InGenious Galileo Thermometer

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A Galileo thermometer (or Galilean thermometer) is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying density. The individual floats rise or fall in proportion to their respective density and the density of the surrounding liquid as the temperature changes. It is named after Galileo Galilei because he discovered the principle on which this thermometer is based—that the density of a liquid changes in proportion to its temperature. This incredible indoor thermometer is based on Galileo's 400-year-old principle of relative density. You can simply read the tag on the lowest floating coloured bubble to see the temperature of the room.

It’s possible to make your own Galileo thermometer at home. It requires a glass vase, sealed glass canisters, measuring equipment, and some careful scientific calculations. Key considerations InventionThe Galileo thermometer functions on a basic principle of physics championed by Galileo: buoyancy. He challenged Aristotle, positing that whether or not an object would float depends on the corresponding densities of the object and the liquid. FAQ Q. How do I read the thermometer if there’s no bulb floating in the middle of the unit?

The instrument now known as a Galileo thermometer was invented by a group of academics and technicians known as the Accademia del Cimento of Florence, [2] who included Galileo's pupil, Torricelli and Torricelli's pupil Viviani. [3] [4] Details of the thermometer were published in the Saggi di naturali esperienze fatte nell'Academia del Cimento sotto la protezione del Serenissimo Principe Leopoldo di Toscana e descritte dal segretario di essa Accademia (1666), the academy's main publication. The English translation of this work (1684) describes the device ('The Fifth Thermometer') as 'slow and lazy', a description that is reflected in an alternative Italian name for the invention, the termometro lento (slow thermometer). [5] The outer vessel was filled with 'rectified spirits of wine' (a concentrated solution of ethanol in water); the weights of the glass bubbles were adjusted by grinding a small amount of glass from the sealed end; and a small air space was left at the top of the main vessel to allow 'for the Liquor to rarefie' (i.e. expand). Some options do not have a base and instead include a metal frame and hook or just a hook so the thermometer can be hung. Shape Attached to each bulb is a weighted tag with a number that indicates a temperature. The weights are calibrated to slightly change the density of the bulbs. When the air temperature around the cylinder changes, the water temperature inside it changes, changing the density of the water. Water density decreases as temperature increases, and vice versa. When the density of the water changes, the bulbs either float or sink. To find the temperature, you look for the bulb that’s suspended near the middle of the cylinder, ignoring those that float to the top or sink to the bottom. Size Knowing the temperature is important, useful information; the means of gauging that temperature, however, can take a lot of forms. The Galileo thermometer, named for the famed Italian scientist, offers both functionality and aesthetics when it comes to measuring the temperature in a room. Larger Galileo thermometers that include more bulbs offer more precision. Some options have as many as 10 or more bulbs. The more bulbs, the wider the cylinder. And more bulbs offer greater precision and a wider temperature range, from as low as 60°F in some cases to 100°F. Added devicesOther Galileo thermometers are simply paired with a globe-shaped glass barometer that’s also filled with a colored liquid. Base or hook

The device now called the Galileo thermometer was revived in the modern era by the Natural History Museum, London, which started selling a version in the 1990s. [6] Operation [ edit ] A. While a Galileo thermometer can be used outside to measure the temperature, it should be done so with caution and only for a short period of time. It shouldn’t be left outside in inclement weather because the unit is relatively fragile and the liquids may freeze if the temperature drops low enough.Although named after the 16th–17th-century physicist Galileo, the thermometer was not invented by him. (Galileo did invent a thermometer called Galileo's air thermometer, more accurately called a thermoscope, in or before 1603.) [1]

Thermometer containing several glass vessels of varying density A Celsius Galilean thermometer in two degree gradations. A risen orange orb denotes 24 °C. Galileo thermometers vary in size, but this doesn’t affect their function. Size does affect where you can display the device and how it looks. Most are between 8 and 15 inches tall, though there are bigger ones, some as tall as 24 inches.The Galileo thermometer includes a glass tube filled with liquid. In the past, this was an ethanol mixture or even wine, but today it’s typically mineral oil. Inside the cylinder are several small glass bulbs, each filled with a colored liquid, either alcohol or water with food coloring. The bulbs are designed to have the same density.