Snapshot Science

Lighting the Olympic flame

Snapshot Science — Tue, 15 May 2012 05:29:36 +0000

Image: Jon Candy @Flickr

The story

The flame that will burn during the London Olympic Games was lit at Olympia, the birthplace of the Ancient Olympics, last Thursday. The torch is lit using the same method as it was at the ancient Olympic Games, a parabolic mirror.

Teaching idea and resource

This story could be used in a lesson on reflection of light for KS3 or KS4 classes. The resource I have provided includes a starter activity (slide 1) to get the students thinking about how the torch is lit as well as a student activity (slide 3) and a handout (slide 4). This asks them to draw in the light rays on the parabolic mirror using the law of reflection before writing an explanation as to how it works. I have included keywords but these can be removed for higher ability students. A model answer is shown on slide 5.

They could then go on to look at how this technique is scaled up in solar furnaces.

Image: Llez @ wikipedia commons

The largest solar furnace at Odeillo in France (shown above) can produce temperatures of up to 3500°C as this video clip shows.

Weblinks

How Olympic torches work website

A parabolic mirror is used in solar ovens. This website explains how they work in more detail.

Science in the News-letter #13

Snapshot Science — Sun, 13 May 2012 19:45:00 +0000

Two very different wind related stories are featured in this week’s edition:

how did dinosaur wind keep the prehistoric planet warm and should the biggest wind farm in England and Wales be built?

May Junior Newsletter

Snapshot Science — Mon, 07 May 2012 05:38:29 +0000

Introducing the May edition of the Junior Newsletter for KS2/3. This edition contains three stories with accompanying questions from the past month, suitable for younger students.

Download your copy to find out how a travelling gnome has been helping science!

Science in the News-letter #12

Snapshot Science — Sun, 06 May 2012 20:47:07 +0000

Are your students pro or anti-nuclear power and what arguments can they use to support their views? Do they understand what ‘pharming’ is or what scientists use the LHC for? In the week’s Science in the News-letter they can find all this out and more – just download by clicking on the button below.

Supermoon!

Snapshot Science — Sat, 05 May 2012 06:09:59 +0000

The Moon appears to be bigger and brighter tonight as it’s elliptical orbit brings it closer to the Earth than at any other time of the year.

If you are teaching about the Moon at the moment this is a great story to teach about the Moon’s orbit and phases as well as the effect of its gravity on the Earth (as tides are expected to be higher this weekend as an effect).

Is a gold medal really gold?

Snapshot Science — Fri, 04 May 2012 11:52:19 +0000

The story

There is no doubt that the gold medals for the London Olympic games are beautiful but how much gold is actually in them?

This is might well be the first of a few Olympic themed postings over the coming months. I wanted to come up with some ideas that were a bit different and unusual so this is my first offering: an enquiry lesson to use when teaching metal properties or density or just as a way of practising maths and science skills.

It could be done with any age class depending on the activities you choose and how much guidance you give. I have given my outline for how I would teach the lesson but bits and pieces can be taken, missed out and mixed around.

Lesson idea

Starter

Introduce the problem and then get initial ideas. I would then ask the class to work in small groups and discuss the properties of gold. This can then be shared to draw out some common properties of metals. If they mention that gold is heavy it is a great opportunity to discuss what they mean by heavy and why this is not a good way to measure properties of substances, whereas density is. A house sized bit of cotton wool would be heavier than a gold coin but would they really say being heavy was a property of cotton wool? You might like to discuss what we mean by density and how to calculate it but not go into too much detail as later on in the lesson the idea is they work it out for themselves.

Then ask them if comparing any of the properties would be a good way to see if the medal was pure gold. There are a range of possible ways: this image demonstrates a common test. Pure gold is a soft metal so biting it might leave teeth marks (and ruin you gold). A more modern method is to measure the melting point.

However, none are as simple as looking at the medal so a little more investigation is needed.

