I guess keeping broadcasting Radio 4 no matter what has very significant priority in Her Majesty's Government's crisis plans. You can use Radio 4 to reach the whole country if needed, with I guess just a few generators.

Just for anyone wondering why Radio 4 in particular - it’s the only BBC station we have on Longwave (198? kHz), so you get over-the-horizon service from a single tower. (which is why carries the shipping forecast, and why it’s of particular interest to submarines in the Atlantic too).

So using it as a “sign of civilization” (one of multiple) sounds quaint, but with a perfectly logical reason behind it.

Are BBC Radio 4 transmissions cryptographically signed? How do you know whether it's the real BBC radio 4 and not something that the enemy's spoofing?

They could be cryptographically signed as the BBC Radio 4 LW carrier is phase modulated with a datastream that can be used for remotely controlling electrical equipment [0].

[0] https://en.wikipedia.org/wiki/Radio_teleswitch

You can't spoof Radio 4. There are too many tells. The news readers are rarely changed and you know their voices. Those voices are also very English and you can't take English schooling and BBC training overnight. Plus the airwaves. To take out 198 longwave and substitute something else is not so easy.

Except that the British succeeded in doing such spoofing in WWII.[1]

[1] https://en.wikipedia.org/wiki/Aspidistra_(transmitter)

That's talking about spoofing someone reading out numbers. You just need a German speaker for that.

The person you're replying to is talking about the impossibility of faking a day of idiomatic BBC Radio 4 broadcasting, and I'm inclined to agree that the individual personalities and programmes are so incredibly ingrained in most British minds and the details are so subtle that you'd have no chance of being convincing.

Sefton Delmer, who was behind that, went much further. Listen to this old BBC radio show about it. [1] Start at 30:55 for the intrusion operation. They did replace German radio stations in-place as they shut down due to air raid warnings.

[1] https://ia800108.us.archive.org/9/items/OperationAspidistra/...

I am sure deepfakes for radio is even easier to achieve than other media. Not only is it audio-only, but it is also low fidelity audio.

The funny thing is that The Archers is extremely likely to go off the air in the very near future (they can't record any at the moment and they only have a couple of weeks in the can). Since the availability of The Archers is the key sign of life for the UK we better all pray that the Boomer on duty changes shift soon! (or this whole radio 4 thing is utter bollocks)

Why aren't they recording at home? My understanding was the many of the characters record individually anyway. At least the child actors definitely did, so it must be possible to act and edit together this way. I think cartoons all record individually.

You only need a half-decent microphone.

You could do it on a bad microphone if you wanted!

The Archers is a timeless part of the background noise in many family kitchens in the UK. Seems a shame not to fight through this little piece of calm for normal families in this time of crisis.

They're building out home recording capacity right now, and will be recording from home (on a slightly reduced schedule) shortly: https://www.bbc.com/news/uk-52084510

"amongst other checks"

If BBC4 goes down, but you're still able to call London on a satellite phone, you don't go nuking Russia. If you have a half dozen different signs of nuclear war and BBC4 is down, it's a point in the "well shit" direction.

That's it - they don't depend on the BBC. It's more a troubleshooting step. If the light in the kitchen doesn't work, but the one in the living room does, there's something wrong with the kitchen light. If everything's off, there's something wrong with your electricity.

So if Northwood goes silent, but the cricket is uninterupted, there's probably something wrong with Northwood. If everything's gone, there's probably something wrong with your radio. But if Northwood's gone, the BBC's gone, but VOA is still up .. you start wondering if something's wrong with the UK.

(For example. I'm not privy to anything the rest of us aren't. But it's clear that it's an item on a checklist that happens to have some novelty value, rather than being our "systema perimetr".)