I work on trains a lot and I’m often irritated by the sun shining in on my laptop and making my screen content almost invisible.
Today’s invention is therefore a program which helps with seat booking.
You enter details of the journey including your preference for a table or sitting facing forwards, the preferred angle of your laptop screen and the departure time.
The program then looks up the weather forecast and will evaluate, for every available seat, the angles at which the sun will hit the carriages at numerous positions along the route.
It is therefore just a matter of geometry to indicate those seats which will allow your laptop screen to be most visible for most of the journey.