Answer: Physical fundamental constants are fixed numerical values that represent important physical properties or relationships in the universe. They are unchanging over time and universally applicable to all of space and time. These constants are essential in physics and science because they provide a basis for understanding the fundamental laws and principles that govern the behavior of matter and energy in the universe. Here are a few examples of physical fundamental constants explained in simple terms:
Speed of Light (c): This constant, denoted as "c," has a value of approximately 299,792,458 meters per second (or about 186,282 miles per second) in a vacuum. It represents the maximum speed at which information or matter can travel through space. According to Einstein's theory of relativity, nothing with mass can travel faster than the speed of light.
Planck's Constant (h): Planck's constant, denoted as "h," is a fundamental constant in quantum mechanics. It relates the energy of a photon (a particle of light) to its frequency. It has a value of approximately 6.626 x 10^-34 joule-seconds. Planck's constant underpins our understanding of the behavior of particles at the atomic and subatomic level.
Gravitational Constant (G): The gravitational constant, "G," has a value of approximately 6.67430 x 10^-11 cubic meters per kilogram per second squared. It governs the strength of the gravitational force between two objects with mass. It plays a crucial role in understanding the behavior of celestial objects, from planets to galaxies.
Boltzmann's Constant (k): Boltzmann's constant, "k," has a value of approximately 1.38065 x 10^-23 joules per kelvin. It relates temperature to the energy of particles in a system and is central to the field of statistical mechanics, which explains how large systems of particles behave.
Avogadro's Number (Nₐ): Avogadro's number, "Nₐ," is approximately 6.022 x 10^23. It represents the number of atoms, ions, or molecules in one mole of a substance. This constant is crucial in chemistry and helps connect the macroscopic world with the microscopic world of atoms and molecules.
Elementary Charge (e): The elementary charge, "e," has a value of approximately 1.60219 x 10^-19 coulombs. It is the charge carried by a single electron or proton. Understanding the behavior of electric charges and electrical phenomena relies on this constant.
These constants serve as the building blocks of physics and chemistry, providing a foundation for scientific theories and equations. They enable scientists to describe and predict the behavior of the physical world, from the behavior of particles at the quantum level to the motion of celestial bodies in the cosmos. These constants are fundamental because they are unchanging and universal, forming the basis of our understanding of the natural laws that govern our universe.