Jens Schröter Holographic knowledge and non-reproducibility

UNPUBLISHED TRANSLATION

1. The marginality of as an

Holography is not one of the central themes of media studies, in Germany at least.1 Media history normally addresses mass media, such as cinema, radio, television and “computers”, which form the “canon” of research into media .2 But there are also no references to holography in the more specialised histories of “optical media”.3 If holography is mentioned at all, then it is in a distorted form. So, in an otherwise ground-breaking text about the role of photographic for the practice of by Linda Williams. Holography appears unexpectedly here in a footnote: “[...], there now seems good reason to question the underlying notion that the entire of cinema from the obscura to holograph represents a continuous line of the Western metaphysical ideology of the visible.”4 Holography seems here - in a footnote dedicated to the so-called apparatus debate - to be part of the prehistory of cinema, which is neither historically nor systematically correct.5 Williams pigeon-holes holography into a line between and cinema, subsuming it - as will become even clearer - into a field of knowledge completely foreign to holography. If you speculate what the reasons for this sweeping absence of holography could be, indications are provided in the last paragraph. In the heterogeneous field of media science(s), there are the traditions that are mainly based on communication theory, on one hand, which refer back to the research into mass media and mass communications. However, holography has not (yet?) become a mass medium like cinema, radio, television or (if you want to include it) computer-mediated communications (email, ). In 1996, Brian Winston discussed the question as to why holographic cinema or television had not yet become established: Initially, there were considerable technical difficulties. It is not at all clear how the enormous informative content of holography would allow transmission. Winston notes that it would definitely be possible to solve some of the difficulties with enough research, yet “no supervening social necessity is accelerating such a development”.6 There was no social “pressure” to develop holographic 3D cinema. Above all, the television industries are really striving to spread HDTV and flatscreens (this is even more the case now, in 2008, than at the point at which Winston wrote his text): “New display

1 The only major and detailed study into its history is Sean Johnston: Holographic Visions. A History of New Science, Oxford 2006. 2 See, for example, the impressive study by Gebhard Rusch et al.: Theorien der neuen Medien. Kino – Radio – Fernsehen – Computer, Paderborn 2007. 3 See Ulrike Hick: Geschichte der optischen Medien, Munich 1999 – This study simply breaks off at cinema. But also in Friedrich Kittler: Optical media. Berlin lectures 1999, Cambridge, UK 2011, Reprinted (Transl. by Anthony Enns), there is no reference to holography. 4 Linda Williams: "Corporealized observers: Visual Pornography and the ‘Carnal Density of Vision’", in: Patrice Petro (Ed.): Fugitive Images: From to , Bloomington, Indiana 1995, P. 3-41, here P. 39 FN. 5 See also Hartmut Winkler: Der filmische Raum und die Zuschauer. "Apparatus" – Semantik – "Ideology", Heidelberg 1992, P. 19-76. 6 Brian Winston: Technologies of Seeing: Photography, Cinematography and Television, 1996, P. 116.

technologies (flat screens) are also being heavily developed and will obviously mesh with digital HDTV. Not until all this is diffused, a matter for more than one decade, will an industrial and commercial window open up for holographic television."7 According to Winston, only when commercial interests make transmittable holographic moving images possible, they would they become suitable for communication and could, by implication, become an object of communication studies. On the other hand, the more culturalist traditions of media studies, which tend to arise from aisthetical or aesthetical disciplines, such as art history, tend to on questions of a - as Williams writes - “ideology of the visual”, meaning on questions regarding the observer’s subject position, such as in debates on central . Even beyond such critical ideologically informed positions such as apparatus theory, it is always about the “observers” and what the images make with them (or versa).8 However even up to now, holography has had at best a marginal position in the art system.9 Holography seems simply to be too marginal, too little established, not visible enough, too poorly aligned to the mass public or to the “observer” to deserve any attention. Perhaps this is the case. But perhaps it just seems like this because of the fixation of different traditions of media studies on communication or aesthetic appearance.10 This is the thesis of this article: Holography has become accepted, it has become established, it is commonplace and is used routinely by the much-evoked “masses” - but not on the level of visual perception and communication. You can easily check this, dear reader. Take your wallet, remove a bank note or your ID card (you can’t get anything more common than this) and take a look. You will notice colourful, iridescent elements - elements which rely on holographic procedures. These, although naturally visible and also equipped with a certain aisthetic stimuli, are not primarily created to be noticed by you. These elements are not intended to communicate anything visual and their aesthetic quality is just an accessory. They are on your and ID cards for another reason: They are to prevent (alongside other methods) you from being able to forge money or identification - i.e. they are virtually impossible to reproduce. Consequently, they are intended to make money and identification cards impossible to reproduce. They are intended to stabilise the difference between the original and any copy - a difference which simply continues to exist contrary to some post-modern discourses. A difference, which has no lesser task in the case of personal ID than to guarantee what you doubtlessly have as your most personal and intimate possession - your identity. Your identity is not your most personal, pre-technical possession. It is only