Main

Although it would be nice to get the students to compare a real Olympic medal to a lump of pure gold that’s not going to be possible. So, tell them they are going to investigate a method that could be used to do this. They will be finding out if a copper penny is made of pure copper. How much guidance you want to give on this task depends on the class. Ideally, it could be totally open-ended with students researching and experimenting in groups. The calculating of volume is a great way to practice maths skills (especially when working out the volume of the coin).

For each group you will need:

a copper coin (2p is best)
a piece of copper (could be foil for an easy volume measurement or a bit of copper piping if you want to ~~be mean~~ stretch them.
balances
calculators
a displacement can (see weblink below if you don’t have any)
access to information on density and calculating volume

You might like to direct them to this great video showing the story of Archimedes’ principle and the Crown of Syracuse.

Plenary

The idea (hopefully) is that they will compare the densities of the coin and the pure copper (which is 8.933 g/cm3). Depending on the age of the coin, they will get different densities. You could go round the groups and compare them.

Wikipedia informs me that:

The coin was initially minted from bronze, but since 1992 it has been minted in copper-plated steel except for a few months in 1998 when bronze was used again. As copper-plated steel is less dense than bronze, post-1992 coins have been slightly thicker. The coin weighs 7.12 grams and has a diameter of 25.9 millimetres. The 2p coin is currently 93% mild-steel and 7% copper.

The reason for the change is the fact that copper is getting very pricey, no point in having a 2p coin that is worth more than 2p! This is an interesting discussion point because it is exactly the same reason why Olympic gold medals are not made out of real gold. They are in fact an alloy of 92.5% silver and 1.34% gold, with the remainder copper (a minimum of 6g of gold – the cheapskates)

Weblinks

Information about the medals

What – no displacement cans?

Xin Nian Kuai Le!

Science in the News-letter #11

Snapshot Science — Mon, 30 Apr 2012 05:10:18 +0000

Make sure you get a chance to look at Venus this week, as it is at its brightest (that is if the rain clouds disappear long enough).

In this week’s edition your students can find out why, along with being introduced to our oldest ancestor and a newly discovered species of amphibian.

What the frack?

Snapshot Science — Sun, 29 Apr 2012 20:03:49 +0000

Credit: bufivla @flickr

The story

Fracking is a controversial way of mining for natural gas reserves that are buried deep underground in layers of rock. It is been banned in some countries but is being carried out in the USA and UK. A few weeks ago the scheme got the green light to be extended in the UK.

Further explanation is shown in the video below.

However, it has it risks and has caused toxic chemicals to leak into water over in the states, as explained in this wonderful music video.

Teaching ideas

Although fracking is not specifically mentioned in any GCSE specs that I am aware of, you may wish to discuss it with GCSE groups when looking at the issues of future fossil fuel supplies (or just as an excuse to play the Fracking Song). Reserves of crude oil are running low and so fracking for shale gas looks to be one way of gratifying our appetite for fossil fuels.

Students could view the information and then come up with pros and cons before deciding whether they think the UK should build more fracking wells.

Weblinks

News article: ‘Gas fracking gets green light’

Interactive which explains in detail how it works.

In this video an 11 year-old girl discusses her views on fracking.

Science in the News-letter #10

Snapshot Science — Sun, 22 Apr 2012 19:48:59 +0000

Click the link below to download this week’s newsletter to use as a display or homework task. Your students can extend their knowledge by exploring stories that link to the GCSE core science curriculum. Items included focus on air pollution, genetics, plant hormones, plate tectonics and energy efficiency.

Science in the News-letter #9

Snapshot Science — Sun, 15 Apr 2012 19:46:31 +0000

After an Easter break Science in the News-letter returns with five stories from the past two weeks for your students to explore.

These include looking at the possibility that we could be visited by alien intelligent dinosaurs and how computer models are being used to count penguins from space*

*The penguins are not aliens this time, the satellites used to take pictures of them are in space. All will become clear if you download the newsletter!