Stork: Let's talk for a bit about scientific computing. That seems to be an area where reality has surpassed prediction.

Wolfram: Probably so. Our Mathematica software can certainly make much nicer displays than the ones in 2001, particularly with our latest and greatest Mathematica 3.0, which should be out before HAL's 1997 birthday. And there's probably even been at least one copy of Mathematica in space by now -- on a portable computer on the shuttle, or something.

But I guess the clearest piece of fundamental progress that's been made, relative to what ones sees in 2001, is in the language used for scientific computing. If one looks at the closeups of screens in 2001, one sees code that looks like BASIC or Fortran. It's very different looking from Mathematica code -- particularly from our version 3.0 code. I suspect nobody thought very hard about it when the screens for 2001 were made. They probably just took something that looked like computer programs that existed in the mid-1960s. But in fact there's been a very important change. You see, in the mid-1960s, computer time was at a premium, so you had to make things as easy as possible for the computer. The result is that the languages were optimized for the way the hardware of the computer would process a problem -- not for the way people might think about a problem.

It's kind of like the underestimation of the power of software I mentioned before. People assumed that you'd have to have computer languages that fit into the structure of the hardware that existed. They didn't understand that you could make layers of software that would make the languages work more like the way people think -- or the way that, for example, math works.

When I built Mathematica, one of my big ideas was to try to make a language that wasn't just tied to hardware -- and instead that was set up to work the way people actually think about computations.

Stork: Like some sort of computer-language analogy to the more "natural" interfaces made popular in the early Apple computers?

Wolfram: Yes, in a sense. But now here's the bad part: I think Mathematica was probably, in a sense, just an accident. You see, computer languages seem to live an incredibly long time. All those languages like Fortran and BASIC that were developed in the 1950s and 1960s are still alive today. They've long outlived all the computers they were originally developed for, and all the issues they originally had to address. But they're still around. And I'm guessing that if Mathematica hadn't come along, they'd still be the dominant languages for scientific computing -- even in 2001. So I suppose I'm guessing that the differences between the scientific computing in 2001 and in reality are probably pretty much a historical accident -- albeit my own personal historical accident.

Stork: What about issues of basic science? Are there things in 2001 that you found interesting from that point of view?

Wolfram: Actually, very much so. I thought the portrayal of extraterrestrial intelligence was really fascinating. For me it's all linked up with questions about computation in nature and the distinctions between natural and artificial things -- things I've been studying for a very long time. I guess the big question is how one knows when something is natural and when it's artificial. How do we know when a signal we get from the cosmos is just natural, and when it's artificial, made by some kind of intentional being?

At the beginning of 2001, we see all sorts of stuff that is obviously natural -- mountains, skeletons, apes running around. But then suddenly we see the monolith -- and it's clearly artificial. How can we tell? Well, unlike all the other things we've seen, it has perfectly smooth sides, and looks like something that's been engineered and hasn't just grown naturally. Actually, that's the heuristic we essentially always use: if something looks simple, then it's probably artificial, and if it looks complicated, then it's probably natural.