7 Winston: Technologies of Seeing, loc. cit., P. 117. See also Brian Winston: Media Technology and . A History: From the Telegraph to the Internet, London, New York 1996, P. 337-342. 8 Or about observers of either gender, as Linda Williams rightly insists. 9 See also the discouraging results from surveys about the status of holography for the art system, carried out in 1989, documented in: D. Tulla Lightfoot: "Contemporary Art-World Bias in Regard to Display Holography: New York City", in: Leonardo, vol. 22, No. 3/4, 1989, P. 419-423. 10 In terms of Martin Seel: Aesthetics of Appearing, Stanford, California 2005 (Transl. by John Farrell).

secured and, thus, created through such external technology of identification.11 Go to a bank without your identification card and try to obtain the central medium of capitalist society, money,12 try to travel without identification card to a country outside of the Schengen Area. You can protest as often as you like and in tears that you are you - no-one will believe you if you cannot submit a piece of identification furnished with tamper-proof holography (or similar technologies). You will arouse extreme suspicion if you dare to present a photocopy of your identification card (or your credit card). You are only you “in person” thanks to the holography of your original identification card, among other things. The Federal Office, responsible for the development of such (and other) security technology on your banknotes and identity documents, notes in an official document, not without a telltale pathos: “The security and protection of individual identities is a basic requirement and basic right of modern citizens. Reliably documenting them with state-of-the-art means of high security technology and protecting them against all conceivable third-party attacks was and is the fundamental tasks and the ultimate aim of our work in the Federal Printing Office.”13 The fact that a “third party” can even endanger the “individual identity” shows how little the latter is independent of the former. Holography is, in this context, a medium which first of all creates the individual identity, to put it bluntly, - this cannot be flamed as unimportant, superfluous, marginal and uninteresting. "Whilst the critics […] condemn holography as worthless however, the actual world-wide use of holograms on products, packaging and documents continues to grow every year […]."14 It is only the fixation on the visual perhaps due to the “ideology of vision” - taken to be focused on the eyes of the “masses” or “observers” - that obstructs the central and routine role of the optical medium (see 2) of holography. As this last sentence already implies, this article will make a differentiation at the end - between visual and optical media (see 3).

2. Holographic knowledge and non-reproducibility

The source of the non-reproducibility of holography is in its epistemology, the “fields of constitution”15, from which it originates. The intention here is not to reconstruct the history of holography en detail. That would go beyond the scope of this essay. It is enough to state that a central condition of the feasibility of holography is the (re)discovery of in the 19th century.16 The underlying idea of holography, to record the interference pattern between the of two coherent sources, assumes the

11 On the ever-increasing number of “identity thefts”, a major problem especially for finance, see Chris Jay Hoofnagle: "Identity Theft. Making the Known Unknowns Known", in: Harvard Journal of & Technology, Vol. 21, No. 1, 2007, P. 98-122. 12 The question of the non-reproducibility also naturally applies to bank cards, credit cards, etc., which often have holographic elements themselves in order to be irreproducible but which can only be ordered if you first submit some personal identification. 13 See produkte_dok_iddok_brosch.pdf, at: http://www.bundesdruckerei.de/de/service /service_downloads/index.html (accessed on: 9.4.2008). 14 David Pizzanelli: "Counterfeit Holograms and Simulations", in: Optical Security and Counterfeit Deterrence Techniques II, Proceedings SPIE, No. 3314, 1998, P. 86-96, here P. 86. 15 See Michel Foucault: The Archaeology of Knowledge, New York 1972, P. 4. (Transl. by A.M. Sheridan Smith) 16 See Jed Z. Buchwald: The Rise of the Wave Theory of Light, Chicago 1989.

