Visualization of thought experiments in special relativity education at the secondary level

Special relativity theory (SRT) presents an attractive introduction to modern physics in secondary education. Understanding the principles of SRT, however, requires a conceptually demanding learning process, involving a variety of robust learning difficulties. Thought experiments (TEs), performed by students themselves, provide a fruitful learning tool to address these difficulties. We present two visualization tools that explicitly support students in performing specific phases of a TE: a computer modelling tool and a paper and pencil representation of space time. We discuss relevant design features and specify how these visualization tools can be used to address learning difficulties

An Educational Reconstruction of Special Relativity Theory for Secondary Education.

Einstein’s derivation of special relativity theory (SRT), based on hypothetical reasoning and thought experiments, is regarded as a prime example of physics theory development. In secondary education, the introduction of SRT could provide a great opportunity for students to engage in physics theorizing, but this opportunity is largely being missed in current teaching practice. One reason could be that secondary students lack some knowledge of electromagnetism that was central to Einstein’s argument. Therefore, we conducted an educational reconstruction to develop a teaching approach that would not rely on advanced understanding of electromagnetism, yet retain the modes of reasoning that were characteristic of Einstein’s approach. In our reconstruction, we identified the light postulate, which is notoriously difficult for students to grasp, as a central concept. We developed a teaching and learning sequence in which students perform relativistic thought experiments and try different interpretations of the light postulate. Through these activities, students experienced how the new concepts meet the requirements for a good theory. Experimental evaluation of the teaching and learning sequence indicates that this can be a fruitful approach to introduce SRT to secondary students

Metabolism within the tumor microenvironment and its implication on cancer progression: an ongoing therapeutic target

Since reprogramming energy metabolism is considered a new hallmark of cancer, tumor metabolism is again in the spotlight of cancer research. Many studies have been carried out and many possible therapies have been developed in the last years. However, tumor cells are not alone. A series of extracellular components and stromal cells, such as endothelial cells, cancer-associated fibroblasts, tumor-associated macrophages and tumor-infiltrating T cells, surround tumor cells in the so-called tumor microenvironment. Metabolic features of these cells are being studied in deep in order to find relationships between metabolism within the tumor microenvironment and tumor progression. Moreover, it cannot be forgotten that tumor growth is able to modulate host metabolism and homeostasis, so that tumor microenvironment is not the whole story. Importantly, the metabolic switch in cancer is just a consequence of the flexibility and adaptability of metabolism and should not be surprising. Treatments of cancer patients with combined therapies including anti-tumor agents with those targeting stromal cell metabolism, anti-angiogenic drugs and/or immunotherapy are being developed as promising therapeutics.Mª Carmen Ocaña is recipient of a predoctoral FPU grant from the Spanish Ministry of Education, Culture and Sport. Supported by grants BIO2014-56092-R (MINECO and FEDER), P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript

Introducing Special Relativity in Secondary Education

Special relativity theory (SRT) is an iconic physics theory and prototypical for how new knowledge develops in this field. Therefore, learning SRT can be valuable for secondary school students. SRT was introduced in the Dutch pre-university level secondary physics curriculum (VWO) as an elective topic in 2013. However, learning relativistic concepts gives rise to some robust misconceptions and little is known on how to teach this topic at the secondary level. This research project aims to contribute to the scientific knowledge base of learning SRT in secondary physics education through the design and evaluation of a teaching and learning sequence (TLS). The first study deals with students’ pre-instructional reasoning on the light postulate, which states that the speed of light is the same regardless of the state of motion of its source or the observer. We developed a reasoning tool, the Event Diagram, that supports secondary students to perform relativistic thought experiments. We found that students used one of two different models for light propagation. Some of them switched models when they experienced a mismatch between different reference frames. The second study presents an educational reconstruction of SRT, yielding a TLS introducing the light postulate by presenting such a mismatch. Evaluation in small groups showed students developed confidence in the light postulate and used it to derive relativistic concepts. In the final study, the TLS was adapted for the classroom and evaluated in seven classes. Also in this context, the TLS resulted in productive reasoning with the light postulate

