There are a lot of fireworks to be seen on the ground. Some are big and "official" ones that look fairly impressive even from the distance, the majority though are pathetic little pops of colour, not more than a camera flash. From my perspective London looks like a huge crowd of paparrazi.
It's Guy Fawkes night.
The first officer on this flight is obviously not familiar with this British tradition and seems to be surprised that New Year's Eve has come early this year. The air control tower at Heathrow tells her the reason why. Unfortunately the poor sound quality and/or his accent lead to the birth of new holiday celebrated in the UK:
"Ladies and Gentlemen, as you can see there are a lot of fireworks in London tonight. The tower just told me that this is because it is Gay Folks day which is always celebrated in the 5th November like this"
A whole load of Germans on this flight now think that the UK is much more liberal and tolerant than they ever thought...:-)