prompter: What you can tell me about Anders Celsius?

assistant: Anders Celsius (1701-1744) was a Swedish astronomer and physicist best known for inventing the Celsius temperature scale, which is now the most widely used temperature scale in the world.

Celsius was born in Uppsala, Sweden, into a family of scientists. His father was a professor of astronomy, and his grandfather was a mathematician. Celsius himself became a professor of astronomy at Uppsala University, where he made important contributions to the study of the aurora borealis and the Earth's magnetic field.

However, Celsius is best known for his invention of the Celsius temperature scale, which he first proposed in 1742. The Celsius scale sets the freezing point of water at 0 degrees Celsius and the boiling point at 100 degrees Celsius. This scale replaced the previous temperature scale, the Fahrenheit scale, which had been invented by German physicist Daniel Fahrenheit in 1724.

Celsius also made significant contributions to the development of early thermometers, including the mercury thermometer, which is still used today. He was one of the first scientists to use mercury in thermometers, and he helped to refine the design of the instrument.

Celsius died at a relatively young age, at just 42 years old, but his legacy lives on through his contributions to the fields of astronomy, physics, and temperature measurement.

prompter: Good reply with correct data (checked with Wikipedia)

prompter: is it not a little strange to say Celsius scale replaced the previous temperature scale, the Fahrenheit scale, when Fahrenheit still lives on in a big part of the world.

assistant: Anders Celsius was a swedish astronomer,physicist and mathematician who invented the celsius temperature scale, also know as the centigrade scale. He was a professor of astronomy at Uppsala University from 1730 to 1744 and built the Uppsala Observation in 1740. Celsius also visited notable observations in Germany,Italy and France from 1732 to 1735. He was born on November 27,1701  in Uppsala, Sweden and died on April 25,1744 in the same city.

prompter: Wdym he visited notable observations?

assistant: Anders Celsius (1701 - 1744) was a Swedish physicist and astronomer, most well-known for the Celsius temperature scale. He developed this temperature scale in 1742 and named it after himself. The scale is still used widely today, although the Kelvin scale, named after Lord Kelvin, is also used in scientific contexts.

prompter: Why is kelvin used instead of celsius in scientific contexts?

assistant: Historically, it was found that Kelvin is the one needed in the formula relating the volume of a gas to its temperature. Take the ideal gas law, PV = nRT. At constant pressure, V = T (nR/P), where (nR/P) is constant. That is, volume is directly proportional to temperature. Obviously, degrees C cannot be plugged in because at 0°C the formula would say the volume is zero, which it is not. A scientist by the name of Renault found in 1847 that a gas expands by 1/273 of its volume for each degree C as you increase the temperature from 0°C.

By defining an absolute temperature in the following way,

T = measured °C + 273 °C

the correct relation between volume and temperature is established:

V=V0TT0
 

where the subscript zero refers to 0°C. Later it was found that absolute zero had a much deeper theoretical significance than the bottom of the gas scale. It is the point where thermal energy ceases. Absolute zero therefore became the rational bottom of the thermodynamic scale.

assistant: I can tell you that Anders Celsius was an astronomer, physicist and mathematician from Sweden who was most well known for his proposal on measuring temperature through the Centigrade temperature scale. It was later renamed the Celsius temperature scale under his honor.

The Celsius scale, when it was initially proposed, had its measurements on backwards. This meant that 0 was the boiling temperature for Celsius, and 100 was freezing. This was reversed by Carl Linnaeus, who was friends with Anders Celsius' uncle, to be more practical.

Much of his career was spent in Astronomy, with his earliest work being new methods to calculate the distance of the sun from the earth.

prompter: Your answer sounded strange, and when looking further into it maybe not correct, Anders Celsius would likly have been aware and have tried the thermometer made by the French astronomer Joseph-Nicolas Delisle with zero at the boiling point, thus creating a reversed scale with increasing numbers for decreasing temperatures, but avoiding negative numbers.

prompter: That is correct. MQTT is a publish/subscribe model protocol. The IoT device can publish changes to the MQTT server and an application can receive those changes by subscribing to the publications. In reverse, the application can publish commands to the MQTT server to which the IoT device subscribes.