Sean Carroll fala sobre os níveis da realidade

quarta-feira, maio 27, 2015

May 27, 2015





A Conversation with Sean Carroll

I've always studied the laws of physics. I've always been curious about how the universe works, where it comes from, what are the rules that govern the behavior of the universe at the deepest level, so I do physics for a living. I study cosmology and the Big Bang and what happened before the Big Bang, if anything. It's a system of things that hooks up in very complicated ways to our human scale lives. There's the natural world that scientists study, and we human beings are part of the natural world.

There's an old creationist myth that says there’s a problem with the fact that we live in a universe governed by the second law of thermodynamics: Disorder, or entropy, grows with time from early times to later times. If that were true, how in the world could it be the case that here on Earth something complicated and organized like human beings came to be? There's a simple response to this, which is that the second law of thermodynamics says that things grow disorderly in closed systems, and the earth is not a closed system. We get energy in a low entropy form from the sun. We radiate it out in a high entropy form to the universe. But okay, there's still a question: even if it's allowed for a structure to form here on Earth, why did it? Why does that happen? Is that something natural? Is that something that needs to be guided or does it just happen?

In some sense this is a physics problem. I've become increasingly interested in how the underlying laws of physics, which are very simple and mindless and just push particles around according to equations, take us from the very simple early universe near the Big Bang after 10 to the 100th years to the expanding, desolate, cold and empty space in our future, passing through the current stage of the history of the universe where things are rich and intricate and complex.

We know there's a law of nature, the second law of thermodynamics, that says that disorderliness grows with time. Is there another law of nature that governs how complexity evolves? One that talks about multiple layers of the structures and how they interact with each other? Embarrassingly enough, we don't even know how to define this problem yet. We don't know the right quantitative description for complexity. This is very early days. This is Copernicus, not even Kepler, much less Galileo or Newton. This is guessing at the ways to think about these problems. …[Continue]

SEAN CARROLL is a research professor at Caltech and the author of THE PARTICLE AT THE END OF THE UNIVERSE, which won the 2013 Royal Society Winton Prize, and FROM ETERNITY TO HERE: THE QUEST FOR THE ULTIMATE THEORY OF TIME. He has recently been awarded a Guggenheim Fellowship, the Gemant Award from the American Institute of Physics, and the Emperor Has No Clothes Award from the Freedom From Religion Foundation. Sean Carroll's EDGE Bio Page