This site is maintained by Henry Welman, former provincial manager (2017-2022) and subject adviser (2001-2016) for physical and technical sciences in the Free State, South Africa. Currently retired, but interested in the well-being of teachers and learners involved in these subjects. Please read the disclaimer at the bottom of the posts.
Showing posts with label Interesting article. Show all posts
Showing posts with label Interesting article. Show all posts
Dr William Smith decorated by President Cyril Ramaphosa in April 2019. Photo credit: Netwerk24.com
Today, Wednesday 21 August 2024, Netwerk24 and News24 reported that the iconic South African teacher, Dr William Smith, died peacefully in Australia after a short battle with stage four cancer.
Dr Smith started his ground-breaking physical sciences and mathematics classes on SABC TV in the 1990s. He was an amazing teacher with a practical and hands-on approach to excellent explanations. He helped millions of learners to understand the subject content better, and he helped thousands of teachers to improve their own explanations of the subject content.
Apart from his amazing career and service to teachers and learners of South Africa, something of special interest to me is that Dr Smith appeared as a boy in a picture that was taken when the second coelacanth was brought to South Africa.
William Smith as a boy on the far right. Photo credit: saafmuseum.org.za
This amazing story can be read here and here. We thank the websites and authors for documenting this interesting history.
My sincere condolences to Dr Smith's family. What a great honour it was to have experienced this man!
This is not a music website but I have thought of making you aware of the tragic destruction of Tchaikovsky's house in north-east Ukraine.
According to an article on the Classic FM website, the house was recently destroyed by the Russian army.
What a sensible loss due to the greed, power, and immeasurable lack of sophistication by some politicians. What you destroy can never be replaced; maybe repaired. Think of what was done during the bombing of Dresden in February 1945, and there are many other examples of how human beings destroy history, culture, and much more. This treasure in Ukraine has now become the prey of such senseless actions as well. What is the message for us in our country?
Click here to read the original article. It contains valuable further links, inter alia a link to a recording of Tchaikovsky's voice. You can also click here for a pdf copy of the Classic FM article.
Prof Rhett Allain from the Southeastern Louisiana University has written a wonderful article about "pi" with very interesting applications for physical science teachers. Click here for a pdf copy of the article, or click here for the original article in which further interesting links are found.
The similarities between the UK Covid problems and what we have experienced locally is nice reading material. Note the fact that marks awarded by teachers at the end of 2020 and 2021 were substantially higher than the normal results obtained in the case of examinations.
The fact that learners wrote the usual national examinations in South Africa in grade 12 was actually a good decision to avoid large statistical discrepancies between the marks of different years.
This shows how important it is to make learners aware that SBA marks are very important to help them. Even tasks such as informal tests, that do not count for SBA, are important to prepare them for those tasks that DO count for the SBA. The value of practical work is very high. Therefore, it should NEVER be neglected.
I have posted a few stories of extraordinary people that we can use for motivation in our daily lives as teachers. It is perhaps time to do so again, and this time around, I thought that we must highlight the life of Joachim Sauer, one of the world's most prominent quantum and computational chemistry researchers, who received his first doctorate in chemistry (Dr. rer. nat.) from Humboldt University in Berlin at the age of 25 in 1974.
Who is Joachim Sauer? He is the husband of Angela Merkel, of whom we have heard a lot recently when she stepped down as the first female chancellor of Germany. She served as chancellor from 2005 until recently.
Everybody knows her as a formidable politician. However, you might find it interesting, in case you do not know it, that she speaks Russian fluently, and that she also holds a doctorate (Dr. rer. nat.) in quantum chemistry, which she received in 1986, a few years before the fall of the Berlin Wall. Before entering politics, she worked as a researcher and published several papers.
Back to Joachim Sauer. In 2019, the American Chemical Society (ACS) published an article about this extraordinary man. This article highlights a few things that we as teachers can use to make sure we do the best in our Physical Science classes. Please read the article of the ACS (I have highlighted a few sentences for you) and notice how Prof. Sauer referred to the role of "teachers" in his life:
Somebody that exposed him to practical work.
Somebody that made sure he took part in Chemistry Olympiads.
The role of an inspiring teacher.
A teacher that was interesting.
Scoop up these noble qualities and become such a teacher in 2022. Inspire your learners, teach them to develop their abilities as much as possible, do practical work, and expose them to the best possible opportunities.
The Verge (theverge.com) recently published an interesting article about the increasing phenomenon that people cannot find their information on their computers, tablets, smartphones, etc. The concept of a "file structure" apparently become unfamiliar to a large percentage of computer users. It also has a message for teachers. Click here to read the original article, or click here to read a pdf copy.
