On the very first image of black hole: Part I

I was utterly amazed by the first-ever image of a real black hole which was released recently. The captured supermassive black hole is located in the center of the galaxy M87, 55 million light-years from Earth. Due to the size and power limitations, currently, no single-dish telescope can image the black hole. Therefore, rather than one telescope, as described by Katie [2], the first picture of the black hole (Fig. 1) was captured in the Event Horizon Telescope (EHT) project with a network of eight linked together telescopes creating a computational telescope the size of the Earth.

Fig. 1: The first picture of a black hole [1]

The EHT project can be summarized as:

1. The area of interest (where the black hole is located) is expressed as n-by-m mesh creating n*m sections
2. Each telescope has recorded astronomical signal from one of the sections. 
3. Considering the real image of the black hole as n*m-piece puzzle, now 8 (the number of telescopes in the project) pieces are known. 
4. A random image containing the available 8 pieces is generated.
5. An artificial intelligence algorithm, compares the generated image with real images. If the randomly generated image satisfies real image properties it is considered as the image of the black hole, if not, the process is repeated from step 4. 

A variety of images have been added to the database to insure that the algorithm can distinguish a fake image from a real image. Moreover, in EHT project, imaging algorithms with additional assumptions and constraints have been used to produce images that are physically plausible [1].

As described in the related published article [1], the model tries to search for an image that is not only consistent with the observed data but also favors specified image properties.

 Assuming a puzzle with maximum 10-20 pieces, simply, with any 8 pieces the real image can be generated with a high degree of accuracy. The challenge here is that the black hole is a puzzle with millions of pieces and out of that million pieces we now only have 8 pieces (Fig. 2)!

Fig. 2: 8 peaces of Fig. 1

In my opinion, it has not be considered that all the images in the database that has been used to distinguish fake images from real ones, have a common property: They all have been taken by humans.

This common property can significantly affect the image that has now been considered as the first ever picture of a black hole. Putting it differently, assume we use the drawings of 3-4 years old kids as our concept of a real images. The image of the black hole will be different, and will represent a black hole in terms of the drawings of a 3-4 years old kids.

What I’m trying to say is that with the laws of physics that we know and with the concepts that we have on the Earth the image of the black hole will look like Fig. 1, but if we accept that the laws of physics can be different elsewhere (i.e. in the black hole), the image will be different. Or even, with the same concepts and process, taking a picture of the same black hole from another planet, by another intelligent creatures will for sure result differently, as the generated image of the black hole is completely dependent of what we consider as a real or fake image!

To be continue...

References
1- Alberdi, A., Gómez Fernández, J. L., & Event Horizon Telescope Collaboration. (2019). First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole.

2- https://www.ted.com/talks/katie_bouman_what_does_a_black_hole_look_like?language=en