 In the previous post, I discussed the importance of evidence and how scientists gather that evidence. We now examine the author. We are bombarded by the opinions of others. The rise of social media has allowed for much greater ability to share one’s views and opinions and to disseminate them. In many cases we can filter truth from fiction if we ourselves are fairly knowledgeable on the subject. Most of us would ignore the ramblings of those who believe in a flat earth, but what if you are not completely conversant on the topic? Add to the fact that many of the more ‘discussed’ issues, such as climate change, are quite complex, at best, we have only a superficial understanding of the topics. So we therefore rely on the authority of the author of the information. So how are we to assess if the author is qualified on the subject at hand? The author or presenter of the information received must meet certain criteria if we are to judge the veracity of the information they give. 1. They must be experts in the field of discussion. Clearly we would not accept an opinion delivered by a blogger who knows little about how science works, let alone medicine, when discussing medical treatments. Take for example Gwyneth Paltrow or Peter Evans who talk about food that “detoxes” you when we have a perfectly good set of kidneys and a liver that that do the job. But what about a person who is a doctor? They may know about their field but not necessarily about another. Would you trust a person with a PhD to give good advice about specific medicines, if their field is education? I think not. Nor would you implicitly trust a medical doctor to provide advice on engineering matters. Unfortunately many ‘communicators of opinion’ use their titles to their advantage to persuade their readers. For example, you may read from certain scientists who have reservations on climate change or vaccination, when a little research shows that their expertise is neither in climate science nor immunology.  2. Authors need to be free from biases. In the 1950’s many doctors and scientists argued that smoking wasn’t that bad. Ignore the fact that they were paid by tobacco companies to say that. In this case they were paid to promote smoking, and thus benefited from the promotion. It introduced a bias in their opinion. However, it can be more subtle. Energy Research Institutes may talk about clean coal, when closer inspection shows that contributors to their research includes mining companies and oil companies. So when we examine the authors’ credentials, we also need to examine any links to things that may result in bias. It doesn’t mean we outright reject their statements, but it does cast concern that needs to be considered. 3. You need accuracy. But what is meant by accuracy? Like the evidence, that means you need a lot of scientists saying the same thing.To explain, let’s look at an example. Say you have an illness and are unsure of the best course of action. You see your doctor who says, “You only need bed rest.” You are unsure, so you seek a second opinion, and they say, “you need to take this medication but you may have some side effects.” But you are still unsure. So you see 10 more doctors, who all say you should take the medication. What will you choose? The fact that 10 more doctors agree should lead you to follow their opinion.  Similarly in science, a research paper may make a particular claim. Further research shows that there are 100’s of other papers which agree with that claim, whereas only 2-3 which don’t. Irrespective of the qualifications of the authors that disagree, and they may have adequate knowledge of the subject, the fact that there are few in number, should be pause for concern. 4. Lastly, the ‘age’ of the authors' statements need to be considered.
If a paper makes certain conclusions in a paper that was written a long time ago, and new evidence comes to light that contradicts that conclusion, then the original conclusions may not be correct. Sometimes the time delay may not be long. During the COVID pandemic, mask wearing was not particularly encouraged at the start of the outbreak by health authorities. But as scientific evidence poured in that showed its benefit, the health authorities strongly encouraged mask wearing and governments started mandating it. The point is: as evidence becomes available, old conclusions may become invalid and this should not be relied upon. As a result, researchers and students are encouraged to ensure they research papers that are recent, that is, less the 10 years old So in summary, when researching a certain claim, ensure that the author has the qualifications, are free from bias, and that their views are supported widely in the scientific community. My third installment will examine how science is communicated and often miscommunicated
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 We are bombarded with information. Traditionally this has been through print media, such as books and newspapers, and audiovisual through the medium of television. However, in the last 25 years, the exponential growth of the internet has resulted not only in a huge increase in the amount of information, but it has also increased the number of sources of information. Prior to the internet, most of our sources of information came from vetted sources, such as journalists and experts in their field. With the advent of the internet, and social media, anyone can now express their opinions and views, increasing the number of ‘voices we hear’. Many of these lack the necessary knowledge of expertise and qualifications. The recent challenges of climate change, COVID, and subsequently the vaccinations have shown how powerful many of those voices have become. With many claiming to ‘have the truth’, how do we know what is the truth? How do we separate fact from fiction? How do we assess the claims made? There are three key principles to consider when evaluating claims
Over a series of three blogs, I’ll address these principles, and in the process hope to give insight on how science works.  The Evidence No matter which side of the debate you are on, evidence reigns supreme, but what evidence, scientifically speaking? Evidence is data driven scientific work, that is, - data is collected, and lots of it, - correlations are drawn between different variables, and - models are developed that attempt to explain the connections. As more data is collected those models are tested, modified if necessary, and at times, the models change if the evidence (read ‘data’) does not fit the model. What is important is how the evidence is collected, since it is imperative that - the data is reliable - the data is consistent with multiple measurement taken - and valid - the data is free from things that could skew the results, such as bias, incorrect methodologies, or other variables that are not taken into account. Within science, there are very strict processes scientists use to ensure their data is reliable and valid.  An overview of the scientific method 1. Scientists design their research (whether it by experiments, or data collection, for example) with the proviso that what they are looking for is not true. In essence, scientists try to disprove things, rather than ‘prove’ them right. For example, a scientist may want to investigate whether certain foods lead to increased heart disease. They will design their experimental work to show that that there is no link! Why? Because of confirmation bias. If you set out to look for evidence that supports your idea (in Science that is called a hypothesis) , then you stand the risk of seeing trends in the data that support your idea, when it actually does not.