Do you plot velocity on the y-axis and time on the x-axis of a graph for a velocity-time relationship or the other way round, and why? What about the relationship between pressure and volume of an enclosed gas? Which one of pressure or volume should be on the y-axis of a graph?
Recently an interesting article has appeared in the evening newspaper NRC Handelsblad in the Netherlands. Who still wants to be a teacher? is worth reading. It sounds almost like some of the debates in South Africa.
Recently I saw a post on the Facebook group RSG Sterre en Planete by Jan Viljoen. He shared a post of Keith Anderson about the fastest manmade object that was not a hypersonic jet or spacecraft, but a large manhole cover. What an interesting story!
Keith Anderson wrote further: "When the US started doing underground nuclear testing, nobody really knew what would happen. One test bomb was placed at the bottom of a 485-foot deep shaft on July 26, 1957, and someone thought it was a good idea to put a half-ton iron manhole cover on top to contain the explosion. The bomb turned the shaft into the world's largest Roman candle, and the manhole cover was nowhere to be found. Robert Brownlee, an astrophysicist who designed the test, wanted to repeat the experiment with high-speed cameras so he could figure out what happened to the cover. So, another experiment was created, this time 500-feet deep, and a similar half-ton manhole cover was placed on top. On August 27, 1957, they detonated the bomb. The high-speed cameras barely caught a view of the cover as it left the top of the shaft and headed into oblivion. Brownlee used the frames to calculate the speed to be more than 125,000 miles per hour; more than five times the escape velocity of the earth, and the fastest man-made object in history."
Physicists have debated the whereabouts of the two manhole covers ever since. Recently, with the help of supercomputers and a lot more scientific knowledge, physicists are certain that they wouldn't have had time to burn up completely before exiting the atmosphere. This means both of the remaining pieces would have passed Pluto's orbit sometime around 1961 and are way beyond the edge of the solar system by now.
You can read two further articles, with beautiful pictures, from MailOnline and BusinessInsider about these amazing phenomena. I have made pdf files of the articles. Click here for article one, and here for article two.
For those who want to know more. The escape speed for Earth is 11,3 kilometre per second. At that speed, one can cover the straight distance between Pretoria and Cape Town (if we take it at 1 315 km) in 116 seconds, or about two minutes. Makes one think about this amazing universe and the achievements of science!
How hard was it to get the Saturn V rocket, 111 m tall and weighing 2,8 million kilograms (click here for more info) to move at 11,3 kilometre per second to take the Apollo 11 crew to the moon in 1969? Nevertheless, Werner von Braun and his team had done it during the Apollo missions! You may want to click the label "von Braun" below this post to read more about Werner von Braun.
Here at the beginning of 2021, it is worth the while to take notice of the amazing story of the SS Warrimoo.
Image: https://www.snopes.com
On 31 December 1899, it crossed the equator and the international date line. This sparked a few amazing facts! Read the original article here or download a pdf version here.
Since the arrival of Covid-19 everybody says: "Wash your hands!" What is soap? Where does it come from? How is it made? Here is a very interesting article about soap, and its history by Professor Judith Ridner, Professor of History at the Mississippi State University. The article was first published in The Conversation. Physical science teachers have the responsibility to widen the worlds of their learners, and here is a good opportunity. Apart from teaching the prescribed content, it does make a difference in their lives to talk "other issues". Use the links in the article to go to other interesting reading material as well. I have also prepared a pdf file of this article. You can download it here. Enjoy!!
It’s common-sense advice. The surfactants found in soap lift germs from the skin, and water then washes them away. Soap is inexpensive and ubiquitous; it’s a consumer product found in every household across the country.
Yet few people know the long and dirty history of making soap, the product we all rely on to clean our skin. I’m a historian who focuses on material culture in much of my research. As I started digging into what’s known about soap’s use in the past, I was surprised to discover its messy origins.
Ancient Mesopotamians were first to produce a kind of soap by cooking fatty acids – like the fat rendered from a slaughtered cow, sheep or goat – together with water and an alkaline like lye, a caustic substance derived from wood ashes. The result was a greasy and smelly goop that lifted away dirt.
An early mention of soap comes in Roman scholar Pliny the Elder’s book “Naturalis Historia” from A.D. 77. He described soap as a pomade made of tallow – typically derived from beef fat – and ashes that the Gauls, particularly the men, applied to their hair to give it “a reddish tint.”
