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Gravitational Lensing by Spinning Black Holes in Astrophysics, and Interstellar (arxiv.org)
40 points by susam 45 days ago | hide | past | favorite | 27 comments

The last author on this, Kip Thorne, was a scientific consultant for Interstellar. He is one of the most well-known experts in gravitation, one of the co-authors of the famous classic general relativity textbook Gravitation often lovingly denoted as MTW for the authors (Meisner, Thorne, and Wheeler)[0].

EDIT: forgot to mention he shared the 2017 Nobel prize after LIGO detected gravity waves.

[0] https://en.wikipedia.org/wiki/Gravitation_(book)

If you are a fan of podcasts: Sean Carroll's interview with Kip Thorne was worth a listen.


What's more he gave a talk[1] and has even written a book[2] about the science behind Inter Stellar.

[1] https://www.youtube.com/watch?v=lM-N0tbwBB4

[2] https://www.amazon.com/Science-Interstellar-Kip-Thorne/dp/03...

Thorne is also the author of Black Holes and Time Warps, which is a much more approachable book on the weird consequences of general relativity for non-physicists.

https://youtu.be/Z4oy6mnkyW4?t=966 details and interview with Tunzelmann on Stand Up Maths, whole video is good if you've the time

Unfortunately, the movie preferred pretty picture over scientific accuracy. The image of the black hole lacked the frequency shift as well as intensity variance described in the paper.

In Kip Thorne’s book about Interstellar he talks about what they had to do to make something that would work for a movie. They had to choose a specific mass and rotation speed that doesn’t really exist in nature or the image would not be something that would be intelligible to the viewer and work for the story. This includes the tidal effect in the film. In the end they were making a science fiction film and not writing a scientific paper.

I agree with you. The fact that the visuals of the black hole didn't include the frequency shift and intensity variance was perhaps the smallest artistic license that was taken and didn't really prevent my suspension of disbelief.

If they wanted to create something physically accurate, then all we'd have seen is a blinding white globe as the accretion disk of a black hole emits tremendous amounts of energy and couldn't be resolved to the iconic shape in the movie by the naked eye.

The hapless astronauts would've likely received a fatal dose of ionizing radiation in minutes (if not seconds), and Matthew Mcconaughey would've been shredded by tidal forces long before he entered the event horizon of a stellar mass black hole.

The movie took some liberty with physics, but managed to capture the imagination of so many people. I much prefer it this way. Those who want to dig deeper can either watch an actual documentary or read some books on the topic.

> they had to do to make something that would work for a movie

Here's an article that includes a picture of what they thought it would really look like: https://www.newscientist.com/article/dn26966-interstellars-t...

I think that would have worked perfectly fine. Maybe throw in some more stuff circling it further out.

In my group and collaboration, we frequently discuss how difficult it is to do outreach because you'll get constantly criticized by fellow scientists about every single simplification.

To me the bigger issue with the movie was that it pretended that Love is a fundamental force in the universe at the level of gravity, electromagnetism etc...

Indeed, gravity, electromagnetism, and the strong and weak forces are all emergent consequences of Love, but that would have confused modern scientistic audience so I don't blame them for glossing over that.

It sure confused me.

It didn't pretend that at all. At best it suggested it. It is a fantastic, moving film - my top 5 all time.

Yes, because it's a movie, not a documentary.

They hired a physicist to run simulations to get it "as accurate as possible". I think comments about the achieved fidelity are warranted.

Rather, it's an example of "No good deed goes unpunished".

You suggest that had they done no effort at asking scientists about the theories, no criticism would be warranted, but since they did and cherry-picked what would best support the narrative, they deserve scrutiny.

And I disagree.

The number of people who’d appreciate such accuracy would be minuscule.

Accuracy is great because it’s both consistent and changes expectations. Everyone expects explosions in movies to be giant fireballs so we get more silly giant fireballs. Movies that go for realistic explosions end up feeling shockingly gritty by comparison.

