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Elu, loodus, teadus ja tehnoloogia

Sentinel-2 delivers first images

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Just four days after being lofted into orbit, Europe’s Sentinel-2A satellite delivered its first images of Earth, offering a glimpse of the ‘colour vision’ that it will provide for the Copernicus environmental monitoring programme.

The info on iriss

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Read about the next ESA astronaut to head to the International Space Station: Andreas Mogensen’s iriss mission starts September

Connecting Berezinskii-Kosterlitz-Thouless and BEC Phase Transitions by Tuning Interactions in a Trapped Gas

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Author(s): Richard J. Fletcher, Martin Robert-de-Saint-Vincent, Jay Man, Nir Navon, Robert P. Smith, Konrad G. H. Viebahn, and Zoran Hadzibabic

A harmonically trapped atomic gas can transition from a BKT superfluid to a Bose-Einstein condensate by reducing the interaction strength between the atoms.


[Phys. Rev. Lett. 114, 255302] Published Fri Jun 26, 2015

Alpha Heating and Burning Plasmas in Inertial Confinement Fusion

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Author(s): R. Betti, A. R. Christopherson, B. K. Spears, R. Nora, A. Bose, J. Howard, K. M. Woo, M. J. Edwards, and J. Sanz

Alpha particles would need to provide 50 kJ of heating to achieve a burning plasma regime – where more energy is released by the fusion reactions than is absorbed by the fuel – at the National Ignition Facility.


[Phys. Rev. Lett. 114, 255003] Published Fri Jun 26, 2015

The dynamics of hurricane balls

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We examine the theory of the hurricane balls toy. This toy consists of two steel balls, welded
together that are sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high
frequency the symmetry axis approaches a limiting inclin…

The induction motor

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We obtain analytical expressions for the torques and angular speed of an induction motor with a
simple geometry, resembling the geometry of the first induction motor investigated by Arago in 1824.
The rotor is a conducting disc rotating between the m…

Oscillations of end loaded cantilever beams

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This article presents several simple experiments based on changing transverse vibration frequencies
in a cantilever beam, when acted on by an external attached mass load at the free end. By using a
mechanical wave driver, available in introductory un…

Earth from Space

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Join us Friday, 26 June, at 10:00 CEST for the ‘Earth from Space’ video programme. Discover the San Andreas Fault – horizontally shifting parts of California at up to 5 cm a year – in this week’s edition

Suverõõmud

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Ristikuleht ujub päiksepaistelisel ilmaga mõne sentimeetri paksusel veekihil. Basseini põhjal paistab ristikulehe vari. Kas selle varju kuju üllatab?

Shared AIM

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Technology image of the week: spreading the word on ESA’s proposed Asteroid Impact Mission, ahead of next week’s Asteroid Day

Gapped Surface States in a Strong-Topological-Insulator Material

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Author(s): A. P. Weber, Q. D. Gibson, Huiwen Ji, A. N. Caruso, A. V. Fedorov, R. J. Cava, and T. Valla

Topological-crystalline-insulators and strong-topological-insulator phases of matter can be present in a single system. This is demonstrated using photoelectron spectroscopy measurements and band structure calculations.


[Phys. Rev. Lett. 114, 256401] Published Tue Jun 23, 2015

Rosetta mission extended

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The adventure continues: ESA today confirmed that its Rosetta mission will be extended until the end of September 2016, at which point the spacecraft will most likely be landed on the surface of Comet 67P/Churyumov-Gerasimenko.

Revisit the launch event

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From ESA’s European Space Operations Centre in Germany, watch the replay of the event to celebrate the launch of the first satellite for the Sentinel-2 ‘colour vision’ mission

Second Sentinel in orbit

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The ESA-developed Sentinel satellite – Sentinel-2A – was launched today, adding a high-resolution optical imaging capability to the European Union Copernicus environmental monitoring system

Imaging Molecular Motion: Femtosecond X-Ray Scattering of an Electrocyclic Chemical Reaction

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Author(s): M. P. Minitti, J. M. Budarz, A. Kirrander, J. S. Robinson, D. Ratner, T. J. Lane, D. Zhu, J. M. Glownia, M. Kozina, H. T. Lemke, M. Sikorski, Y. Feng, S. Nelson, K. Saita, B. Stankus, T. Northey, J. B. Hastings, and P. M. Weber

Femtosecond x-ray pulses image structural changes in a molecule.


