More Thoughts on Interstellar

I don't watch many movies, which is why I seem to think about the ones I do watch more than most people do -- and, usually, more than the movie itself warrants.  I've been doing that lately for the movie "Interstellar".  "Interstellar" was apparently intended to be a vehicle to both celebrate science and educate the public about science, so I had high hopes of being able to make use of it in the classroom.

Sadly, it came off more like "The Core", which also combined a threat of human extinction, an uncritical enthusiasm for science and technology, serious scientific problems, and reliance on deus ex machina.  In "The Core", the deus ex machina is money:  any problem in science or technology can apparently be solved in a matter of months if unlimited government funds are provided. "Interstellar" has two main dei ex machina:  "bulk fields", and the inevitable flow of progress (or evolution through rose-colored glasses).  The difference is that the problems with "The Core" were obvious from the trailers; we knew going in that this was going to be ridiculous, so there were no high hopes to be dashed, just the expectation of silliness.

Anyhow, let me get off my chest a few more specific problems with "Interstellar", then I'll let it rest.  In case you haven't guessed, SPOILER ALERT.

1.  Blight is some sort of global biological pathogen that seems to attack all plants.  In the book, Thorne suggests it attacks chloroplasts; he doesn't even try to justify the line in the movie about it breathing nitrogen (but that's not my main complaint).  Presumably it is carried on the wind, and the massive dust storms would make sure every place is exposed.  The problem, then, is not to get away from the Earth; the problem is to get away from blight.  It would be a huge problem to try to evacuate whatever remained of the human species, together with the food plants they needed, without bringing this pathogen along as well.  In fact, if it was easy enough to do that, why not just build giant decontaminated greenhouses and move people into them?  Why would the greenhouses need to be in outer space instead?

Building greenhouses on Earth would save many, many problems -- or at least defer them for a significant period of time.  There would be no need to spin them for artificial gravity; the Earth's atmosphere and magnetic field would shield the greenhouses from cosmic radiation; it would be much easier to access raw materials; it would be easier to maintain pressure; it would be easier to control the temperature.  Thorne writes in his book that there would be plenty of oxygen still in the atmosphere for decades to come, but enough carbon dioxide to begin making the air poisonous; that is an easy problem to deal with.  However, the air would be full of blight spores, the greenhouse would need to be hermetically sealed, with only occasional (probably emergency) access to treated outside air.  The level of CO₂ would steadily increase in the absence of photosynthesis, probably leading to a Venus-like runaway greenhouse effect in the geological blink of an eye, but by locating greenhouses on the south-facing slopes of hills near the oceans (to moderate temperatures) in the high latitudes, the situation could be kept bearable for some time -- perhaps long enough to develop algae and plants that can withstand blight and bring the atmosphere back under control.  Earth would still be a hostile planet, but much less hostile than the one Cooper elects to move to.  Mankind would already have something of a substantial head start in terraforming the Earth!

2. Wormholes inherently involve strongly curved space, which is equivalent to strong gravitational fields. For a small wormhole, like the one found (in the movie) in orbit around Saturn, the tidal forces would rip apart any space ship traversing it.  Unless, of course -- bulk fields!

3. If the "five-dimensional beings" are invisible to us except for gravity, we are also invisible to them except for gravity.  Seriously:  they would only be able to see through light if they absorb light, which would make them visible.  Yet, through the magic of "progress", they are able to locate specific places, times, and people on Earth, and they are able to construct a virtual reality for Cooper that both interacts with the past and even gets the colors right.  A movie that is supposed to be strong in science should not make the science look like pure magic.  

I know that many people love Arthur C. Clarke's statement, "Any sufficiently advanced technology is indistinguishable from magic."  Maybe, in some sense, that is true, but it is not true that anything you can imagine being done by magic can be done by a sufficiently advanced technology.