We need to admit that the article, “We need to admit that the black hole photo isn’t very good”, isn’t very good
Today is a pretty glorious day for astrophysicists, astronomers, science enthusiasts, and just about any human being. The first images “of a black hole” were unveiled to the public. Or rather, the first images of light bent around a black hole.
I must admit, although I have a degree in physics I couldn’t fully appreciate how incredible this image was without an excellent explanation by Veritasium. I mean, I understood that light bent around black holes and that was presumably what we saw in the photo, but I didn’t realize that we were literally looking at objects behind the black hole. That is, we were looking at light that looped around the black hole. This blows my mind. Perhaps even more mind-blowing is that this phenomenon was predicted so well by our understanding of physics (or rather, the understanding of many brilliant and hard-working physicists which they illuminated to the rest of us lay-people).
But the formation of an image across the universe constructed with photons that were once on the other side of a black hole wasn’t impressive enough for some people. Some people expected more — likening the blurry image to the dark ages before instagram filters or before humanity perfected selfie photography. This blurry image simply does not do! Slate has thus made us aware of the inadequacy of our astro-photographers.
As a public service in the same spirit as Slate, I would like to add on to their article with this article. Below, I will describe some ways in which the cited article is, as we must admit, not very good. (I will do my best, but do keep in mind that this is not my field…)
The article could have told us how inadequate the camera was according to the author’s standards. The camera used to take this photo was not just one radio telescope, but a global network of radio telescopes. Each individual telescope was pointed toward the target black hole, ~53 million light-years away, and images were captured over time. The network of telescopes were synthesized into an effective “Earth-sized” telescope using “very-long baseline interferometry”, a technique that relies on recording precise timing of the incoming light measurements and analyzing the differences in those timings between the individual telescopes. Perhaps the author was disappointed that this array was only a global distribution of radio telescopes and that we didn’t also have Moon and Mars locations.
The article could have told us how inadequate the data transmission and consolidation was. In total, more than 5 petabytes of data were collected. As part of that data collection and consolidation, the fact that a pallet of hard drives with data had to be sent from the South Pole observatory to the northern hemisphere because it was too large to transmit may have been scoffed at by the author. Why bother with such little data? That should have been one hundred pallets of hard drives, all presumably the latest 14TB capacity (or more). Perhaps the author thought, ‘maybe if we collected 500 petabytes this image might be worth looking at’.
The article could have told us how inadequate the data analysis and synthesis was. Sure, this effort involved tens of sites (by my quick count on Wikipedia there are >60 sites involved in the EHT array). Sure, this effort took since 2017, when the data finished being collected. Sure, this effort required the alignment of all the different data which was collected across 3 days. Sure, this image is only possible because of the incredible advances we’ve made in computing and image processing. But why not wait for another ten years when we have improved image analysis algorithms to give us a 3D rendering of this black hole image and at a higher resolution? I assume that’s the big technical critique of the author, although it was not well-stated.
Anyway, my point is that there are a number of technical aspects to this milestone that us lay-people (and especially those of us who do any sort of imaging) can marvel at. I assume the author was having a bit of fun in the moment, which is why I’ve elected to have a bit of fun and try to tie-in some aspects that are mind-blowing to me. This blurry but absolutely awe-inspiring photo is a testament to our progress as a species. It’s a product of our times, as improved analyses will be products of future times.