Saturday, November 15, 2014

Interstellar

 "Honestly, Interstellar really sucks" -- this is not quite true, but I couldn't help thinking of this scene.



When I asked my spouse whether she would come to watch latest Christopher Nolan' movie Interstellar, she replied: "No way!".

"But it's about black holes.", I said.
"Exactly." - she replied.

"But Kip Thorne, a world-famous physicist, was involved in the production.", I said.
"Even more so." - she replied.

"But the director is Christopher Nolan!", I replied.
"Indeed."

"But it's gonna be a Hollywood Blockbuster!", I continued
"Forget about it"

"But it's the movie of the year!"
"Exactly."

That was the end of the conversation. As a matter of fact, she went to watch the movie without (and even before!) me, but I guess this is normal within women logic.

Anyway, together with part of the Lisbon gang, yesterday we finally went to watch Interstellar in its iMAX curved-spacetime, relativistic glory, so now we too are entitled to talk about this movie.





Personally, I have to say I don't really care about relevance to reality when watching a movie, especially a scifi movie like Interstellar. Thus, I don't care whether wormholes are impossible to form, nor about time travels or extra dimensions (I do care a bit more when they say such extradimension is "Love", sic.) if this help the movie's cause. Anyway, having said so, Interstellar is the classical Hollywood product, with inter-stellar cast, nice and fast screenplay and an outstanding picture. Probably, considering it's an almost-three-hour long movie, the most amazing thing is that time flies...even without spacetime distortions!

Richard Price has recently written a review on the movie which, first of its kind, has appeared in the scientific journal Classical and Quantum Gravity. It's a very enjoyable reading and makes some good points:

1) "The explanations, or even presentations of the science, are brief, easily missed, or in fact really missing. The wormhole gets a few sentences and a “demo” with a folded piece of paper; the tidal effect on Miller’s planet (which has technical issues) gets none (did I blink and miss it?); the black hole accretion disk (which has technical issues) is not explained.  Lots of things are happening. Maybe too much, and clear explanations of the science, as well as of the human themes in the plot, are subservient to an immersive experience."
I totally agree and this is an important point for a movie which presents itself as scientifically realistic. Indeed, from Kip Thorne's endorsement one would expect that the scientific parts of the plot would have been explained to the general public, while they pass by very quickly (too quick for a movie that is almost 170 mins long!). My colleagues and I were left with the impression that they put a lot of effort to make realistic images of the black hole by solving Einstein's equations, but they didn't bother too much to explain why it was important to do so. As Price says, the fact that on the planet close to the black hole tides are huge is really brilliant I have enjoyed it quite a lot, but I doubt most people in the audience have understood why that happened.

2) "Much work has gone into [computer-graphic generated] images, but the pace of the movie does not slow for them, nor are they explained."
This reinforces the previous comment; judging from the interviews to the Director and to Prof. Thorne, I would have expected that more time would have been spent to let the spectator appreciate the picture (which is really great, that's a fact). It's again hard to understand how this was not possible in a 3-hr movie.

 Anyway, putting on the physicist's mask, here are some further comments I didn't read yet:

1) I've particularly appreciated one of the messages the movies sends around, namely that the girl has to know what happens inside a black hole to find the theory that synthesizes gravity with quantum mechanics (aka quantum gravity). This is really at the core of science. We know how gravity works (as you have read in the news, we have just made a spacecraft land on a comet 500 millions kilometers away from us by sending it 10 years ago, thus predicting its gravitationally-driven trajectory over a decade), we also know how quantum mechanics works (the computer/tablet/smartphone from which you read this post proves that) and we also have a rough idea of where quantum effects are important for gravity. This happens precisely inside a black hole. What we don't know is how quantum gravity works because, at variance with Interstellar cast, we are not quite close to enter the event horizon of a black hole and will probably never be. Even if we were, what happens inside a black hole stays inside the black hole, and it is currently unclear among the community whether or not the "singularity" hidden inside black holes would ever be in touch with us. Anyway, I think the movie makes it clear that physics needs experimental evidence to keep going. As theorists we tend to forget this, but we shouldn't.

2) Kip Thorne's popular-science book "The Science of Interstellar" is one of Amazon's best sellers. There, one could find the solutions for all the unanswered questions in the movie. There is surely a lot of interest in gravity, black holes, wormholes, time travels, etc... and Interstellar cinematic experience hinges a lot on public curiosity for these phenomena. If this can help in bringing young minds to science (similarly to what Stephen Hawking's "A Brief History of Time" has done with previous generation of students), that would be a way greater success than Interstellar box-office gain!

Now, putting off the physicist's mask:

1) Gender equality in science is an issue, even more so in physics. The movie reinforces this problem, since for a supposedly one-way mission to civilize another planet NASA chooses 4 men (and a robot) and only one single woman. OK, they brought embryos to grow in the new planet but, hey, I don't want to be on Anne Hathaway's shoes if she would have landed in a new planet alone with that gang of sexually-repressed scientists for good.

2) I've completely missed why solving quantum gravity was so important for the survival of human race. Is it because -after having understood the theory- humans were able to create wormholes and to forge the interior of black holes at will? At some point Matthew McConaughey says he was able to communicate with his daughter because in the future human race was able to use black holes and gravity to send messages back in time. But was it so because, having the daughter been instructed  in the past, mankind eventually learned how to do so? There's clearly a sort of circularity in this argument and causality is easily lost. Technically (again putting on the physicist's mask), this is called "closed timelike curve" and, as weird as it might sound, such curves of spacetime exist inside spinning black holes! This raises the famous grandfather paradox, that is, you can travel along one of these curves back in time and kill your ancestors before you were even born.... (I swear i'm not paid to study this).

Anyhow, rephrasing Frank Zappa's words, "writing about movies is like dancing about architecture", so I stop here and suggest you to head to the closest cinema (preferably one with iMAX screens) and enjoy the movie.


Addendum: I forgot to mention how dangerously close this movie is with Contact. Similar bucolic life, the scientist daughter, same father-daughter relationship, even same final paranormal contact between the two through some sort of spacetime portal. Last but not least, same actor (although I have to admit McConaughey has really improved since the other movie...)




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