I don't really get what your comment has to do with what I said. It seems like a strawman pretending I said, "This book is stupid, I read 100 pages and I still don't know how to make a game!" Or, "this book is stupid, I read 100 pages and I still don't know how to connect to a database!" I'm not even complaining that the exercises are hard, I'm complaining that they're incomprehensible to me.

Also, since you've pointed out that the book is called "The Structure and Interpretation of Computer Programs", wouldn't it make more sense for the exercises to be about computer science things instead of math and physics? I own The Art Of Computer Programming by Knuth and it has plenty of exercises in it that are both computer science related and make you think about hard problems.

That would be a valid argument if the GP was a physicist, I guess. Why should GR be a prerequisite for CS?

Well, this is a book written by MIT professors in support of an MIT course. Students will be concurrently taking classes in these other subjects. Which makes it a great undergrad text for an engineering school, and probably pretty tough if you don't have the math and physics background.

He said it was a sarcastic example. As far as I know, the book doesn't mention general relativity

Because GR is the basis for everything human. See Chimpanzee Politics, Schrödinger's cat, etc.

Why was I downvoted? I believe I made an informed and appropriate point.

I voted you back up. But the answer to your question is 'for the same reason you don't teach GR as a prerequisite to tying shoelaces.' Small children and shoelaces wouldn't be here without GR either, but it's just too abstract for most people.

The problem for the poster above is that if you read SICP outside MIT or especially outside college, you're not surrounded by a bunch of science nerds who can be persuaded to explain general relativity in return for beer and a pizza. If you're not swimming in a sea of science, then problems involving the behavior of fish seem much trickier to solve. I've seen this problem iwth a few other MIT books, eg Horowitz and Hill.

Horowitz and Hill? Hmmm, I don't remember running into any out-of-domain stuff whilst working with that book at uni, but then maybe that's your point - I was at uni, so it fitted nicely, but for someone coming at TAOE without an engineering background might struggle. Do you remember any concrete examples? Was it something like needing to understand wave propagation to understood why the modulation circuit worked, or things like that?

I'd have to go and dig out my copy now to check. The main things I remember offhand were problems with no discussion of the answers, and examples of 'bad circuits' which you were encouraged to build to find out why they went wrong. Great if you're in a class, not so great if you're studying alone.