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Accessing the Boltzmann Constant in Python

The Boltzmann constant is a physical constant used in physics and chemistry to describe the relationship between temperature, energy, and the thermodynamics of gases. More specifically, it connects the relative kinetic energy of particles in a gas with the thermodynamic temperature of the gas.
The Boltzmann constant (k) is a physical constant equal to 1.3806 x 10^-23 joules/kelvin (J/K). It was first proposed by Ludwig Boltzmann in 1877 as part of his statistical mechanics theory of thermodynamics. This means that for every Kelvin increase in temperature, there will be an increase in energy by 1.38 x 10^-23 Joules (or 0.0000000000138 Joules). (Note that temperature must be in Kelvin, not Fahrenheit or Celsius). That might not sound like a lot, but if you consider this on a large scale, it adds up quickly! The Boltzmann constant is one of the seven key constants in physics that you should know about.
The famous equation involving the Boltzmann constant PV = NkT states that the product of pressure (P) and volume (V) equals the product of N (the number of molecules of gas), T (absolute temperature), and k, the Boltzmann constant. This equation highlights that there exists a direct connection between several key physical variables through the Boltzmann constant.
The reason the Boltzmann constant is so important is that it captures phenomena at both macroscopic and microscopic levels. At a macroscopic level, it explains why certain systems have different levels of energy; for example, why hot water has more energy than cold water or why air heats up when compressed. At a microscopic level, it explains why certain molecules are more likely to react with each other than others; for example, why some molecules are more likely to form bonds than others or why some molecular interactions require more energy than others. It also helps us understand how chemical reactions work on an atomic level by providing insight into how molecules interact with each other due to differences in their energies.
To access the Boltzmann constant in Python, we use scipy.constants, a library of mathematical constants that provides access to hundreds of physical constants.
To get started, we will first need to install scipy.constants. You can do so by running pip install scipy on your terminal or command prompt if you are using Windows. Once installed, we can easily import this library into our project like so:
Here we have imported the package as “sc” and henceforth all constants can be accessed as part of “sc”. The Boltzmann constant can be accessed as either sc.Boltzmann or sc.k (see equation above). Thus both these statements produce the same result. The output of the program will be:
as expected. Note that the above values are in J K^-1 units.
It turns out scipy.constants supports the access of the Boltzmann constant in other units as well. For this, it provides a dictionary of physical constants, of the format physical_constants[name] = (value, unit, uncertainty). We can access the Boltzmann constant in J K^-1 units as well as in other units by providing a suitable name. For instance:
In other words, the output says that 1.380649e-23 is the value with units J K^-1 and uncertainty 0.0. We can try other names for the Boltzmann constant, like so:
The output will be:
thus providing you a rich vocabulary of units to choose from.
In summary, accessing the Boltzmann constant in Python is easy and straightforward once you have installed SciPy Constants! With just one line of code, you can easily retrieve the value of this constant in a range of units! As a programmer, having quick access to this important physical constant can help save time when coding programs related to physics or thermodynamics! Whether it’s for school projects or research work, knowing how to quickly retrieve this data makes programming much easier and more efficient!
If you liked this blogpost, learn how to access Euler’s number in Python!
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