Seeing is believing

Part II: law-and-order edition

In a previous post I was lamenting how scientists and science popularizers and ultimately all people adopt a seeing-is-believing attitude when confronted with visual evidence in the form of photos and videos unless actively reminded to take a more critical stance.

A colleague told me that his daughter’s high school textbook discusses black holes at some point and presents the famous picture of the supermassive black hole in M87 as visual evidence that they exist. Too bad they also write (in the same page) that a black hole is the leftover of a stellar explosion, when in fact the supermassive black hole in question is not of stellar origin: it would take a star weighing a few billion Solar masses to make it, assuming stellar physics scaled to those masses -which it doesn’t.

For good measure, my new academic home, INAF, published a calendar of 2020 that looks like this (yes it’s still hanging in my office four years later):

It may be of interest to point out that in a closed universe Black Holes do not exist – in a very technical meaning of the word ‘exist’, obviously. I did not double check the theoretical argument, nor am I suggesting that we should not be able to ‘see’ something that looks like M87’s black hole under the appropriate observational circumstances. What I am pointing out is that -in what appears to be pretty standard GR- the existence of the very theoretical entity that is supposedly ‘directly’ depicted by the ‘photo’ of M87’s black hole may be problematic.

Note that naïve visual realism is not an issue with mainstream scientists and popularizers only: even the freaking flat Earth people claim that

a photograph cannot ‘imagine’ nor lie

when referring to purported photographic evidence of Earth’s flatness. In fact their ‘zetetic’ epistemology -which consists in pretending not to have priors- is much closer to the stance of the median scientist than one is comfortable to admit.

Interestingly, the translation scholar Ira Torresi makes a very similar point (similar to mine, not to the flat Earthers’) in this book chapter that covers how courts of law treat photographic and video evidence. Some quotes are in order:

In the current understanding that one finds outside semiotic scholarly literature […] pictures can only be absolutely true or absolutely false; unlike words, they cannot be used to argue. Thus, the risk of dismissing pictures as false without taking into account the messages they convey, or accepting as evidence pictures that may be true, but not relevant to the case in point, is a very real one

and

In common law in general, sketches and other pictorial representations produced by a person involved in a proceeding, as well as oral reports provided in previous proceedings or gestures, are considered to be ‘hearsay statements’, whose admissibility is subject to particular provisions and must be argued in court. In contrast, photographs and video recordings do not count as statements, but are considered to be ‘real evidence’: Photographs and films are excluded from the definition [of ‘a statement’] and continue to be admissible, at common law, as a variety of real evidence […]. Apparently, the common law system does not take into account the efforts of those photographers who have gone to great lengths to have their photographs recognised as (artistic, political, cultural, gender …) statements (e.g. Spence 1988)

The identity relationship that is commonly held between photographs and reality (‘the picture is what it depicts’) or one’s representations of reality (‘the picture is what I see in the picture’) is made explicit in several criminal laws or procedure provisions

[…] the postulate that lies behind the very use of photographs as official evidence of a person’s identity: i.e. there is a purely denotative relationship between the photograph and what it depicts. According to this postulate, photographs do not interpret reality; they represent it as it is. They cannot lie; they are immutable and are therefore perfect evidence

Perhaps this will change now that AI can produce realistic-looking yet fake images with little effort. But just how cool is it that basically the same issue is shared by judges and lawyers (concerned with the law of man) and scientists (concerned with the law of nature)?