I think the objection was to an author inadvertently introducing a perpetual motion machine into a story without apparently realizing it (like in “Closed and Common Orbit” or like Frank Herbert did in Dune). 3BP explicitly introduces bizarre future physics with the full expectation that both the characters and the readers will see it as bizarre and new (kind of like the “electron psychology” that Van Vogt introduces in “Far Centaurus”).
You’re asking me to justify the consistency of two opinions when I only hold one of them. Both things are fine by me, inasmuch as I don’t expect myself to understand future science, OR for future science to make much sense from the perspective of modern science. McGuffins are McGuffins; as long as the story revolves around them consistently, and especially as long as the characters make sense to me, I find zero pleasure in disputing the technology.
Now, there are exceptions that prove the rule. I once read a vampire novel in which someone cured her vampirism with a dose of Antarctic fish blood. The blood had antifreeze in it, which helped–but she was deathly afraid of ever eating ice cream again, because if her body temperature dropped below the antifreeze’s potency, she’d instantly turn into an icicle.
That drove me crazy, because a single bite of ice cream wouldn’t reduce your whole body temperature that much, and if it did, ice cream would be deadly for everyone. It wasn’t the future tech that was a problem, it was a fundamental misunderstanding of ice cream.
I read another book in which a wizard unwrapped a new deck of playing cards and then exploded it, and all 52 cards shot out and murdered his enemies around the room. I was 100% fine with the magic, but who doesn’t know that a new deck of cards has 54 cards in it, plus a couple of useless ad cards? And then to make matters worse, the wizard went to a corpse and plucked the Joker out of its throat. A deck with 52 cards in it doesn’t have Jokers!
So that’s where I draw the line. But perpetual motion machines? Seventh-dimensional atomic particles that function as supercomputers? Not even the tiniest bit a problem for me.
Again, to each their own.
This probably deserves a separate thread, but I just noticed that PBS, for its May 22 program, The Great American Read, put out a list ofAmerica’s 100 Best-Loved Novels for people to vote on.
The weasel words “Best-Loved” is critical. While there are a bunch of classic novels from Jane Eyre and Moby Dick to Heart of Darkness and The Great Gatsby, it also includes Fifty Shades of Grey.
If they let that in, they’ll let in anything, so I searched for sf.
Two pure genre titles made it: Asimov’s Foundation Series and Herbert’s Dune.
More books marketed as mainstream rather than genre, but clearly in the genre, were there: Jurassic Park, The Handmaid’s Tale, The Sirens of Titan (not Slaughterhouse 5, which is incomprehensible), Frankenstein, The Hitchhiker’s Guide to the Galaxy, and 1984. I never read it, so I’m not sure whether The Clan of the Cave Bear goes here or in fantasy. Same with Ready Player One. The Intuitionist by Colson Whitehead is some kind of allegory and might be in any category.
Adult fantasy has, of course, the Game of Thrones series and The Lord of the Rings, as well as Robert Jordan’s The Wheel of Time series, and the Outlander series. King’s The Stand is horror but it fits in here. The Picture of Dorian Gray is horror, too. The Mind Invaders is a thriller but looks to have a fantasy premise.
Children’s and YA fantasy abound. The Chronicles of Narnia series, Harry Potter series, Charlotte’s Web, The Little Prince, the Hunger Games series, the Twilight trilogy, and Alice’s Adventures in Wonderland. (What, no Oz?)
By my rough count, only about half the list can be classified as adult nongenre literary works. It’s amazing how many of those have non-mimetic elements. One Hundred Years of Solitude is magical realism. Toni Morrison’s Beloved has a ghost. The Brief Wondrous Life of Oscar Wao by Junot Díaz has a curse. Rómulo Gallegos’ Doña Bárbára is a witch. Siddhartha by Hermann Hesse is a Buddhist parable. The Alchemist by Paulo Coelho is another religious parable. The Left Behind series is fantasy by my definition, but I don’t know where believers would place it. Swan Song by Robert R. McCammon is post-apocalyptic. The Lovely Bones might be considered a fantasy. This Present Darkness by Frank E. Peretti and The Shack is religious fantasy. Bless Me, Ultima by Rudolfo Anaya might also be.
Who got kicked out to make way for these authors? Dead white men. No Hemingway, Faulkner, Dos Passos, Roth, Updike, Bellow, Sinclair Lewis, Upton Sinclair, Steinbeck, Pynchon, Jack London, David Foster Wallace, Wallace Stegner, Tom Wolfe, Dreiser, Mailer, Capote, Vidal, Nabokov, Doctorow, Bradbury, Kerouac, John Irving, Jack London, Malamud, Henry James, Steven Crane, O. Henry, O’Hara, Styron, Don DeLillo, Donald Barthelme, Hammett, or Chandler. And that’s limiting the list just to Americans. The foreign list starts with Joyce, Kipling, Doyle, Dumas, Huxley, Conrad, and goes on and on.
The 21st century is No Country for Old Dead White Men. Starring Javier Bardem. No Cormac McCarthy either.
A rough count of the book shows that about 50 of the books are by white guys (Hemingway, Dumas, Conrad and London are on the list by the way) (I didn’t count how many were dead). I was disappointed that Sinclair Lewis, O. Henry and John Irving weren’t on the list (but you or I probably could come up with a hundred authors that ought to be on this list).
I see Exapno listed Jack London twice. Maybe only one of them got kicked out? 
Re: Clan of the Cave of the Clan Bears. If you consider paleo-sociology a science it’d be science fiction. On the other hand the main character is a Mary Sue so it’s reads like fantasy.
If Mary Sue’s are excluded, then a lot of science fiction is in trouble.
I wonder if this thread skews older (are we mostly Old I’m-Not-Dead-Yet! White Men?), and if a list made by “over-forty educated avid readers” would have more classics. I assume so.
But, then, I would’ve assumed PBS would have older viewership (please don’t tell me my demographic chose fifty shades of anything…).
Related side note: Took me til my 60s to finally join a book club, and it’s full of thirty-somethings. We had an initial organizational meeting, and the leader announced that I would choose the book. Everyone looked at me, and I blurted “Ummm… Dandelion Wine, by Ray Bradbury!” A few had read ƒ451, but otherwise, blank faces.
(I hadn’t read it in 30 years, but it holds up, albeit a bit wholesome for this club, but I warned them they’d have to take off their Lit Crit Hats, and their Cynical Hats, before reading
No, I was addressing the titan, who said thus:
Sorry. I should have double checked everything.
No problem.
I can accept a perpetual motion machine, if the author realizes what a Big Damn Deal that is, and gives it the depth that it deserves. What I can’t accept is a casual perpetual motion machine. It’s not just something that you can shrug off in an aside. And even the serious authors that do posit perpetual motion machines generally give them limitations: For instance, in Asimov’s The Gods Themselves, the “hill that goes downhill both ways” turns out to just be tapping a vast and previously-unaccessed, but still finite, resource, and for which overexploitation would have truly horrific consequences.
As for Clan of the Cave Bear, it’s mostly “realistic”, but the Neanderthals (I can’t remember what they call themselves; probably something like “The People”) are described as having such excellent memories that they can they can remember everything their ancestors ever experienced. Which is pretty clearly magical. And it’s made even more bizarre, in that we’re asked to accept that The People haven’t figured out that sex leads to babies, and have only an extremely vague notion of paternity. OK, I could maybe accept that by itself, but how can you not know who your father is when you can magically remember his experiences?
Then I was pretty close with this post https://boards.straightdope.com/sdmb/showpost.php?p=20970872&postcount=81