There is an interesting article on the Science magazine web site entitled “Physicist who inspired Interstellar spills the backstory—and the scene that makes him cringe. The physicist here is Kip Thorne and “Interstellar” is of course the new movie. (I feel like I grew up with MTW, but that is of course an exaggeration – it was published about 2 weeks after I entered MIT.) Kip Thorne has done a lot of work on General Relativity, but in recent years he has mostly been known for being one of drivers behind the search for gravitational radiation.
What got me to thinking was this statement at the end of the interview :
We learned [that] when you have a fast-spinning black hole, without any accretion disk, and let it just lens the distant sky—a star field—we saw a fantastically beautiful structure that is sort of like a fingerprint, but much more complex. We’ve long known that you’ll get multiple images of each star [around a black hole], due to [the combination of] light rays that come pretty much directly to the camera, [and] rays that go in and circle around the black hole once and come to the camera. But what we found was that on the side of the spinning black hole where space is moving towards us, [you see this beautiful structure].
It was completely unexpected with huge amounts of internal structure in it, regions where the star field appears to be quiescent and other regions where the stars seem to be whirling around in little vortices. To me it’s a lovely kind of discovery in the sense that it is really very beautiful and it arises from a collaboration between a scientist and a group of computer artists. We are submitting a paper about this and about the particular method that Double Negative uses to the journal Classical and Quantum Gravity.
So, thinking about how a black hole might appear to a nearby spacecraft, and actually trying to calculate it for a movie, leads to new research, research which will be very relevant to the attempts to create an Event Horizon Telescope (or EHT) using millimeter wave Very Long Baseline Interferometry.
The EHT is probably the most under-appreciated profound astronomy effort currently underway. (In my experience, VLBI tends to be under-appreciated, which may be why the NSF is thinking of shutting off the VLBA.) The EHT will probably only be able directly observe two event horizons, that of the black hole at the center of the galaxy, Sagittarius A* (Sgr A*), and the back hole at the center of M87, but that could be enough to revolutionize physics.
What doesn’t seem to have penetrated much outside into the wider community is that the EHT is a fundamental test of General Relativity and strong gravity. We really don’t know that black holes exists (although we know that lots of mass is concentrated at SgrA*, we don’t know it has an event horizon, or what sort of event horizon or ergosphere it might have). Maybe gravity and nature do things in some other fashion than the predictions of General Relativity. The EHT will be able to find this out.
So, that’s another post entirely, but what got me here was how a movie (which most scientists would think of as a distraction) has led to real, and maybe very important, science. Can people think of other examples? I know in my own work, many of my best ideas have a Sci-Fi background, of the “how would you start interstellar travel” or “what energy sources would aliens use” type, but those are more like thought-experiments, which have a long history. Can anyone think of example of scientifically motivated entertainment leading to real science? I would love to hear of it.