Introducing Special Relativity in Secondary Education

Special relativity theory (SRT) is an iconic physics theory and prototypical for how new knowledge develops in this field. Therefore, learning SRT can be valuable for secondary school students. SRT was introduced in the Dutch pre-university level secondary physics curriculum (VWO) as an elective topic in 2013. However, learning relativistic concepts gives rise to some robust misconceptions and little is known on how to teach this topic at the secondary level. This research project aims to contribute to the scientific knowledge base of learning SRT in secondary physics education through the design and evaluation of a teaching and learning sequence (TLS). The first study deals with students’ pre-instructional reasoning on the light postulate, which states that the speed of light is the same regardless of the state of motion of its source or the observer. We developed a reasoning tool, the Event Diagram, that supports secondary students to perform relativistic thought experiments. We found that students used one of two different models for light propagation. Some of them switched models when they experienced a mismatch between different reference frames. The second study presents an educational reconstruction of SRT, yielding a TLS introducing the light postulate by presenting such a mismatch. Evaluation in small groups showed students developed confidence in the light postulate and used it to derive relativistic concepts. In the final study, the TLS was adapted for the classroom and evaluated in seven classes. Also in this context, the TLS resulted in productive reasoning with the light postulate

Wat betekent lichtsnelheid voor leerlingen?

Een verslag van de redeneerwijze van leerlingen om relativistische verschijnselen te begrijpen

Event diagrams: Supporting student reasoning in special relativity through thought experiments

This chapter presents event diagrams as a representational tool that allows students to visualize relativistic phenomena. It puts particular emphasis on thought experiments that can help students obtain a deeper understanding of physical phenomena that are hard to imagine. The chapter is intended for readers who look for instructional models to teach concepts of special relativity at the secondary school level, and also, for those who wish to learn more about thought experiments as instructional tools. Students perform the thought experiment by drawing light propagation in the event diagram. Compared to the traditional presentation of thought experiments, the event diagram stimulates students to reason with light propagation more explicitly. Like all external representations, event diagrams are a simplified and idealized display of reality and are inherently limited. To wrap up, the authors have shown how their tasks stimulate students to perform thought experiments by drawing light propagation in event diagrams

Students’ preinstructional reasoning with the speed of light in relativistic situations

Special relativity theory (SRT) has recently gained popularity as a first introduction to “modern” physics thinking in upper level secondary physics education. A central idea in SRT is the absolute speed of light, with light propagating with uniform speed relative to the reference frame of the observer. Previous research suggests that students, building on their prior understandings of light propagation and relative motion, develop misunderstandings of this idea. The available research provides little detail on the reasoning processes underlying these misunderstandings. We therefore studied secondary education students’ preinstructional reasoning about the speed of light in a qualitative study, probing students’ reasoning through both verbal reasoning and drawing. Event diagrams (EDs) were used as a representational tool to support student reasoning. Results show that students productively use EDs to reason with light propagation. In line with previous research, we found two alternative reference frames students could use for uniform light propagation. Most students show a flexibility in their use of reference frame: They not only evaluate light propagation in their preferred frame of reference, but also relative to other frames. Some students experienced conflict between an alternative reference frame and the speed of light and changed their reasoning because of that. This finding suggests promising directions for designing education

Visualization of thought experiments in special relativity education at the secondary level

Special relativity theory (SRT) presents an attractive introduction to modern physics in secondary education. Understanding the principles of SRT, however, requires a conceptually demanding learning process, involving a variety of robust learning difficulties. Thought experiments (TEs), performed by students themselves, provide a fruitful learning tool to address these difficulties. We present two visualization tools that explicitly support students in performing specific phases of a TE: a computer modelling tool and a paper and pencil representation of space time. We discuss relevant design features and specify how these visualization tools can be used to address learning difficulties