Physics will get you

So working in technology I am always surprised when people forget basic physics and how it applies to our everyday lives. Being a physics student in college there are certain things I will probably never forget; newtons laws, speed of light, theory of relativity, power calculation, electricity calculations, and my personal favorite the wave equation.

So a couple of things that I think we need to remember from everyday physics:

1. Theory of relativity: simplified only light can really travel at “speed of light”. electrons and electricity , and correspondingly network packets over ethernet travels no where close to the speed of light.

electricity on a typical high shielded coax cable is roughly 2/3 speed of light.more relaistic is that it travels at 1/3 speed of light . not to get into the intricacy of physics but rest-assured an electron will never travel at the speed of light. unless ofcourse you in star-trek land .

2. Optics: Even though fiber optic is dependent on light transmission , the actual speed of the signal on fiber optic is not the speed of light. first of all speed of light is absolute in a vaccum. fiber optic is not a vacum.second the speed of the signal is effected on defraction, reflection , dispersion so in actuality it is never travelling over a given distance at the speed of light.

But thats ok. Don’t go selling stock of alcatel, lucent engineers are smarter they send several signals over the same fiber. so in that way the total throughput is a lot more. but at the same time 1 signal still has physics governing it.

3. The speed of light even if transmitted across the US is still going to have a ping time of 1.3ms. So basically you can take a beam of light and send it across the US, it takes 1.3ms for another person to see it. Again this is my back of the paper of calculation.

4. Ping-Pong: The avg time taken for signal to be sent and to get a reply back, can be calculated by ping-pong test. You simply send a signal and wait for the reply. The time take divided by 2 is the time taken for your signal to be sent.

5. Electrical power: Let do some simple calculations first

Power=Voltage x Current

So if your server takes 200 watts of power at 110 volts , it is 200/110 amps as draw.

Leave a Reply