğu fikri de onemli. Bu fikre gore hizlandirilan bir cisim enerji kaybederek asla isik hızına ulasamiyorken, isiktan hizli bir cisimde ters şekilde hızı azalıp isik hızına yaklastikca disariya enerji vermesi gerekir. Bu baglamda isiktan hızlı gitmek zamanda geriye gitmek demektir.
5. Dusunce evrenin sonsuz uzunlukta donen ve ici tozlarla dolu olan bir silindire benzetilmesi fikri uzerinden cok yüksek yogunluktaki kutlelerin nasıl uzay zamani büktüğünden ve kara delikleri oluşturduğundan bahsediliyor. Kara deligin merkezinde tekillik olduğu ve çıplak tekillik aracigilyla kara deligin merkezine cekilen objenin bir anligina da olsa görülüp uzay zamanda atlama yaratmasının mümkün olabileceği fikri sunuluyor. Notron yıldızlarinin bunun doğal ornekleri olması ve tipler tarzı zaman makinesi konseptleri burada anlatılıyor.
6.dusunce de einstein-rosen koprusu araciligiyla carl sagan in kurgusal romanina bilimsel temel saglamak icin araştırma yapan bilim insanlarının nasıl bir solucan deliğiyle uzayda kestirme yol kat edilebileceğini kesfettiginden bahsediliyor. Daha sonra bunun zaman da yolculuk icinde kullanilabilecegi farkediliyor.
Kitabin geri kalanininda ki dusuncelerde olay biraz daha felsefi kısma kayıp varolacak her seyin zaten var olduğu fikri uzerinden blok evren fikrini sunuyor. Güvercin kutusu benzetmesiyle her kutunun butun resmin parçası olduğu ve bunların numaralı dizilip dizilmemiş olabileceği fikirleri konu ediliyor. Diğer bir fikirde evrenin olayların yaşanmasıyla çatallanarak sürekli farklı doğrultulara gittiği ve paralel evrenlerin bu sekilde oluştuğu yönünde. Bunu timestampted rastgele dagitilmis fotograf karelerininin birbirine zincirlenip zamanin akisini oluşturması benzetmesiyle acikliyor yazar. Baska bir kilit fikir ise denklemlere gore zamanda geriye gitmenin mümkün olacagini fakat bu geri gidisin başlangıc noktasının zaman makinesinin icadı noktasından geriye gitmeye izin vermeyeceği yönünde. Kitabin geri kalanı zaman yolculugu senaryolarindan olusan farklı hikaye ornekleri uzerinden paradoksları degerlendiriyor.
Sonuc olarak Zaman uzerine 9 Dusunce bilimsel temellere dayanan ve gayet öğretici bir kitap fakat çok büyük fikirler barindirdigi icin tek okumada sindirilip sunulan butun fikirlerin birbirine bağlanması zor bir kitap. Bir noktada tekrar okumak faydalı olabilir.
1.Dusunce de özel ve genel gorelilik teorileriyle zamanin nasıl 4. boyut oldugundan ve kütle cekimin nasıl uzay - zaman dokusunu büktüğünden bahsediliyor. Burada özel gorelilik kuramı, uzay icersinde sabit giden seylere ne olduğunu tarif ediyorken, genel gorelilik buna ek olarak hizlanan seylere neler oldugunu ve bu seyleri kutlecekimin nasıl etkilediğini de tarif ediyor. Isik hızına yakin hızlarda 50% de biraz (%13); 90% de çok daha fazla (86%), hareket eden objeler icin zaman yavaşlarken, mesafede kısalarak uzay ve zamandaki bozulmalar birbirini tam olarak dengeliyor. Goreleligin sadece teoride kalmayıp navigation icin denklemlerinin aktif kullanildigi da bu bölümden ilginc bir nottu.
2.Dusunce zaman algisinin nasıl termodinamiğin 2. Kuralı olan entropinin artis egilimiyle uyumlu olduğu ve zamanin okunun bu yonde aktigi (algısı) isleniyor.
