As Society Marched On, this became less and less the case, and in modern works a very small age gap is often considered ideal, with a maximum allowable (as opposed to "ideal") age gap proposed, and often applied equally in either direction (older man vs. One commonly-applied formula is the "half your age plus seven" rule, in which the older partner's age is divided by two and then increased by seven to reach either the ideal or minimum allowable age for a romantic partner.

Traditionally, a man was expected to be established in his career and lifestyle before marriage, whereas a woman usually transferred directly from her father's household to her husband's within a couple years of reaching adulthood, so it was considered ideal for the man to be at least somewhat older.

The year of 1967 was the beginning of a golden era in Formula One.

The sport had just changed to a three-litre formula, the glorious Ford DFV engine had appeared as a customer power unit, and it made a perfect showcase for the skills of all-time greats like Jim Clark, Graham Hill and Jackie Stewart. A 1967 Lotus 49 looks as perfect as any racing car can.

I met Bob at a restaurant on a summer afternoon in 2014.

I was enjoying a glass of white wine and sharing an entree with a good friend when he sat down next to us at the bar.

Homo naledi, which was first announced in September 2015, was alive sometime between 335 and 236 thousand years ago.

The DFV engine is easier to find - you can still buy a new one as long as you have the requisite £60,000 - so the only (relatively) cheap item is the then-ubiquitous Hewland gearbox, which is also still available new.

However, the older we get, the calculations start getting outrageous: You can read more here. For anyone interested in learning how I built this app, here’s the code.

If you know R, Shiny apps are surprisingly easy to create.

The rule would theoretically create a paradox for people under 14, because the younger partner would have to be older than the older partner, but 14 is about the youngest you can be and make anything even remotely resembling adultish decisions respecting relationships anyway, so this rule works out rather well.

This has the advantage of allowing for a larger age gap the older the partners get; the four-year age gap between a 22-year-old and an 18-year-old is significant (and just barely allowed by this rule), but the same age gap between an 86-year-old and a 90-year-old isn't worth comment.