We sometime visited a telephone company and saw a trunk of wires, hundred of switches, relays and thousands of connections. The whole thing looks complicate and like a gigantic puzzle. Technology indeed changes the world and the ways we lead our life. Lately, while trying to find out whether I should use DSL or install Cable for the Internet, I opened the little phone box just outside garage and also examined the cable setup inside garage. They are very simple and similar, only two wires. One looks like a twisted pair of tiny wires and the other is a coaxial cable of RG6. The two wires used for the phone look so fragile and tiny, I almost think it is a miracle that has worked for so many years of service in my house. First, it can ring the bell and when I answer the phone, it carries the phone conversation to and fro without any hiccup. It also connects to a fax machine. These two tiny wires can transmit several pages of document to another side of the world within a few minutes. It has worked for 30 years, amazing. Remember, it is only a twisted pair of two tiny wires that accomplishes the task as it is the only connection between my house and the outside world. With DSL going through the twisted pair, I can see the whole world via millions of websites with tons of information more than I can handle most of the time. Without the knowledge of electromagnetics and its theory, most people will think it is a miracle.
It is indeed the information theory and technology transform the world to a well-connected universe that brings people together and the world visibly becomes smaller. If you work in a cubicle of building A and talk to someone in the building B, it makes no difference whether building B is just across the street or in Bangalore of India. In fact, even without wires can accomplish the same feat, it is radio, wireless connection. We know in the world of electrical engineering, the lumped element model circuit theory, distributed element model transmission lines and EM wave are all related and can be deduced from the Maxwell's four equations with some assumption of the boundary conditions. In ordinary power applications, circuit theory is good enough. For information transfer, the concept of transmission lines applies well. With radio and TV transmissions, EM theory rules the wave. In fact, when we use the mobile devices outside our houses, it needs hot spot that transmits the EM wave. In our house, we use DSL or Cable to get the necessary information via modem and then it creates a hot spot for house through wifi, a wireless EM wave. Of course, with the understanding of the electrical engineering, the whole thing no longer a mystery, it becomes a logical consequence of the mother nature. But think again, it is still a miracle with only two tiny wires or one coaxial cable that accomplishes such a complicate human task.
People very often say they find miracle everyday. Some find God, some see Jesus, some see Madonna on the screen door and some see the mysterious light coming from the heaven or even in the Internet. These miracles happen everyday and around our living space. The only difference of these miracles from our two tiny wires is that the former seems to happen in un-opportune time and can't be predicted. However the latter is here everyday that we all take it for granted and ceases to be a miracle by definition.
