A Study on The Basics of Quantum Mechanics

What is Quantum Mechanics? Asking this question reminded me of a confusing idea created by some theoretical physicists from Europe over one hundred years ago. After researching further so that I now understand it to a considerable degree, the idea of it being ridiculously confusing has dissipated from my mind. I now can say that I have gone ‘down the rabbit hole’ (widely used term for when you learn quantum theory) of quantum mechanics. Before I begin I must say that Quantum theory is by no means easy to comprehend or know. In fact, one of the creators of the theory named Richard Feynman said “I think I can safely say that nobody understands quantum theory.” Another named Niels Bohr said that “Anyone who is not shocked by quantum theory has not understood it.” While these may be just inferences of the people at the time they still give an insight of what is in store for us. Nowadays people can easily understand this theory if they grew up with it, and it seems to be the case for me.

In order to explain with clarity we must start with basic principles. In an atom the electrons orbiting the nucleus follow exact orbits. Whenever energy is transferred to them they jump to outer orbits instantly. There is no space in between the orbits. The electron is either here or there. When the electrons move out they require energy to do so. When they move closer they release energy in the form of photons, and this is how we get light. Because of this electrons need to get a certain amount of energy to release the energy at whichever frequency. If the electron moves a large distance back to the nucleus it releases a lot of energy. In order to have a higher frequency light you must have more energy. When the electron travels less distance it gives off a light of less frequency. If an atom receives a certain amount of energy the energy will be distributed among all electrons. The electrons will move about the same distance out and back. Therefore the electrons will all radiate around the same frequency of light. Because of this whenever we heat objects they glow from red to blue to violet, because of it’s average amount of energy. The frequency of light emitted gives reason to how hot the object is in most cases. Of course, every type of element can turn to different colors at different temperatures. This is true for all things except for one substance classification: black bodies. The experiment Black Body Radiation gives reason to believe all of the information above. A black body is a substance that absorbs all light subjected to it. When heated to a certain temperature it glows a certain color that is the same with all black bodies. Using experimental data Max Planck, the father of quantum mechanics, created what is known as Planck’s law and defined the variable h. This law said that light energy transferred in packets, or quanta. These packets of energy are usually in small amounts, as shown above. If something is a quantum it is the smallest thing. Therefore, the name of this entire theory (quantum theory) is about the smallest particles of the universe and how they move and act.

At the time everyone believed in classical science from people like Newton and Maxwell. Classical science was very straightforward and simple for people to understand when compared to quantum mechanics. It was very logical in the way we see the universe. Classical science said that everything could be predicted completely to the very last subtle movement or vibration. Scientists thought this way because everything was derived from Newton's and Maxwell’s equations. There was no reason or experiment found that could debunk this theory. By the twentieth century four experiments proved that we need more explanation of the physical world around us. These experiments were black body radiation, the photoelectric effect, the double slit experiment, and optical line spectra. These experiments proved that at the base level of all of the universe that things acted on probability, not certainty. Quantum mechanics applies to all things, but it only effects extremely small particles that move at very fast speeds. On the surface where we are when I push an object it goes forward, not in a wave. Einstein did not like the idea of quantum mechanics. He thought that the universe was completely cause and effect, and that everything could be determined completely from what was before. After numerous experiments we can safely say that there is no way to really ask why everything works the way it does. We cannot go any further into the universe because there is nothing farther down to go.

What is a wave? We might make this very hard to ponder but in reality it is very easy. Think of an ocean wave, that is what a wave is. It has a big area it covers and travels at the same speed. It hits a wide range of objects but is not one definite place due to it moving in a slightly circular way move of the time. What is a particle? Think of a ball. It travels in discrete ways, such as forward and backward, left and right. It hits a object, not many like a wave. In an ocean analogy, the waves are waves and the stones are particles. They are not the same and never will be. However, in Quantum Mechanics, rocks are waves and waves are rocks at the same time. In the next paragraph we will discuss this in more detail.

