Reading notes: An Immense World

I’m about halfway through Ed Yong’s An Immense World and it’s quickly becoming one of my favorite nonfiction books I’ve read this year.

I love Yong’s style: a friendly, calm tone that sounds almost effortless. Short, conversational sentences. Simple words. No reaching for intricate phrasing or poetic imagery when a short explanation will do. The effect is something like having dinner with your favorite high school science teacher — a science teacher with perfect recall of an entire field’s worth of relevant knowledge. It’s a 2-inch thick, 500-page book covering a century worth of international research and it’s just so… easy to read.

A book of this breadth and complexity would be, I think, an incredible piece of work even if it was an impenetrable, academic, punctuation-averse fire swamp in the finest tradition of Das Capital. But it’s not. It’s a symphony that plays like a pop song.

I also love the way it’s structured. Roughly, the book is divided up topically — a chapter for sight, sound, touch, etc. — but within each chapter the narrative wanders and connects dots in a way that feels both free-form and orchestrated. He seems to write in short, 3-5 page sections, ending each with a very deliberate ‘segue statement’ that connects to the next and makes for a gentle ‘cliffhanger.’ A sentence like ‘Speaking of ultraviolet vision…’ appears, and when the next section opens with, say, hummingbirds, we have some framing for why we’ve come here. This seems to make it pretty easy to follow a single thread that jumps from moles to manatees to snakes to bees and so on. It’s a lovely, deceptively simple technique.

A few notes:

Your senses can affect the way you perceive time. If smell is your primary sense, like a dog, you perceive the world through smells that might linger after their source has left. A dog can smell not only your immediate presence, but sometimes also what you’ve eaten recently, other people or animals you’ve interacted with, or what detergent you used to wash your clothes. A dog perceives the world through a ‘topography’ of memory.
For sea birds and polar bears, the sea and ice are not the undifferentiated expanses that we experience. They are topographies of smell: mountains and valleys, trails leading here and there.
The ‘frame rate’ of your eyes — the speed at which light enters your eye, is collected by your retinas, transmitted to your brain, and processed into visual information — also affects your sense of time. For a certain predatory fly in the Mediterranean, called the killer fly, it’s visual processing and reflexes are so much faster than ours that ’if you looked at an image at the same moment as a killer fly, the insect would be airborne well before a signal had even left your retina’ (page 74).

It’s possible that each of these visual speeds comes with a different sense of time’s passage. Through a leatherback turtle’s eyes, the world might seem to move in time-lapse, with humans bustling about at a fly’s frenetic pace. Through a fly’s eyes, the world might seem to move in slow motion. The imperceptibly fast movements of other flies would slow to a perceptible crawl, while slow animals might not seem like they were moving at all.
— Page 76

Vision is so ‘expensive’ in terms of complexity and energy that for many animals it’s not worth it. That makes sense. Processing live video is an extremely demanding task for a computer, and high-resolution eyesight likewise seems to require a much more complicated and energy-hungry brain. Sharp vision, likewise, requires a lot of light, so animals with sharp vision, like us and raptor birds, tend to be diurnal and complex: apex predators with a rich energy source. Sharp vision is also usually ‘slow’ in that it takes a relatively long time for all that light to be transmitted to the brain and processed. So if you want to see in fine detail, you won’t be able to react fast. Animals that can see in either very dim light (or darkness) or see at very high ‘frame rates’ aren’t usually able to see in great detail. It’s a tradeoff.
What vision offers — sensing over long distances — can sometimes also be done with hearing or smell at lower ‘cost’. Smell is especially interesting because it doesn’t require straight lines, as photons do, and it doesn’t require immediacy. Smells can linger and tell you about the past or the future. An elephant can smell rain coming from miles away.
Echolocation is maybe the best of both worlds? It offers an image of the world via reflection, as vision does, but it can function in total darkness and doesn’t require complicated, vulnerable eyes. I’m guessing it probably requires similar levels of brainpower and energy as vision, though: hence a bat’s need to eat half its body weight in insects every night. Whales with sonar are maybe a similar story: complex animals that need a lot of energy-dense food. Nonetheless, it’s perhaps an effective way to sense an environment in high resolution when there’s no light.
‘Beauty is not only in the eye of the beholder, it arises because of that eye.’ Seeing is not just a matter of passively taking in information. It also directly affects the world on an evolutionary basis: flowers color themselves to catch the eyes of bees. Poisonous frogs are colored to warn birds. ‘Since eyes define nature’s palette, an animal’s palette tells you whose eyes it is trying to catch.’ In that sense, the world is literally what we make of it: ‘eyes are the paintbrush of nature’.