The New Covent Garden Market itself is currently in the middle of a multi-decade redevelopment, they've slightly reduced the footprint and sold off some land for development, and the remains (still a massive area) is being _very_ slowly converted into a more modern design - sadly not really a market where you can actually go on foot to buy things, but a co-location area for lots of wholesalers to warehouse and deliver from.
The TV license is certainly bit ridiculous, but being legally blind doesn't necessarily mean you can't see at all, just you fall below the legal threshold where it's judged that poor sight will interfere with your day-to-day life. Lots of people registered as blind can still watch the TV just fine even if they won't be able to see the detail.
The threshold is a lot higher than people think. I would be at the level of legal blindness without my glasses. I use my phone without glasses daily. A small laptop screen without glasses would be alright too, but desktop monitors are too big.
Of course, to be considered legally blind, your vision has to be that bad with the best correction available. (Below 20/200)
The whole concept is unfixable. Once the fibre comes out, it's not going to go back in. It's that deadly combination of fragile and cheap. Just unpack a new drone and off you go. Don't spend a week (and 10 casualties going into the grey zone to collect it) winding it back up only to find it's broken in the middle.
The drone moves, the base station doesn't. The spool goes on the thing that moves, so it just has to unspool to move further. If the spool was on the fixed position, the drone would have to drag thousands of meters of fibre behind it, needing more powerful motors and creating a risk of snagging/snapping.
If you want to pay more you can also get Pettersen ultrasonic microphones. These have a USB microphone and will also work with my sbts-aru recorder. Which means you could in principle also geolocate where the bats are.
For datacentres that require air conditioning as opposed to natural ventilation (most of them) a very popular approach is to use evaporative cooling towers [1] in combination with W2W chiller units [2]. The chillers cool the internal water circuit and heat the external water circuit, the excess heat is dumped to the environment by evaporating water in the cooling towers.
Of course it's possible to use air-cooled equipment and this is more common in cooler climates or smaller data centres, so it's not a rule of nature that cooling servers wastes water but it's certainly a very common outcome.
There's a physical product that implements the same idea [1]. I'm not sure how it actually works (presumably there's a patent somewhere, is there an alternative solution?) but it's quite a magic feeling to hear the fire alarm go off and the doors independently close by themselves. If you're in a building that uses these, you can test yourself by playing a recorded fire alarm sound - they work on quite a few different ones (and it really doesn't have to be that loud!). They also have a surprisingly long battery life, ~10 years I think so the detection mustn't take much power at all.
In many large buildings (schools, etc. in particular), you want the internal fire doors to close to keep the fire from spreading. Of course, exits must be provided for each isolated section.
Yeah, that's a given, but the point of fire doors is to maximize overall survivability instead of the "average doors crossed per minute" stat in isolation.
An interesting construction detail of the cheap modern microwave is that it only operates on one half of the mains electric waveform: microwaves use a single high-voltage diode which acts both as half-wave rectifier and voltage doubler. Thus the magnetron only operates for 10 ms in every 20 ms.
In theory 2.4 GHz communication protocols can easily time their transmissions to fit in the gaps left by the microwave. 50% bandwidth loss but no other effect.
This obviously isn't foolproof in practice, when 2.4 GHz was a thing I remember my WiFi dropping off whenever somebody was nuking some food. But perhaps this might have been a quirk of my Panasonic inverter microwave - which obviously is not the simple standard circuit.