The higher the number of samples taken, and if they are consistent, the more reliable the data. So when doctors say there is a strong link between smoking and lung disease, we take this seriously because it’s based on a huge amount of data collected, millions of people in close to 10,000 research papers. 3. When scientists design experiments, they often compare the data to a ‘standard.’ This is referred to as a control.
An example will help. A scientist wishes to test a drug for a heart disease. They will examine many patients (to ensure reliability). They give the drug to one group and then to another group, they may give something that looks like the drug, but actually contains no active ingredients, (called a ‘placebo’) When they get the results, they compare the two groups. You will very rarely get a super clear delineation (such as, all the people who received the drug improved, whereas all the placebo group did not). You will get some overlap; there will be some who received the drug but for whatever reason, did not improve. Similarly you might find that some in the placebo group improved. But if a VAST majority do improve with the drug, then there is a strong link to the drug and improvement. 4. The next step is to communicate the results, and researchers will then communicate their results by writing a paper and drawing conclusions. They will rarely speak in absolutes (“the drug definitely works”). Rather, they will be cautious. They understand that, as with any research, more evidence is better. So they may conclude, for example, ”People on Drug A showed a 25% improvement compared to a placebo” 5. Finally, the researchers will submit their work (or paper) for publication in a reputable journal. Is that it? No. The journal will review the paper, drawing on the expertise of other scientists in the field to critically examine the paper. If that passes the evaluation, the paper is published. Once published, other researchers can try to repeat the work, and will publish papers supporting the work, or critiquing the work, if they collect data that does not support the original paper. This is what is meant by a paper that is peer reviewed. It has gone through a very lengthy and comprehensive process to ensure that the data collected is done well and the conclusions drawn are appropriate and free from bias. As you can see, the process is rigorous to ensure the evidence collected is reliable and valid. So when you read online (or elsewhere) about some claim it is very important that any mentioning of evidence is backed up by quoting the actual research, that is, peer reviewed papers , which means it is data driven. It is not enough to say that evidence exists without actually quoting the actual research. In that case, it is just an opinion. In the next post we will examine the source of information, who is the author and whether they have the credentials for the information., so subscribe Instructional videos, especially those that involve writing on a board or screen, are easy to produce for educators. This is especially true for mathematics and physical science courses where equations need to be explained. A common way is to simply set up a camera towards a blackboard or white board and simply record yourself writing and speaking. Although quite basic technically, this method suffers in that you aren’t actually looking at the camera when you are doing the writing. Another method, employed by a number of educational channels is to write on a screen/computer and then record this. You hear the presenter, but don’t see them, as you see the writing on the screen. However, there no “human” evidence, either the hand writing, or the person talking. There is some research on the efficacy of this instructional method and the presence of a hand, or better still, the presenter, leads to improved engagement and therefore retention of content. It’s this reason why a number of presenters simply film their writing on paper from above as a way of communicating. One alternative method involves the use of a light board and it’s the way I have been producing content where I simply need to “instruct as I write”. The concept is fairly simple, though has a little more preparation required. The presenter writes on glass with a fluorescent whiteboard marker with the camera on the other side of the glass. This way the presenter is looking straight at the camera whilst writing. Of course, you will ask, do you have to write in reverse? No you don’t, you simply write normally, but to address the reversed image, when you edit the video, you flip the video horizontally. So now it’s the correct way round, and if you are right handed, you’ll appear left handed!  My rough and ready effort. Clearly I am not a designer, but it works just fine. Obviously not where I use it! There are a few things to consider.
