A Straw Aeroplane

I came across this on the internet a while ago and thought I'd give it a go. Turns out its a great little activity for students and gives them a good incite into planning and conducting an experiment, with almost no prep needed from the teacher.

The only materials that are required are some drinking straws, card and selotape. The card is cut into strips and then taped into circles (see pic below). These circles are then taped onto the straw. You should find with the arrangement shown below these little things will fly a good 10 or 15 meters (I was sceptical too but give it a go).

The length of straw used determines how far they fly, as does the number of card circles added. Either of these can be used as the basis for an ivestigation (we found about 2 straws taped together is best). Get the students to choose one variable and work out a way to investigate it. A great experiment that requires almost no materials or planning.

Science Teaching In The UK

Global science levels are measured using the PISA science scale. This is an exam taken by a sample of 15 year olds once every 3 years. The PISA science scale is scored on a scale which has an OECD mean of 500 and a standard deviation of 100. As can be seen in the table below the UK comes in at 515. Whilst this is above average, it is behind many other economically developed countries including Chinese Taipei and Liechtenstein. Finland comes top with a score of 563.

There are many potential reasons for Finland dominating the PISA scale, including a very high level of spending (% GDP) on education, the schooling system (many students are still in their first school at 15 when the test is taken) and the importance placed on education in Finnish society. Science teaching is dominated by an ‘experimental orientation’; a hands on way of understanding the basics of science. A further consequence of having first schools which go up to the age of 16 is that specialist science teachers are available to even the youngest children; something which is rarely the case in the UK.

The graph below shows the percentage of students in each country that are classed as ‘top performers. These students attained a score of at least 633 score points on the PISA science scale. (The numbers at the bottom are the mean scores listed in the table above)


This is where Explosive Science comes in. As chemistry graduates we are able to expose students as young as 4 or 5 to stimulating science. Primary schools in the UK have neither the facilities nor the qualified science teachers to provide children with exciting science. This combined with more emphasis on virtual learning means that many children in the UK are managing to go until 13 or 14 without actually doing an exciting science experiment, by which time they are uninterested and bored.

At the end of every primary school workshop we ask the question ‘hands up who wants to do science when they grow up’, and we have yet to leave a school without every child present putting both their hands in the air.

The public/private school divide in science is difficult to estimate – many private schools do not take SATs. However students from private schools occupy many of the science courses at university (49% of the science places are occupied by privately educated students despite only 9% of the population being educated privately) implying that even if they are not better at science, they are pushed harder to follow it. The article in the Guardian below is about this divide. By showing students in public schools how exciting science can be we hope to close this gap.

http://www.guardian.co.uk/education/2009/oct/06/private-school-universities-strategic-subjects

Nick and Paddy's Top Five Rudeboy Scientists

No, this isn’t a late night Channel 4 countdown – this is probably higher budget, and much more interesting. Before we begin we should consider what it means to be a ‘rudeboy’ in science. Science rudeboys are few and far between. Earning the title ‘rudeboy’ is hard, and whilst intelligence is important, it is certainly not everything. Take Gregor Mendel, a hugely intelligent man who is widely credited as the father of modern genetics. Gregor spent much of his life in a monastery, interested in beekeeping and gardening. Hardly gripping. Compare this to Albert Hofman. Hofman not only discovered LSD, but tested it out on himself, having no idea of the dosage or the side effects. Whilst riding a bike. Hofman went on to do further research into hallucinogens, investigating magic mushrooms, salvia and other varients of LSD. In short, Hofman would not of been out of place in ‘Trainspotting’. As we will see below, to be a rudeboy in science you have to back yourself, not play by the rules, be outspoken, and generally change the way people think.

