Present at the Future (8 page)
Read Present at the Future Online
Authors: Ira Flatow
“A gymnast tries and tries a certain move, and in total frustration after an hour just gets off the beam and says, ‘I’m going home.’ They come back the next day and they get on the beam, and they’ve got it. And it’s sort of magic, or they say, ‘Well, I must have been tired.’ But if you talk to them—if you asked them, ‘Well, if you practiced in the morning, would you come back in the afternoon?’ They’d say, ‘No, I’d wait until the next day.’ So for those sorts of skills, whether it’s a pianist stuck on a passage who finally has to put it away, or a gymnast, that, I think, is very likely to involve this kind of sleep stage requirement.”
Stickgold says that it doesn’t matter at what time during the day you do your training, as long as you get six-plus hours of sleep at night. Which explains why, as we get older, it gets harder to learn new skills—older people get less sleep. Maybe nature knows this. Maybe when we are young, our bodies know we need more sleep to learn new skills, so we sleep longer to consolidate them.
“Everybody knows that when you drop below six hours of sleep, you’re not running on all cylinders. And it’s just trying to fight a strange sort of macho culture thing of sleep deprivation being cool. And it’s a bad scene throughout the country, the amount of sleep deprivation. There are estimates that there might be more traffic fatalities from fatigue than even from alcohol.”
There is a study showing that immediately on waking up, people’s reaction times and reasoning times are equivalent to those when they’re legally drunk. You don’t want to jump out of bed and run an errand in the car. But if you’re a medical resident at a hospital on call for 24 or more hours, you have no choice.
“I think we want to say, ‘Physician, heal thyself.’ I think it’s a big problem. People seem to know it and seem not to want to deal with it. There was a wonderful study with students, where they would wake them up in the middle of the night—math majors—and ask
them to do math problems. And they would write out the solutions to these math problems and go back to bed. And when they checked them afterwards, they discovered that for the first line or two, they’d be doing fine, and then it would just be garbage. I think there’s a real issue there for how much they’re learning. But even more important, when you wake someone up from deep sleep and you look at their EEG—their EEG says their brain is still asleep—and I think some of these residents are prescribing while they’re still asleep.”
These new findings about sleep and consolidation of skills may explain why teenagers and babies sleep so much. Dr. Walker says that infants’ brains are continually learning new motor skills, which may demand a great deal of sleep to consolidate. As for teens, they may be playing sports, learning to play an instrument, or learning to drive a car—all practiced skills that need sleep to be cemented into the brain’s wiring.
Injured brains may benefit from sleep too. “A good night of sleep may be able to help reestablish connections in the brain of stroke victims,” says Walker. “Since the brain undergoes these plastic changes, patients can take on new tasks and learn new ways of doing things they did prior to their stroke. Sleep may incrementally assist their recovery.”
Walker and his colleagues plan on taking this next step: testing this theory with stroke victims to see if their condition improves with sleep.
So to learn a new skill, to perfect that new Mozart concerto, nothing may help more than a good night’s sleep.
WHERE THE VERY BIG MEETS THE VERY LITTLE
There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.
—The Hitchhiker’s Guide to the Galaxy
Isn’t the universe supposed to be getting easier to understand? I mean, aren’t all the smart people who study quantum physics, relativity, string theory, extra dimensions, and water on Mars and bring back samples from comets encased in tennis racket–like foam collectors supposed to be making the world look simpler? If so, then why does it appear that the more we know, the more we don’t know? The more we learn, the more there is to learn? Still?
I mean here it is the twenty-first century. A hundred years since Einstein was in his heyday, almost four decades since humans set foot on the moon, 50 years since Sputnik, not to mention the Voyager missions to the planets and telescopes, such as the Hubble Space Telescope, that can peer 13 billion years back into time. It is the age of leptons, baryons, muons, neutrinos, and antimatter. Yet we still
have no idea what 96 percent of the universe is made of. (And oh, by the way, we didn’t know that we didn’t know what most of the universe was made of until very recently.) And we don’t know why there shouldn’t be more of the stuff we don’t know about, either.