understanding of interference as a property of the of light. The recording of the interference between object waves and reference waves permits the exact reconstruction of the object wave. The idea of recording these interferences was formulated in 1948 by Denis Gabor - for the purpose of avoiding limitations in the reproductions of electron microscopes: “It is known that the spherical aberration of electron of the resolution of an sets a limit at about 5 Å. [...] The new microscopic principle, as described below, offers a possibility to avoid this difficulty, as it allows the electron lens to be completely relinquished.”17 In short, this is the point of Gabor’s early considerations - it is possible to avoid the , lens systems and their limitations. This accounts for the unique status of holography in the history of technological method: It is the only procedure that can depict objects without these having to be projected through a lens.18 The hologram does not underlie geometric optics or perspective projection and the 1:1 correlation of and object points.19 In fact, every object point is correlated with every , which is why each sliver of a broken hologram contains the entire image20 (meaning also the enormous information content, which makes a holographic transmission difficult). The technological visual media, which follow the perspective projection and work with lenses, are clearly in the overwhelming majority: photography, , television, video and even many of the digitalised and digitally generated images belong to this. Could this dominance lead to an implicit structuring of the term “technological image”, to naturally assume its connection with lenses, etc. so that alternative phenomena - like holography - disappear from view?21 Be that as it may: The fact that holography arises from wave-optical knowledge, while all other imaging technologies (on the level of the projection of objects on the ) follow geometric optics (i.e. perspective), still has another epistemological point22: Historically, geometric optics, i.e. the conceptualisation of the light in the form of straight rays - like in perspectives - is the older knowledge. It is, as an approach, still a firm component of optics. In a modern textbook about optics, it says: “In many situations, the great arising from the approximation of Geometrical Optics more than compensates for its inaccuracies [in comparison with wave optics, J.S.].”23 One of these situations is the calculation of optical systems on the basis of lenses. Wave optics describes phenomena such as deflection, polarisation and interference of the light, phenomena, which cannot be described by geometric optics - but which normally do not need to be described at all. Refraction and

17 : "A New Microscopic Principle", in: Nature, Vol. 161, No. 4098, 15. Mai 1948, p. 777/778. 18 do not need a lens either, but offer no image of the objective. Instead, they provide only a trace of its shadow. 19 See B. A. R. Carter: "Perspective", in: Harold Osborne (Ed.): Oxford Companion to Art, Oxford 1970, P. 840-861. 20 Albeit with a resolution that decreases in proportion to the part size. 21 In Kittler: Optical media, loc. cit., P. 71, there is the reference "like all optical media even today, they required the development of usable lens systems" – under such a premise, the lens- less imaging method of holography cannot be part of a history of optical media. In general, : Wholeness and the Implicate Order, London et al. 1980, P. 144-147, sees the lens as a paradigm of modern, scientific (and – under explicit reference to holography – disparagingly called “mechanistical”) reasoning. 22 This is why William’s classification of holography between camera obscura and cinema is a misclassification, locating holography in a field of knowledge which is foreign to it. 23 Eugene Hecht: Optics, , Munich et al. 2002, P. 149.

