Any question answered...

why does the moon have nights that are 14 days long?

Because it's period of rotation on its own axis is about 28 days. There is no "dark side", there's a side which is not visible from earth due to tidal lock, but the sun sees all parts of the moon as it revolves on its axis.

XKCD explained it all only yesterday:

Is there an easy way to get a list of all UK street names, including duplicates? I'm not sure I've got the programming-fu to call the Ordnance Survey API, and though they provide CSV name files for the raw data, they're in 800+ files (one per 20km OS grid square) and contain lots of other name data (woods, hills, etc.). Is the answer, as I suspect,'better brush up on your data manipulation skills'?

Is there an easy way to get a list of all UK street names, including duplicates?

There is, but you probably don't qualify to access it, because in the UK information gathered at the expense of mere tax payers isn't for plebs like us
https://services.geoplace.co.uk/street/registration

There must be a ‘simple’ macro you can program to strip and dump that data?

Clicked blindly until something downloaded, which appears to be a demo gml file with a few roads in it. All the gml is really basic so it would be very easy for someone to dump into a text file, it’s all ordered like < highway:name > whatever road < /highway:name >

Clicked blindly until something downloaded

that's the spirit

It’s called a cantilever brake for a reason. Maximum efficiency is reached when the straddle cable is at 90 degrees to the line from the brake pivot to the cable clamp/anchor

Get mini Vs.

Do you want just named roads or numbered roads too or something extra? It's easy to do with Powerquery

Just named roads; ideally I want to look at name frequencies and have a hunt for patterns. Will investigate powerquery, ta.

I've done it here if you like. Only took a couple of minutes. Only about 800k results so you can stick it in Excel if you like (link is a tab separated file).
https://1drv.ms/u/s!Atnj-YxkG3Vkhu88g9fYPMSc99QOTg

Powerquery is good but takes a while to understand

what power bank is the best for phone recharging or are they all pretty much the same and I should just get the cheapest?

+1 on that question! I was just recently wondering about the same thing.

I think they are much the muchness, only thing to look out for is the number of outputs, and also whether you want it to do anything else as well, I have one plain and boring one, but also one which is combined with a lantern\torch for when I am camping...

Do you have any experience with regards to a degrading performance over time? I could imagine the cheap no-name ones go downhill more quickly / after fewer cycles... or do they?

Sadly not, I haven't used mine enough to notice any degradation...

Wirecutter is your friend for this sort of thing https://thewirecutter.com/reviews/best-usb-battery-packs/ though sometimes they have products I can't find in the UK

TL;DR anker

Many thanks - you're a scholar and a gentleman! Will download that this evening and have a play.

Anker are good. I have a PNY one that’s also decent. Can buy it from PC world etc. I’ve had a cheap one that I bought local, one of the cells swelled up and cracked through the case.

Ime 10,000 mAh is a decent amount of charge that should last all day, maybe two

Another vote for Anker.

Generally Anker. I also like iWalk as they have models with cables attached.

Other things to consider are if you want quick charge and which version, whether you want to charge it with USB-C, micro USB, lightning, etc and what ports you want on it (for instance you may need USB-C PD if you're planning to charge some tablets/laptops with it).

Have a Anker PowerCore 10000 Redux and am happy with it. Small, fairly light and gives about three charges.

As others have said, Anker. They tend to be true as regards to their stated capacity unlike many of the cheap no name ones.
But they do not support pass through charging on their power banks.

I just saw a Xiaomi powerbank on Alix that had a little display telling you the remaining charge. Quite nice design. Might not be good value though.

I’ve got a ravpower 16700mah one, has two USB ports and does pass through which is handy sometimes. Has lights for remaining charge, and will stop charging once something is full. Happy with it.