“Hi, Jason. You’re right that the theory of Big Bang inflation agrees exquisitely with our observations. But just remember that nearly perfect agreement with the data does not by any means constitute proof.” So physicists have faith, but they aren’t necessarily sentimental? “Right. The best science usually comes out of scrutinizing our most cherished principles and theories.” There you have it. Some of these cosmological questions border on the religious and the spiritual. And in a way, so does our next one.
5. What is the basis of consciousness?
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ere’s another question that was sent to me by more than one person—Edward Perl in cell and molecular physiology, and Jesse Prinz in philosophy. That’s a good sign that it’s a humdinger. It’s an old question to philosophers, but a newer one to scientists. Plato thought about it. In the 1600s René Descartes said that body and mind must be made of different stuff: the body exists in time and space; the mind exists only in time. But today science says no: body and mind are different aspects of the same thing. Consciousness comes from the way the brain’s neurons work and the way they’re organized. But we have no idea how consciousness works. Historically, Science magazine has said, studying consciousness has been “a dubious career move” for anyone who didn’t already have tenure (and maybe a Nobel, to boot). But that’s starting to change. Let me point out Dr. Perl: he’s sitting right over here at the end of the second row on the left. His background is in medicine, and he’s been studying this stuff for far longer than I’ve been alive. And over there near the back corner is Dr. Prinz. Hi, Jesse. I like the Ramones shirt. Dr. Prinz is one of a relatively new crop of philosophers who are applying hard scientific evidence to the way they think about philosophy. He’s done a good bit of thinking about consciousness, too. Somehow, when you smell a tiger lily or look at the Mona Lisa or listen to “Sheena Is A Punk Rocker,” certain neurons and glial
cells in your brain “fire” and help you recognize and make sense of what you’re smelling, seeing, or hearing. When you see something red, you somehow experience the color red, rather than some other color or no color at all. You somehow turn tiny electrochemical impulses into your experience of the world— and in a sense, into you. We can use tools such as MRI and PET scans to pinpoint areas of the brain that are involved in sensory experiences. We see which parts of the brain light up, so to speak. But as Dr. Perl told me, we still have no idea what’s behind that process inside the brain. How could electrochemical activity produce consciousness? Dr. Perl’s research involves an aspect of consciousness that we’d like to think we could do without—pain. All of us have neurons that are involved in sensing it. Somehow, when a toothache or a tetanus shot causes those neurons to light up, we hurt. We don’t know for sure whether our brains have neurons specifically dedicated to pain, but Dr. Perl tells me that we’re beginning to think that our brains process pain information in several regions that operate in parallel. Lucky for us, consciousness isn’t all pain— it includes wakefulness, perception, reflection, simulation, our sense of personal identity, anything running through our thoughts at any given moment, and maybe lots more. It may be that different regions of the brain generate different aspects of consciousness. People who have injured their brains can have consciousness-related problems that seem limited to the functions controlled by the injured brain area. Dr. Prinz described consciousness to me like this: your senses are always taking in lots of information. You only pay attention to a small subset of what you take in—your brain broadcasts that small subset to its short-term storage centers. But that’s only part of the picture—right, Dr. Prinz? “Right. Essentially the same kind of thing happens in my laptop, but I doubt my laptop is conscious. Consciousness occurs only when attention is underwritten by specific kinds of neural processes.” Okay. So what do we think those neurons actually do?
“Well, I think the best current account goes something like this: when we attend— that’s psychological jargon for ‘when we pay attention’—certain kinds of neurons, called fast-spiking neurons, become more active. They send out signals that cause some of the cells in our perceptual pathways to start firing in synchrony. This synchronic firing allows those cells to send signals that can be received by the brain’s working memory— it allows one area of the brain to talk to another. And it may be that this synchrony is essential for consciousness. If it is, we’re within reach of identifying the neural correlates of consciousness.” Sounds like that might have some pretty big philosophical implications. “Well, maybe. Philosophers are more interested in why brain events—which are changing patterns of neurochemical activity in populations of neurons—feel like anything at all, rather than nothing. I don’t think that finding the neural correlate answers that question, but it may help us answer why we ask that question in the first place. What is it about the way that we introspect our conscious states that prevents us from discerning that they’re just brain states? Typically, people have a problem with the idea that minds are just brains.” Okay. Good stuff. Thank you, Dr. Perl and Dr. Prinz. Next question:
4. Can we find a sustainable energy source?
T
his one comes from Tom Meyer in the Department of Chemistry. Most likely, the electricity that runs everything in your house comes from coal that was formed three to four hundred million years ago. U.S. coal supplies may be good for another 100 to 250 years, which just might give us enough time to find a replacement. Ideally, our new energy sources would be renewable, efficient, and would cause no long-term damage to the earth. There are a few different candidates—solar, wind, geothermal, oceanic, and maybe nuclear. endeavors 13