Pitch-black outside

When I left the house this morning, it was still so dark outside I thought I'd got it all wrong. But no, it was half past seven. "So why, why, why is it still pitch-black?", I asked myself. Am I going crazy? The winter solstice was on 22nd December – which means that day was the shortest day of the year. Surely, if the days are getting longer now, shouldn't it also be getting lighter in the morning?

My gut feeling told me there was something wrong somewhere. So when I got to work I went straight on the Internet and googled "sunrise, sunset and solstice".

I found an amazing paper written by some physics professor from the University of Rosenheim. And hey, my gut feeling was right!

Please don't expect me to explain the details. Most of what the professor said actually went straight over my head. But it seems that the shortest day of the year is just that – the shortest day of the year. It doesn't mean it's the day with the latest sunrise or the earliest sunset. The day with the earliest sunset is actually around 10th of December – and the day with the latest sunrise is not until around 5th of January.

The whole thing seems to have something to do with the fact that the earth doesn't go round the sun in an exact circle and that the earth's axis is tilted. There were lots of fascinating curves and equations which I didn't even try to understand. Maybe you can ask your physics teacher.

For my part, I'm just happy to know I'm not going crazy!