We investigate argon bubble flow in liquid gallium within a container large enough to avoid wall effects. Flow with and without applied horizontal magnetic field is studied. We demonstrate the successful capture and quantification of the effects of applied magnetic field using dynamic neutron radiography and the previously developed and validated robust image processing pipeline, supported by the in silico reproduction of our experiment. Significant reduction of the amplitude of bubble tilt angle variations due to applied horizontal magnetic field is successfully resolved through a 30 mm thick liquid metal layer. Our results clearly show the potential of expanding the range of gas/liquid metal systems that can be studied using downscaled though representative experimental setups.

We demonstrate a new image processing methodology for resolving gas bubbles travelling through liquid metal from dynamic neutron radiography images with an intrinsically low signal-to-noise ratio. Image pre-processing, denoising and bubble segmentation are described in detail, with practical recommendations. Experimental validation is presented—stationary and moving reference bodies with neutron-transparent cavities are radiographed with imaging conditions representative of the cases with bubbles in liquid metal. The new methods are applied to our experimental data from previous and recent imaging campaigns, and the performance of the methods proposed in this paper is compared against our previously achieved results. Significant improvements are observed as well as the capacity to reliably extract physically meaningful information from measurements performed under highly adverse imaging conditions. The showcased image processing solution and separate elements thereof are readily extendable beyond the present application, and have been made open-source.

For human ethics, it can convincingly be argued that justice is a central cornerstone and basis. Here, it is suggested that this can, to some extent, similarly be applied to robots. The article makes the argument that Rawls’ veil of ignorance in his conception of justice as fairness can effectively be replaced by a much more natural condition of prudent egoism in a finite world. Observing ones’ own important interests in an encompassing context paves the way for a guideline for the conduct, which is binding for humans, robots and each and every pragmatic agent with a minimum level of rationality. These arguments do not see humans (forever) in any privileged position: any agent, single human, state, alien or artificial with a certain minimum of general cognitive (and effective) capabilities is bound by a universal negative imperative. This entails that precautious procedures are preferable, and some general prudently constrained flexibility is required for self-consistency and survival.

Time is one of the undisputed foundations of our life in the real world. Here it is argued that inside small isolated quantum systems, time does not pass as we are used to, and it is primarily in this sense that quantum objects enjoy only limited reality. Quantum systems, which we know, are embedded in the everyday classical world. Their preparation as well as their measurement-phases leave durable records and traces in the entropy of the environment. The Landauer Principle then gives a quantitative threshold for irreversibility. With double slit experiments and tunneling as paradigmatic examples, it is proposed that a label of timelessness offers clues for rendering a Copenhagen-type interpretation of quantum physics more “realistic” and acceptable by providing a coarse but viable link from the fundamental quantum realm to the classical world which humans directly experience.