reflection as description categories are sufficient because the structures that are interactive with light (, lenses, etc.) are large in comparison with the wave length of light. If it was different, you could also see around corners, as the light would flow around them in a wave-like manner (like water). This actually happens to a small degree - it is exactly the effect known as . However, such wave-optical phenomena occur in the field of geometric-optical technology as probems - diffraction restricts the resolution of lenses (see Gabor) - but such disturbnces were historically the starting point for new knowledge and, consequently, new, wave-optical technologies. Wave-optical knowledge includes geometric-optical knowledge; the latter is only an approximation of the former. This means that (a) wave-optical imaging technology of holography can include the phenomena of geometric optics but (b) not vice versa. In concrete terms, (a) means: A holographic recorded lens still works like a lens, while a holographically depicted mirror still works like a mirror.24 Today, the construction of holographic and optical elements is an important branch of research and industry, as space-saving optics can be created for very special purposes. Incidentally: Such systems operate today in many supermarket scanners in the western world - another example for a frequent operational mode of holography which is used plentifully, but is in no way a “mass medium”.25 Just as precisely, (b) means that no geometric-optical technology - such as the photographical optics of a - can copy holographic images because the information saved in the wave-optical images exceeds the potential of the geometrical-optic image. A holographic image contains more spatial information about the object than a of the object, simply because holography can save both the amplitude and the phase of light, thanks to the recording of interference pattern.26 This additional information cannot be reproduced with geometric optics.27 A photocopy of a hologram no longer appears captivatingly three-dimensional and no longer changes when the viewing angle is changed (iridescence). For this reason, imaging technologies

24 See Johnston: Holographic Visions, loc. cit., P. 69 for one of the first Soviet experiments on holography, during which Yuri Denisyuk holographed a mirror. 25 See, for example, LeRoy Dickson et al.: “Holography in the IBM 3687 Supermarket Scanner”, in: IBM Journal of Research and Development, Vol. 26, No. 2, 1982, P. 228-234. 26 For this reason, holography was also soon used to depict volume, e.g. in particle , where the processes in detectors such as bubble chambers needed to be displayed, see C. Henderson: Cloud and Bubble Chambers, London 1970, P. 55-59. If you were simply to photograph the content of such a detector, all the events from the various depth levels would occur on one, i.e. together on the image plane, which would completely obscure the processes in the chamber. Interestingly or more tellingly, in Peter Galison: Image and Logic. A Material Culture of Microphysics, Chicago 1997, holographic detectors are not mentioned. From reading Galison’s study, Wolfgang Hagen: “Die Entropie der Fotografie. Skizzen zu einer Genealogie der digital-elektronischen Bildaufzeichnung", in Herta Wolf (Ed.): Paradigma Fotografie. Fotokritik am Ende des fotografischen Zeitalters, Volume 1, Frankfurt a.M. 2002, P. 195-235, here P. 196 FN 4 then drew the conclusion that photographic techniques would bow out of particle research in the mid 1980s, where holographic detectors for bubble chambers were still equipped in 1989, see T. Kitagaki et al.: “A High Resolution Holographic Freon Bubble Chamber for the Fermilab High Energy Neutrino Experiment”, in: Nuclear Instruments and Methods in Physics Research, No. A281, 1989, P. 81-92, here P. 81: "It was therefore logical to apply the technique of holographic photography to the Tohoku 1.4 m bubble chamber". 27 It goes without saying that holographies can, in turn, be reproduced by other holographies.

based on wave optics is well suited to safety applications.28 They were soon used for money:

“The first with a hologram patch was the 1988 Austrian 500 Schilling note. In 1994, Kuwait integrated a hologram patch onto three of its banknotes and Bulgaria issued the first banknote in the world with a hologram strip, the LEAD® strip. The first banknote with hologram window strand was issued in Finland in 1985, followed by the Latvian 5 latu note, which was issued in 1996. In Germany, the first banknotes were equipped with holograms during the last appreciation of the D-Mark series in 1996. At that time, the 50, 100 and 200 D-Mark notes were enhanced with a hologram patch as an additional security measure. By 2000, 80 different denominations from over 30 countries were in circulation with a hologram. In 2003, 150 denominations were equipped with various optical features, such as in the thread, as a foil strip or as a patch. Currently, approx. 350 denominations are in circulation with a hologram element.”29