5. Carl Scheele

Scheele, a Swedish born scientist, is a person few have heard of, which is unfortunate as he was a good chemist, discovering no less than 8 elements (including Molybdenum, and Chlorine before Davy) in his life, as well as developing processes for producing phosphorus and prussic acid. Many of his discoveries were hijacked by others, and there is even proof that he discovered oxygen before Lavoisier. Scheele had little formal education as a chemist, instead he made it up as he went along. Ultimately this would lead to his downfall; deciding that a true chemist should taste all of his chemicals, Scheele was the unfortunate discoverer of hydrogcyanic acid, and the rest, as they say, is history.

4. Wolfgang Pauli

A theoretical physicist much respected by his colleagues for his deep insight into the newly emerging quantum theory, Pauli was a genius. He was, however, not shy at disclosing his feelings on others research, commenting on one paper that ‘this theory is worthless. It isn’t even wrong.’ It was said that ‘Pauli would not just criticize your work; he would insult you for producing it.’ Friends with Bohr, another prominent scientist of the time, many of their conversations reportedly ended with Pauli shouting ‘shut up, you are being an idiot, I will not listen to another word.’

3.Lord Kelvin

Lord Kelvin, a ‘victorian Superman’, gained renown in almost every branch of the physical sciences, producing revolutionary work on electromagnetism, thermodynamics and light, churning out a massive 661 papers and 69 patents. Kelvin started university at the age of 10, and in his teens published papers on pure mathematics that were so good, he had to publish anonymously to avoid embarassing his superiors. Kelvin argued fiercely and was loathe to admit he was wrong about anything. One subject he was adament on was the age of the earth (although he revised he estimate about 5 times), so much so that Rutherford has been quoted as saying ‘I came into the room, which was half dark, and presently spotted Lord Kelvin in the audience and realized that I was in for trouble at the last part of my speech dealing with the age of the earth, where my views conflicted with his. To my relief, Kelvin fell fast asleep.’ It appears that even the world’s greatest thinkers have trouble staying awake in lectures after a heavy night out.

2.Richard Feynman

Described as an ‘eccentric genius’ Feynman was a particle physicist, quantum legend, founder of QED, and in between found time to help make the first atomic bomb in Los Alamos. One of Feynman’s hobbies was lockpicking, and he famously told a story of his days on the Manhatten project where he managed to open most of the safes on site and find the American nuclear secrets. He eventually demonstrated the problem to the Army officials in charge. Horrified, they promised to do something about it. The response? A memo ordering the staff to keep Feynman away from their safes. He was also known for his working out of complex physics problems on the back of napkins. Not a big deal, except he preferred to do it in topless bars, and even classed his favourite one as ‘his office’. His life mottos were ‘don’t trust anything rigorously grounded in science’ and ‘what do you care what other people think?’ Feynman changed the way we think about particle physics, whilst at the same time being the sort of man you could chat to in the pub.

1. Sir Isaac Newton

Sir Isaac Newton is a rudeboy of the highest order. Described by Bill Bryson as ‘brilliant beyond measure, but solitary, joyless, paranoid and distracted,’ Newton laid the basis for physics for centuries to come. Most people know about his laws of motion, gravity and optics (indeed it was Newtons equations of motions which put man on the moon in the 1960’s), but many do not know of the other experiments he carried out in his (home built) lab – he inserted a long sewing needle into his eye socket ‘just to see what would happen’, he stared at the sun for as long as he could, and blinded himself for a week. Whilst investigating diffraction he decided to see if he could make the lens in his eye diffract light, and decided the best way of testing this was to jam a pen in between his eye and his eye socket (incidentally it worked). He was so frustrated by the limits of mathematics at the time that he invented differential calculus; and then kept it a secret for 3 decades. A large proportion of his life was dedicated to alchemy, and a sample of his hair studied recently showed it contained almost 40 times the normal amount of mercury present in humans. So obsessed was Newton with gold that he was put in charge of the Royal Mint, where he would routinely have suspected counterfeiters hanged. Much of Newton’s work in alchemy is unknown as he was so secretive, as are his involvements in countless secret societies. A true rudeboy, and a contender for histories cleverest man, Newton was definitley one of a kind.

