Well, I'm going to do something rare for me and stay on-topic. I've been awake since 0445 for the 3rd day in a row. I *think* it's the first flights coming into land at Heathrow. We're south-east of them and I think flights loop around London from the South or South West, and then head West over central London to land at Heathrow (which is on the Western edge of London).
Of course, once I'm awake at that time, I start to brood.