3.ve 4. Dusuncelerde kuantum un bu konuyla alakasına giriliyor ve kuantum tunelleme ile parcacik/dalgalarin nasıl bir trajektuar uzerinde hareket etmek yerine ihtimaller doğrultusunda farklı yerlerde gözükmesi fikrine bağlı olarak isik hızı olan c nin 4.5 katına kadar ulasan hızlarda deneyler yapildigindan bahsediliyor. Burada isik hizinin bir bariyer olduğu fikri de onemli. Bu fikre gore hizlandirilan bir cisim enerji kaybederek asla isik hızına ulasamiyorken, isiktan hizli bir cisimde ters şekilde hızı azalıp isik hızına yaklastikca disariya enerji vermesi gerekir. Bu baglamda isiktan hızlı gitmek zamanda geriye gitmek demektir.
5. Dusunce evrenin sonsuz uzunlukta donen ve ici tozlarla dolu olan bir silindire benzetilmesi fikri uzerinden cok yüksek yogunluktaki kutlelerin nasıl uzay zamani büktüğünden ve kara delikleri oluşturduğundan bahsediliyor. Kara deligin merkezinde tekillik olduğu ve çıplak tekillik aracigilyla kara deligin merkezine cekilen objenin bir anligina da olsa görülüp uzay zamanda atlama yaratmasının mümkün olabileceği fikri sunuluyor. Notron yıldızlarinin bunun doğal ornekleri olması ve tipler tarzı zaman makinesi konseptleri burada anlatılıyor.
6.dusunce de einstein-rosen koprusu araciligiyla carl sagan in kurgusal romanina bilimsel temel saglamak icin araştırma yapan bilim insanlarının nasıl bir solucan deliğiyle uzayda kestirme yol kat edilebileceğini kesfettiginden bahsediliyor. Daha sonra bunun zaman da yolculuk icinde kullanilabilecegi farkediliyor.
Kitabin geri kalanininda ki dusuncelerde olay biraz daha felsefi kısma kayıp varolacak her seyin zaten var olduğu fikri uzerinden blok evren fikrini sunuyor. Güvercin kutusu benzetmesiyle her kutunun butun resmin parçası olduğu ve bunların numaralı dizilip dizilmemiş olabileceği fikirleri konu ediliyor. Diğer bir fikirde evrenin olayların yaşanmasıyla çatallanarak sürekli farklı doğrultulara gittiği ve paralel evrenlerin bu sekilde oluştuğu yönünde. Bunu timestampted rastgele dagitilmis fotograf karelerininin birbirine zincirlenip zamanin akisini oluşturması benzetmesiyle acikliyor yazar. Baska bir kilit fikir ise denklemlere gore zamanda geriye gitmenin mümkün olacagini fakat bu geri gidisin başlangıc noktasının zaman makinesinin icadı noktasından geriye gitmeye izin vermeyeceği yönünde. Kitabin geri kalanı zaman yolculugu senaryolarindan olusan farklı hikaye ornekleri uzerinden paradoksları degerlendiriyor.
Sonuc olarak Zaman uzerine 9 Dusunce bilimsel temellere dayanan ve gayet öğretici bir kitap fakat çok büyük fikirler barindirdigi icin tek okumada sindirilip sunulan butun fikirlerin birbirine bağlanması zor bir kitap. Bir noktada tekrar okumak faydalı olabilir.
October 14, 2024
In this short book Gribben explores how it would be theoretically possible to time travel. He argues that time travel would not necessarily violate any of the fundamental physical rules of the universe. He quotes Arthur C Clarke who said that that "when a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."
Gribben is an excellent popular science writer. I have read and enjoyed several of his books. He clearly and calmly explains some amazingly odd ideas. He is also very good at clearly explaining the experimental results that provide credence to some of the wild speculation.
He provides lucid explanations of wild possibilities. For example, he discusses the possibility of passing through a black hole as a wormhole in time. The problems include getting into a black hole without being crushed, the black hole closing shut once you enter it, getting out of the black hole and having some control over where you are when you exit the black hole.
