From Galileo’s Thermoscope to the Digital Sensor: Unveiling the Evolution of the Thermometer that Revolutionized Science
Measuring temperature accurately may seem as routine as putting a thermometer under the tongue or against the skin. However, this everyday gesture was once a revolution. Before, detecting fever or cold depended on intuition and subjective comparisons. The thermometer brought objectivity, the possibility of replicating results, and the beginning of a more rigorous science. Its evolution, from Galileo to digital sensors, reflects centuries of ingenuity.
From intuition to precise data
Before the thermometer, methods were as simple as they were imprecise: a kiss on the forehead or a hand on the skin. The problem was evident: they depended on individual perception. With the thermometer, medicine moved from conjectures to certainties, improving diagnoses and treatments.
The origin of the instrument
In antiquity, thinkers like Philo of Byzantium and Hero of Alexandria built devices based on air and water expansion. Although rudimentary, they were the first attempt to measure heat objectively. In the Renaissance, Galileo developed the thermoscope, which allowed observing thermal changes. Shortly after, Santorio Santorio added a scale, transforming the device into a quantitative tool used for. It was a decisive step towards modern science.
The first thermometers had a problem: they also reacted to atmospheric pressure, mixing barometer and thermometer functions. The solution came in the 17th century. Fernando II de Medici promoted the creation of a sealed model in 1654, considered the true precursor of the modern thermometer. Over the centuries, the Celsius scale, Fahrenheit scale, and sealed mercury consolidated its use in everyday life and in laboratories.
Today, digital and infrared thermometers allow recording minimal variations in seconds. Their applications range from hospitals and kitchens to industries, satellites, and beyond. What remains unchanged is their essence: turning the invisible into reliable information. The thermometer continues to be a metaphor for the pursuit of precision in science and technology.
