Sunday, February 12, 2012

25 IR imaging experiments added

I have added 25 experiments and their videos to the world's first website for IR imaging experiments launched last month. These experiments are all easy to do.

For example, to the right is an experiment that involves only a paper strip and a cup of tap water. Hang the paper strip above the water and slightly lower it into the water. Guess what you will see? Wait for a while and look at the IR view again. What will you see?

The first video shows what an IR camera recorded when the paper strip was just lowered to touch the water. You may expect that the paper would cool down because it has touched the water that appeared to be cooler than the ambient temperature. But, on the contrary, the paper warmed up! How is that possible? We all know that heat flows from hot to cold. How could heat flow from the cool water to the warmer paper strip and warm it up even more?

The second one shows what an IR camera recorded 20 minutes later. It shows that, on the paper, the thin strip just above the surface of water appeared to be the coolest.

Can you explain these temperature distributions and their time variations? I will leave these questions to you.

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