[Phys. Rev. Lett. 114, 255501] Published Mon Jun 22, 2015

Magnetic complexity begins to untangle

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After a year in orbit, the three Swarm satellites have provided a first glimpse inside Earth and started to shed new light on the dynamics of the upper atmosphere – all the way from the ionosphere about 100 km above, through to the outer reaches of our protective magnetic shield.

Free fall in a box

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Space Science image of the week: The housing for a free-floating test mass on LISA Pathfinder, ESA’s new fundamental physics mission

Let’s talk about digital learners in the digital era

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This paper reports on a literature review of the concept of “Digital Natives” and related terms. More specifically, it reports on the idea of a homogeneous generation of prolific and skilled users of digital technology born between 1980 and 1994. In all, 127 articles published between 1991 and 2014 were reviewed. On the basis of the findings, there appears to be no commonly-accepted definition of a “Digital Native”. The concept varies among individuals, societies, regions and nations, and also over time. Moreover, there are a number of variables other than age that may help us understand the nature of students’ use of digital technologies. The so-called “Digital Native” literature demonstrates that despite students’ high digital confidence and digital skills, their digital competence may be much lower than those of their “digital teachers”. Given the confusion surrounding “Digital Native” and its affiliates, we propose to unify them under the concept “digital learners”.

Roles of course facilitators, learners, and technology in the flow of information of a cMOOC

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Distributed Massive Open Online Courses (MOOCs) are based on the premise that online learning occurs through a network of interconnected learners. The teachers’ role in distributed courses extends to forming such a network by facilitating communication that connects learners and their separate personal learning environments scattered around the Internet. The study reported in this paper examined who fulfilled such an influential role in a particular distributed MOOC – a connectivist course (cMOOC) offered in 2011. Social network analysis was conducted over a socio-technical network of the Twitter-based course interactions, comprising both human course participants and hashtags; where the latter represented technological affordances for scaling course communication. The results of the week-by-week analysis of the network of interactions suggest that the teaching function becomes distributed among influential actors in the network. As the course progressed, both human and technological actors comprising the network subsumed the teaching functions, and exerted influence over the network formation. Regardless, the official course facilitators preserved a high level of influence over the flow of information in the investigated cMOOC.

In abundance: Networked participatory practices as scholarship

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In an era of knowledge abundance, scholars have the capacity to distribute and share ideas and artifacts via digital networks, yet networked scholarship often remains unrecognized within institutional spheres of influence. Using ethnographic methods including participant observation, interviews, and document analysis, this study investigates networks as sites of scholarship. Its purpose is to situate networked practices within Boyer’s (1990) four components of scholarship – discovery, integration, application, and teaching – and to explore them as a techno-cultural system of scholarship suited to an era of knowledge abundance. Not only does the paper find that networked engagement both aligns with and exceeds Boyer’s model for scholarship, it suggests that networked scholarship may enact Boyer’s initial aim of broadening scholarship itself through fostering extensive cross-disciplinary, public ties and rewarding connection, collaboration, and curation between individuals rather than roles or institutions.

Conceptualizing and investigating instructor presence in online learning environments

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As online learning opportunities continue to grow it is important to continually consider instructor practices. Using case study methodology this study conceptualizes instructor presence, the intersection of social and teaching presence as defined within the Community of Inquiry literature, and is based in the implementation phase of online courses which is important to note since instructors often teach courses they did not design or develop.  The investigation of the instructor presence behaviors of 12 online instructors and the emerging profiles of instructor presence provide a gateway to strategies for online instructors and offer a window into the ways instructional presence elements work together while providing insights into how to make the best use of online instructor time.  In practical terms, the profiling method provides a useful way for practitioners to improve their own experiences.