I would have preferred more scientifically accurate movies. Judding by the comments, many more prople who prefer otherwise.

I hope once day, there will be a movie that accurately portrays the reality. I know I am not alone. There are dozens of us! Dozens!

But those souls believe it ruins interstellar

I had 3 semesters of physics in the university and can’t tell whether interstellar is accurate or not. Ok, I’m no genius, but this leads me to an assumption most people wouldn’t get the difference anyway. There’s just no point to be very accurate when making a movie. You have to be only approximately accurate.

You have to tell a story. And people like it.

Sometimes, an audience can feel accuracy even when they don't know it.

A film that has a deep, complex internal consistency can engage audiences and them feel like they want to know more. They don't have to understand the details, but they like to feel that you do.

Reality is a rich source of such consistent details. In historical films, for example, few audience members will really appreciate that you got all of the costumes correct down to the specific year, but the film can feel better than one that mixes Georgian with Victorian with French Court styles.

Getting the physics right won't automatically make a story better. It can constrain the story too much. But if you choose to go down that route, and can still tell a good story, the audience will benefit even when they don't know what they're looking at.

It's why actors like to go into "back story" for a character even when the audience doesn't know what that back story is, and why they work on physicality (walking like the character, holding a fork like the character, etc.) even when nobody will notice. One beautiful example of that: look at the way people moved chess pieces in Queen's Gambit. Even if you don't play, you knew that the actors knew it (and indeed, it came as no surprise to me that they were trained by Gary Kasparov). It's a little thing, but it was just one of a million things that helped that project go right.

I would argue that the examples don't all apply the same. The successful examples you listed are all about human actions, subtleties about how people are acting and behaving. Humans are just naturally very good at sensing these things, unconscious or not. But something like black holes? The overwhelming majority of people have almost no context and even less intuitive understanding of such an alien thing. I doubt that miniscule details would affect a sense of reality when the subject in question is so foreign from the viewer that it is essentially no different to them than something completely fabricated.

It's entirely possible. I'm just talking about how I would have gone about it.

It's not that the audience wouldn't have appreciated that moment or not. It's rather that the film suffered (in my opinion) from a lot of focus on getting the details right, which meant that the things they got wrong jumped out to me -- not as a physicist, but as a storyteller.

They didn't want to tell a story about physics -- which is a fine choice. They wanted to tell a story about love in a sci-fi setting -- again, a fine choice. But it meant that the film looked like "Look here at what we got right, look over there at what we got right, NO DON'T LOOK OVER THERE NOTHING TO SEE."

It's a choice every sci-fi film has to make. I think that this film was less successful (artistically) than it could have been because they made the wrong choice there. I think they'd have done better not hiring a physics consultant than having one and not giving them absolute control over things -- which shows up in things like those tiny details.

This is, of course, just the way I look at it. I'm not here to say it was a good or a bad film, or whether you should enjoy it. I'm saying, "I didn't enjoy it, and I think this is part of why." Not from a physics standpoint, but an artistic one. You are, of course, free to disagree with that on every level. I just thought it might be interesting to hear how a different director saw it.

I wish movies would respect their audience. They tend to dumb things down. It would be fun to see someone really go after it, and let the public catch up. Here's what I think when I see this:

Interesting to see the edges of a black hole. Nothing gets more powerful than that. Why build bigger and bigger colliders if you can get accurate data with something on a cosmic scale.

Interesting to see what particles of spacetime do there. A string is a particle with one dimension. Why is it constricted like that. And what applications exist in manipulating that constricted degree of freedom.

If we are imaging black holes, and manipulating instruments in the plasma of stars, and there's no consequences, at what point is everything out there a refraction pattern controlled by our actions. A star or a galaxy leaves our ability to view it. We still know about it through black hole imaging. No way nature could do that. We manipulate that distant celestial object to rely on our ability to image a black hole, and then suddenly stop. What happens?

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