Thanks for the story!

I was being a bit tongue in cheek there, but there is a solid point behind it which applies in other languages too, e.g. French, Italian, Spanish.

Nearly all languages come in variations, even dialects, that can reach mutual incomprehensibility. Accent plays a large part in this. There is much more of this sort of variation in the original countries than in offshoots, so the problems were greater there. Standard forms qeveloped, or were mandated (e.g. in France), around a middle ground. For instance Old and Middle English centred on Mercian, in the west Midlands. On top of that, accents had to make enunciation clear and minimise elision, slurring, etc.

BBC English and Home Counties English are where these show up most for English (US TV shows a similar middle ground, but only as between the US variants). They weren’t standardised because they were Home Counties, they were picked up in the Home Counties from the mid 19th century on because they were standardised and the Home Counties were where interactions centred then. You can find traces of non-standard English in those areas, at least in historical works – there was nothing special about English from the Home Counties, rather they took on the standard. If you like, the “by definition” part can be read as “by definition of Home” in “Home Counties”.

Anyone who can understand English can understand this standard, but it is not the case that anyone who speaks it with some other accent can be readily understood by the speakers of other variants (this also applies to variants of written English, but to a lesser extent – which shows that the accent used is material). Likewise for other languages.

About that comet, though – wouldn’t it have passed silently by the station, them being in space and all?

Doofuses.