talesin maybe jws doesn't want to reply anymore but your " My point? Know your facts, before you make statements in a debate."
I find it interesting because you say the argument is wrong because green is not a primary color. Do you know there are different basis? Do you know there is RGB and is used extensively? You can represent any color using that basis is limited by how many bits you assign to RGB(red, green, blue)? jws is correct that if you set a threashold maybe your eyes cannot tell where the change occurs but a computer using RGB values would be able to tell where it occurs and draw a line for you. Yellow is a mix of red and green in RGB.
Viviane I think I don't explain my self well. The point about infinity was that for example you can count the infinity of all integers but you cannot count the infinity of real numbers. Different infinities are not equal. And since our sample is finite there is no reason why we couldn't create a filter. You say unknows and uncertainties. That is the reason you add variables with ranges. Noise on signals is an unknow but it doesn't stop us from modeling them. If you had all the data you would be able to created it I have no doubt, if you don't have all the data I agree that you will never be able with 100.0% certainty say I found the first human or the set of first humans(since multiple could be born at the same time). And since our data is so limited such a filter would only work in theory if you say it wont you obviously don't understand what I am saying and there is no point on to continue to debate.