terça-feira, 20 de Abril de 2010
UMA DAS TRAGÉDIAS DO NOSSO SISTEMA EDUCATIVO
O "New York Times" de terça-feira traz sempre a página de ciência. Desta vez traz uma entrevista com o físico norte-americano Sean Carroll, autor do recente livro "From eternity to here". O bold é meu:
"Q. WHEN YOU GO TO A COCKTAIL PARTY, DO YOU TELL PEOPLE THAT YOU ARE A PHYSICIST? SOME PHYSICISTS WON’T.No fim, dá uma razão para se fazer física:
A. I do! But I know what you’re talking about. Whenever you say you’re a physicist, there’s a certain fraction of people who immediately go, “Oh, I hated physics in high school.” That’s because of the terrible influence of high school physics. Because of it, most people think physics is all about inclined planes and force-vector diagrams. One of the tragedies of our educational system is that we’ve taken this incredibly interesting subject — how the universe works — and made it boring."
"The rules of nature are ultimately our rules and when we try to understand them, we learn something about ourselves."O resto pode ser lido aqui.
A Conversation With Sean Carroll (the Physicist)
Sean Carroll Talks School Science and Time Travel
By CLAUDIA DREIFUS
Published: April 19, 2010
The world of science has two Sean Carrolls. One is an evolutionary biologist. The other is a cosmologist and theoretical physicist, an expert on time and the early moments of the universe. As it happened, the physicist stopped by the offices of The New York Times on a recent March morning. Dr. Carroll, a 43-year-old research professor at the California Institute of Technology, had come to New York for an appearance on "The Colbert Report." He was in town promoting his meditation on the physics of time, a trade book with the clever title "From Eternity to Here."
Natasha Calzatti for The New York Times
PRESENT Sean Carroll studies, among other things, why time has a direction.
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Q. WHEN YOU GO TO A COCKTAIL PARTY, DO YOU TELL PEOPLE THAT YOU ARE A PHYSICIST? SOME PHYSICISTS WON’T.
A. I do! But I know what you’re talking about. Whenever you say you’re a physicist, there’s a certain fraction of people who immediately go, “Oh, I hated physics in high school.” That’s because of the terrible influence of high school physics. Because of it, most people think physics is all about inclined planes and force-vector diagrams. One of the tragedies of our educational system is that we’ve taken this incredibly interesting subject — how the universe works — and made it boring.
Q. LEON LEDERMAN, THE NOBEL PRIZE PHYSICIST, HAS PROPOSED THAT WE REFORM HIGH SCHOOL SCIENCE BY REQUIRING PHYSICS IN THE SOPHOMORE AND NOT THE SENIOR YEAR. WILL THAT HELP — OR IS IT REARRANGING DECK CHAIRS ON THE TITANIC?
A. I don’t think it’s the right solution. What we need to do is find a new way to teach the spirit of physics. What we do now is water down what professional physicists do and make it into this dry puzzle-solving thing with little pictures of pulleys and things like that. We ought to teach kids more about the Big Bang and entropy and particles. Every high school graduate should know that everything in the universe is made of a handful of particles. That’s not a hard thing to know. But that’s not what’s emphasized.
Yes, there is a quantitative aspect to science that should not be denied, but it can be in the service of interesting rather than boring problems. Ten years after high school, most students are not going to solve a problem with pulleys and levers. But they still might want to know about the expansion of the universe and about cool things in atomic physics and lasers — which they’ll find interesting and fun.
Q. “FROM ETERNITY TO HERE” IS ABOUT THE PHYSICS OF TIME. WHY DO YOU STUDY TIME?
A. Because it is a crucial part of how we think about the universe. It turns out that one of the great mysteries of time — why it has a direction — is really a question about how the early universe was organized. There’s something called “the arrow of time” and it is simply the direction in which time passes from the past to the future. There are many ways in which the past and future are different: things become messier toward the future; we remember yesterday and not tomorrow; actions we take now affect the future but not the past. All of those reflect the arrow of time.
