It’s apt that I’m writing this review on the train to Cambridge, Stephen Hawking’s home turf. A good few years ago we were taking a young German on a tour of Cambridge. He had no interest in science, but when we saw Hawking trundling along King’s Parade in his powered wheelchair our visitor instantly knew who he was. If you ask a person in the street to name the two most important physicists of the last 100 years they would probably name Einstein, then Hawking. Which is odd, because I wouldn’t put him in the top 20.
That sounds harsh, but I think Hawking is to physics what Katherine Jenkins is to opera. To the general public, Jenkins is obviously a great opera singer, after all she’s always on the TV. But those in the opera world will point out she has never sung a complete role. It’s not that she’s a bad singer, she just isn’t what the public thinks she is. Similarly by saying I might not put Hawking in my top 20 I’m not saying he’s not a great physicist. But bear in mind that well over 200 people have won the Nobel Prize in physics over the last 100 years. I’m just saying that most of those who know the field would have to consider Feynman or Dirac or Rutherford or a whole host of others before they got round to Hawking.
Yet Hawking remains a star. I went into Kitty Ferguson’s chunky biography of Hawking hoping I would understand this better, as well as getting a detailed feel for his work. The two obvious factors driving his stardom are the remarkable story of his having a full working career despite being told he would die in his 20s of his degenerative disease and his media exposure, driven by the huge success of A Brief History of Time which started the popular science bubble – but would Ferguson reveal more?
It is perhaps telling of the subject that I found myself more interested in the biographical parts than the science. It doesn’t help that this is often fairly abstruse – many of Hawking’s indubitably ingenious ideas are speculative and at the edge of our understanding, more grounded in maths than real observational science, which gives Ferguson a real challenge in explaining them. On the whole she does well, but the section on the relationship of space and time near the big bang was very difficult to read. I was also a little disappointed by the obvious omissions of explanation, even in something relatively straightforward like Hawking radiation.
Ferguson tells us that black holes lose energy this way, as a virtual particle pair that forms near the black hole can have the negative energy particle sucked into the hole while the positive energy particle zooms off, reducing the overall mass/energy of the black hole. There are two problems with this she doesn’t explain. One is how a particle can have negative energy – an antimatter particle, for instance, doesn’t have negative mass, so why negative energy? The other is why the majority of particles from virtual pairs sucked into the black hole are the negative energy ones. Why aren’t an equal number (statistically) of positive energy ones sucked in, producing no net effect? These kind of simple questions are often the ones popular science readers like answered.
The good news is that I did feel I had learned a lot more about Hawking’s ideas (if it was sometimes hard work) and about his personal life. The were some insights into Brief History of Time too (I couldn’t believe he got a $250,000 advance for the US version), though not really explaining its runaway success. I found the book genuinely interesting, despite Ferguson occasionally verging on hero-worship of Hawking. There were a couple of minor factual quibbles. I was unnerved to read that the New Cavendish laboratory in Cambridge was built in 1974 as I started attending lectures there in 1973. And the author’s American origins came through in her lack of understanding of British life before the 1960s – she suggested that somehow not having central heating made Hawking’s childhood home ramshackle – but it was the norm back then. These are trivial indeed, though.
If you are genuinely interested in Hawking this will definitely fill in a lot of the gaps in both his personal life and many popular science explanations of his work. If you made an attempt on Brief History of Time and failed, this is probably not for you.
Review by Brian Clegg