Brain Trust (3 page)

“People who work at night have a 150 percent higher rate of metabolic disease,” says Panda. And with people in the United States now averaging more than 160 hours of TV viewing per month, “we have 100 to 120 million people who are social shift workers,” says Panda. Did you think the twinkling lights on the NASA nighttime map that align so evenly with the diabetes map were due to factory lights? Nope. They’re due in large part to the throbbing screens that stay on in American households long after dark. Led by the TV’s silver tongue, Americans have made the social decision to act like shift workers. “And this population is more at risk for every type of metabolic disease,” says Panda.

The first reason for this is obvious: If you’re awake more, you eat more. Panda points out that Americans consume 30 percent of their daily calories after eight o’clock at night. If there were a way to create a nighttime auditory map, you’d hear the roar of a great, collective munching in those same regions you see the light of TV screens.

But the effects of this nighttime munching go a step further than simply packing on extra pounds.

Let’s take a closer look at your liver. Among its many functions is storing excess calories as glycogen and then, when you’re starving, converting this glycogen into usable glucose. Actually, it’s the liver’s little autonomous mitochondria that do this, and like any population of millions of single-celled organisms, they’re constantly dying and dividing, which in the case of your liver generally maintains a constant population. And, generally, it’s at night,
when their food processing duties are (or should be) decreased, that these mitochondria do their dividing.

“Our circadian clock separates functions throughout the day so that our organs stay healthy,” says Panda. Mitochondria don’t multitask well—if they work when they’re dividing, they’re much more prone to making faulty copies of their DNA. Over time, mutations creep in, and down that path lies all sorts of metabolic badness.

And the clock in your liver isn’t a sundial—it doesn’t simply monitor lightness and darkness and click through its organ functions based on time of day. Instead, “it gets information about time by when we eat,” says Panda. Your liver needs to know when you’ve taken your last bite of the evening so that it can tell mitochondria it’s safe to divide. “And if you eat all the time, the clock gets the clue too many times, it tries to adjust too many times, and it never knows when it’s breakfast,” says Panda.

Many millions of years precede electricity, and it’s this great chunk of time for which our bodies are optimized. Simply, evolution hasn’t had enough time to prepare us for nighttime work—our clock isn’t nearly nimble enough to flip its schedule to allow efficient night sleeping on the weekend, following day sleeping during the workweek (and instantly back again).

Panda explored this with mice. Mice who are given the ability to eat for only eight hours a day quickly adjust their habits to consume the same number of calories as mice that are allowed to eat for sixteen hours per day. So given an equal calorie count, you might not expect any health differences between eight-hour and sixteen-hour feeding mice. But eight-hour mice live longer. And everyone knows that mice given a high-fat diet gain weight, right? But Panda’s new work shows they don’t—not if they consume this high-fat diet in an eight-hour window.

“Look at one-hundred-year-olds around the world, across all
different diets, and across all different professions, and you find one common denominator,” says Panda. “They always stick to a scheduled feeding pattern, and they always have an early dinner followed by a defined fasting time.”

So if you want to live long and prosper, don’t eat at night. If you want to lose weight on your current high-fat diet, eat your calories in an eight-hour window.

What’s the basis of our biological clock?

Panda found that it’s cells in our eyes that express the photopigment melanopsin, which allows us to measure the intensity of ambient light. The more light, the more melanopsin is expressed, and the more awake our biological clock allows us to feel. An older person who has difficulty falling asleep at night may have perfect sight, but blindness to light intensity due to faulty production of melanopsin. Likewise, if you’re wide awake after a flight from Los Angeles to New York, you soon might be able to take a pill that shuts down melanopsin, allowing you to sleep when you get in.

A Swedish study of identical twins separated

at birth found that lifestyle trumps genetics in determining how long people live. Writing about the study in the
New York Times
, Jane Brody describes the secrets of a long life as “the Three ‘R’s’ of resolution, resourcefulness, and resilience.” Extroversion, optimism, self-esteem, and strong ties to community help too.

“Humans can’t build tiny things that fly autonomously,” says Michel Maharbiz, electrical engineering and computer science guru at Berkeley. “As you scale things down a couple problems come up.” One is airflow: “Turbulence and optimal wing structure are different for a tiny flier than they are for an airplane. Small things fly more like a two-armed chopper, horizontally sweeping,” says Maharbiz, who’s extremely entertaining to chat with because he says things like “Mike Dickinson at Caltech is one smart mo-fo!” or “My entertainment in life is to build cool shit.”

And then there’s the power problem. “You can’t miniaturize the combustion engine enough,” says Maharbiz, “and lithium-ion batteries are ten to forty times less efficient than burning hydrocarbons.” To power a tiny flier, the power provided has to be worth the engine weight. Currently, it’s not.

