Most physical properties of a material change with temperature
(perhaps not very much!). In the previous section we
investigated some things that change size with temperature.
In this section we will study materials that
change color with temperature.
These can be used to make an unusual kind of thermometer that lets us
visualize
how temperature varies from place to
place.
The samples in the kits are called "liquid crystals." They actually contain tiny drops of a liquid, encapsulated in the plastic film. They will last longer if you take care of them properly, so please read the page Taking care of the thermal sensing sheet. It isn't necessary to know how they work to use them, but if you would like to know more, we have provided a page of information about them.
About 6% of the population are "color-blind," which means that they don't perceive color the same way as the majority -- for example, some color blind people cannot distinguish red from green. Color blind people will be able to see the variation in appearance of a liquid crystal caused by a change in temperature, but they will not see the distinctions quite so clearly, and they will not name the colors the same way.
| Main Pages | Estimated time required | Link to activities in the manual |
|---|---|---|
| Exploring liquid crystal | 30 minutes | |
| Calibrating the liquid crystal | 45 minutes | Liquid Crystals #3 |
| About liquid crystals | 30 minutes | |
| Discussion of liquid crystals | 30 minutes |
Materials needed for this section