The photoelectric effect in external fields

Atoms and negative ions interacting with laser photons yield a coherent source of photoelectrons. Applying external fields to photoelectrons gives rise to interesting and valuable interference phenomena. We analyze the spatial distribution of the photocurrent using elementary quantum methods. The photoelectric effect is shown to be an interesting example for the use of coherent particle sources in quantum mechanics.Comment: Contribution to the Einstein special issue, slightly updated reference

Content Seeking Students: Site-and-Sound Bites as Participants in Ubiquitous Social Computing

Discussion of digital, collaborative environments for architectural work often focuses on the structure of discourse, rather than upon its substance. An implied assumption is that the various means of electronic-based communication are suitable for any kind of subject matter, whether visual, sound-based, or text. Our project team has chosen to challenge this assumption by example: We have created new media artifacts for collaborative architectural education. Our project is an attempt to leverage on-going research concerning the efficacy of "ubiquitous social computing” (USC) for design-studio teaching. With a pilot project already put in place by one of our team's leaders, we have supplemented graphic and verbal communication among participants with purpose-crafted video for their use and exchange. Smart-screens, placed strategically within students' "social enclaves,” provide access to curated content. Our approach challenges traditional educational emphasis upon explicit types of architectural knowledge. The construction of tacit knowledge, usually derived from first-hand architectural experiences, is here effected by mediated, digital-based experiences. Nevertheless, the social dimension of the USC framework may be significant in negotiating the interface between immediate and mediated experiences

Under Construction: Alternative Spaces of Discourse at the National Library of Israel (Critical Essay)

AbstractA new building for the National Library of Israel (NLI), scheduled for completion in 2021, is the culmination of a two-decade process of institutional transformation. Formerly known as the Jewish National and University Library, the NLI has historically served simultaneously as Israel's official state repository, as the Hebrew University's central library, and as a “library of the Jewish people.” Like other national libraries around the world, including elsewhere in the Middle East, the National Library of Israel has had to grapple with accelerated changes in management of library collections due to the proliferation of digital media. More fundamental, however, have been changes in the cultural expectations about how libraries should function. Since 1998, the NLI has sought to expand its mission to promote not only scholarship but also cultural “discourse” among Israel's diverse constituencies. The architectural design of NLI's new edifice was intended, therefore, to do more than house the functional requirements of a modern library. It was commissioned to express through its design the significance of the transformed institution for the Israeli public. Towards that goal, a highly publicized competition for the NLI's design was held in 2012. The original two-stage competition ended in controversy after the architect endorsed by the jurors was dismissed. Yet a review of designs submitted by four Israeli architects in that first competition shows how public spaces, affiliated with public institutions, are expected to foster public discourse in Israel. Whether that discourse is cultural or political, contentious or contradictory, these alternative designs for the NLI illustrate common themes based upon specific environmental tropes, familiar across a broad spectrum of Israeli society.</jats:p