海角大神

I finished 鈥淧robable Impossibilities: Musings on Beginnings and Endings,鈥� Alan Lightman鈥檚 newest essay anthology, on a camping trip high in the Blue Ridge Mountains 鈥� an especially appropriate setting, I came to find.

Just a few feet from the campfire, and light-years below Orion鈥檚 Belt and the Big Dipper, I stared at the night sky between chapters and engaged in that age-old human pastime of wondering at the size of the universe and my relative insignificance in it.

The anthology, which covers a mix of history and physics, is organized into 17 related essays that explore the seeming paradoxes inherent in an ineffably large cosmos. Through vignettes and journal entries, Lightman offers observations in a tone that is edifying and companionable 鈥� a bonus for those of us who are not theoretical physicists like the author.聽聽

In particular, Lightman鈥檚 colorful similes 鈥� strewn like Easter eggs throughout the essays 鈥� offer greater understanding. It鈥檚 much easier to grasp Einstein鈥檚 general theory of relativity, which posits that 鈥済eometries of space and time are affected by mass and energy,鈥� when Lightman explains that 鈥渁 mass like the Sun bends space the same way that a bowling ball on a trampoline sinks and flexes the mat beneath it.鈥� Those everyday comparisons really help.聽聽

The small human details Lightman includes about his interviewees are also delightful. Alexander Vilenkin, a subject of the essay 鈥淲hat Came Before the Big Bang,鈥� isn鈥檛 just the director of the Institute of Cosmology at Tufts University near Boston; he鈥檚 the professor with an Einstein doll from his daughter that sits on his jumbled office bookshelf.聽

But there are moments when the mix of intimate reflection and cosmic material feels unbalanced. The middle of the collection enters the doldrums when Lightman鈥檚 essays give too much attention to his personal life and lose a sense of galactic wonder.聽

The occasional repetition of words and ideas also trip up the collection. Must every scientist, artist, and mathematician be introduced as 鈥渢he great鈥�? Isn鈥檛 鈥渁 thousand billion鈥� more easily called 鈥渁 trillion鈥�? Lightman also references the same passage of John Milton鈥檚 鈥淧aradise Lost鈥� more than once.

Still, curious readers will likely find ample room to marvel at peculiarities of the universe. For example, the number of neurons in the human brain (100 billion) is roughly the same as the number of stars in any given galaxy.

Lightman鈥檚 work is an invitation to wonder and to marvel at the universe鈥檚 scope and our limitations in understanding it. In theoretical physics, there are rarely definite answers, but that鈥檚 no matter. 鈥淲ith the luxury of true freedom of mind, there are larger concerns,鈥� he writes. 鈥淟ook at the sky.鈥