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Dr Magdalena Kersting is an educational researcher and science communicator who is passionate about engaging students to Science through the teaching of Einsteinian Physics. In this podcast , I talk to her about her work, what motivates her and her thoughts on the importance of science communication. Apart from My usual endeavours , I’ve started a podcast. It’s purpose is to interview science communicators from various fields, to encourage and inspire students if science whether they be in high school or beyond. Here is the first. And I have many more to come with a growing list of excellent experts in their fields Geraint Lewis: Cosmologist his work, views on science and education and teaches us some welsh!  When people think of famous FEMALE scientists, Marie Curie comes to most people’s minds. She was Polish but moved to France and, with the collaboration of her husband Pierre, discovered two new elements, Radium and Polonium, and established the new science of radioactivity, a term they coined.
She also stands out for being the first woman to receive the Nobel Prize for Physics and is the only person to have won two Nobel Prizes in different categories (the other in Chemistry) All this in an age when Science was the chief domain of men, and as a result, she had to fight some discrimination to get her science heard. “Radioactivity”(2019), directed by Marjane Satrapi is a movie that looks at the life of Marie Curie, played by Rosamund Pike. Based on the graphic novel by Lauren Redness, the story is told in partly a flashback fashion. The movie opens with her collapse in 1934 and her being rushed to the hospital. We are then taken to various stages of her life, in chronological order. it explores her life after her arrival in Paris in 1891 (the movie starts in 1893), her scientific work, her life with her husband Pierre whom she married in 1895 , the collaboration she had with her husband in discovering the two new elements, up until his untimely death in 1906, the scandal that involved her extramarital affair and finally her humanitarian work during World War One. I'm resisting a full synopsis of the movie. Her life is very well chronicled, and worth researching and for the most part the movie is faithful to her story (though there are some glaring errors) There are a number of key themes that run through the movie. First is the strong determination that Marie Curie possessed, and this is well brought out by Rosamund Pike. At times it borders on arrogance and in fact her husband (played by Sam Riley ) says as much. This is not surprising since this allowed her to achieve what she did. As well as this, the movie champions Marie Curie as a female role model, who is independently minded and a few key scenes bear that out. I do see this as a strength of the movie. Another key theme is the impact that their work on radioactivity had on the future. At a number of stages we get fast forward to future events that involve radioactivity, some positive, some negative. It seems that the director wishes to remind the audience that Curie's work had an impact on our modern world. I’m not sure if they were necessary, but I will let other viewers make up their own mind The issue here is that the intent seems to suggest that the Curies’ discoveries are responsible for these events. This is a long bow to draw. Not only was Radium and Polonium not involved in some of the ‘consequences’ later shown, There are many more other discoveries that were needed for those ‘consequences’ to occur. Finally, is the point that there was a growing awareness of the dangers of radioactivity, with the slowly declining health of not only Marie herself, but her husband as well. As a science communicator I wanted to watch the film to get a better appreciation of Marie Curie as a person, in the midst of her scientific work. I had hoped for some more detail on her scientific work, but the movie is more about her as a person than her scientific work. So although we get a good insight on her process of extracting the new elements from pitchblende, and the resulting discovery of Radium and Polonium, it does not take prominence over the story arcs of her relationship with Pierre and her later life after his death. Overall the science process is accurate, though not fully detailed. This includes the extraction of unknown elements form the pitchblende and then the used of chemical means to isolate and crystalise the elements. I jarred a bit by the use of animations to demonstrate the atoms. At one point Bohr models were shown to show Radium and Polonium, when they weren’t in use until much later. Similarly a nucleus is shown with protons and neutrons and that structure wasn't established until the 1930’s. However, I understand the director’s choice here, as they are the models more familiar to the general public than the Thomson model which was the model at the time. So is the movie worth watching? If you want to get an understanding of the life of Curie during the time of her discoveries, it’s fair. It is slow in parts, with some smaller themes not really necessary, such as Pierre’s interest in spiritualism. Some parts are fictionalised. In the movie, Marie Curie is not at the Nobel prize presentation , yet in real life she did attend., though it was both two years later. Curie is seen to question the safety of radioactive substances, but this is not substantiated in reality. I wish they also touched on her later life post war. I found the ending a bit weird, involving her death scene. I won’t elaborate on the details but they suggested Marie had some regret in her discoveries, with Pierre saying “you cast a stone in the pond, but you cannot control the ripples” This is probably my main gripe. To somehow suggest Curie was responsible for future events and that she somehow know this. The use of cut scenes in the future were used to make this point and they really impinged on the flow of the movie, and as stated earlier, really don’t connect well to the work of the Curies Go and watch it but I think you will get a deeper understanding of the amazing and complex life of Marie Curie from a good biography.  I recently had an experience that hit home the concern of new teachers leaving the profession.