Exploring the interaction equivalency theorem

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Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of int…

University of Toronto instructors’ experiences with developing MOOCs

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We interviewed eight University of Toronto (U of T) instructors who have offered MOOCs on Coursera or EdX between 2012 and 2014 to understand their motivation for MOOC instruction, their experience developing and teaching MOOCs, and their perceptions of the implications of MOOC instruction on their teaching and research practices. Through inductive analysis, we gleaned common motivations for MOOC development, including expanding public access to high quality learning resources, showcasing U of T teaching practices, and attempting to engage MOOC learners in application of concepts learned, even in the face of constraints that may inhibit active learning in MOOC contexts. MOOC design and delivery was a team effort with ample emphasis on planning and clarity. Instructors valued U of T instructional support in promoting systematic MOOC design and facilitating technical issues related to MOOC platforms. The evolution of MOOC support at U of T grew from a focus on addressing technical issues, to instructional design of MOOCs driven, first, by desired learning outcomes. Findings include changes in teaching practices of the MOOC instructors as they revised pedagogical practices in their credit courses by increasing opportunities for active learning and using MOOC resources to subsequently flip their classrooms. This study addresses the paucity of research on faculty experiences with developing MOOCs, which can subsequently inform the design of new forms of MOOC-like initiatives to increase public access to high quality learning resources, including those available through U of T.

Exploring intensive longitudinal measures of student engagement in blended learning

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In this exploratory study we used an intensive longitudinal approach to measure student engagement in a blended educational technology course, collecting both self-report and observational data.  The self-report measure included a simple survey of Likert-scale and open-ended questions given repeatedly during the semester. Observational data were student activity data extracted from the learning management system.  We explored how engagement varied over time, both at the course level and between students, to identify patterns and influences of student engagement in a blended course. We found that clarity of instruction and relevance of activities influenced student satisfaction more than the medium of instruction.  Student engagement patterns observed in the log data revealed that exploring learning tools and previewing upcoming assignments and learning activities can be useful indicators of a successful learning experience.  Future work will investigate these findings on a larger scale.

The use of a mobile learning management system at an online university and its effect on learning satisfaction and achievement

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This study investigates online students’ acceptance of mobile learning and its influence on learning achievement using an information system success and extended technology acceptance model (TAM). Structural equation modeling was used to test the structure of individual, social, and systemic factors influencing mobile learning’s acceptance, and how said acceptance influences learning satisfaction and achievement. Unlike earlier TAM-related research that did not provide a broad view of technological acceptance and its impact on learning activities, the present study’s results highlight the relationship between behavioral intention/learning satisfaction and learning achievement. Additionally, this study tests the theoretical model of successful mobile learning by empirically accepting mobile learning management systems. The findings further imply that students at online universities have started to accept mobile technology as a new learning tool; consequently, its acceptance has influenced their learning achievement both directly and indirectly. These discoveries should facilitate a better understanding of students’ usage of mobile learning systems in higher education, and provide timely guidance for its development and implementation.

Learners’ goal profiles and their learning patterns over an academic year

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The present study aimed to examine distance learners’ goal profiles and their contrasting patterns of learning and achievements at three different points during an academic year, i.e. in the beginning of the course in relation to learners’ general orientations to learning, at the middle of the course in relation to learners’ completion of an assignment, and towards the end of the course in relation to learners’ preparation for course examination.  Two hundred seventy-six adult distance learners completed three survey questionnaires that assessed their motivation and learning at these three  learning points.  Using person-centred analytical procedures, this study located four groups of learners based on different combinations of mastery and performance-approach goals. MANOVA results have shown that multiple-goal learners (High mastery/High performance, HH) who held strong mastery and performance-approach goals used more deep and regulatory strategies and showed a higher level of learning interest across three waves of surveys than did those focusing solely on mastery (HL) or performance-approach goals (LH). However, the multiple-goal learners did not have better achievement levels compared to those focusing solely on mastery goals (HL).  Given that multiple goal learners learnt with a more engaged pattern, it is less likely that these motivated learners will drop out of distance learning courses and programs. Future studies should explore how these goals can be promoted simultaneously in distance learning.

