I was on the phone with a friend when she asked me that question. I always have this urge to never answer that question straight. But this time I had an additional thought.
My cell phone was charging from the wall, so what I was actually doing was pacing around in a rough semicircle about the wall socket like a tethered cow. I told her that. And then as she was about to go on with the next line of conversation I interrupted her – I do that a lot; see I’m doing it to myself now – about this thought I had about the question.
When I try to be smarty-pants and tell people ‘talking to you’ in reply to that question, they usually (after a quick undertone muttering) emphasize that they meant in a broader sense. So I could tell them I’m enjoying my weekend at home. If they want me to broaden it out a bit more, I could tell them I’m studying my final year of a masters in Physics. But as you keep smearing this out, notice that the smearing goes necessarily in only one direction, the past. There cannot be any smearing into the future.
Thus, as you broaden out your answer, you are no longer answering ‘what are you doing now?’, rather ‘what have you been doing?’ The more you smear it, the further the mean of that distribution gets from now, and the further you get from answering that question.
Can you ever really answer it? By the time you’ve said what you were doing, you’ve already done another thing, which is to tell someone what you were doing. It’s like telling someone what time it is. So this involves a bit of seeing into the future, which is impossible. However, it can be counteracted effectively with the smarty-pants answers. So maybe the only correct answer must be like ‘answering your question’, because even though you can’t see into the future, in all cases where there is no sudden calamity or anything and you do get to finish that answer, you will have answered the question and thus answered it correctly.
After I told her all of this, I said maybe I’ll put this in my blog. I don’t think she realized I was serious.