Experiment with infrared in fall leaves.

Today we talked about the colors of fall leaves. Why do leaves turn from green to red, yellow, and orange? Micah thinks it is because “they are going old and their hair is getting older colored too.”

While this is a great image, it is not “scientifically correct”. Since fall and winter days grow shorter, there is not enough light or water (via dew) for photosynthesis to occur. So trees will shut down their food-making factories and rest, living off the food they stored during the summer.

The green chlorophyll disappears from the leaves, revealing yellow and orange colors. Small amounts of these colors have been in the leaves all along. We don’t see them during the summer because they are covered up by the green chlorophyll.

The bright reds and purples we see in leaves are made mostly in the fall. In some trees, like those amazing red maples lining the streets, glucose is trapped in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn cause the leaves turn this glucose into a red color. The brown color of trees like oaks is made from waste left in the leaves.

Out of curiosity, we decided to explore how much thermal action was continuing in the autumn leaves.


You will need:

For our experiment, we collected 5 different colored leaves from various trees.

Then we used my old-school iPhone to take photos of each leaf in the same location (to keep from introducting new variables).

After uploading the photos to the laptop, we used the Creative Kit photo editing software in Google to test various “effects” on the leaves. To do this, open the photo using Creative Kit by pressing the “Edit” button under the photo in the Google+ album display.

When the photo is opened, look at the top bar and click on the “Effects” button. Scroll down the various effects until you get to “Heat Map 2.0”. Click on it. Use the style tab to play with “Thermal” and “Infrared” effects on each leaf. Save new copies of your infrared and thermal photos.

For use in temperature measurement, the brightest (warmest) parts of the image are customarily colored white, intermediate temperatures reds and yellows, and the dimmest (coolest) parts blue.

We compared the infrared effect with the thermal effect and noted that the brown leaf was “cooler” than the red leaf on infrared.

The thermal effect seemed to reveal the concentrations of sunlight and shadow in the actual composition of the photo than anything else. We decided to re-photo everything just using the infrared effect and compare natural leaf color with infrared effect leaf color. As always, our experiment is to be continued.