Exploring students’ intention to use LINE for academic purposes based on technology acceptance model

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The LINE application is often conceived as purely social space; however, the authors of this paper wanted to determine if it could be used for academic purposes. In this study, we examined how undergraduate students accepted LINE in terms of using it for classroom-related activities (e.g., submit homework, follow up course information queries, download materials) and explored the factors that might affect their intention to use it. Data were collected from 144 undergraduate students enrolled in an English course that utilized some activities based on LINE app using a questionnaire developed from TAM. Data were analyzed to see if relationships existed among factors when LINE was used to organize classroom experiences. The findings revealed that perceived usefulness and attitude toward usage had positive relationships with intention to use while perceived ease of use was positively related to perceived usefulness. In contrast with TAM assertions, this study did not find any relationship between perceived ease of use and attitude toward usage. Also, the number of social networking sites that students are using had no relationship with intention to use. The study also suggested some kinds of LINE-based learning activities preferred by students, which would be proposed for future courses. This study revealed several useful implications that TAM can be employed as a useful theoretical framework to predict and understand users’ intention to use new technologies in education.

Developing, using, and interacting in the flipped learning movement: Gaps among subject areas

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The purpose of this paper is to investigate the current video collection of an open-access video website (TED-Ed).  The research questions focus on its content as evidence of development, its viewership as evidence of use, and flipping as evidence of interaction in informal learning.  In late September 2013, 686 video lessons were posted on the TED-Ed website that spanned 12 academic subject categories and 60 academic subject subcategories, as labeled and sorted on the TED-Ed website itself.  The findings of the analysis of the TED-Ed video collection indicate several gaps in the humanities, social science, and natural science academic areas in terms of the number of video lessons and viewership.  Despite the gaps in the numbers of video lessons and the viewership across those three academic areas, the areas have very similar averages of daily flipped lessons.  The future research agenda should focus on the motivation of viewers to create flipped lessons as evidence of learning in an open learning environment. 

Sentinel-2 launch timeline

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On 23 June, a Vega launcher will loft the first of ESA’s dual Sentinel-2 satellites into orbit from Europe’s Spaceport in Kourou. For the mission control team, liftoff will mark the end of many months of careful preparations and the start …

Follow the launch event

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Live from ESA’s Space Operations Centre in Germany: follow the event leading up to the launch of Sentinel-2A. Streaming begins at 01:00 GMT (03:00 CEST)

Watch Sentinel-2A launch

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Follow the Sentinel-2A launch live from Europe’s Spaceport in French Guiana on 23 June. Streaming begins at 01:30 GMT (03:30 CEST), with liftoff scheduled at 01:52 GMT (03:52 CEST)

Using Tracker to understand ‘toss up’ and free fall motion: a case study

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This paper reports the use of Tracker as a computer-based learning tool to support effective
learning and teaching of ‘toss up’ and free fall motion for beginning secondary three (15 year-old)
students. The case study involved ( N = 123) students from express pure physics classes at a
mainstream school in Singapore. We used eight multiple-choice questions pre- and post-test to gauge
the impact on learning. The experimental group showed learning gains of d = 0.79  ±  0.23 (large
effect) for Cohen’s d effect size analysis, and gains with a gradient of < g >  total =
0.42  ±  0.08 (medium gain) above the traditional baseline value of < g >  non interactive = 0.23
for Hake’s normalized gain regression analysis. This applied to all of the teachers and students who
participated in this study. Our initial research findings suggest that allowing learners to relate
abstract physics concepts to real life through coupling traditi…

Moving toward centre

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Centripetal acceleration, linear and angular speeds are three mathematical quantities that are of
primary interest to analyze the uniform motion of objects in circles. The formula of centripetal
acceleration is usually derived from the difference ? V…