Galileo thermometer how does it work

While more famous for being a physicist and astronomer, Galileo also used his furious intellect to develop a number of different compasses that were used by the military, spent a great deal of his working life attempting to perfect and further develop the telescope, and as a result of his continuing interest in, and fascination with fluid mechanics, also invented the thermoscope. As much a sought-after and desirable home decoration as well as being an incredibly effective and efficient way of measuring temperature, the Galileo thermometer is a sealed, liquid-filled glass tube in which a number of glass bulbs each filled with different liquids float.

Each of these bulbs has a metal tag, upon which a number that indicates a temperature reading, attached to it, and rises and falls according to fluctuations in, and the rise or fall of, the temperature of the air around the thermometer. The metal discs attached to the bottom of each of the glass bulbs that indicate the temperature are designed to act as perfectly designed and engineered counterweights that act as a weighted balance for the bulb that they are attached to. While the bulbs vary in size and contain a different amount of colored liquid the fluid inside the bulbs often contains food dye and alcohol , they are finely adjusted so that they each have roughly the same density.

The crucial component that allows a Galileo thermometer to work are the differently weighted and sized metal tags that are attached to the bulbs. As the air surrounding the thermometer increases or decreases in temperature, the temperature of the water inside the thermometer also increases and decreases, which causes it either expand, as it gets warmer, or contract, as it cools down.

As the temperature of the water fluctuates, so does its density, which in direct opposition to the way the temperature affects it, decreases, as the density rises and increases as the density gets lower. One last factor determining accuracy is how the spheres are calibrated. If it is every two degrees, you should have no problem estimating the temperature with reasonable accuracy. However, as the interval between the medallions increases, more estimation comes into play, and thus more margin of error.

Finally, while the device can be used outside, it will work best indoors. The physics on which these instruments are based on works best within a specific temperature range—most thermometers will only have medallions for temperatures between 64 and degrees Fahrenheit. But for getting a general idea of the temperature of a room, the Galileo thermometer is a viable option that is functional and decorative. AcuRite is better known for its weather stations. However, it also produces various other weather instruments, including this Galileo Thermometer with Glass Globe Barometer.

Based on the principles of Galileo's work, each instrument allows you to read both the temperature and atmospheric pressure on a beautifully designed desktop stand. The addition of the barometer is a nice touch. The water level in the spout of the glass globe reveals the variations in barometric pressure.

When the barometric pressure increases, the spout's water will be low, and fair weather can be expected. If the water is high, it indicates lower pressure and bad weather can be expected. While you can't tell the exact barometric pressure using this technique, it will allow you to monitor trends. Reviews from buyers say that the thermometer and barometer are well constructed and look as great as it does in Amazon's pictures.

You can't go wrong with the price either, which is considerably cheaper than some other Galileo thermometers we've seen. AcuRite offers a one-year warranty on this thermometer and barometer, and while it's quite large at The Galileo thermometer is a decorative instrument that measures ambient temperature, and unlike the Fitzroy storm glass —it is reasonably accurate. We think it's an excellent option for those looking for a unique gift for a weather enthusiast.

The fact that it works makes it that much better. Are you looking for even more weather gift ideas? We recently updated our list of more than two dozen useful and educational weather gifts suitable for meteorology enthusiasts of all ages. The Galileo thermometer is certainly not the most precise instrument in the world but it is certainly clever. You can find a great selection on Amazon. Tibi is a science journalist and co-founder of ZME Science. He writes mainly about emerging tech, physics, climate, and space.

In his spare time, Tibi likes to make weird music on his computer and groom felines. Home Other Feature Post.

While it's not the most precise instrument, it's certainly one of the most attractive. January 28, Reading Time: 3 mins read. By using our site, you agree to our cookie policy. Cookie Settings. Learn why people trust wikiHow. Download Article Explore this Article parts. Related Articles. Part 1. All rights reserved. This image may not be used by other entities without the express written consent of wikiHow, Inc.

Identify the temperature stamped onto each medallion. The thermometer consists of a glass tube filled with a clear liquid, in which colored glass spheres float. Each sphere has a metal medallion hanging from it.

The medallions are different weights, which makes the spheres float or sink different amounts. You will see a temperature engraved onto it. Different Galileo thermometers have different ranges of temperatures that they can report. The Galileo thermometer works because of the principle of buoyancy, which states that objects that are denser than their surroundings sink, and objects that are less dense than their surroundings float.

The temperature surrounding the thermometer will make the liquid in the thermometer more dense as it cools, or less dense as it heats up.