Evidently there are some very talented physicists who have spent much time on trying to come up with theoretical ways to solve these problems. Gribben describes their work. Each explanation of a theoretical solution to one of the problems ends by Gribben admitting that the solution is far beyond any capability we have now or will have in the foreseeable future.
He has interesting stuff on possible ways to time travel by getting around the limit of the speed of light. He also discusses the possibility of time travel using a "rotated naked singularity". Honestly, I lost him on that one.
Science fiction has a long history of science fiction stories. Gribbin is a fan. he discusses some early SF stories that hinted at the solutions being explored now and some recent stories popularizing new theories.
I came away from this enjoyable book convinced that it ain't happening anytime soon. But I am not even a scientist, never mind a distinguished scientist, so my elderly opinion is probably not worth much.
Gribben is an excellent popular science writer. I have read and enjoyed several of his books. He clearly and calmly explains some amazingly odd ideas. He is also very good at clearly explaining the experimental results that provide credence to some of the wild speculation.
He provides lucid explanations of wild possibilities. For example, he discusses the possibility of passing through a black hole as a wormhole in time. The problems include getting into a black hole without being crushed, the black hole closing shut once you enter it, getting out of the black hole and having some control over where you are when you exit the black hole.
Evidently there are some very talented physicists who have spent much time on trying to come up with theoretical ways to solve these problems. Gribben describes their work. Each explanation of a theoretical solution to one of the problems ends by Gribben admitting that the solution is far beyond any capability we have now or will have in the foreseeable future.
He has interesting stuff on possible ways to time travel by getting around the limit of the speed of light. He also discusses the possibility of time travel using a "rotated naked singularity". Honestly, I lost him on that one.
Science fiction has a long history of science fiction stories. Gribbin is a fan. he discusses some early SF stories that hinted at the solutions being explored now and some recent stories popularizing new theories.
I came away from this enjoyable book convinced that it ain't happening anytime soon. But I am not even a scientist, never mind a distinguished scientist, so my elderly opinion is probably not worth much.
September 10, 2022
I have never come across John Gribbin before but I will definitely be seeking out his previous books as I thoroughly enjoyed this one. He covers some incredibly complex concepts such as quantum physics but apart from a few scary-looking equations (which we are told we can skip if we wish!) the science is clearly and accessibly explained, using examples that are very easy to follow. I learned so much from this book, although I read it in small chunks rather than all at once because there is a lot of information here to absorb.
Subjects covered include light moving faster than light, black holes and wormholes, how to build a time machine, and parallel universes. He cites relevant science fiction stories to show the crossover between fiction and reality, and how sci-fi often has ideas first, that are then proven by the science. Some of the ideas presented here as fact are mind bending, but the scientific references are there; physicists have shown, using equations, that this stuff could happen. Science fiction becoming fact - I loved it!
If you are intrigued by the concept of time travel and would love to know the science behind it, or even if you want to write a time travel novel and want to incorporate as much real science as you can, read this book. Everything you need to know is here.
With thanks to Netgalley and Icon Books for providing an advance review copy. All opinions here are my own.
Subjects covered include light moving faster than light, black holes and wormholes, how to build a time machine, and parallel universes. He cites relevant science fiction stories to show the crossover between fiction and reality, and how sci-fi often has ideas first, that are then proven by the science. Some of the ideas presented here as fact are mind bending, but the scientific references are there; physicists have shown, using equations, that this stuff could happen. Science fiction becoming fact - I loved it!
If you are intrigued by the concept of time travel and would love to know the science behind it, or even if you want to write a time travel novel and want to incorporate as much real science as you can, read this book. Everything you need to know is here.
With thanks to Netgalley and Icon Books for providing an advance review copy. All opinions here are my own.
April 14, 2025
Time has always been a profound puzzle for humanity. Einstein revolutionized our understanding by showing that time is not separate from space but forms a fourth dimension in a unified fabric called spacetime. In this framework, we live in what physicists call a "block universe" where past, present, and future all coexist. The flow of time, as we perceive it, is an illusion created by our limited senses and consciousness. Time itself doesn’t flow, instead, we move through spacetime, tracing a path from one moment to the next.
