1 layer, 7 beakers 2 layers, 19 beakers 3 layers, 33 beakers No layers, 1 beaker
I will carry out experiments on Huddles I & II and the Control simultaneously, and do Huddle III on its own, due to limitations in numbers of beakers/thermometers. I will maker sure that all the beakers, as in a real rookery, are all touching. To keep groups held together, they will be encircled by an elastic band. The hot water will come from a kettle.
To time the experiment(s) I will use stopwatches. Every 60 seconds, the temperature of the thermometers will be measured. The beakers will be left to cool for 20 minutes. The starting temperature of the water, the amount of water per beaker, the time periods over which the temperatures are measured, the (circular) shape of the huddles will all be kept exactly the same, or at least as similar as is possible. The starting temperature of the water will be 70o.
Prediction:
I predict that increasing the amount of beakers will decrease the amount of heat they lose, because the more penguins in a huddle, the less surface area exposed to the air per penguin. In my control experiment, with 1 beaker, the entire surface is exposed, meaning that more heat can be lost by convection, cooling the water faster. In Huddle I, each beaker is in contact with at least 3 others, meaning less of the beakers’ surface is exposed to the air. Heat lost from 1 beaker can be transferred to another beaker, and visa-versa, allowing beakers in a huddle to retain more heat that they would unaccompanied.
In Huddle III, all beakers in layers 1 & 2, along with the central beaker, are all in contact with 5 other beakers. However, beakers in the outside layer are touching only 3 others. I predict that because of this, beakers on the inside layer(s) will all cool at the same rate, and beakers on the outside layer, will all cool faster.
Pre-Test
Before my final experiment, I conducted a pre-test, to ensure that my method was sound. My pre-test consisted of a 1 layer arrangement, similar to Huddle I in my final experiment. The results are shown below.
My preliminary test was conducted, and thought it went well I discovered that fixing the starting temperature of the water was extremely difficult and time consuming when using only a kettle. I decided to start my experiment at round about 75o . I then continued on to my final experiments. Their results are shown below, along with averages and accompanying graphs.
Results:
Analysis:
From my results, my prediction seems accurate. The control cup cooled down the fastest, and in the 20 minutes, its temperature dropped by an average of 33.8o. The largest huddle formation, Huddle III, however, only dropped by 14.3o in the centre. This means that by huddling, 19.5o of heat was retained in the huddle centre, proving just how effective the penguin’s strategy is. Even on the outside of the huddle, the average temperature drop was only 19.3o in Huddle III.
My graphs also show that huddling, as stated in my prediction, provides most heat in the centre of the huddle, because the centre has more layers of insulation around it.
Conclusion:
Huddling is an extremely effective method of heat loss prevention, as can be seen from my experiments. Penguins in the centre of the huddle, from my results, could stand to lose more than 50% less heat than they would do on their own. Even penguins on the outside and middle layers of the huddle stand to gain from the insulation huddling provides.
Evaluation:
Although my experiment was successful, there was lots I could have done to improve it. For example, the thermometers used to read the temperatures had to be read manually by eye, and provided very imprecise results. I could have gained by using electronic thermometers, with a computer and/or data logger to obtain my results.
I could also have made the starting temperatures of the water all the same, by using a different method of heating combined with the above thermometers.
In real life, penguins move constantly within the huddle to give everyone a chance in the middle and to create heat via movement and friction. My experiment did not reflect this movement, which is very important to the huddle.
