Catastrophic events

The classes are now over, for this term: we have finished ‘Changes to the Earth’s Surface’, and I am looking forward to hearing people’s feedback.

After a week to take measurements, I asked how everyone’s rain gauges had performed. We used the questions I posted already to prompt discussion. It was good to hear the children’s thoughts about what might have gone wrong and how we could improve the design. Many people had not measured any rainfall over the past week – I assured them that a zero result was still important for many reasons. (If adults are interested in reporting of null or negative results you might like to read a discussion on Nature Network, find out about The Journal of Null Results and read some more discussions on negative results here and here.)

We revisited drought and flooding. I showed some little animations from the UK about three different types of rainfall. I think these are simple but comprehensive. We looked again at the maps of annual rainfall again, from the Australian Bureau of Meteorology, that had so baffled the children the previous week. This time we all talked through the key, and looked out for years when there had been loads more rainfall than usual, or far less rainfall. We then watched videos of flooding in 2011 and drought in central Australia (BBC programme from 2008). Some children were a little upset by watching these, but we went on to talk about how people can predict, plan for and cope with these catastrophic events.

After briefly recapping plate tectonics, we covered earthquakes by making seismic waves with slinkys – you can see these explained with simple animations on the BBC Schools website and on some lecture notes from San Diego State University. We talked about how engineers can test structures to see if they will cope with earthquakes. We watched some videos of these ‘shake tables’ and then built structures ourselves with Duplo (TM) and shook the table to see if they would fall down or not. This was a great deal of fun! I think the children particularly enjoyed building structures that they knew would fall down.

Building with DuploDuplo tower

 

 

 

 

 

 

 

The teachengineering.org website goes into shake tables and earthquakes in much more detail if you are interested. There are two lesson plans that look good although I have not tried them out: Earthquake in the Classroom, and Shake it Up!

I read a few passages from ‘The House on the Volcano’ by Virginia Nielsen. We talked a little about how these catastrophic events are explained by pre-scientific communities as being due to supernatural reasons. When relief organisations are trying to help people or to evacuate people from areas at risk, it is important that they take into account people’s beliefs. (For those in NSW, this touches on parts of the syllabus for Human Society and its Environment.)

The House on the Volcano

For cyclones, tornadoes, hurricanes and tsunamis, we started by reading from ‘The Day of the Elephant’, a beautiful picture book about the 2004 Boxing Day tsunami.

The Day of the Elephant

As a challenge, and to find out how much the children already knew about these events, I had prepared paragraphs and pictures of each of these events. These covered:

formation,

what they look like,

how they form,

what damage they do,

how we can predict them

and how we can prepare for them.

I read these out at random, or handed them to the children, and we sorted them into a huge grid on the floor. I think this activity worked well. All the children were engaged, and keen to work out where each piece went. For future classes I may stick them onto backgrounds like a large jigsaw, so a picture is formed when the children have completed the activity.

natural disasters grid

The same session I brought along a home-made ‘vortex cannon’. This is a very fun piece of equipment to make, that shoots a small vortex of air out of the front. We made ours out of plastic milk cartons, one carrier bag, some gaffer tape and some elastic bands. I can’t find the specific instructions I followed, but if you check on YouTube there are many videos of people making and shooting these, some on huge scales.

We also made a ‘tornado in a jar‘ very simply, with water and dishwashing liquid. The children passed this around to each have a go.

On the final week the children gave their presentations. They varied in confidence and it was great to see each child standing up to have a go. I hope all the children and parents felt it was a welcoming and supportive audience listening to them. I loved all of them but wanted to particularly show off the poster that one child made about volcanoes:

volcanoes poster

I had also set up some ‘stations’ to demonstrate a few of the topics we had covered in the classes, so that the children could take their parents round and explain everything to them. The most popular was making the sedimentary rock models disintegrate by pouring water on them (simulating weathering and erosion). I forgot to bring everything, particularly the ‘bones’ from the Xenosmilus activity on Week 1, and I forgot to put out some of the items I had brought along. I apologise if I disappointed anyone.

I think our classes recovered well from the point which was described in my last blog entry. I will devote a future blog post to looking at what I advertised, and seeing if I delivered everything I said I would. I’m sure there are many things I would change when delivering these classes again. In particular, I would spread out the presentations so that there were a few each week for the last three weeks, rather than all in one go. But overall I felt it was a great success.

Next term I will scale back again, and only offer Friday classes in my house. We will be covering materials, the nature of matter and chemistry.

 

Respect for class teachers

I take my hat off to class teachers working in mainstream education. I am definitely best at working with small groups of children. By this I mean up to about four children! After this number, I start to feel I have to plan ‘filler’ activities for one set of children to do while I concentrate on the others. And that’s not why I teach science to home-educated children, and I can imagine its certainly not what the parents of these children want.

On Wednesday I was tired and I hadn’t fully prepared my materials. Everyone helped me to cut and paste some pictures of the water cycle on card. That took up a good half an hour before we did anything that I had planned.

I also planned an activity that was far too difficult for this group. I expected the children to copy contour maps with average rainfall and average temperatures for Australia. I wanted to use these maps to discuss floods and drought, but we will have to cover this another way.

australia's average annual rainfall australia's average daily temperature

We did manage to have some discussion about the water cycle, and to make our rain gauges. We have just come through a week with quite a bit of rain. I hope the next week will gift us some precipitation to measure.

Some children filled out sheets to help them to think about the experiment: what variables might affect the results and how they could keep as much as possible constant.

We also watched a couple of good videos/animations about the water cycle and the different types of rain:

Revolution (Life Cycle of a Drop of Water) on Vimeo

Types of Rainfall, from curriculumbits.com

Friday’s class went better although my own children were not in great moods and I particularly found the presence of my middle son distracting and disruptive. Nevertheless, we talked about the scientific method, poured water on our sedimentary rock models to simulate weathering and erosion (because the older children had missed this) and went on to cover much the same material as in the Wednesday class. We briefly talked about how the government might try to predict and prepare for floods, but by this point the children were not paying much attention so I gave up my losing battle.

I believe that the best way to learn science is to have hands-on experience but I can’t really bring a flood or a drought into the classroom. So how can I nudge the children into thinking about, and learning about floods and droughts? Reading or seeing eyewitness accounts is one possible way. Bringing some plants along would be an additional visual aid. It would also be great to find a computer game or simulation where your land, crops or livestock get affected by extreme weather. I might look out for something like this.

So far, the books I have found about natural disasters have been a bit dry. I borrowed a copy of ‘Australian Weather Disasters’ from the library, and we also have a back copy of Science Illustrated with a feature on how to survive catastrophic events. I can copy pages of this (for personal use) if anyone is interested.

Australian Weather Disasters Australian Weather Disasters (flood page)  Science Illustrated How to Survive

I also found some Australian Federal Government resources online about disaster prediction and management. There is even a Disaster Resilience Education for Schools website with a few games on. If your children have a look at this website please let me know what you think of it.