Absolute Temperature

You are sure to be familiar with the concept of temperature.  The quantity of hotness or coldness of a body (living and nonliving) may be measured using a thermometer. It is interesting to note that a temperature that cannot possibly go down any further is termed the absolute temperature. Also known as thermodynamic temperature, the amount of heat is measured with the help of a Kelvin scale. 

Absolute temperature equals -273.15 degrees Celsius. The lowest point of the Kelvin scale is zero just like other scales measuring temperature. There is a slight difference between zero on the Kelvin scale and other scales. This particular temperature is described as the absolute zero where the matter attaining this temperature has almost no motion with no capability of the body to become colder. It is an extreme form of coldness known to scientists so far.

Temperature explained

Well, the temperature is not a form of energy as many people believe. Instead, you can define it as a measurement of the kinetic energy within a tiny particle such as an atom or molecule. Simply describing something as hot or cold does not cause a vivid image to be conjured up by the human brain. You would need a reference point to compare the level of hotness or coldness. The meteorological reports are often revealed with the help of two columns. One depicts the temperature or amount of heat in the atmosphere whereas the other shows you the level of humidity. Hot and humid is not something you can measure accurately, therefore. You are referring to how a human being feels in such an environment. Absolute temperature is something that is not observed by humans when they follow a standard routine.

Relation between kinetic energy & temperature

The energy of a body in motion is defined as kinetic energy. This energy is found in everything around us. You will even find it in dense, solid non-living objects where the molecules are packed closely together. The average kinetic energy of all molecules is known as their temperature. The speed of molecular movement increases once the concerned object /substance absorbs heat. The increase in speed of the molecules increases kinetic energy as well. The molecules are separated as each tends to move away from the other. A continuous increase in temperature may cause the solid to melt and enter the liquid state too. Likewise, a liquid may change its state and turn to gas eventually. The stored energy that is used to cause movement of the molecules within a substance increases in temperature as its vibratory motion continues to be on the rise.

What is absolute zero temperature?

The simplest way to define absolute zero temperature is to state it as the lowest possible temperature to be found on earth. It is customary to use the Kelvin scale to determine it. Absolute Temperature stands at zero on this scale.  You may clarify it further by converting it into -273 degrees Celsius or -460 degrees F. The absolute temperature will not support any kind of heat either. 

All the microscopic particles within a perfect crystal will remain stationary at this temperature. The idea does seem to be fantastic and many find it hard to believe in this theory due to a lack of practical evidence. However, absolute zero or absolute temperature does exist in theory. Scientists working on Thermodynamics temperature have been trying to attain absolute zero. The results have been inconclusive so far. Putting cryocoolers as well as dilution refrigerators into the application has resulted in near-zero temperatures at present.

How is absolute temperature measured?

Absolute temperature is denoted as K with the Kelvin scale being used to measure it. The reading on the scale begins at -273.15 °C which represents absolute zero. The temperature has no practical applications as of now but scientists use it to study the laws of thermodynamics and corroborate the properties revealed by ideal gases. You may use the Rankine scale as an alternative to the Kelvin Scale too. It is used rarely, with Kelvin being the preferred standard for measuring absolute zero to date. An interesting fact to note is that the ratio between two absolute temperatures calculated by two different scales remains identical regardless of the type of scale used.

You are welcome to go forward and study this aspect of temperature more closely by going through the definition of this standard provided in the Maxwell–Boltzmann distribution formula. You would also find references mentioned in  Fermi–Dirac statistics and Bose-Einstein statistics. The kT unit used in conjunction with the numbers represent the Boltzmann constant (k) and the temperature (T)

Temperature Scales

There are three main scales used to measure temperature at the moment. Kelvin is used to measure absolute temperature with absolute zero equalling zero on the scale. You will find several other lesser-known scales used for various purposes. Notable among them are:-

• The zero on the Rankine scale is equal to absolute zero just like the Kelvin scale. A temperature difference of 1 Rankine is equal to 1 degree F
• The Delisle scale measures inversely. The higher degrees are colder with the lower temperature being warmer

You would be able to understand how each scale works by looking at the comparison table below:-