#or its servitors who dont have enough neurons left to do so

[absolxguardian]

I don't think Heinlein understood binary either. I'm dsycaclic and all I need to convert from binary to decimal is a list of powers of 2 and paper/something to write with. A whiteboard with a grid of the place values printed on it might also be useful. Someone who could have been a computer (profession) would be able to do it much faster and much more accurately. Massive books are just going to be slower.

I love how much of a blindspot for the computer scifi authors had.

So in Heinlein's Tunnel in the Sky, humanity has developed instant interstellar travel, through what's effectively star gates. China has taken over Australia and "terraformed" it by building an inland sea, we've got weather control technology and stasis fields so that people with terminal diseases can be frozen in time until we figure out how to cure them. Most of the military is women, as changing population dynamics mean men are only like 1/5th of the population.

And at one point in this far off future, the protagonist decides to idly calculate how long it'd take to evacuate all of earth through the warp-gates, so he pulls out his slide-rule.

Instant travel to other planets? Of course. Restructuring an entire continent? Easy. Controlling the entire atmosphere? No problem. Slowing time itself to save people? Absolutely! The army is mostly women, because for some reason not as many men are being born? Yeah, why not!

But digital computers (WHICH ALREADY EXISTED AT THE TIME THIS NOVEL WAS WRITTEN) getting small and cheap enough that a high-schooler could own one and keep it in his backpack?

Well now you've wandered into the realms of fantasy. This is science fiction, we only talk about the possible futures, not silly fantasy stories with magic and dragons and such! No computer will ever be smaller than an a room, and even if you did manage to shrink one enough to be maybe the size of a washing machine, no high-schooler could afford one!