Today’s invention is inspired by my fellow train traveler, and ardent New Scientist reader, Pete.
In discussion with him today, I mentioned that certain commuter trains transport groups of people who form a book group with in-transit literary analysis.
Given my less erudite mindset, I therefore suggest a bowling alley in a train carriage.
Passengers could, with some allowance made for sudden accelerations, set up either a jack or skittles at one end and fling a ball from one end of the carriage to the other.
This relies of course on the availability of coaches where everyone gets a seat. It would also enable the kinds of conversations about relative velocity, so beloved of Physics textbook authors.