Interstellar has a lot of physics in it.
Like, really, a lot of physics. While some science fiction is quite happy to loiter on the "putty" end of the Mohs Scale of Sci-Fi Hardness [TV Tropes], Interstellar at least aspires to the more unscratchable reaches. The general consensus seems to be that the bulk of it (until the denouement, at least) is at least vaguely plausible; the involvement of Kip Thorne [Wikipedia] certainly doesn't hurt the credibility in that regard. The space tech also feels real: It seems delightfully plausible that our first interstellar voyages would be on clunky, ruggedly built ships with a distinctly 70s vibe — I am 100% willing to accept the Endurance in a way that I simply cannot accept the Enterprise from the shiny Star Trek reboot. If spaceships ever leave the realm of engineering for that of graphic design, it's going to be a long time in the future indeed.
So, naturally, most of the back-and-forth about the film's plausibility has centered on the physics in the second and third halves*, from the gravity-induced time dilation to the precise nature and limits of the tesseract**. That's all well and good, but there's much more interesting science to be picked apart here.
Specifically, I'm interested in all the social science behind how we get to the world portrayed in the opening act.
I am by no means a sociologist of any stripe, but even so I've picked up on a few facts and prognostications. The United States is set to be majority minority by 2043 [Associated Press]. There will still be plenty of white people around at that point, but we're not going to outnumber all other racial groups at that point. Even now, racial demographics are hardly uniform across professions. Our CEOs may be as lily white as ever, but as of 2009, 75% of farm workers in the United States were born in Mexico [PDF from the National Center for Farmworker Health]. This isn't new information. There's a long history of immigration to this country from Latin America, and the concomitant white hysteria about the resulting demographic trends is also old hat.
Interstellar ignores all this. The farmers are all white. Almost everyone at NASA is white***. Pretty much everyone we see on the space station at the end — certainly everyone with a speaking role — is white.
Now, I don't actually think this is inherently implausible. White privilege isn't going to go away with our majority status, and it's going to be a long time indeed before whiteness stops being profoundly advantaged by the systemic racism of American society. It is all too easy to imagine the most privileged whites buying up the best arable land as the food crisis deepens, leaving oppressed, marginalized groups to die of starvation. Horrifying, appalling, and unspeakably inhumane, yes, but easy to imagine.
It is also not something that Interstellar engages with. At all. The film mentions that the global population has crashed and makes very clear that the survivors are having a rough time of it (tho not so rough that they don't have electricity, gasoline, and running water), but very much avoids making you think about how many lives have already been cut tragically short, let alone whose lives and why theirs, specifically. Insofar as the movie concretely describes the population crash, it comes across as an impersonal, neutral population shrinkage, without imagining the nauseating policies that would guide and direct the decline, disproportionately and deliberately destroying some groups while leaving others more intact.
This is a failure of imagination, a failure of science fiction as such. Science fiction is all about imagining potential futures, asking how do we get there from here, and what happens when we do? Interstellar is a film that can imagine waves the size of mountain ranges, planets made of frozen clouds, but cannot imagine an America where whites aren't the center of attention, won't imagine the disturbing steps necessary for that to be the case.
There is absolutely science fiction that does this, that engages with the social sciences and imagines potential futures that take into account present trends, but it still feels like a niche, in much the same way that we have "gay movies" instead of just "movies with queer characters". It isn't enough. By all means, pick apart the physics of Interstellar, but don't give it a free pass on the sociology. If you want to write realistic science fiction, you cannot ignore the people that all the physics is going to be happening to.
Writing for Grantland, Wesley Morris is right to say that Interstellar depicts "not America, per se, but Americana.". Americana is white, it is heterosexual, it ignores all the forces of oppression that are baked into American culture and posits a conservative world where marginalized groups simply don't exist. Interstellar isn't a crystal-hard sci-fi movie about what could plausibly happen to us given a few artistic liberties, it's a bunch of theoretical physics slapped over a preposterous fantasy of this country as it isn't, wasn't, and never will be.
*It's a long movie.
**The one exception to this trend is the blight that's making Earth so uninhabitable in the first place. When I watched the movie, I remember getting the distinct impression that it was a bacterial/viral infection that metabolized nitrogen instead of oxygen (which seems . . . implausible, biochemistry-wise). Upon poking around online, it seems that other people had wildly different impressions on this point. I don't have access to the script, nor do I have the inclination/money to go see it again in the theater. For now, let's just agree that there are important vulnerabilities inherent in monoculture farming and move on with our lives.
***I looked for current demographic information on the ethnicity of NASA employees, but couldn't find it it in their numerous data sheets. If anyone has pointers to information on this front, they'd be much appreciated.