# B3D, Chapter 4: Response

## Michelle Imber

My initial reaction to Chapter Four, for some reason that I can't quite pinpoint, has been somewhat negative. I feel like there were lots of pages but not that many new concepts, perhaps because we've worked out some of the formulas and things before, and like I just kept reading but couldn't think of that much to say. It might have something to do with the fact that I'm tired--but then again, after reading everyone else's responses, I wonder if others felt that somehow there was less substance to work with in this chapter than in the previous ones. Or perhaps it was just that the substance which was there was a lot of "straight math," as it were, and I'm less comfortable playing around with the numbers. Hmmm.

At any rate, one thought that continually popped into my head as I turned the pages of Chapter Four was, "What I wouldn't give for a good movie!" Sometimes representing four dimensions in two is insufficient for those of us with poor visualization skills; at such times I find myself yearning for the usage of time as a third dimension. There is something to be said for the use of a temporal dimension to compensate for the lack of a spatial dimension: it gives us some idea of what we're lacking. To that end, I would really like to see a three-dimensional projection of a hypercube rotating over time. The book mentioned a hologram near the end of the chapter, which is something I have often thought would make this class a googol times easier. Imagine if we had a rotating holographic projection of a hypercube that we could examine from different angles and over time. In fact, I would like holographic models of everything. That, I suppose, can be left to the 57th edition which will naturally come out on holographic CD-ROM in a decade or two. Right?

Let's see, what else can I say about this chapter? Three-dimensional graphs in two-dimensional graphics have always been a source of frustration for me. Without the ability to look at the thing from different angles, I'm lost. I liked the example of Tom Webb's research, though. I took Geology 31 last semester (plug plug plug), which used to be Tom Webb's course but was subsequently passed on to Tim Herbert and Laurie McDonough, who executed it fantastically. We talked a bit about pollen cores and how researchers would look at different kinds of grains to tell what kinds of vegetation had been predominant in the area. Incidentally, the same sorts of technology are used to look at polar ice cores, which have layered bands of all the dust and grainy things that were circulating around the world in a given year. If you wanted to date a volcanic eruption, you might look in a certain ice core and actually count the bands to figure out what year the ash came from. And we know when our ice ages occurred partially because we can count the kinds of benthic foraminifera (microscopic sea-critters) in different areas of the world at different time. The little forams respond to changes in oxygen isotopes or water temperatures in ways that tell us how cold the world was at various points. There are so many potential axes when you're dealing with such variables that I often wondered how the researchers kept them straight. I guess they had lots of these three-dimensional graphs and cool rotating displays and things, because they had to keep track of date and latitude and longitude and the number of one kind of microscopic organism versus the number of another kind and how much oxygen-16 or oxygen`-18 was taken up by either. Quite a lot to be mindful of. Hooray for multi-dimensional graphs!

Prof. Banchoff's response