Light travels in a very peculiar way that is different than we thought. Light travels as both a particle and a wave. In the double slit experiment, two slits were made in an opaque material. Light was shown through both slits. On a wall behind the two slits there was an interference pattern, shown in the picture. Because light travels as a particle and a wave we find that the photon becomes a particle when it hits the wall. The wall serves as the act of measuring. In this experiment the waves overlap and cancel each other out in the two waves. When this experiment was done again with one photon emitted at a time, we get the same result. The same interference pattern is seen for some odd reason. Because the photon travels as a wave the photon technically travels through both slits at the same time. When an ocean wave travels through two gaps we see ripples emanating from both slits. Likewise when we release a photon into the experiment. When it hits the measurement object it acts like a photon and sensors sense where the photon hit. The wave talked about moves like an ocean wave, but in reality is a probability wave. The probability wave shows all of the possible results and it takes measurement to get a result in that field. Everything is fuzzy until you measure, but even measurement is flawed, and that is called the uncertainty principle by Werner Heisenberg. We will go over this in the future.

This idea can be shown with an experiment called Schrödinger's cat. A cat was put in a bunker with poison gas that had a fifty percent chance of being released. When you are outside the bunker you do not know whether the cat is alive or dead. At this moment two things are happening at once. Before we measure everything is uncertain. The cat is alive and the cat is dead. When we open the bunker and see whether the cat is alive or dead we force nature’s hand, and the probability is gone. This experiment makes it easier to see what is happening. At every photon released it goes through both slits as a wave and the waves counteract each other. It is the act of measurement that forces nature to decide which place the photon will land. The photon then looks like a particle because it hit the wall. From these experiments we can see that there is a probability to how things work. Schrödinger also created many equations that we can use to find the probability of something happening. There are certain areas of the wave that are more probable than other parts. Particles also rotate clockwise or counterclockwise. Either they are one or the other. Before we measure it could be either and they are always changing. When we measure the rotation is confirmed until it changes again.

With everything happening at once it is difficult to objectively define time in the physical world. One particle at any time is in any place at any speed until measurement. This directly alters how we see the universe. Nothing is certain and everything is possibly happening at the same time until we force nature to give us a measurement. The next paragraph will talk about how even a measuring machine fails at completely accurate measurement of speed and position.

Measurement is flawed. The uncertainty principle states that you cannot measure a particle's position and momentum at the same time with complete certainty, even if your instruments are completely accurate. To conceptualize this idea think of it as if you were on an ocean wave. How can you find the position of the wave? Look for where the wave pulse is. While at the wave pulse how can you find the frequency of the wave? If you go to one wave you cannot measure how close or how far it is from other waves. Likewise, if you are measuring how close waves are to each other you cannot pinpoint where the actual wave is because you are measuring a wide area outside of the actual wave. It may sound very weird and foreign, but it makes sense. So good luck at trying to find out where everything is because it is not theoretically possible in the realm of science! Once you measure it’s position it has already moved an unpredictable amount.

There is a chance that anything could happen at any time at any place under any circumstances. In fact, right now there is a chance that a car will materialize right in front of you. However, the chance of this happening is extremely small and obviously negligible but still exists. This view of the world is radically different than any other previously thought. In fact, Einstein rejected this view, saying that god doesn’t play with dice. Einstein debated against many other famous scientists about this very idea and has given theoretical experiments that prove this view false. Today we have the technology to do these experiments and after doing them we can conclude that Einstein was wrong. Bohr, Planck, Heisenberg, Schrödinger, and many more scientists were right.