Finally, we can’t build the actuator part of it, “the little muscles and skeletal components,” says Maharbiz. Again, at least not efficiently enough for its power to justify its weight.

So there you go. The answer to, Can we build tiny, flying spy-bots? is No, not yet.

But nature can.

“There’s tons of these things flying around,” says Maharbiz. “They eat for energy, and they’re great at miniaturizing flight systems.”

We call them bugs. And while we can’t build tiny flying robots, we’re getting better at collaborating with nature on tiny flying cyborgs.

Cyborg green June beetles, to be precise. (Which, as you’ll note, is pretty frickin’ sweet.) Guys like Maharbiz favor these beetles because the bugs are big enough to carry some gadgetry and small
enough to do things like deploy as a swarm into a collapsed building to search for the biosignatures of survivors, or fly through combat areas gathering information without being blasted.

Here’s how it works.

First, Maharbiz implants a thin silver wire just behind the beetle’s eye into the flight control center of its brain. To it, he attaches a tiny battery repurposed from a cochlear implant. An electric pulse of about -1.5 V starts the beetle’s wings, and the same positive pulse stops them. (One can only imagine that a stronger pulse would transform a beetle into a firefly.)

Then the trick is steering.

“You can either pack a muscle full of force fibers or tubes that suck up energy,” says Maharbiz, “so muscles can either be strong or fast, not both.” So to get the (fast) rate of wing strokes at the (strong) power needed to fly, evolution’s equipped beetles with a sweet little oscillator that allows them to pump their wing muscles once—hard!—and count on rebounding musculature to keep the wings pumping for another four beats. It’s like the rebound of a stick off a drumhead—one stroke for five beats, repeat as necessary for flight and/or the opening of the iconic 20th Century Fox fanfare.

What this means is that a beetle’s wings can only buzz at one speed—the oscillator rebounds at a fixed rate, so you can’t simply drive beetle wings faster or slower for increased or decreased thrust. Still, Maharbiz found that wires delivering pulses to these resonators could control the amplitude of wing beats. Both wires pulsing 10 Hz at ten beats per second for three seconds increases wing amplitude and makes the beetle gain altitude. The same pulse in only the right wing makes the beetle turn left—like paddling harder with the right oar of a rowboat. By uniformly throttling down the wing amplitude, you can land the beetle.

The cool part is that precision piloting isn’t needed here. “We don’t try to fly the beetle—we try to
guide
the beetle,” says
Maharbiz. Nature remains the pilot, used for leveling to the horizon, powering the system, and all the other intricacies of flight currently lost to human engineers.

A quick online search returns video of the cyborg beetle in action as well as a pdf with the full specs for creating your own. Seriously.

Maharbiz writes, “When I dream of the
future, I see machines built from what we would now call ‘living things’: tables that are derived from plant cell lines, which breathe your office air and use ambient light for energy to fix themselves or grow new parts; houses whose walls are alive and whose infrastructure hosts an ecology of organisms who perform tasks both microscopic and macroscopic; computational elements whose interfaces completely blur the line between cell and chip.”

The one hundred-ish skills in this book can help make you awesome. But your ability to put them to use is bound by one thing: your ability to learn. The more you can learn, the more awesome you can become. So consider this a keystone entry.

First, think about how you attack a pile of study material. “People tend to try to learn in blocks,” says Robert Bjork, Distinguished Professor of Psychology at UCLA, “mastering one thing before moving on to the next.” But instead he recommends interleaving, a strategy in which, for example, instead of spending
an hour working on your tennis serve, you mix in a range of skills like backhands, volleys, overhead smashes, and footwork. “This creates a sense of difficulty,” says Bjork, “and people tend not to notice the immediate effects of learning.” Instead of making an appreciable leap forward with your serving ability after a session of focused practice, interleaving forces you to make nearly imperceptible steps forward with many skills. But over time, the sum of these small steps is much greater than the sum of the leaps you would have taken if you’d spent the same amount of time mastering each skill in its turn.

Bjork explains that successful interleaving allows you to “seat” each skill among the others: “If information is studied so that it can be interpreted in relation to other things in memory, learning is much more powerful,” he says.

There’s one caveat: Make sure the miniskills you interleave are related in some higher-order way. If you’re trying to learn tennis, you’d want to interleave serves, backhands, volleys, smashes, and footwork—not serves, synchronized swimming, European capitals, and programming in Java.

Similarly, studying in only one location is great as long as you’ll only be required to recall the information in the same location. If you want information to be accessible outside your dorm room, or office, or nook on the second floor of the library, Bjork recommends varying your study location.