Science Buddies: "Ask an Expert"

I had a student who choose this topic and when she went to do her experiment I was a little confused because in her conclusion she said that huddling together did not produce any more heat than the puppy being by itself. I asked her and her mom to tell me how they did the experiment and we went through all the steps again and she said she did them all except that she used glass jars with tin foil on top instead of a metal cap. I gave her a jar with a metal cap (empty pickle jar) and told her to try that with the one she was using with the foils and see if there was any difference. She emailed me back that there was no change. Do you have an idea why this might not be working? or what other information do you need? thanks

Hello!
There are a lot of places in this experiment where things could go wrong. The whole on the top could let out to much heat, the jars could be too thick. Did the student follow the procedure by the letter? Not following the procedure to the letter might increase the inherit experimental error.
However, experiments never work perfectly and this could be a great way of learning about experiential error and human error.
Hope this helps

Adam

Hi there,

Adam has given you some good advice. I wanted to chime in because I have actually studied huddling and its thermal effects in animals.

As Adam mentioned, there are several factors that may have affected the results. With the tin foil tops, it may be that the heat is escaping out the tops of the jars faster than it can escape out the glass sides. Foil is a conductor, and glass is relatively insulating (compared to metal). The metal tops on jars are lined with other substances, so they are not complete conductors. Even with your one jar with an actual top, it could be that heat was just escaping too quickly from the other jars with the tin foil tops.

One way to test for this would be for your student to use styrofoam to cover the tops of all the jars. Foam is a great insulator, and this would force the heat to escape through the glass sides instead of the tops (as long as the hole for the thermometer is not too big!).

You could also see how the graphs compare among the different treatments. While the initial temperatures may have been the same (because of how quickly - or slowly - the jars got from being heated to being measured), the change in temperature over time may have been quite different.

I hope this helps. If you get more details about your student's procedures, please let us know!

Heather