But naturally, there was immediately an objection: If holographies are so difficult to reproduce, how can they be used on a large scale on ID cards, credit cards and banknotes? Clearly, they must be reproducible in some way - and they are under very special conditions. By 1980, commercial procedures for embossed holograms had been developed. 30 Holograms can be reproduced by mechanically stamping the interference pattern onto an appropriate material. In this way, it is possible to reproduce small holograms in large numbers - without the reproduction being possible for any normal person on a photocopier: “The forging of a hologram demands an immense amount of equipment, with high- quality , precision optics, extremely vibration-free optical laboratory tables, photochemical development, galvanisation to cast the embossing tools, special embossing foil and embossing machinery.”31 It can be seen that: Reproducibility is not something that exists or doesn’t exist. But rather, it is something which is distributed differentially and diversified. A certain reproducibility is available to large and well-financed companies and/or state institutions: “This equipment, teamed with the special knowledge of technicians, only exists in a few laboratories in the world.”32 It is not available to most people. In this respect, you could argue that Walter Benjamin’s famous description of the era of technical media (Benjamin referred predominantly to photography and cinema) as an era of technical reproducibility must be differentiated. Reproducibility has - as said - different levels. And vice versa, this

28 Pizzanelli: "Counterfeit Holograms", in: Optical Security, loc. cit., discusses various trials and procedures to forge safety holograms and comes to the conclusion that holography is a very good and effective copy protection method, in contrast to the occasional claims to the contrary (as in 1998). 29 http://de.wikipedia.org/wiki/Hologramm (accessed on 11.4.2008). 30 See Johnston: Holographic Visions, loc. cit., P. 372-377. On P. 374/375 he explains the details of the introduction of holographies as a copy protection method for credit cards. On P. 376, you can read that 95% of the holography market was defined by embossed holograms in 1993. 31 This is the statement from a company which creates holograms for safety applications, among other things http://www.topac-holographie.de/3126.0.html?&L=1 (accessed on 11.4.2008). 32 http://www.topac-holographie.de/3126.0.html?&L=1

classification creates different levels of non-reproducibility.33 This is a constitutive and sometimes forgotten part of modern media history. Especially because reproducibility is increased with technological media, it must be restricted - e.g. in order to maintain the authenticity of money and identification. The operating of “ideological state apparatuses”, as they were termed by Althusser, is urgently and always dependent on this non- reproducibility. But there’s even more: As the example of money as a central medium of capitalist society shows, non-reproducibility is also urgently necessary to maintain the commodity form.34 Nothing shows this more clearly than the current outcry about the potential of digital technology to create loss- free copies. If a digital file can be described ultimately as a clearly countable amount of 0 and 1, then it can also be copied exactly. However, it is precisely this potential that leads within the music and film industries to the problem that music CDs and film are being copied and in the quantities, in which they are copied, it is causing a decrease in the sales of these products. In the meantime, (sometimes draconian) penalties are threatened for the copying of copy-protected products (which is still very possible - for DVDs, the programme DVD Shrink was very popular35). This can be understood as an example for the “law of the suppression of radical potential”.36 Benjamin saw a potentially radical power in reproducibility, which could change capitalist .37 So that this doesn’t happen, this radical potential is being slowed down and defused - through a heterogeneous ensemble of legal regulations and forms of technical non-reproducibility. This also shows: Media does not define our situation (according to the famous aperçu of Friedrich Kittlers), at least not alone. The form and potentials of media technology cannot be deduced from their technical immanence alone. Holography has started a wide, large-scale, ordinary career as a technology which helps to thwart the radical potential of technical reproducibility. The fact that it is used as such and not differently is not a result of its technical immanence (instead of its non-reproducibility, you could also emphasise and foster its three-dimensional pictorial appearance), but rather the situation - which conversely requires such technology of non- reproducibility in order to remain as this specific, e.g. late capitalist, situation.38

