{"693658":{"#nid":"693658","#data":{"type":"news","title":"Terahertz Imaging Could Reveal Medieval Texts Hidden in Book Bindings","body":[{"value":"\u003Cp\u003EWhen the Jewish community was\u0026nbsp;\u003Ca href=\u0022https:\/\/mjhnyc.org\/blog\/1492-letter-regarding-jewish-property-in-spain\/\u0022\u003Eexpelled\u003C\/a\u003E from much of the Iberian Peninsula in 1492, many of their books stayed behind and served a new purpose. Paper was too valuable to throw away, so texts were often reused to build bindings or covers for other books.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003ECenturies later, Jewish texts can still be found inside book covers in Catalonia. But intact volumes remain much more difficult to investigate without damaging them. Researchers are exploring terahertz imaging, a nonionizing technique that uses electromagnetic radiation between the microwave and infrared regions of the spectrum, to detect writing beneath the surface without taking the binding apart.\u003C\/p\u003E\u003Cp\u003EA National Endowment for the Humanities Collaborative Research planning award with the Binational Science Foundation supports this research.\u0026nbsp;\u003Ca href=\u0022https:\/\/ece.gatech.edu\/\u0022\u003ESchool of Electrical and Computer Engineering\u003C\/a\u003E Professor\u0026nbsp;\u003Ca href=\u0022https:\/\/ece.gatech.edu\/directory\/david-s-citrin\u0022\u003EDavid Citrin\u003C\/a\u003E and collaborator\u0026nbsp;\u003Ca href=\u0022https:\/\/sites.biu.ac.il\/en\/leor-jacobi\u0022\u003ELeor Jacobi\u003C\/a\u003E, senior lecturer in Bar-Ilan University\u2019s Department of Jewish Art, will build partnerships with archives in Catalonia and test the technology on historical materials.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EHidden History\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EThe project grew from Citrin\u2019s nearly 10 years of work using terahertz imaging to examine art and archaeological objects, including paper, glass, and ceramics.\u003C\/p\u003E\u003Cp\u003ECitrin\u2019s team has already tested whether terahertz imaging can distinguish text buried within layers of paper. Previous experiments distinguished iron-gall-ink characters written on opposite sides of a single sheet and on two stacked sheets without separating them. But medieval pasteboard bindings can contain up to 20 recycled sheets, so the researchers still need to determine how well the technique will perform on thicker stacks and on aged, varied historical materials.\u003C\/p\u003E\u003Cp\u003E\u201cIf we could find new texts inside materials, this opens up all kinds of possibilities,\u201d he said.\u003C\/p\u003E\u003Cp\u003EImaging the interior is only part of the challenge. Researchers also need to determine which ink traces belong to which surface or layer of paper. That\u2019s where machine learning can help. The team records terahertz measurements across a sample, producing depth-sensitive data. In recent experiments, a convolutional neural network classified whether ink appeared on the front, back, both sides, or neither side of a sheet. Extending that approach to multilayer historical bindings is one of the next steps.\u003C\/p\u003E\u003Cp\u003E\u201cIt\u2019s those two things together, the measurement and the machine learning, that have made this work,\u201d Citrin said.\u003C\/p\u003E\u003Cp\u003EThe researchers don\u2019t necessarily need to decipher every word buried within a binding to determine if it is valuable for further research. Citrin said identifying Hebrew characters, for example, could help researchers flag promising book covers for closer study. Ultimately, the goal is to develop an approach that could be applied across large collections.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u201cThese bindings are archives within archives,\u201d Jacobi said. \u201cIf terahertz imaging lets us identify hidden manuscript fragments without dismantling the binding, we can search collections on a scale that was previously impossible.\u201d\u003C\/p\u003E\u003Cp\u003EThe potential extends beyond these texts.\u0026nbsp;The same approach could also reveal Arabic, Latin, Catalan, and other centuries-old texts preserved in reused materials. Identifying where fragments originated geographically could help historians understand how manuscripts and books traveled, offering insights into mediaeval and early modern intellectual life and trade. Studying the construction of the bindings themselves can also provide useful information for art history and conservation.\u003C\/p\u003E\u003Cp\u003EFor Citrin, that intersection between engineering and history is part of the appeal. He has a longstanding interest in art history and believes projects like this one extend scientific research beyond the laboratory.\u003C\/p\u003E\u003Cp\u003E\u201cI think it\u2019s important to bridge the gap between the humanities and STEM,\u201d he said. \u201cHumanities questions can push imaging technology toward problems it would not otherwise encounter, while engineering can give scholars access to evidence that has been inaccessible for centuries.\u201d\u003C\/p\u003E\u003Cp\u003EIf the technique ultimately works on historical materials, it could let scholars search for hidden texts without sacrificing the binding relics that preserved them.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003EA new application of terahertz imaging could help scholars read texts hidden inside centuries-old book bindings without taking them apart.\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"A new application of terahertz imaging could help scholars read texts hidden inside centuries-old book bindings without taking them apart."}],"uid":"34541","created_gmt":"2026-10-30 14:40:47","changed_gmt":"2026-10-30 14:55:56","author":"Tess Malone","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2026-10-30T00:00:00-04:00","iso_date":"2026-10-30T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"681605":{"id":"681605","type":"image","title":"citrin.png","body":"\u003Cp\u003EAn example of a hidden manuscript in a book binding from \u0022Piel Sobre Tabla,\u0022 BNE, (Creative Commons)\u003C\/p\u003E","created":"1793371271","gmt_created":"2026-10-30 14:41:11","changed":"1793371271","gmt_changed":"2026-10-30 14:41:11","alt":" From \u0022Piel Sobre Tabla,\u0022 BNE, (Creative Commons)","file":{"fid":"266032","name":"citrin.png","image_path":"\/sites\/default\/files\/2026\/10\/30\/citrin.png","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2026\/10\/30\/citrin.png","mime":"image\/png","size":2204221,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2026\/10\/30\/citrin.png?itok=FFYC-EJc"}}},"media_ids":["681605"],"groups":[{"id":"1214","name":"News Room"},{"id":"1188","name":"Research Horizons"}],"categories":[],"keywords":[{"id":"187915","name":"go-researchnews"}],"core_research_areas":[{"id":"39531","name":"Energy and Sustainable Infrastructure"},{"id":"193652","name":"Matter and Systems"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003ETess Malone, Senior Research Writer\/Editor\u003C\/p\u003E\u003Cp\u003Etess.malone@gatech.edu\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}