Editing 2133: EHT Black Hole Picture

{{comic
| number    = 2133
| date      = April 5, 2019
| title     = EHT Black Hole Picture
| image     = eht_black_hole_picture.png
| titletext = [five years later] Ok, it seems we were accidentally zoomed in slightly too far. But imagine there's a cool-looking twisted accretion disc just outside this black square!
}}

==Explanation==
This comic references the {{w|Event Horizon Telescope}}, an international project dedicated to imaging {{w|black hole}}s {{w|Sagittarius A*}} and {{w|M87*}} with angular resolution comparable in size to their event horizons.  The first image of M87 was released to the public on Wednesday, April 10, 2019, five days after this comic's release, and appeared on the same day in the comic [[2135: M87 Black Hole Size Comparison]].

The image was produced from data gathered since 2006, collected by over a dozen radio telescopes around the world and combined through a process called {{w|interferometry}}.  Normally, a telescope's resolution is limited by the size of its aperture, but by recording radio signals at multiple sites, the minute differences between the signals can be digitally processed into an image with much higher resolution.  The telescopes used for the EHT are in Hawaii, North and South America, Europe, and Antarctica, and so the effective diameter of the collective EHT is almost the size of the Earth itself.  As each telescope recorded observations of the black holes, the results were written to hard drives and mailed to observatories at {{w|MIT}} and the {{w|Max Planck Institute for Radio Astronomy}} for processing.  Astronomical recordings can involve astronomical amounts of data, so the raw, original, feed from a telescope may never be stored if it is too dense -- it is instead processed live by computers to capture the information of interest, and the processed result is stored.  <!-- Should add remarks here about how many petabytes of data were processed and how much computing power and time was used, when that's announced.  -->

The first image released by the EHT was expected to be in April 2017, but unforeseen events delayed it by two years, to April 2019.  Randall predicts this trend will continue, and makes a joke by analogy to real-world difficult experiences capturing important moments.

Luckily this comic was not in any way prophetic, and five days after this comic was released [https://www.bbc.com/news/science-environment-47873592 the EHT team released a black hole picture] for the world to enjoy.

The comic shows [[Cueball]] giving a press conference on the recent photographing of a black hole.  However, the photograph is a disappointment, caused by the spectacular failure of several systems:

* You cannot download the picture.
Obviously, it would be quite impractical to fail to reliably provide this in an astronomical system. Cueball describes the system as being like {{w|Pinterest}}, where {{w|JavaScript}} prevents you from right-clicking on an image so that you could save it (or at least attempts to, there are many workarounds).

* You cannot screenshot the picture.
Cueball states that they then tried to take a screenshot, but the key combination to make a screenshot instead turned off the monitor where the picture was being displayed whenever they tried to use it, requiring extra time and effort each attempt in order to return to the view of the black hole. This could reference the fact that many mobile devices incorporate the power button in their screen shot combination and the power button can also turn off the screen.  Laptops and operating systems may also have undocumented key combinations that blank the screen, which users can accidentally press when in a hurry and create further stress for themselves.

* The viewing period ends before a physical camera can be used.
As a last act of desperation, Cueball took out his phone and attempted to take a photo of the screen showing the black hole, but by that time, the observation had ended, and the photo was lost.

In reality, none of this ''should'' be an issue as the picture would be immediately saved by the system and would not need to be downloaded from the site, but NASA especially knows that developers of a system can never predict the obscure happenstances that can combine to create failure at the end.

Cueball then states that they would try to take a picture of a black hole again next year.

The title text explains that (after presumably five years of annual tries), the picture failed again as the telescope was too zoomed in and only captured a featureless square. Since a black hole by definition returns no light sent to it, the photograph would be entirely black. Researchers however are primarily presumably trying to obtain images of the more interesting edge known as an {{w|accretion disc}}, which could actually be meaningfully photographed.  The joke is that the black hole could only be photographed once a year, and in each year some incidental set of mistakes combined to prevent the photograph from actually being shared with anybody.  This could be a reference to the {{w|cosmic censorship hypothesis}}, which states that a "naked" singularity cannot be viewed from outside an event horizon, where in this case the censor is some kind of "butterfly of doom" that bedevils astronomers who attempt to image one anyway, similar to some interpretations of the {{w|Novikov self-consistency principle}} (a possible resolution to various {{w|time travel paradoxes}} which asserts that any event which would lead to a paradox must have probability zero).

==Transcript==
:[Cueball is standing behind a lectern, with "Press Conference" and the EHT logo displayed on a projector screen behind him.]
:Cueball: We linked up our observatories, got everything aligned, and there it was:
:Cueball: The first image of a black hole!

:[Zoom in on Cueball. A question is asked from off panel.]
:Off-panel question: Can you share the picture?
:Cueball: Well, here's the thing...

:[Cueball lifts his arm holding his hand with its palm up.]
:Cueball: Turns out our telescope feed is like Pinterest, where you can't right-click to save an image.
:Cueball: So we tried to take a screenshot, but the key combination kept turning off the display instead.

:[Zoom back out to show that the image on the projector screen has changed to show a blurry picture of a white computer screen against a black background. The EHT logo remains at the bottom of the projector screen.]
:Cueball: I grabbed my phone and tried to take a picture of the screen, but I was too slow. The observation had ended.
:Cueball: We're planning to try again next year, and we'll definitely record the screen this time.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Public speaking]]
[[Category:Astronomy]]
[[Category:Smartphones]]