I'm studying property of sound wave and I was wondering what is difference between two waves (one is original and one is 180 flip phase of original) ?

Amplitude and frequency remains same and also wavelength is same, so are they same?? I could not detect any difference from hearing two sounds. If different what is different and can human/computer detect it? What is basically difference between two waves?


Question: Margin and Padding of <Body> Tag
Answer: 
First of all, it's probably 4px and not 4. Second, that's just the way the browser vendor decided should be the default.
It is saved in the default browser stylesheets.
You can, but you shouldn't. It differs with each browser. Google it! How do I change default stylesheet on &lt;insert browser here&gt;?
There probably are slight differences, you should be able to tell... by looking at the default stylesheets :)


That difference is one of the main reasons we as designers use a CSS reset, to normalize all of the CSS awkwardness that follows different browser implementations.