Some time this afternoon.
Caught myself staring at a somewhat stationary helicopter high up in the sky and wondering what does it feel like to be up there and look down from that height at the city below, wondering what the people on board could possibly be doing. Wondering if the fluctuating amplitude of the whirring sound by the helicopter’s rotor is due to constructive and destructive interference. The sound then drowned in silence.
But it came back again gradually. So I looked up and there it was again. The pilot had maneuvered it round in a roughly 0.5km radius circle and stopped at almost the same spot, hovering there with its light flashing meekly now and then.
Soon it went off, in that circle and back at the ‘resting place’ in mid-air once more. After that, it just flew continuously in circles, round and round for countless times, not that I kept track of it.
Eventually I could only hear it but see no more from my window. I thought it flew away. But sooner than my brain could process, it was back – playing statue in the sky like before.
I decided to switch my focus back on distillation columns, although the helicopter-observing was a teeny weeny bit more fun than differentiating HETP from HTU.
The next time I remembered about the mighty little flying machine, I could still hear the solid sound of its rotor spinning in the distance. I resumed to my papers and the last time it popped into my mind, it was just serene silence and me again.