Galileo thermometer facts for kids
A Galileo thermometer is a cool tool that measures temperature using a clever trick! It was invented by the famous scientist Galileo Galilei. He noticed that liquids change how dense they are when their temperature changes. This thermometer shows you the temperature by watching colorful glass bulbs float or sink inside a tall glass tube.
Today, Galileo thermometers are mostly used for decoration. But you can still easily read the temperature from them!
Contents
What is a Galileo Thermometer?
A Galileo thermometer is a sealed glass tube filled with a special liquid. Inside this liquid, there are several small, colorful glass bulbs. Each bulb has a tiny metal tag hanging from it. These tags are weighted differently. This makes each bulb have a slightly different average density.
How Does This Thermometer Work?
When the temperature of the room changes, the liquid inside the big glass tube also changes its density.
- If the room gets warmer, the liquid inside the main tube becomes less dense.
- If the room gets colder, the liquid inside the main tube becomes more dense.
The colorful glass bulbs inside the thermometer either float or sink depending on how dense the surrounding liquid is.
- A bulb will sink if it is denser than the liquid around it.
- A bulb will float if it is less dense than the liquid around it.
- A bulb will stay in the middle if its density is the same as the liquid.
Reading the Temperature
Each colorful glass bulb has a small metal tag. This tag shows a specific temperature. To find the current temperature, you look at the bulbs that are floating.
- Find the lowest floating bulb.
- The temperature written on its tag is the current temperature.
For example, if you see bulbs marked 20°C, 22°C, and 24°C floating at the top, and the 26°C bulb has started to sink, then the temperature is 24°C.
History and Use
The idea behind this thermometer comes from Galileo Galilei. He was a brilliant Italian scientist who lived a long time ago. He discovered that the density of a liquid changes with its temperature. While he didn't build this exact thermometer, his ideas led to its invention.
These thermometers are often calibrated, meaning they are set up to show temperatures in steps, usually every 1°C or 2°C. While they are not as precise as modern digital thermometers, they are a beautiful way to see science in action. They make great decorative pieces for homes and classrooms.
Images for kids
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A Celsius Galilean thermometer showing two degree steps. A risen orange orb would mean 24 °C.
See also
In Spanish: Termómetro de Galileo para niños
