[omra]

I think the entire statement is silly in that it attempts to compare two entirely different branches of mathematics, it would be almost as arguing between physics and biology. Physics is the study of matter and energy. Biology is the study of life. Any attempt to assign some "order" to them or declare one "harder" than the other is subjective and pointless.

However, there are some factual problems with your reply which I want to address. The Classification of Finite Simple Groups was a large endeavor spanning over an entire century. It was not made "by about 100 mathematicians".

The fact that the current was not working is not sufficient enough to conclude that the result was a failure or that pure mathematics is somehow worse than computer science. It would be similar to writing some code, and then suddenly realizing that you have to rewrite it if you want to get acceptable performance or to stop it from becoming spaghetti code. Neither of this sheds bad light on the field of computer science.

The key note errors you refer to are not much different from bugs, which of course are inevitable.

[btilly]

Let me address the claim of factual errors.

I pulled my estimate of the effort put into the classification from the second paragraph of http://en.wikipedia.org/wiki/Classification_of_finite_simple.... Do you have a better source that I should have used? If so, then cite it and update Wikipedia.

I pulled my estimate of the effort for the Linux kernel from https://www.linux.com/learn/tutorials/560928-counting-contri... and then extrapolating from the fact that if 1316 had patches for one major kernel release, that over all versions we probably had thousands of developers contributing code but probably not tens of thousands.

The facts that I presented are the best that I have available.

On the overall question of the comparison, I did not choose what should be compared, I merely compared them by the most convenient criteria that I could and came to the opposite conclusion from the previous poster.

[omra]

I've already counted 90+ authors and contributors from a _brief_ history of finite simple groups, using [1]. This includes "et. al", from which I have assumed best practice of APA Style Guidelines, indicating at least 6 authors. I also could have counted more using [2], but I believe this is sufficient.

I feel that the statement that "only 100" mathematicians worked on the classification of finite groups is disingenuous. There is clearly a disparity between contributing a kernel patch and dedicating your entire life to researching a mathematical topic.

As for the Linux kernel, I would like to point out that the original paper [3] states that 7,944 developers have contributed since 2.6.11 (which is more than your estimate, but important regardless). A paragraph later on is a little more telling:

>[D]espite the large number of individual developers, there is still a relatively small number who are doing the majority of the work. In any given development cycle, approximately 1/3 of the developers involved contribute exactly one patch. Over the past 5.5 years, the top 10 individual developers have contributed 9% of the total changes and the top 30 developers have contributed just over 20% of the total.

That is to say, 30 developers have made 20% of Linux. This is not unlike the classification of finite groups, where a small amount of people have done a large majority of the work. It would be insane to say only 100 people have ever looked at finite groups. Indeed, proving something is exponentially harder than learning it. Similarly, you would not say that 7000 people use Linux, because 7000 have hacked on the kernel.

As for your last comment regarding about how you did not choose the topic, I agree. But I think that this entire debate is silly: neither side is more important than the other, more difficult than the other, mutually exclusive, or so on. I do not agree with Dijkstra on this point, and I feel that his fame is no reason to excuse him from it.

[1] http://www.ams.org/journals/bull/2001-38-03/S0273-0979-01-00...

[2] A History of Finite Simple Groups, by FCC Doherty.

[3] http://go.linuxfoundation.org/who-writes-linux-2012

[btilly]

I would assume that "et al" hides a lot of the same people contributing to multiple papers. The wikipedia estimate is likely wrong, but I don't think by an order of magnitude.

I agree with you on the Linux kernel. I even noted that about half only contributed one patch.

I suspect that I disagree with you about what Dijkstra's point was. When you're programming, there is nowhere to hide from the fact of your code not running. By contrast in pure math, a surprising amount of sloppiness can be hidden in the fact that minor papers do not always get completely rigorous view. Therefore if you're inclined to that form of sloppiness, you're better off in pure math. (Which is not to say that all people in pure math are sloppy in that way.)

I don't think he's right - I've met too many programmers and bad computer scientists to have illusions that all are capable - but he does have a point.