Cake In a Mug

Not exactly science, but something fun to try in the kitchen. Explosive Science takes no responsibility for how bad this tastes (unless it tastes great obviously)

http://howto.wired.com/wiki/Make_Cake_in_a_Mug

Universal Indicator and Why We Still Let Our Mums do Our Washing

Recently Paddy and myself have been doing quite a few reactions in plastic bottles for our chemistry demonstrations (http://bit.ly/2yCjdJ) and so we have been drinking a lot of bottled water. We had recently got our hands on some universal indicator, and thought we might use it to try and find out a bit more about the water we were drinking.

Universal indicator is a few different indicators dissolved in ethanol, which is can be used to work out the pH of a solution. Don’t worry if you don’t have any of it, because it’s very easy to make indicators in the kitchen (http://bit.ly/s0EIm). Anything that is acid turns red when indicator is acid, and anything that is alkaline turns blue.

To start off we looked to see if there was any difference in sparkling water (12p a bottle from Tesco if you’re interested) that had just been opened and some which had been left open for a few days. The water on the left was the one that had been left open for few days and clearly contains less bubbles.

Both the solutions turned red on the addition of the indicator. This is to be expected as dissolving carbon dioxide in water produces carbonic acid. We couldn’t see any real difference in the colours, so we decided to move on.

Next we tested the difference in bottled still water and tap water. The bottled water (right) turned out to be pretty neutral, whilst the tap water (left) turned a nice green colour, meaning the water is slightly alkaline. This is an indication of hard water – to be expected living in the London area. A good explanation can be found here - http://bit.ly/39tP5b

Next we tested some washing powder. True to the advertising, Persil washing powder turned out to be pretty neutral. Flash floor cleaner on the other hand was almost as alkaline as caustic soda tested previously. A timely reminder of the importance of putting the correct cleaning agents in the washing machine, and the reason Paddy and myself still let our mums do our washing.

Boiling an Egg

When I was at university I had an organic chemistry tutor whose answer to every difficult question about solvents or reagents was, ‘Nick, don’t worry about it, it’s just cooking.’ How pleased I was then to read an article entitled ‘Chemistry really is just cooking’ (http://bit.ly/l30YF). One particular part of this article caught my eye, and that was how to boil an egg. I love eggs cooked in a variety of ways (for those interested there is a very good guide to poaching eggs here http://bit.ly/Knz5Z), but I had never heard of a way to make a boiled egg easier to peel. So in the name of science I tracked down two eggs, and gave it a go.

The article suggests that boiling eggs in an acidic solution makes them harder to peel than those boiled in an alkaline environment. I decided to make the experiment fair I would boil two eggs for three and a half minutes, one with 2 tablespoons of vinegar in the water, and one with a tablespoon of bicarbonate of soda in the water (bicarb makes the water alkaline – solutions contain the hydroxide ion as well as carbonic acid). I then timed how long it took me to peel the eggs.

In the end the results were much better than I was eggspecting (sorry, couldn’t resist). The picture below is the peeled egg cooked in vinegar. It was a nightmare to get the shell off and I gave up after two minutes with egg yolk all over my fingers.

The egg boiled in bicarb on the other hand was much easier to peel. The shell came away in large chunks in less than a minute, and in the end I had a perfect soft boiled egg. The only downside of this is that the article was correct about the smell – boiling eggs in this way does give off quite a distinct sulphur smell. The alkaline solution reduces the stickiness between the shell and the egg itself making the egg much easier to peel.

Verdict: A great quick experiment to do in the kitchen, and at the end of it you get to have lunch. More eggciting experiments to follow.

Hi

Starting tomorrow this blog will be used to test some out some home science that can be easily carried out in the kitchen or garden. I hope it will inspire some of you to have a go yourself, and it will be a good way for me to document the experiments I would like to test out.

If you like what you see, we would love to hear from you - info@explosivescience.com