Now, the origin of the arrow of time is a mystery. Based on the laws of thermodynamics, we understand how it works. But we don’t understand why there is an arrow. It comes down to conditions near the Big Bang; the universe started out highly organized and has been becoming more random and chaotic ever since. What I said on Colbert was that the universe is like a mechanical toy that started all wound up, and has been winding down for the last 14 billion years.
Q. YOU WRITE THAT THE NATURE OF TIME IS SUCH THAT WE CAN’T GO BACKWARD.
A. It’s likely that we can’t do time travel. But we don’t know for sure. The arrow of time comes from the increase of entropy, meaning that the universe started out organized and gets messier as time goes on. Every way in which the past is different from the future can ultimately be traced to entropy. The fact that I remember the past and not the future can be traced to the fact that the past has lower entropy. I think I can make choices that affect the future, but that I can’t make choices that affect the past is also because of entropy. I can choose to have Italian food tonight, but I cannot choose to have not had it last night. But if I travel into the past, all that gets mixed up. My own personal future becomes part of the universe’s past. We’re not going to make logical sense of that. So the smart money would bet that it’s just not possible.
Q. THE CENTERPIECE OF THE RECENT MOVIE “BENJAMIN BUTTON” AND THE ABC TELEVISION SERIES “FLASH FORWARD” IS THE TIME TRAVEL. HOW DO YOU RATE THE SCIENCE OF THOSE ENTERTAINMENTS?
A. Well, the Benjamin Button character ages in reverse. In “Fast Forward” people glimpse the future. These are great story-telling devices.
But the writers can’t resist the temptation to bend the rules. If time travel were possible, you still wouldn’t be able to change the past — it’s already happened! Benjamin Button, he’s born old and his body grows younger. That can’t be true because being younger is a very specific state of high organization. A body accumulates various failures and signs of age because of the arrow of time. But this is fiction and real bodies all go from being young to old. I think the screenwriters of Benjamin Button blinked because they didn’t take their premise far enough. Though Benjamin Button’s body is born old and grows younger, his mind is born young and grows older. He remembers the past just like we do. His personality is that of a young person when he’s young, even though his body is that of an 80-year-old man. Reversing the mind’s arrow of time would be more dramatic than reversing the body’s arrow.
Q. YOUR WIFE, JENNIFER OUELLETTE, IS THE DIRECTOR OF THE SCIENCE AND ENTERTAINMENT EXCHANGE. WHAT IS IT?
A. It’s a program of the National Academy of Sciences to help Hollywood get good advice. Directors and screenwriters are brought into contact with scientists who advise them on the science in their stories. Now, many scientists aren’t right for this job because they are scolds. They immediately tell the producers what mistakes they’ve made. That’s unhelpful. Jennifer tries to find them consultants who will say, “This is how you can make your story more compatible with the laws of physics.”
Q. WHAT KINDS OF STORIES HAS SHE CONSULTED ON?
A. One that I can talk about is from the series “Bones.” It’s sort of a forensic anthropology procedural show. Every week they need a clever way to kill somebody. One of their writers wanted to kill someone using physics. I didn’t have any great ideas how to do that. So we called my friend Juan Collar at the University of Chicago. He had this brilliant idea where you could insert a little piece of radioactive substance into someone’s chair. Its half life was such that by the time people got suspicious about the death, all the radioactivity would be gone and it would be hard to discover. The “Bones” people built their story around that.
Q. HOW DID YOU MEET MS. OUELLETTE?
A. We met on the blogosphere. I started a blog about physics back in 2004, when there weren’t many. And then I read about a science writer named Jennifer Ouellette who was reported to have a blog with the intriguing name, Cocktail Party Physics. So we began e-mailing and we finally met at the American Physical Society meeting in Dallas in 2006. We had dinner and hit it off immediately. Six months later, we were engaged.
Q. GETTING BACK TO COSMOLOGY, WHEN YOU THINK ABOUT TIME, THE UNIVERSE, THE BIG BANG, DOES IT MAKE YOU FEEL SMALL?
A. You’re allowed to feel small. As the 1970s rockers sang, “All we are is dust in the wind.” But there’s another way to think about that. Instead of being humbled by how tiny we are, we should be impressed that we can understand it. The rules of nature are ultimately our rules and when we try to understand them, we learn something about ourselves.