I spoke with a new teacher who had only graduated at the end of last year. Let’s call her Lisa. By all accounts she was a capable new teacher, knew her content well, delivered engaging lessons to her students, was willing to learn herself, and important, passionate about wanting to teach and motivate students to science. And, last year, I was excited to hear that a local well known school with a strong reputation was considering her employment. When I met her again last week, I discovered she had left the profession. She was burnt out. What happened? The school placement fell through and instead got employment at another school. This school has its challenges especially where it is socio-economically, and I am sure there are dedicated teachers there. However, Lisa’s experiences were far from supportive. She arrived discovering that each teacher was working on their own unit of work, there was no collaboration in producing programs across each year. More alarmingly, when Lisa asked to see the programs, she was told that there was no sharing, she had to do it all on her own. When she had classroom management issues (we will all have them) she got no support from her immediate supervisors. She was left to fend for herself. To me the attitude she was facing was akin to a parent telling a toddler , “get your own food, I’m busy and I font's care”. Thus it isn't that surprising she started getting panic attacks, and eventually left. This resonated with me, as I had a very similar experience in my early career. I don't think this isolated. Recently , I heard a similar story from a more experienced teacher who was also placed in another school, who got no support from her faculty, especially with dealing with student issues, from the faculty head no less. Studies seem to suggest the attrition rates for new teachers can be as high as 25% in the first 5 years and a Commonwealth Study from 2014 found 5.7% teachers leave in any given year - see the link below for further details. I appreciate the fact that teachers leave for a variety of reasons, misplaced expectations, changes in circumstances, other professional opportunities, but high on the reasons provided in studies is a lack of support. Being based in NSW, Australia, I refer to the the Department of Education and Training (DET) and DET do have policies in place to support new teachers. But I am concerned that possibly these polices aren't always enacted on. Add to the fact that many new teachers, especially in government schools, are placed in schools that have a high turnover rate - schools in disadvantaged areas, schools that are remote, or both. Yet, these are the places that need experienced teachers to effective teach in challenging circumstances. I acknowledge I am no expert in understanding the complexities of the reasons behind the teacher attrition, but as a science educator I am especially cognisant of the need of effective science communicators to advance a passion for science and grow a scientific literacy in our community. And when we see good science educators leave because they get no support, we all lose. Please add to the conversation - experiences, thoughts, ideas
 I just finished watch the film, “The Current War” starting Benedict Cumberbatch and Micahel Shannon
The film was made in 2017, and then received a director’s cut and re-released in 2019. It was slated for cinema release here in Australia in March 2020, but the COVID pandemic stopped that. The movie being released on Apple and Google for purchase or rental. For those that don’t know the meaning behind the title, it refers to a competition between two standards of electrical distribution: direct current, or DC, championed by Thomas Edison, and alternating current or AC, championed by George Westinghouse. By the late 1870s, both men were already well known. Edison, played by Benedict Cumberbatch, had invented the lightbulb, phonograph and started developing a system to distribute electricity to power the light bulbs. He was by then a very famous individual. Westinghouse, played by Michael Shannon, the great rail engineer and industrialist, had built his fame and fortune by inventing the train air brake which made a significant impact on the development of the rail industry. By the late 1870’s and into the ‘80s, Westinghouse sought to distribute electricity by a much better system, AC. Its chief advantage: it could be transformed, thus increasing its voltage, and then transport it long distances without significant power loss. DC distribution was only effective I sort distance and thus would require power stations every few km or so, and this could only be practical in large cities. The movie carries the story as to how these two men responded to the competition between the two systems, culminating in the tender to light the 1893 Chicago World Fair. It shows the unscrupulous tactics employed by one of them to discredit the other. I resist giving too much away, since you may not be fully familiar to the story and would like to see the movie for yourself with fresh eyes. Knowing the story pretty well, I was impressed by the movie to present the story with some balance. Yes, there is a bit of a ‘villain’ element, but the character portrayal isn’t too one dimensional, and you get a sense of the humanity of all the main characters represented. Edison and Westinghouse are usually the two figures that come to mind in the “Battle of the Currents” how it is also referred, but often Nikola Tesla is left out. I am glad the movie chooses to include Tesla’s in the story, played by Nicholas Hoult, as he makes a significant contribution to the story. Having read a few other