Ancient people used these early soaps to clean wool or cotton fibers before weaving them into cloth, rather than for human hygiene. Not even the Greeks and Romans, who pioneered running water and public baths, used soap to clean their bodies. Instead, men and women immersed themselves in water baths and then smeared their bodies with scented olive oils. They used a metal or reed scraper called a strigil to remove any remaining oil or grime.
By the Middle Ages, new vegetable-oil-based soaps, which were hailed for their mildness and purity and smelled good, had come into use as luxury items among Europe’s most privileged classes. The first of these, Aleppo soap, a green, olive-oil-based bar soap infused with aromatic laurel oil, was produced in Syria and brought to Europe by Christian crusaders and traders.
French, Italian, Spanish and eventually English versions soon followed. Of these, Jabon de Castilla, or Castile soap, named for the region of central Spain where it was produced, was the best known. The white, olive-oil-based bar soap was a wildly popular toiletry item among European royals. Castile soap became a generic term for any hard soap of this type.
The settlement of the American colonies coincided with an age (1500s-1700s) when most Europeans, whether privileged or poor, had turned away from regular bathing out of fear that water actually spread disease. Colonists used soap primarily for domestic cleaning, and soap-making was part of the seasonal domestic routine overseen by women.
Companies began to develop and market a variety of new products to consumers. In 1879, P&G introduced Ivory soap, one of the first perfumed toilet soaps in the U.S. B.J. Johnson Soap Company of Milwaukee followed with their own palm-and-olive-oil-based Palmolive soap in 1898. It was the world’s best-selling soap by the early 1900s.
Soap chemistry also began to change, paving the way for the modern era. At P&G, decades of laboratory experiments with imported coconut and palm oil, and then with domestically produced cottonseed oil, led to the discovery of hydrogenated fats in 1909. These solid, vegetable-based fats revolutionized soap by making its manufacture less dependent on animal byproducts. Shortages of fats and oils for soap during World Wars I and II also led to the discovery of synthetic detergents as a “superior” substitute for fat-based laundry soaps, household cleaners and shampoos.
Today’s commercially manufactured soaps are highly specialized, lab-engineered products. Synthesized animal fats and plant-based oils and bases are combined with chemical additives, including moisturizers, conditioners, lathering agents, colors and scents, to make soaps more appealing to the senses. But they cannot fully mask its mostly foul ingredients, including shower gels’ petroleum-based contents.
We teach our learners about isotopes and one of them is carbon-14. I am pretty certain many teachers also tell their learners about carbon-14 dating. The Guardian has recently published a very user-friendly and interesting article about the history of carbon-14. Click here to go to the page with interesting articles and follow the links from there. We have such appreciation to The Guardian to publish such educational articles.
Cling wrap is used on a daily basis in our lives. Did you know about the serious health issues involved when bad chemicals start to migrate from the cling wrap? One of the Lejweleputswa teachers, Mr Thuntsi Thekiso of Kheleng Secondary School, made me aware of this. Click here to go to the page with interesting articles and from there follow the link to the article itself. Scary indeed!
We work with directions in physics; in fact, we work with it a lot of times. Have you ever wondered why north is at the top of our maps? What if we have maps where Australia is not "down under" anymore, as shown below?
Not checking your USB ports or using flash drives from untrusted sources could be a disaster for you. The possibility exists that somebody can steal your passwords via you USB ports. See this interesting article. Would it not be wonderful if we can live in a world of honesty and integrity? Nothing of this sort of thing would happen.
Tomorrow is the end of the April school holidays and term two will commence on Tuesday. It will obviously be a very busy term - as usual - for all of us in the teaching profession. Long hours, challenging work conditions, terrible amounts of paperwork and administration, and especially huge pressure on everybody, from school up to the provincial head office, involved in getting better results in grade 12; at least for those grade 12 learners who are going to sit for the final examinations in October/November. Lately, I have often wondered for how long it will be necessary to pursue all the extreme measures to achieve better grade 12 results. Those who are going to sit for the final examinations in grade 12 have - apart from normal teaching hours - matric camps, extended hour programmes, extra classes, extra resources, TV/IBP lessons, community radio broadcasts, and other initiatives. All in the name of getting better results at the end of secondary school. What is wrong with our South African system and its people that sufficient success cannot be achieved with "normal" input, normal working hours, etc.? The question could be asked: "Is there a healthy balance between work and the personal lives of teaching professionals?" What is the personal cost for an unhealthy balance between work and personal life? It is certainly something to think about. Recently an interesting article from the World Economic Forum appeared about the good balance between work and life in Denmark. The balance is actually the best in the world. I wonder how we compare with Denmark? The original article is available here, and a copy in the cloud is also available here with highlights of interesting parts. Best wishes to all for term two!
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