Galileo thermometer

The Galileo thermometer shown in the photograph is based on the dependence of density on temperature. The liquid in the outer cylinder and the liquid in the partially filled floating glass balls are the same except that a colored dye has been added to the liquid in the balls. Explain how the Galileo thermometer works. 

The invention of the thermometer is generally credited to Galileo. His instrument, built near the end of the sixteenth century, relied on the expansion of air with an increase of heat. Traditional liquid-in-glass thermometers were devised in the 1630s and are standard equipment today in research settings, medical practice, and meteorological measurement. 

Measuring body temperature is important for the detection of disease and assessment of the response to treatments. The first thermometer was developed by Galileo in 1603. Thermometers for measuring body temperature have been in use since about 1870. The first measurements taken were axillary, and later oral and rectal measuring methods were introduced. The working principle of those thermometers, the expansion of matter by temperature increase, is still used for body temperature measurement in mercury-in-glass thermometers. Electronic thermo-... 

It is believed that Galileo invented the liquid-in-glass thermometer around 1592. Thomas Seebeck discovered the principle behind the TC—the existence of the thermoelectric current—in 1821. The same year Sir Humphry Davy noted the temperature dependence of metals, but C. H. Meyers did not build the RTD until 1932. Today, some 20 different types of temperature sensors are available, and Table 3.160 lists the temperature ranges and accuracies of a number of them. 

Although there is no record that he ever calibrated the tube, he used it in temperature study. Galileo s thermometer was impossible to calibrate even if he had decided on fixed points with which to establish specific temperatures because it was exposed to the atmosphere and subject to variations in atmospheric pressure. By 1640, it was realized that the air thermometer was subject to variations of barometric pressure and the sealed thermometer was created. However, the need to establish fixed points of reference had still not been addressed. 

The gas thermometer was discovered by Galileo. Liquid thermometers were introduced later. Fig. 1 is a diagram of Gahleo s air thermometer, Fig. 2 of a liquid thermometer as used at the present day. 

In the sixteenth century, there was a revival of interest in the mechanical devices of the Greeks. Although it is not known with certainty who at that time first conceived the idea of measuring temperature or degrees of hotness, Galileo Galilei is usually credited with the invention of the first thermometer. His writings contain only one reference to the instrument, which he likely did not consider of any importance. His friends and students, however, fortunately recorded a description of the instrument that he invented shortly after 1592. 

During the Renaissance, Europeans developed instruments that could refine these ancient Greek theories. The Italian scientist Galileo, for example, used a closed glass container with a system of gauges that showed how air expands and contracts at different temperatures (the principle of the thermometer). The French philosopher Blaise Pascal developed what became the barometer, a device to measure surrounding levels of atmospheric pressure. 

The preclassical period was filled with discussions that were confused and controversial. Galileo may be credited with the discovery of thermometry. Galileo attempted to quantitate the subjective experiences of hot and cold. In the HeUinistic era, air was known to expand npon supply of heat. Galileo used this in his bnlb and stem device we to this day nse this device, which we call a thermometer. It used to be called a baro-thermoscope. Toricelli, a student of Galileo s, developed the barometer. He showed that the time taken to drain an open tank using an orifice at the bottom is proportional to... 

Italian scientist Galileo Galilei invents an early thermometer. 

The temperature of a system has not always been an obvious measurable of a system, and the concept of a minimum temperature is relatively recent. In 1603, Galileo was the first to try to quantify changes in temperature with a water thermometer. Gabriel Daniel Fahrenheit devised the first widely accepted numerical temperature scale after... 

Why would Galileo s thermometer give different readings from day to day, even when the actual temperature was the same ... 

---