The two other experiments stated in the first few paragraphs were optical line spectra and the photoelectric effect. The photoelectric effect is about how light is shown on some metals. On certain metals, electrons leave when they receive ultraviolet light. Classical science stated that it is possible to increase the amount of kinetic energy by changing the intensity of the light. After many experiments, this idea of science was debunked. It is not the intensity of light but the frequency that changes the amount of energy reflected. Because of Planck’s ideas of quantized energy higher frequency means higher average energy. Therefore when we are transmitting high frequency light we are also transmitting a higher average amount of energy when compared to low frequency light. Einstein said that light was a stream of photons, and this time was correct. The next experiment is about the optical line spectra. When gasses or liquids are heated they radiate light because they receive energy and the electrons move to inner and outer orbits. When this light goes through a refracting object, we see distinct lines. Classical mechanics had no explanation of why this happens. Niels Bohr created theories and equations which he used to predict the spectrum levels of Hydrogen, and validated Quantum mechanics this way.

The final concept in quantum mechanics is the most confusing and awe inspiring. While we have used experiments to prove this as correct we still have not found out why or how this works. Two particles can become entangled when they are close enough to each other and their properties are connected. These particles will not become unentangled no matter the distance. There could be particles that have been entangled since the big bang and are now galaxies apart but have no connection we can see in between. They are just connected. When one particle is rotating clockwise the other is always rotating counter clockwise, and vice versa. So when we measure one we are effecting the other particle that can be millions of millions of miles away. This happens instantaneously with no delay. Quantum entanglement creates a wormhole in a way. If we influence one particle to rotate clockwise the other will always rotate counterclockwise. We can indirectly influence things across the entire universe. The possibilities of how we could use this are endless. For instance, we can teleport people via this method. Someone walks into a scanner and their entire body is scanned so we know where every atom and particle is. Then we make entangled particles at the destination recreate the original human. Today all we can do is teleport photons. A major problem with teleporting people is that we cannot scan a person’s body without destroying it. So for a small period of time we won’t have the person existing at all. Then they will materialize and might be able to continue living. Another question we would have to answer is what exactly is a human? Is it just the atoms and particles or does the human being have a soul or something else besides the matter? Although this question is for now a very philosophical we will see when we teleport a human. If this experiment works we will learn more about us, in the philosophical questions such as “Do we have free will?” Another big problem is with the measurement. We can’t measure both momentum and position exactly, so we could have a margin of error and mess up people’s DNA code and body structure. If we only measure position then we can be left with not knowing how hot something is or what chemical process is in effect. When teleported, the body will have to react instantly to many changes in environment in order for us to have a full replication without problems. We can look forward to maybe being able to use this in the next several hundred years, but we will have to have a lot of problem solving and ingenuity to be even close to being able. It might also take a lot of power to do as well, costing the everyday human a lot of money.

Quantum mechanics has many other uses we can use to better our society. Because a particle’s rotation is fuzzy we can interpret clockwise as one and counter clockwise zero. By harnessing this in a computer we can have the smallest particles do the largest amount of computing. All processors right now work by doing everything one at a time. That is how it finds solutions. A quantum computer could process every possible solution at every time. This means that it can do what a processor could do in days in seconds. Another cool addition to this is the computer would be smaller than a grain of sand, making computers incredibly small. Of course, we would need monitors to see things with and human- sized tools to communicate with the computer. Another application of quantum mechanics is to create an incredibly fast internet. Once again, we use clockwise and counter clockwise as one and zero. The two ends (computer and internet provider) are connected via entangled particles. This would make our internet extremely fast with no wires needed in any location. We could go anywhere in the universe with our devices and would still have internet at blazing speeds. If astronauts went to Mars they could use the internet at the same speed that we would use it here.

Without the quantum theory we could not create or invent the modern technology. Transistors and integrated circuits use this theory to make our world work. Transistors and integrated circuits are used in just about every electronic device we use and enjoy today. If this theory didn’t exist we would still be using steam engines from the 19th century. With this theory our universe has become more vibrant and exquisite than we could have ever imagined before. We came from the static cause effect universe to a universe filled with an infinite amount of possibilities around the corner. Now we know that we are constantly changing and everything around us is constantly changing. Now we know how all of the particles move randomly.