Theoretical Physics

On a previous post that I put about Asperger's Syndrome, I mentioned that I am very fond of a fair number of individuals who possibly have AS. One of those individuals is a man named Stephen Hawking. He is a theoretical physicist, mathematician, professor, etc. I read a book that he wrote called The Universe in a Nutshell. I got it from my Uncle Al for Christmas, and except for my Ipod, it's possibly the most memorable Christmas present I have ever received. It was the beginning of my interest in theoretical physics. So, what is theoretical physics? Well, that can be tough to define, but I would say that it's physics that explains or suggests answers and solutions to the realm in which we are not familiar with. Nobody has ever been inside a black hole, as far as I know. Nobody was around during the big bang. There is a vast amount to learn on this topic that encompasses how the universe manages to exist as it is. In this post, I might say a few things that will go over your head and not understand. I'll do my best to speak english.

One important subject is the four known forces of the universe; the strong force, the weak force, the electromagnetic force and lastly the gravitational force, aka gravity. The strong force is the force that holds an atom together, with its protons neutrons, etc. The weak force is the force that repels atoms from each other. The electromagnetic force is, you guessed it, electricity and magnetism working together. Lastly, gravity is a force between every single pair of bodies in the universe. It would seem that the weak force would be the weakest force of all four right? Well, actually gravity is the weakest of them all. The force of gravity is affected by the multiplication of the two masses of bodies. Because Planet Earth weighs far more than Jay Leno, I'm not attracted to Jay Leno as much as I am to Earth. So how does gravity's weakness in force play out in real life? When something falls here on Planet Earth, no matter how fast Earth's gravity was pulling it, the atoms will always repel each other when the object lands, due to the weak force. How is gravity a weaker force than the electromagnetic force? Go to your refrigerator right now. Do you see any magnets on your refrigerator? If you do, then you see that despite the VAST mass of planet earth, the force of gravity pulling the magnet downwards is easily offset by the electromagnetic force keeping the magnet on the refrigerator. Lastly, how is gravity weaker than the strong force? When one manages to break an atom, and release the energy, it can become catastrophic. It's one of the reasons why we have all heard of E equals m c squared. When a mass is multiplied by the square of the speed of light, that right there packs a punch. And that is exactly why Hiroshima was completely obliterated on August 6, 1945. That should be a sign that the strong force is more powerful than gravity.

Another important concept of theoretical physics is that there is the macroscopic and the microscopic understanding that govern everything. The microscopic deals with atoms and particles while the macroscopic deals with the much larger view.

Quantum Mechanics is the study part of theoretical physics of the very small, and the Heisenberg Uncertainty Principle is the cornerstone of the Microscopic world. It states that no matter what, we always will have an uncertainty in the exact position and the exact velocity of every and any object. The mass of the object times the uncertainty of the position times the uncertainty of the velocity is at least .00000000000000000000000000000000626 Js. This value is known as Max Planck's Constant. This might seem to be a miniscule and very irrelevant fact, but note this. Classical physics suggests that if we know the exact position and the exact velocity of every particle in the universe (not just most particles, ALL OF THEM) then we would be able to declare everything that has happened in the past and everything that will happen in the future. We would know for a fact how the dinosaurs died out. We would know how much longer Earth will remain inhabitable. But, The Heisenberg Uncertainty Principle says that will never happen. Now, I am not as knowledgeable about this stuff as some of these guys, so I have no clue how the value was determined. But Hawking declared in his book that even GOD himself is limited by this value as well. I feel that it's very naive to declare the limits of God's capabilities. Another concept that plays into this issue is black holes. You have probably heard of black holes. They are stars that have collapsed upon themselves and suck in everything (yes, including light) due to its immense gravitational field. That is very ironic because it was thought that gravity only sucks in objects with mass. Think of a black hole as a large sink in the universe. The gravitational force for all objects is stronger for objects as they get closer to each other. If an astronaut were falling through a black hole, his body would become ripped open because the black hole's pull would be stronger on his legs than his head. Anyways, Hawking declares that any object sucked into a black hole has information that will be completely lost forever. If he's right, that is yet another reason why we will not determine how the dinosaurs died or how long Earth will exist.

On the opposite side of theoretical physics is a phenomenon called relativity. Relativity was an idea created by Albert Einstein while he was working in a Swiss Patent Office. During the time that he was working on this concept he was getting roughly ten hours of sleep a night! In other words, get your sleep! Relativity covers both General Relativity and Special Relativity. General Relativity starts with the letter G, and so does the word gravity. Special Relativity deals with light. General Relativity talks about how a large mass, such as a planet, will cause objects to curve as they pass nearby due to the gravitational field that it creates. It explains why spacetime is "curved." Spacetime is the concept that there are four known dimensions: three spatial dimensions and one time dimension. Right now I'm typing this at a seat in the library, but many times before other people were typing in this exact same seat in this same three dimensional space. Likewise, as time carries on, I have been to many other places besides this seat. This theory demonstrated that Sir Isaac Newton was wrong about his concept of absolute time. He declared that there was no beginning and there will be no end. Imagine a train that goes on in infinity and never really had a starting point. Well, relativity showed that theory to be false. On the other side of the coin is special relativity involving light. No matter where you go, no matter what you do, special relativity says that the speed of light is always 186,000 miles per second (aka c). If I can throw a ball 30 mph, and then throw a ball while in a car going 60 mph, I can throw the ball 90 mph, right? Well, no matter how fast or slow your car is going, when you turn your headlights on, that light will travel c. Here's something else. If I'm in a locomotive going 30,000 mps and I shine a light from the ceiling to the floor, I will record data to see how fast it moved. Let's say a bystander outside of the train watches the exact same thing. From my perspective, the light shined in a straight line. From the other person's perspective, the light shined at an angle because it was moving in a train. So, therefore, because the other person saw it differently, doesn't that mean that we'll have differing values for the speed of light? Actually, no, and that's because since I was in a very fast moving vehicle, time slowed down for me to the exact amount in which when I do the math and when the other person does the math, we will both calculate the speed of light to be c. In fact, if you were on a plane for the rest of your life, that would add roughly one second to your life span.

So, we have Quantum Mechanics and Relativity. One focuses on the small, the other on the not so small. Currently in the physics community, the task now is to create one theory that explains both. This challenge is still ongoing, but one proposed theory is something called string theory. It states that all atoms are made of oscillating strings. String theory still is not considered a breakthrough, and one of the reasons why is that there are five different possible string theories that physicists have. In his book The Elegant Universe, Brian Greene comments that when one has five different theories for the same thing, he/she is looked upon as unknowledgeable on the concept. Let's face it. He's right. Another fact about string theory is that if it's correct there are ELEVEN dimensions in the universe. Ten spatial and one time dimension. We obviously have found three spatial dimensions, but what about the other seven? With that, physicists go on and on about their theories, but in the end, this concept is really, really in its infancy.

This is just the basics of the realm of theoretical physics that I have fallen in love with. There are many books that discuss this in much better detail than I can here. And since I'm too simple-minded, I may not be able to comment and understand this beautiful universe as well as I'd like. But, it's still fascinating, IMHO.