How do the electrons move in a network cable?

[Heresyte]

I spent all day yesterday trying to find the answer to this without success. I know it must be out there, perhaps I just don't know the correct terminology to use in order to find it.

My question is this:
When I transfer data from one computer to another, the network card in the first computer does something, which causes the electrons in the cat5 to do something, and the network card in the second computer is able to understand this something as data which is displayed to the user.

What I want to know is what those somethings are, especially what actually goes on inside the cat5. For example, if I were to graph the current/voltage of the cat5 over time, what would it look like? How would it differ between one piece of data and another? And how does the computer that is receiving the data interpret these currents as being data?

All I have been able to find are higher level explanations (e.g. "The computer sends a packet..."), nothing that explains what is happening on the physical level. If anybody could help me with this that would be awesome! Thanks!

 

[berkeman]

The key term here is "transmission line". The information travels down the transmission line as an electromagnetic wave:

http://en.wikipedia.org/wiki/Transmission_line

Information is typically transmitted with some modulation scheme:

http://en.wikipedia.org/wiki/Modulation

The information can be baseband (the information is transmitted at about the same frequency as the AC signal in the TL), or it can be mixed up in frequency to modulate an RF carrier wave.

In any case, the electrons in the two wires of the twisted pair of your Cat-5 cable are just vibrating back and forth a very short distance (less than a mm, I would think, but I'm not going to calculate it right now), at whatever frequency the EM wave is that is propagating down the twisted pair TL. The electrons do not move down the wire carrying information. They vibrate in sync with the propagating EM wave that is transferring the information down the Transmission Line at about 2/3 the speed of light.

 

[oswaler]

I understand your frustration in trying to find a detailed explanation of how electrons move in a network cable. The reason for this is that it is a complex and technical topic that requires a deep understanding of physics and electrical engineering.

To answer your question, let's start with the basics. A network cable, such as a cat5 cable, is made up of multiple wires that are twisted together in pairs. These wires are made of copper, which is a good conductor of electricity. Each wire has a plastic coating to insulate it and prevent interference from other wires.

When data is transmitted from one computer to another, the network card in the first computer converts the data into electrical signals. These signals, also known as binary digits or bits, are represented by different voltage levels. For example, a high voltage level may represent a 1, while a low voltage level may represent a 0.

The network card then sends these electrical signals through the wires of the network cable. This is where the movement of electrons comes into play. The electrical signals cause the electrons in the wires to move in a specific pattern, known as a signal waveform. This waveform consists of a series of high and low voltage levels that correspond to the binary digits being transmitted.

As the electrical signals travel through the wires, they encounter resistance from the copper material. This resistance causes the voltage levels to decrease, which can affect the integrity of the signal. To prevent this, network cables are designed with a twisted pair structure. The twisting helps to cancel out any interference and maintain the strength of the signal.

At the receiving end, the network card in the second computer interprets the incoming electrical signals and converts them back into data. This is done by analyzing the voltage levels and converting them into binary digits.

To answer your question about how the current/voltage of the cat5 cable would look like over time, it would depend on the specific data being transmitted. For example, if a stream of 1s is being transmitted, the voltage level would remain high for a longer period of time compared to a stream of 0s. This is because a 1 is represented by a high voltage level while a 0 is represented by a low voltage level.

In summary, the movement of electrons in a network cable is fundamental to the transmission of data between computers. The electrical signals generated by the network card cause the electrons in the wires to move in a specific pattern, which is then interpreted by the receiving computer as