Open course ware

SPEAKER: I'd like to move now to a special announcement and bring back President Susan Hockfield, who will describe the next chapter, I would say, in the unfolding of the OpenCourseWare movement. SUSAN HOCKFIELD: Yes. [CHUCKLES] You don't have to sit here. You may move back to-- [LAUGHTER] Thank you all. That was a great panel. Thank you. Thank you, audience participants also. This is open sourcing of information. You all participate. So I get the great fun of today, which is announcing the next chapter in OpenCourseWare. Now as you have probably gathered of the [INAUDIBLE] today, if you all weren't there at the very beginning, that OpenCourseWare was designed really for university and college faculty and their students. And the idea was to share what we do on this campus with what happens on other campuses. And it has been successful, I would say, probably beyond almost anyone's wildest, wildest dreams, depending on how you count visits to the OpenCourseW...

GERALD SCHNEIDER: OK, I'd like to introduce neuroscience to you by going through a bit of history that I use to describe three kinds of goals that recur in this field since the 19th century-- three different kinds of goals, and then what modern people are doing, sort of a synthesis, the subsystems approach we'll describe in the fourth lecture. But these are the goals, and we're going to start today talking about this one, OK. Number one, coming up with specific narrow circuits which could explain behavior. And if we could do that adequately, we would be able to come up with a machine that would behave just like a person. So I'll talk about how that goal originated with the discovery of the reflex arc, which was not in the 19th century. It was long before, at least the concept of reflexes, discovered a long time ago. That led to a philosophical view called reflexology. I'll explain that to you. I'll talk a little bit about the machines that have ins...

OK, so I'd like to go now to the next segment of the course. Think you can probably appreciate little bit better this triangle I had on before about how what biochemists did was they tended to break cells open, look at the component parts, through other things in there, and then proteins. But an awful lot of stuff having to do with function is proteins, and what geneticists, the discipline of genetics would do, which made mutants of living organisms, and that looked at how function was affected by mutating individual genes, how those were both very powerful approaches. Genetics told you what was really important, and biochemistry told you how it worked at a molecular level, but the real problem is knowing whether this thing you had doing something in the test tube was actually the one that did it in life. And I think I told you when Arthur Kornberg isolated the very first DNA polymerase, he was able to copy DNA. And he got a Nobel prize, and it was the first enzyme th...

I'd like to talk. Thank you. One of the things I'd like to give a little insight into today is the mathematical basis for hearing. For example, if a musical tone, a pure musical tone would consist of a pure oscillation in terms of the vibration of the air. It would be a pure oscillation. So, [SINGS], and if you superimpose upon that, suppose you sing a triad, [SINGS], those are three tones. Each has its own period of oscillation, and then another one, which is the top one, which is even faster. The higher it is, the faster the thing. Anyway, what you hear, then, is the sum of those things. So, C plus E plus G, let's say, what you hear is the wave form. It's periodics, still, but it's a mess. I don't know, I can't draw it. So, this is periodic, but a mess, some sort of mess. Now, of course, if you hear the three tones together, most people, if they are not tone deaf, anyway, can hear the three tones that make up that. So, in other words, if this...

OK, so what I'd like to do today is pick up where we left off last time, with respect to how this genetic material actually functions. We discussed last time the experiments that identified DNA as the fundamental genetic material, the transforming principle. We identified the eventual work by Crick and Watson's work at the structure of DNA as a double helix. We mentioned why that was so tremendously important, because it contained within it in principle the secret of replication, namely two strands, each of which contained the full information, and therefore each of which included in principal serve as a template for making the other strand. And that is, after all, the big issue about life is how do you, in fact, copy life? And then, I mentioned briefly these experiments by these post-docs, Matt Meselson and Frank Stahl about 50 years ago to demonstrate that the semi-conservative model of DNA replication was right by v...