The Planck Constant and Its Applications

The Planck constant is the basis of a fundamental natural law. The Planck constant was derived from a relation that Max Planck devised. This equation is

E=hv

The E stands for energy and the v stands for the frequency of the electromagnetic wave. The quantity h, is the Planck constant, which is the proportion constant between the values of E and v (for every E, there are h v's). For example, consider a star. The star gives off more light and is brighter if it has a lot of energy. And since energy creates heat, hotter stars give off more light (i.e. a higher frequency of the electromagnetic wave).

Using the Planck constant, the speed of light in a vacuum (186,383 miles per second), and the gravitational constant, the Planck length can be determined. According to the theory, and supported by all our current knowledge of physics, the Planck length is the smallest length anything can be. This may not seem possible, but there is a length that is simply indivisible. A good analogy for this is a pixel on a computer screen. To our eyes, the many dots blend into a full image, but at subatomic (well perhaps sub-subatomic) levels, there is actually a smallest length. No one knows what kind of matter (if it exists) could be at this primitive level. The Planck length is exactly 1.61625281*10^35 meters (0.0000000000000000000000000000000000161625281 meters). A theory of the Big Bang violates this claim, because if the Universe began from an infinitesimal point it would go through a period, however short, where the dimensions of the Universe would be smaller than the smallest possible length. There are two possible ways to excuse this possible exception. One is that the Universe never got that small, and a Big Bounce occurred. A Big Bounce occurs when a Universe contracts into a very small region and then re-expands into another, separate Universe. Therefore, the Universe never reached a size below the Planck length before billowing out into another Universe. The other possibility is that the Universe did go through a Big Bang, but the time in which the Universe would have been smaller than the Planck length is shorter than (you guessed it) the Planck time. The Planck time is another unit indirectly derived from the Planck constant. The Planck time can directly be calculated after the Planck length is known, because the Planck time is the amount of time it takes for light (the fastest thing in the Universe. Actually, there is a theory that there is a particle that travels faster than the speed of light, see the Tachyon) to travel over one Planck length. The actual value of one unit of Planck time is 5.3912427*10^-44 seconds (the actual value is 0.00000000000000000000000000000000000000000053912427 seconds).

There are Planck values for all units. The rest of the Planck values are: the Planck mass, the Planck charge, the Planck temperature, the Planck area, the Planck volume, the Planck momentum, the Planck energy, the Planck force, the Planck power, the Planck density, the Planck angular frequency, the Planck pressure, the Planck current, the Planck voltage, and the Planck impedance. Since I cannot express all of these units at length, I will discuss a few special cases. Some Planck units are the smallest possible of that unit, such as the Planck Length, while some are the maximum, such as the Planck temperature. The Planck temperature is the highest possible temperature. The lower bound on temperature is absolute zero, or -459.67 degrees Fahrenheit. It may seem odd that the lowest possible temperature is so high (on a larger scale) compared to the highest possible temperature, which is over 400,000,000,000,000,000,000,000,000,000,000 (400 nonillion) Fahrenheit. The Planck mass is also a special example. The Planck mass is around a milligram, and some particles, such as the electron neutrino and the electron antineutrino weigh much less than the Planck mass. However, when energy and mass are added together, the energy-mass of the electron neutrino, and for this matter anything, exceeds the Planck mass. The Planck area and volume are easily calculable from the Planck length, for obvious reasons. Another Planck unit, the Planck Density, is derived using the Planck Length and the Planck Mass (since mass within a certain volume is density). This density is 10^96 kilograms per square centimeter or 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 kilograms per square centimeter. To put this into perspective, imagine the Milky Way. At this density, it would take the mass of over a trillion Milky Way's (each with 300 billion stars) to fill the space of a single atom. This is even denser than black hole singularities (see here and here for more info about Black Holes).

In brief terms, Planck's relation and the application of the Planck constant to create the various Planck units was an advance in science that helped us to understand the fundamentals of Quantum Physics and the origin of the Universe.