reviews, there was some criticism that Tesla wasn’t explored further. He did develop the AC induction motor that contributed to the eventual success of the AC distribution. But this movie is really about the vying for the better system for electrical distribution, which was predominantly a battle between Edison and Westinghouse. Like all movies that start of with “Inspired by true events” there are some inaccuracies. Two events are juxtaposed towards the end that did not occur at the same time. In fact one occurred three years before the other. The death of a character occurred 5 years after the time portrayed. In both cases the director clearly made some changes to the story to better fit in with the narrative of the story. I don’t think this seriously detracts from the story as a whole. And there are parts that are stylistic and probably didn't happen. Did investor arrive on a Westinghouse train to be greatly by Edison in the snow with a circle of lights? Apart from the excellent Cumberbatch, Shannon, and Hoult, the supporting cast also do a great job, with Tom Holland playing Edison’s secretary Samual Insull, Matthew Macfadyen playing JP Morgan and Katherine Waterston, playing Westnhouse’s wife, Marguerite. Cinematography is excellent as is the soundtrack and the director, Alfonso Gomez-Rejon, uses both well to advance the story as well as connect the two main protagonists The movie is light on physics, it is a hollywood movie after all, but I think serves Physics well as it gives a context to why AC distribution won out in the day. So overall I enjoyed the movie and recommend it. I would especially encourage students of physics watch it, to give a bit of historical context to electricity and its supply. or A LESSON UNITS, UNCERTAINTY AND SIGNIFICANT FIGURESI find students when they start a physics course, have a weak understanding of how measurement works and how values are discussed, and so I cover key concepts of units, uncertainty and quoting of significant figures, before I start the physics course proper.
What follows is a an activity I do with the students over the course of 1-2 hours. (I include some thoughts in red) Determining the Density of a pice of paper Divide your class into groups of 3 Give each group a single sheet of A4 (or 'letter') sheet of paper and ask the to determine its density as accurately as possible. Give as little instructions possible but provide them only a meter ruler and access to a set of digital scales. Finding the length and width is relatively straight forward, but the thickness is another matter. I find the students generally fall into two camps, they either fold the paper multiple times to ge a thicker section (which has its limitations) or they ask for a stack of paper and measure that (again, the size of the stack contributes to uncertainty) Once they determine the dimensions and the mass, and thus calculate density, get them to write their answer on the board. When I survey their responses, most get similar 'numbers', however, there will be some with different units (I insist on them quoting units) and many over quote significant figures. So as I discuss the results in the class I ask "Are these results the same?" To the ones who over quote numbers, I ask "how confident are you of those number?" I then ask about the thickness measurements, "How certain are you about the number being that precise value?" This then all leads to a discussion on - talking the same 'language' - SI units - how we express our uncertainties - the role of significant figures (check out my video here) At this point , teach the points measured above, including how to express uncertainties Once you have covered the concepts , get students to repeat the task, but prior, teach them how to use a micrometer. Students now need to determine the density, using same units, and quoting with % error and in correct significant figures. When results are compared on the board, all their results should fall within the uncertainty of the over the results (hopefully :) ). This could be graphed to make it more clear. Feel free to provide feedback below and any modifications you tried I was asked in one of my comments on YouTube why 'g' was designated as -9.8 m/s2.
In their words "if gravity goes down , why isn't it positive." So I thought I would respond as I am sure there are many students who ask the same question when they start a course in physics. When we determine 'g' as an acceleration we commonly use the Newtonian view of gravity as a force, and thus when we divide the force by the mass we get acceleration. But it is better to think of 'g' as the gravitational field strength, or in another way, the value of the energy by way of its position in gravitational field per unit mass. (we can also call this conventionally, the amount of potential energy per unit mass) the symbol for potential energy is U So g = U/m. But U, the potential energy is deemed to be negative*, because a. moving away from the mass generating the field always increases U and b. U is set as 0 at ∞ So how can you always increase U by going up to 0? It's negative that is why in texts U = -GMm/r (I encourage you to look at my video on GPE Explained for more detail) So if U is always negative, the so is U/m, which is g So that is why books use -9.8m/s/s for gravitational acceleration, and therefore any vector going down, such as velocity or displacement will also need to be negative. * the choice to have U = 0 at ∞ is arbitrary and is set by convention. There is no physical reason why it should be negative. To to ensure consistency, it is agreed that U = 0 at ∞ |
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