Imagine spacetime as an endless array of pigeonholes, each representing a specific moment. Every pigeonhole holds complete information about the past and only uncertain glimpses of the future — not because the future doesn’t exist yet, but because it already exists, just beyond our current reach.
Quantum physics adds another fascinating layer. It suggests that for every event, there may be an infinite number of parallel outcomes, giving rise to a multiverse of alternative realities.
John Gribbin’s Nine Musings on Time brings these complex ideas to life with clarity and curiosity.
Imagine spacetime as an endless array of pigeonholes, each representing a specific moment. Every pigeonhole holds complete information about the past and only uncertain glimpses of the future — not because the future doesn’t exist yet, but because it already exists, just beyond our current reach.
Quantum physics adds another fascinating layer. It suggests that for every event, there may be an infinite number of parallel outcomes, giving rise to a multiverse of alternative realities.
John Gribbin’s Nine Musings on Time brings these complex ideas to life with clarity and curiosity.
July 14, 2025
In Greek mythology, the Muses are goddesses who embody the arts and sciences, inspiring creativity in various fields. There are nine Muses, each associated with a specific area: Calliope (epic poetry), Clio (history), Erato (love poetry), Euterpe (music), Melpomene (tragedy), Polyhymnia (sacred poetry), Terpsichore (dance), Thalia (comedy), and Urania (astronomy). ( wiki )
entertaining guide about deepest mystery of the Universe "Time" ..answers intruging questions like what is time ?,Is time travel possible etc ..Mentions how scientific concepts are derived from science fiction ... Hard scientific ideas explained in simple language ...Best book for a beginner
recommended
entertaining guide about deepest mystery of the Universe "Time" ..answers intruging questions like what is time ?,Is time travel possible etc ..Mentions how scientific concepts are derived from science fiction ... Hard scientific ideas explained in simple language ...Best book for a beginner
recommended
August 20, 2024
Immensely readable and enjoyable. Time travel is one of those sci-fi tropes that rarely does any justice to the actual science around it, often to the point of making any physics-literate reader cringe. Gribbin, however, does a great job of introducing the various theories of time travel and their limitations, comparing them with their popularizations in science fiction.
October 25, 2022
قرأت الترجمة العربية لهذا الكتاب الذي اتاح لي فهم العديد من المبادئ الاساسية في ميكانيكا الكم والنسبية العامة. لم أتوقع لكتاب قصير مثل هذا ان تكون له تلك القيمة العظيمة. الكتاب يتناول موضوع معقد في اسلوب شيق قريب جدا من الاسلوب القصصي, وهو من الكتب التي تستطيع(ين) انهائها في جلسة واحدة. اشكر المترجم والمراجع على جهدهم الرائع
March 9, 2023
I always love the idea of these science books, but I must have the wrong sort of brain, because, within a few sentences I’m boggled. The mixture of science and science fiction is interesting and just about got me through the book, but as for learning anything from it…no chance!
January 31, 2023
A dip into the unique and interesting aspects of possible Time Travel all wrapped in under 150 pages, does makes me more curious to read further into the topic.
April 30, 2024
Now I'm dying to read all of the science fictions and physics nonfiction books mentioned in this book!
So fascinating!
So fascinating!
June 17, 2024
على متن صفحات الكتاب، يسير بنا "جريبين" في تناولاتٍ لمفهوم الزمن عبر العقود الماضية والحاضرة، في العلم والأدب، مع عرضٍ للصعوبات والمفارقات الفيزيائية المتعلقة للتنقل خلاله.
June 26, 2024
I love physics so much it makes me want to weep
January 15, 2025
Does a good job of explaining the wobbly side of physics, does require some knowledge but isn't too bad to get into
Read
February 13, 2025From Kate
August 31, 2025
Short and sweet - actually quite funny having an astrophysicist criticise how time travel is displayed in works of fiction
Displaying 1 - 19 of 19 reviews