The Sun could be made of bananas, and it wouldn't make a sod of difference to us. Though that said, it would make for tasty but rather scorched banana bread. It's not that the Sun is on fire because it's made of flammable stuff. The Sun is on fire because there is such a lot of it. The crushing force of gravity increases pressure and correspondingly heat within its contents, producing the mind-numbingly melty temperatures within.
This is one of the many surprising assertions made in We Need To Talk About Kelvin by Marcus Chown, which I mentioned receiving and enjoying last week, so I was consequently thrilled when I heard he'd be interested in guest blogging here on December 11th! YAY! So, I've read the book, and experienced no less than three Eureka moments.
Such as: Stuff is made up mostly of nothing but energy. According to Chown, if all the space were removed from atoms, the entire human race could be fit into the space of a single sugar cube. It's actually highly mysterious that I don't plummet straight through the seat on the Tube and to gory death on the tracks below, book in hand, as tiny electric forces are basically the only things holding me up. For the record, this is not a great thing to think whilst one is sitting on the Tube reading.
Which brings me neatly around to the book, of course. We Need To Talk About Kelvin, jacketed with what seems to be aggressive non-threateningness, is a book about relating everyday phenomena, such as starlight, your reflection in a window, the fact that aliens haven't enslaved everybody yet - into powerful illustrations of quantum mechanics at work in the world. It's peppered with fascinating anecdotes about the scientists involved in the work of proving these things, from Galileo to scientists whose work is only just being published now.
Possibly the most impressive thing, to me personally, was the discussion on quantum probability. I've read some extremely good books on the subject while doing my Mephistophela (and increasingly Sleepwalker) research - Quantum: A Guide For The Perplexed by Jim Al-Khalili and Brown's Minds, Machines, and the Multiverse: The Quest For The Quantum Computer, amongst others, but to me personally, Chown's recounting of the phenomenon was the clearest.
One hesitates to write things like, "We live in an age where..." It's just so portentous. You could imagine it being said by Mr. Voice in a movie trailer. In fact, it almost certainly has been. But the fact of the matter is that the incessant daily scramble to stay on top of mundane things blinds us to the fact that we are all participants in an ongoing elaborate miracle - that the universe is a juggling trick where all the balls are in the air at exactly the same time, and science is a series of constantly opening doors leading to ever more astonishing worlds where our idea of "true" and "normal" meets the quantum idea of "true" and "normal" and they immediately get into a huge fist fight. As it happens, on a clear day, you really can see forever. And that's pretty amazing.