It’s very humbling. But at the same time, very exciting. “It’s the golden age of physics. I wouldn’t want to live in any other time.” You hear that a lot from astronomers, theoretical physicists, and mathematicians whose numbers cover blackboards across the world. There is no better time to be present at the future than in the wild and woolly world of physics.
On the other hand, the more physicists discover about the universe, the stranger it appears. “I don’t see much indication of it getting terribly simple just yet,” says Dr. Roger Penrose, professor of mathematics at Oxford. “I think one likes to think that eventually there will be some simple principle that governs everything, but we’re certainly a long way from that now.”
THE THEORY OF EVERYTHING
To understand the excitement, we’ve got to go back a hundred years or so. Back at the turn of the century—that one before this one—a lowly patent office clerk, Albert Einstein, turned the world of science on its head, in an era that became known as the age of relativity (1905–1915). In 1905, he published his special theory of relativity, which equated mass with energy: e = mc
2
. Ten years later, he would publish his general theory of relativity, which described gravity as nothing more than a curvature of space, caused by the presence of massive bodies such as stars and planets. Einstein was so far ahead of his time that some people considered his 1905 theory to be quite nutty. The 26-year-old physicist couldn’t even secure a teaching job.
Nevertheless, his seemingly oddball ideas about the universe—such as the path of light being bent by gravity—were verified in 1919 by observations made during a solar eclipse. Thus, the predictions Einstein had made in advance about his theories were borne out by experiments. (That’s a very important concept for a theory to gain acceptance: the ability to conduct experiments to test predictions made by the theory.)
What followed was another sharp turn in science: the age of quantum mechanics. Instead of looking out into the vast cosmos where galaxies and stars warp space, quantum mechanics looked in the opposite direction at the ultrasmall world of the atom. It found that movements of subatomic particles, such as electrons around the nucleus, could not be precisely described the way planets orbiting the sun can be. Unlike the well-defined, smooth orbits and flowing curves described by Einstein’s theory of relativity in the wide open spaces of the universe, the paths of the subatomic particles followed a whole other set of rules, in which you could not really ever be sure where they were. You could say they were probably here or probably there—and give the odds of finding them in any of those places—but you couldn’t know for sure. And yet in this tiny subatomic world, the probabilistic math of quantum theory proved to be extremely accurate. Time and again, experiment after experiment proved the
power of the theory. Over the next few decades, quantum mechanics went on to gain nearly universal acceptance. Ironically, Einstein, though a winner of the Nobel Prize for helping discover the principle of the quanta, never quite totally believed in it. Recall his famous “God doesn’t play dice” quote. While he couldn’t deny the overwhelming evidence for the success of quantum mechanics, Einstein thought it to be an incomplete theory.
And it still is. After all, says Dr. Roger Penrose, it certainly works on one level, on the tiny, subatomic level, where distances are measured in millionths and billionths of a meter. But how does that translate to a world we can see and touch? “The problem is when you try to apply the rules of quantum mechanics for a large object.” Erwin Schrödinger, the renown Austrian quantum physicist, pointed this out famously when in 1935 he created a thought problem, a paradox, dubbed Schrödinger’s cat. “It wouldn’t be hard, according to the rules of his own equation, to make a state in which the cat was alive and dead at the same time. And this, he says, is ridiculous.” That’s why, says Penrose, “quantum mechanics is extremely well confirmed and a beautiful theory, in many respects, and it certainly agrees with all observations that have been made so far. The only trouble with it is that it doesn’t really make sense, and I think a theory ought to make sense.”
So physicists were faced with a dilemma: They had two theories, two explanations, that were very successful in their own corners of the universe but could not describe the other’s realm. Relativity theory—gravity—was good for explaining the giant scale of planets and stars and galaxies. Quantum mechanics was very good at describing the tiny world, but it could not explain the larger world we live in.
