There's no such thing as being as close to 0 as you can get without getting there. For any real number greater than zero, there are an infinite amount of numbers in between. Actually, what you said works when you look at the limiting case. This is the only way to get a number infinitely small (i.e. infinitely close to zero), but in this case, your number can be shown to be equal to zero. There's no way to get infinitely close to a number without being equal to the number. If you find any two (real) numbers, either the two numbers are equal, or there are numbers in between the two numbers (meaning it's still possible for one number to get even closer to the other). So any time you hear someone use the term "infinitely close to zero", then technically the number they're referring to is equal to zero, but they're using it as a limiting case.
0.000....(to infinity) with a 1 and the end is zero. I could show this mathematically if you want, but you can understand this intuitively by noting that the 1 at the end never actually shows up. The closest non-flawed real thing to zero would be the situation I described above.
This is true for any (non-zero) real number, n, regardless of size. But saying this is true for any natural number is way different than saying it's true for the limit. By it's very definition, the limit of 1/n has to be able to made smaller than ANY natural number k > 0. You can't say "Well if you stop at any given n in R there's always a smaller number" if we're referring to the limiting case. In the limiting case, there exists no number greater than zero that's smaller than 1/n. So the number is infinitely close to zero, and has a property that no number except zero can have, and thus, is zero (if we're talking about the limiting case, as Neo and Khamsim are). Adding an infinitesimal amount to something doesn't make it non-zero. The only reason we can manipulate expressions of this form is because we assume the values are finite but very small at first, and then when we finish whatever math needs to be done, we then take the values to become infinitesimal (zero). If your physical answer is still infinitesimal in a situation where zero can't be an answer, then you have a problem.
So yes, from a purely mathematical perspective infinitely close to zero IS zero. A number infinitely close to any other number is that same number (in R). Infinitely small and zero are identical. This isn't something that's debatable. It's provable. Ironically, we actually just went over this in analysis a few days ago (they wont let me test out for some reason so I have to sit through the whole course D: I have to take Mechanics I/Quantum I/E&MI too. I think it's BS that if a person already knows a subject, they have to pay hundreds to take the course anyways instead of just testing out and saving time and money).
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