TASK DEFINITION: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
PROBLEM: In French, if I want to quantify a very small amount of time (but not fixed: it can be 5 ms or 0.1 ms) I can use a pouieme. Is there an equivalent in English? I'm not looking for an expression but for a standalone word. EDIT : In fact, I need to create a c++ class which will measure time and be equal to a 1/600s. In French, pouieme is a cute word which can means a very small but undefined amount of time. The issue is that I must write english code and that's why I would like to find a standalone equivalent.

SOLUTION: A blink of an eye and a split second come to mind. Edit: If you insist on a single word, you'll have to go with an instant, or get creative and change the sentence structure to accommodate a different part of speech, like momentar(il)y.

PROBLEM: Duplicate: What day is next Tuesday? I have always considered next Friday to be not this coming Friday, but the one after. This Friday is the Friday at the end of this week. I have a Canadian friend, however, who enforces the more literal meaning of next Friday the Friday that comes next. Is there a correct meaning for next Friday, or does this entirely depend on cultural differences?.

SOLUTION: People generally understand next Friday as the Friday after this, that is, if you are on a Thursday, and someone tells you to meet him next Friday, it doesn't mean the next day, but rather, Friday week, the Friday after. Some pedantics will believe and argue that it is, as you say, the Friday that comes next. That is valid reasoning. However, if you want to be understood by the majority, 'next Friday' will mean Friday next week. So, in order to mean the Friday that actually comes next, you would say this Friday, but next Friday is generally understood by more people to mean the Friday after this.

PROBLEM: I was googling the reason for why it's called 'shotgun' to ride beside the driver when it suddenly hit me - why on Earth is the firearm called 'shotgun'?! Is there any other kind of a gun than one used for shooting?! Why is it called 'shotgun' instead of just a 'gun' or a more technical term (9-gauge, barrel gun etc.)?.

SOLUTION:
The 'shot' in shotgun refers to the ammunition that the gun fires. Whereas a pistol or rifle fires bullets (single metal balls), a shotgun fires a shell packed with shot (hundreds of tiny metal balls).