Hmm. What to do? Where to look for an answer? Would it help us reconcile the two if we could find a circumstance in which both ideas might be working at the same time? Of course it would. But when would that be?
How about the birth of the universe: the big bang, almost 14
billion years ago. Here, the universe and everything that ever existed would be infinitesimally small, so quantum mechanics would be in action. Yet things would be incredibly massive, so gravity would be in its glory too. All we needed to do, then, was to figure out what was going on at that time and the problem would be solved. Bingo!
And good luck.
Einstein spent the last 30 years of his life trying to unite the two ideas into a theory of everything. He failed. Ever since then, physicists have been trying to tread the same ground, trying to unite the two worlds. And so far, they have not succeeded. “I don’t see much indication of it getting terribly simple just yet,” says Penrose. “I think one likes to think that eventually there will be some simple principle that governs everything, but we’re certainly a long way from that now.”
And that brings us to today, where it appears that our universe continues to defy our understanding. We have the head-scratching discoveries about the composition of our universe—the mysterious dark energy and dark matter—and the complicated theories that try to explain these discoveries, the string theories and their extra dimensions.
So, as Rod Serling used to say, “presented for your consideration” are the challenges facing cosmologists as they try, like scientists for hundreds of years before them, to understand the world we live in. Cosmology is not easy to grasp in just one gulp. Over the years, I’ve had to read and re-read, listen and re-listen to scientists describe the spooky world of quantum physics just to make sure I heard and understood them correctly. That is why I’ve presented many views, from some of the world’s leading cosmologists and thinkers. You’ll note that they don’t always agree, which makes cosmology one of the more interesting and fun topics of discussion.
Duct tape is like the force. It has a light side, a dark side, and it holds the universe together….
—CARL ZWANZIG
The 1990s have been called the golden age of cosmology as scientists gather new information about the size, the shape, and the makeup of our universe. Some of the research provides an update, such as the age of the universe now being set at about 14 billion years. Some of the research results are very surprising, such as the discovery that the universe is accelerating outward, propelled by some strange, repulsive dark energy that makes up two-thirds of the universe, or the continuing search for dark matter, which we can’t see but we can feel. And in trying to explain these almost science fiction–like properties, researchers have had to turn their eyes from the very big to the very little, to the tiny world of subatomic particles, string theory, and beyond.
Dr. Lawrence Krauss, chairman of the physics department at Case Western Reserve University, says that while we have just finished a decade of “incredible revolution” in the field of cosmology, major questions remain to be answered. “We don’t know what most of the energy in the universe is. We don’t know what most of the matter in the universe is.”
“When you look at the beautiful pictures on the Hubble Space Telescope, you’re struck by the colorful galaxies and stars. What we know,” says Dr. Michael Turner, chair of the astronomy and astrophysics department at the University of Chicago, “is that the visible part of the universe is just a tiny fraction of what’s out there. Most of the stuff out there is dark. So if you think about it, the cosmic infrastructure is this dark matter, and it’s just decorated by the pretty galaxies.”
Dark? What about all of those stars and galaxies, the moon and planets that light up the night sky? Astronomers are saying that all the stuff we can see is only a small percentage of what makes up the universe. The rest of it is dark.
“We’ve had kind of a seventy-year-old detective story,” says Turner, as he begins to tell his yarn. “It begins with Fritz Zwicky in the 1930s, who realized that the gravity of ordinary stars couldn’t hold together clusters of galaxies,” because there just wasn’t enough of it. Zwicky, an astronomer born in Bulgaria who immigrated to the United States to
work at California Institute of Technology, observed the universe through an array of telescopes and discovered in 1933 that there just wasn’t enough visible mass in the universe to create the gravity to hold the galaxies together. But Zwicky was an eccentric guy and hard to work with, so scientists kind of ignored what he had to say, though they really couldn’t punch holes in this observation.