Student article – Do penguins keep warmer with lots of penguins around them, or is material better at keeping their heat in? – Sophie Knoyle and Chloe Coombs
Ysgol Plasmawr, Cardiff
(Also in this team was L Jones, and teacher advisor was C Amos for Science and K James for literacy).
Reviewed by Ceire Wincott BSc, Postgraduate student in Drug Design and Discovery at Imperial College, London
In the Antarctic penguins huddle to keep the heat in because it’s very cold. We predicted that the penguin in the middle is warmer with penguins around it than with material around it. We also experimented with different numbers of penguins in the huddle.
As you can tell by the question, two experiments were needed. The two experiments were ‘The experiment with one, seven and nineteen test tubes’ and ‘The experiment with different materials’.
Our independent variable was the temperature. Our dependent variable was the quantity of test tubes needed in the experiment with nineteen test tubes, seven test tubes and one test tube. The dependent variable for the material experiment is the materials. Six different materials were used: kitchen roll, foam, card, tin foil,
felt and cotton wool. That is the only thing that changed during the experiment.
Make sure the same amount of water is in each test tube.
Make sure the water temperature is 60˚c at the start of each experiment.
Make sure we check the temperature at the correct time.
Make sure the same amount of material is around each test tube.
Make sure materials don’t overlap as this could affect the results.
First, measure 11cm up the test tubes and draw a line with a white board pen.
With the experiment with 1, 7 and 19 test tubes, boil the kettle and pour the boiling water in to all of the test tubes (19) up to the line.
Next, put the thermometer into the test tube in the middle and wait for the temperature to drop to 60˚c.
Measure a piece of material 11cm x 6cm.
Do this with all of the different types of materials.
Next, put the different materials around the test tubes by using sellotape.
Do this with all the different types of materials.
Then, place one test tube and a thermometer into the beaker, and wait for the temperature to drop to 60 c.
For both experiments carry out the following steps.
Start the timers – one for 1 minute, one for 5 minutes, one for 10 minutes and one for 15 minutes.
Then, wait for the 1 minute timer to finish and record the temperature in the table.
- Repeat with all the different times (1, 5, 10 and 15 minutes).
- Repeat the experiment twice to get accurate results.
- Repeat this experiment with all of the materials.
- Repeat this by using 1, 7 and 19 test tubes.
Results: Experiment 1
The graph shows the results for the experiment with 1, 7 and 19 test tubes. It shows the temperature drops as the time goes on. The more test tubes, the warmer the test tube in the middle stays.
We saw that the penguin on its own was the coldest because there was nothing surrounding it to keep the heat in. If penguins didn’t huddle, they would lose their heat very quickly because there would nothing to keep the heat in. With the seven test tubes, it keeps the heat in more than the one on its own because there are test tubes surrounding that keep the heat in. The experiment with nineteen test tubes kept the heat in the most.
Results: Experiment 2
We saw that the material that kept the heat in the most was tin foil. After 1 minute the material that kept the heat in the best was the cotton wool. After 5 minutes the material that kept the heat it the most was the tin foil. After 10 minutes it was still the tin foil and after the full 15 minutes it was the tin foil again, the average temperature was 32.3˚c. As you can see, the temperature dropped 27.7˚c after the 15 minutes. The material that lost the most heat was the kitchen paper. The temperature dropped 33.7˚c after the 15 minutes.
The graph shows the results for the materials. You can see the tin foil is the best material to keep the heat in. Also, the graph shows that every 5 minutes the temperature drops.
We have discovered that penguins are warmer in a group than with materials surrounding it. In the experiment with 19 test tubes the highest temperature was 59.7˚c. In the experiment with materials surrounding the test tubes the highest temperature was 48˚c and this was tin foil.
In real life, we think this shows penguin feathers are very good at keeping the heat in. We have proved that the more penguins in a group, the warmer the penguins will be. While doing the experiment, we saw that penguins are better huddling in a group than wearing materials. The materials don’t keep the heat in as well as a group of penguins.
The penguins on the outside were colder. The average after fifteen minutes on the inside with 18 test tubes surrounding was 54˚c, but on the outside the temperature was 48˚c. This shows that penguins on the outside are colder. That’s why real penguins take it in turn to be in the middle of the group. They also take it in turn to be in the middle because the penguin in the middle will get too hot.
Analysis and Evaluation
The experiment very successful, and everybody hypothesised correctly – the penguins are warmer in a group than with materials surrounding them. If we were to do the experiment again, we would start the temperature at 75˚c, instead of starting it at 60˚c. Also, we would do the experiment over a longer time. This would give us different results, and we could see if nineteen test tubes keep the heat in for an hour. This would be very interesting. We would also like to see how much time it takes for the test tubes to reach room temperature. Next time, we will do the experiment with different materials.
Do Penguins Keep Warmer With Lots of Penguins Around Them Or Is Material Better At Keeping Their Heat In?
Review of Student Article by Ceire Wincott BSc, Postgraduate student in Drug Design and Discovery at Imperial College, London
What are the strong points of the article?
This is an interesting idea and the experimental practice is very good. There are lots of measures put in place to ensure the experiment is suitably repeatable and that the results could be compared across the two experiments; crucial in this kind of study. Also the wide range of materials used in the second experiment shows that the students had thought about this and planned carefully. The data recording is clear with the graphs very nicely illustrating the findings. The evaluation section showed that the students were keen to learn how to improve their approach. Given our increasing emphasis on energy conservation and the investment in insulation techniques, it is great to see scientists examining what we can learn from the nature.
What could the student have done differently?
It would have been interesting to know the average body temperature of a penguin and tried to replicate/sustain that temperature. The test tubes could have been placed in a cold environment – more representative of the Antarctic but this would have been difficult to control in school. I would always carry out an experiment like this until the temperature stabilises i.e. until the temperature drop between readings slows right down. This would give you a better idea of how insulating each material is.
Building on what they have discovered, what further exploration would be useful/interesting?
Having read this study I am interested to read more research into penguin feathers and the insulation they provide. Are they much better than the feathers of other birds? It would also be interesting to explore why ‘huddling’ works more effectively than material insulation. Do other animals in cold climates behave in a similar way or do any of them use other materials? You have got me thinking!