14 of 14 people found the following review helpful
on 12 April 2008
This is much more than a book about galaxies. Within the small space of a Very Short Introduction John Gribbin manages to pack in as great deal about the history of astronomy, cosmology, and the fate of the Universe. Although it is in a (sort of) academic series, it's as readable as his less academic books, and bang up to date. Explains how our Milky Way is just an average galaxy, one of hundreds of billions of galaxies in the expanding Universe. Great value!
14 of 15 people found the following review helpful
It's almost impossible not to be overawed by galaxies. As these pages tell us, the largest of them (giant ellipticals) contain more than a trillion stars spread over hundreds of kiloparsecs (1 kpc = 1000 x 3.25 light years). The most distant galaxies detected so far (using Hubble Ultra Deep Field) have shown up in a minute patch of sky that appears blank to other telescopes. Yet this patch, from an area about one thirteen billionth of the sky, contains over 10,000 galaxies, whose light started its journey towards us over 13 billion years ago. (How these proto-galaxies manage to emit light suggesting this immense distance/time when only 800 million years old is one of many questions you will probably ask yourself while reading. Most are answered in this book.) Future astronomers, looking beyond these primitive galaxies and using the next generation of telescopes, expect (and hope) to see ... nothing, for they'll then be looking at the 'dark age' between the Big Bang and the time when galaxies started forming. Such science is truly awe-inspiring.
Modern cosmology began only in the 1920s, when Edwin Hubble made his two major discoveries (that independent galaxies exist outside our Milky Way and that there is a precise relationship between a galaxy's redshift and its distance). But cosmologists have managed to cover a lot of ground (and space) in the succeeding 80 years or so. It is to Gribbin's great credit that he manages to convey the essence of this progress in so succinct and accessible a manner - there aren't any equations in sight to vex the more mathematically challenged. For most general readers, the basic principles of cosmology are challenging enough already. But for those who know Gribbin's other books, they'll probably find the going easier here than in, say, Shrödinger's Cat.
My only quibble concerns sequencing. After explaining how astronomers use the Doppler effect to calculate how stars are moving through space, Gribbin continues in a seemingly contradictory fashion: 'but the cosmological redshift is not caused by motion through space and is not a Doppler effect.' We have to wait 20 pages or so for the riddle to be resolved. Similarly, one of the graphs uses the Omega symbol several pages before explaining its significance. But such things aside, this is a superb introduction to a mind-changing subject. As in the better VSIs, non-specialists are helped by a straightforward Glossary which explains, for example, the difference between Galaxy and galaxy, and Universe and universe, usages which professionals take for granted but which confuse non-specialists. An outstanding introduction to the subject.
5 of 5 people found the following review helpful
on 3 October 2011
Fascinating book, about the history of both galaxies as we know today and how we learnt that the Milky Way is but a very small and unremarkable island in a very large ocean filled with Islands. I can't think of a book that's made my head hurt (in a good way) as much as this one. You get a sense of the scale and size of our universe in very clear terms but it is impossible to fathom how big it truly is. Quite surprised to learn that our galaxy will one day collide with another one, but don't worry we won't be around to see it.
on 5 March 2015
‘Galaxies’ is a natural progression from ‘Stars’ in the VSI series but is much more reader-friendly in that it deals with the subject without recourse to equations and exotic maths. This said, the reader must be prepared for some very large numbers in terms of distances and if nothing else these demonstrate how inconsequential the Earth and the solar system are in the known Universe. Also how ridiculous it is to talk realistically about interstellar travel.
The content covers both factual knowledge and those aspects of galaxies that are speculative or theoretical however all these are described in non-academic terms suitable for the general reader. The format is similar to ‘Stars’ in that it includes sections on the origins, formation, evolution, measurement of and the probable future scenarios for galaxies, plus an interesting account of how mankind has developed techniques and equipment to investigate these stellar bodies. Whilst there are a few concepts that may be difficult to grasp, the book is certainly written in the spirit of Very Short Introductions and worth reading.
3 of 4 people found the following review helpful
Of all the astronomical objects that are visible to the human eye, perhaps the most fascinating ones are the galaxies. This is in large measure due to the most familiar spiral galaxies, of which our own Milky Way is an example. Their twirling, irregular shapes are fascinating to the eye, for more or less the same reasons that the rings of Saturn attract attention. They are an exception to the universe that is filled with perfectly spherical or pointlike objects, with very little of internal structure. And just like Saturn, the fascinating shape of the galaxies has only been revealed with the advent of a telescope, and not until well into the 20th century did we realize that these "island universes" lay far outside out of the Milky Way.
If you are interested in finding out more about galaxies, what they are, how did we come to know about them, how they develop, and what their ultimate destiny is, then John Gribbin's book is an excellent introduction to the subject. It is accessible to a non-expert, and very little scientific understanding is assumed. It is very readable and interesting, and it will take a reader on a fascinating intellectual journey across the universe. After reading this book, you will be looking at the universe with a whole new set of eyes, and would hopefully appreciate our own place in cosmos.
on 11 December 2013
A very short review of a very short book. Brilliant, easy to read and left me in awe of our place in the universe. Nothing will quite seem the same again, and for me renewed the thought, "Is there a creator?"
0 of 1 people found the following review helpful
on 21 July 2012
Essentially, this book presents a useful account of our Milky Way, the origin and fate of galaxies. Galaxies are made of hot bright stars and cool dark clouds of gas and dust. They can be defined according to their shapes. The Milky Way is spiral in shape with diameter not significantly smaller than the average and there is a massive black hole at the centre. It seems that the black hole and galaxy must have formed together.
Without dark matter, galaxies could not grow at all. Most galaxies occur in clusters that are held together by gravity. Individual galaxies within the galaxies are moving around their centre of mass while the whole cluster is expanding in the Universe. The fate of galaxies depends upon the fate of the Universe which could be a Slow Rip, Big Rip or Big Crunch. In spite of this, the Andromeda galaxy is rushing towards us and will merge with the Milky Way in about 4 billion years' time!