As Lynch and Edgerton discovered and Elkins (Op. cit.) reiterated, scientists talking science to scientists use non-aesthetic criteria to compose their images. In everyday understanding of the term, however, the technicians do use an aesthetic to produce pictures intended for the public rather than science. Such astronomical “pretty pictures,” as the scientist-artists modestly termed them, were not aimed to reflect real physical quantities and couldn't always be used for accurate science. Instead these “pretty pictures” were qualitative and aesthetic. In contrast, the technicians believed that the quantitative work they did calculating values for professional work was outside the realm of aesthetics.
      Elkins (Op. cit.) takes the discussion much further. In his opinion artistic traditions originate from painting and photography. The space imagery topic is enriched by his observations linking it to wider aesthetic histories. He avoids imposing one interpretive framework on both science and art or applying artistic criteria to all scientists' visual outputs. Instead he respects the different languages of humanities and those of scientific analysis and speaks of images in whichever set of terms is favoured by the discipline itself.

 

The Aesthetic of the Sublime

 

      Central to his critique of space images is the doctrine of the sublime, taken from Burke [14] and Kant [15]. Elkins' (Op. cit.) main point is to refute astronomical imagery as being sublime, either in its popular forms or its purist manifestations of scientific imaging for scientific purposes. “Outer space just does not mix — at least not yet — with the central themes of painting.” He takes Kant's Mathematical Sublime as the most pertinent argument in favour of the sublime aesthetic — but it is worth first considering, as he does, Burke's own eighteenth-century version of the sublime and its contrast with “the beautiful.”
      For Burke, the sublime in art evokes monstrosity, terror, and infinity. It conjures the strongest human emotions based on “obscurity,” which arises from the indefinite and powerful emotions of fear.

 

Power is undoubtedly a capital source of the sublime - that's where its energy is derived (p. 65).

 

W. J. T. Mitchell [16] clarifies Burke's innovative role in arguing against classical aesthetics that depend on proportion and form. Instead, the sublime is located in pain, in the unrepresentable, the insensible and mysterious.
      Burke's stress on difficulties of comprehension and what lies outside representation are amplified by Kant. Definitions of the sublime in the Critique of Judgement (Op. cit.) depend on terms and associations that belong to his century. Since space imagery is “nature,” the following statement summarises one of his lines of argument: The sublime is:

 

The absence of anything leading to particular objective principles and corresponding forms of nature, that it is rather in its chaos or in its wildest and most irregular disorder and desolation, provided it gives signs of magnitude and power, that nature chiefly excites the ideas of the sublime.

 

Both Kant's dynamic and mathematical sublime are discussed by Elkins (Op. cit.). As he records it, the dynamic sublime is the appreciation of a contrast between powerlessness before nature of the human physical body, and the parallel knowledge that the mind lets us think, providing a different and reassuring kind of knowledge, which offsets the horror of the direct physical experience. In the dynamic sublime, there are thus mingled feelings of horror, paralysis, loneliness, and comfort. Elkins is more interested in Kant's mathematical sublime.
      Elkins suggests Kant's mathematical sublime might help understand space photography — its connections to the ideas of infinity, of magnitude, and consequent feelings of awe and fear within the unstable boundary when the grasp of an idea transfers from intuition to cognition. This state of uncertainty and fear is triggered by difficulties with sheer immensity, and vastness beyond intuitive grasp. The best the human can do before such incomprehensible magnitude is to capture it in an intellectually contained category, such as infinity. However, that containment is only a transitory interlude. The next phase is to realize that the human ability to provide a mental tool for comprehension, such as the concept of infinity, succeeds only giving a short-lived relief, before one realizes that the word infinity does no justice to what is really being attempted: Words and concepts defy the vastness of the experience, reawakening a kind of vertigo. “That is the sublime — a pleasure that comes from displeasure — the displeasure of realizing that the imagination has been, and always will be, defeated.” (Elkins, Op. cit.:29). Kant calls himself the sublime a “negative pleasure.”
      These ideas of the sublime entail the breakdown of interpretation and failure of imagination. Elkins' fascination lies in what is unrepresentable and he turns to astronomy to provide cases of extreme doubt — at the far limits of our ability to derive meaning by scientific means from visualized informational traces. To complete that task, he disdains ‘pretty pictures'. He proposes his own iconic qualities to analyse space images, such as blur, the ruined grid, or darkness, each of which enables descent down a ladder of disorder where the bottom rung is outside knowledge, experience, or recognition. He repeatedly indicates how strange the astronomical world is:

 

People talk about the behaviour of gases in nebulae by analogy with jets and bubbles in fluids but there is nothing in human experience analogous to a neutron star or black hole (p. 94).

 

He analyses images from gravitational lensing, where the correspondence with faint visual traces of a lensed galaxy are compared with predictive equations, and with ever increasing magnification or enhancement to achieve comprehension. As he says: “What is at work here is not an abstract Kantian infinity but a set of particular observations and equations,” which leads to “a real mathematical regime of interpretation, without the sublime, and without infinity” (p. 91).
      The Hubble Deep Field (fig. 6) — the attempt to see beyond galaxies into deepest spacetime — is so strange that familiar galaxy shapes break down, presumably under operations of physics during unusual conditions of the early universe. Elkins probes the philosophical and material realities of the almost black visual space in the Hubble images, between the deepest and earliest galaxies where interpretation has deep fragility and is “confusion-limited.” By the end of the discussion of astronomy he has descended the metaphorical ladder to the point where there is nothing left to look at in these pictures: “The object has departed.”