Skip to main content

Black Holes: a very short introduction - Katherine Blundell ***

Black holes have to be amongst the most fascinating phenomena of astronomy/cosmology and as such make a perfect topic for a new addition to OUP's vast collection of pocket guides, the 'very short introduction' books. I read my copy on a couple of 45 minute train journeys - it's long enough to give a good grounding in the basics of black holes, without being heavy or over-technical.

We are taken on a tour that includes the early black hole-like concepts, and the nature of the real thing, what would happen if you fell into one, the black hole's thermodynamics (which is more interesting than it sounds), how we discover things like their mass and spin rate, how they grow (and shrink) and plenty more. Considering this is just 93 pages, Katherine Blundell packs in the good stuff.

The writing style is generally approachable, and this is a popular topic, so I was all set to give the book four stars, but there were sufficient issues to pull it back down. The first was the errors. Almost every popular science book has at least one, but there seemed rather more than usual. The expected one, which I couldn't blame Blundell for, was in the description of Hawking radiation, which doesn't make a lot of sense. The reason I don't blame the author is that almost all popular science descriptions of Hawking radiation don't make sense, because all of us, except working physicists, assumed Hawking described it correctly in his book. Unfortunately he didn't - in attempting to simplify a messy theoretical concept, he came up with an 'explanation' that doesn't hold water, which was then, unsurprisingly, repeated elsewhere over an over. It's unfortunate timing that there has been a lot of publicity this year for this problem. 

Less forgivable were a couple of oddities. The Andromeda galaxy is described as being 6 million light years away. It is actually around 2.5 million light years. While you might argue this is order of magnitude correct, even the worst taxi driver wouldn't take you on a route that was 3.5 million light years too far. We are also told that white dwarf stars are cold. This seems to suggest a lack of understanding of stars - you can't radiate blue-white light and be cold. What might have been intended is that over time white dwarfs do cool in the way that ordinary stars don't, because there's no hydrogen fusion to heat them, but it's a very slow process and observable white dwarfs tend to be pretty toasty.

Finally, there's the matter of omissions. Most of the work on black holes is theory rather than observation, and there's a rich vein in the theory around, for instance, the concept of firewalls - whether an observer passing into a black hole would not notice the event horizon or would burn up, as some theories suggest. Other theories put the entire universe in a black hole, making the possibility of a holographic reality. It's a shame this fun speculation isn't there, both to see and be analysed, especially as so much about black holes is based on theory rather than observed data.

Not a bad book, by any means, but enough issues to raise a small flag.


Paperback 

Kindle 
Using these links earns us commission at no cost to you
Review by Brian Clegg

Comments

Popular posts from this blog

The Laws of Thought - Tom Griffiths *****

In giving us a history of attempts to explain our thinking abilities, Tom Griffiths demonstrates an excellent ability to pitch information just right for the informed general reader.  We begin with Aristotelian logic and the way Boole and others transformed it into a kind of arithmetic before a first introduction of computing and theories of language. Griffiths covers a surprising amount of ground - we don't just get, for instance, the obvious figures of Turing, von Neumann and Shannon, but the interaction between the computing pioneers and those concerned with trying to understand the way we think - for example in the work of Jerome Bruner, of whom I confess I'd never heard.  This would prove to be the case with a whole host of people who have made interesting contributions to the understanding of human thought processes. Sometimes their theories were contradictory - this isn't an easy field to successfully observe - but always they were interesting. But for me, at least, ...

The AI Paradox - Virginia Dignum ****

This is a really important book in the way that Virginia Dignum highlights various ways we can misunderstand AI and its abilities using a series of paradoxes. However, I need to say up front that I'm giving it four stars for the ideas: unfortunately the writing is not great. It reads more like a government report than anything vaguely readable - it really should have co-authored with a professional writer to make it accessible. Even so, I'm recommending it: like some government reports it's significant enough to make it necessary to wade through the bureaucrat speak. Why paradoxes? Dignum identifies two ways we can think about paradoxes (oddly I wrote about paradoxes recently , but with three definitions): a logical paradox such as 'this statement is false', or a paradoxical truth such as 'less is more' - the second of which seems a better to fit to the use here.  We are then presented with eight paradoxes, each of which gives some insights into aspects of t...

Einstein's Fridge - Paul Sen ****

In Einstein's Fridge (interesting factoid: this is at least the third popular science book to be named after Einstein's not particularly exciting refrigerator), Paul Sen has taken on a scary challenge. As Jim Al-Khalili made clear in his excellent The World According to Physics , our physical understanding of reality rests on three pillars: relativity, quantum theory and thermodynamics. But there is no doubt that the third of these, the topic of Sen's book, is a hard sell. While it's true that these are the three pillars of physics, from the point of view of making interesting popular science, the first two might be considered pillars of gold and platinum, while the third is a pillar of salt. Relativity and quantum theory are very much of the twentieth century. They are exciting and sometimes downright weird and wonderful. Thermodynamics, by contrast, has a very Victorian feel and, well, is uninspiring. Luckily, though, thermodynamics is important enough, lying behind ...