33 However, Benjamin: "The Work of Art in The Age of Mechanical reproduction", in: Classical Theory, Craig Calhoun (Ed. et al.) III. Edition (Transl. by Harry Zohn, Hannah Arendt (Ed.)), P. 441-464, also wrote in a little noted passage, P. 458: "Precisely because authenticity is not reproducible, the intensive penetration of certain (mechanical) processes of reproduction was instrumental in differentiating and grading authenticity." 34 See Stefan Meretz: "Der Kampf um die Warenform. Wie Knappheit bei Universalgütern hergestellt wird", in: Krisis. Beiträge zur Kritik der Warengesellschaft, at: http://www.krisis.org (accessed on: 11.4.2008). 35 Tellingly, DVD Shrink is illegal in Germany as a copy protection programme. Nevertheless, it can be found all over on the internet. 36 See Winston: Media Technology, loc. cit., P. 11-13. 37 See Benjamin: The Work of Art, loc. cit., P. 444: "One might generalize by saying: the technique of reproduction detaches the reproduced object from the domain of tradition. By making many reproductions it substitutes a plurality of copies for a unique existence. And in permitting the reproduction to meet the beholder or listener in his own particular situation, it reactivates the object reproduced. These two processes lead to a tremendous shattering of tradition, which is the obverse of the contemporary crisis and renewal of mankind. Both processes are intimately connected with the contemporary mass movements." 38 A highly interesting example in this respect is interferential photography, an exotic and forgotten process form the 19th century, which has recently been rediscovered for security applications - as its specific form (iridescent chromaticity), which is due to the use of wave- optical effects, cannot be reproduced by geometric optics, see Hans I. Bjelkhagen: "New

Media and the situation form a conflict situation which can only be split painstakingly into these two components. For this reason, the somehow fruitless debate of whether “media technology” defines “society” or vice versa “society” defines “media technology”39 should be abandoned. There has never and will never be a “society” without “media technology” and vice versa. Their contraposition and the question of “who and whom?” is already an artefact that demands the operation of artificial separation. Rather, it would be valid to closely describe the socio-technical networks.40

3. Summary

In this light, the fact that consideration of media history only relates to large- scale visually successful technology and/or to those which aesthetically and narratively address “observers” can almost be understood as a displacement of the hegemonial uses of media technology. As if - anthropocentrically - the public and their understanding of the contents or observers and their understanding of forms were always the only important thing. As if it could not also be important to examine what functions media could have beyond addressing the human senses. In mass media usage and in aesthetic uses, media remain visible and audible above all else. However, they can also be used inconspicuously in the background. This entire history of media in the background should be given greater consideration. Holography is based on knowledge of wave optics, but this means it is not automatically an image medium, in the sense of a visual medium, targeted at human senses. It is necessary to emphasize that optical media does not have to be visual media. The concepts commonly used in image studies - a “history of vision” and a “history of optical media” - can be clearly separated. The latter relates to media, which operate with the use of various forms of optical knowledge, while the first relates to the appearance of images created for human perception (their phenomenology and its discursivation).41 The “history of optical media” is more extensive than the “history of vision”, but the latter should also not - for instance in the convulsive appeal for any “post-structuralist subject critique” - be neglected as “anthropocentric”: The appearance for observers is not the sole gauge - but it also is not the contrary. Both the focus of the “optical” and that of the “visual” are valid and mutually irreducible perspectives. It is at least a merit of holography, which is so maligned by media historiography to underline this point.

Optical Security Device Based on One-hundred-year-old Photographic Technique", in: Optical Engineering, Vol. 38, No. 1, 1999, P. 55-61. Although it initially disappeared because it could not be reproduced, it is now re-emerging for exactly this reason! 39 See Hartmut Winkler: "Die prekäre Rolle der Technik", in: Heinz B. Heller et al. (Ed.): Über Bilder Sprechen. Positionen und Perspektiven der Medienwissenschaft, Marburg 2000, P. 9-22. 40 Evidently a claim, which connects to actor-network-theory, see Bruno Latour: Reassembling the social: an introduction to actor-network-theory, Oxford, UK 2005, esp. P. 74-78. 41 See W.J.T. Mitchell: "There are no Visual Media", in: Oliver Grau (Ed.): MediaArtHistories, Cambridge/MA 2007, S. 395-406, who criticises the term “visual media” because all media are mixed sensual and semiotic phenomena. Mitchell is correct. The differentiation of “visual” versus “optical” presented in my argumentation should only illustrate that not every technology, that (also?) operates by optical principles, targets the eyes. In principle, Mitchell also confirms that there is a fixation on visibility (P. 404), which - according to my argument - actually obscures certain functions of media.