Naval technology at the time of creation

That would have to have been a very old text. The current limits for detecting both directed and undirected signals are much longer than that. The range of recent searches was in the 10s or 100s of parsecs, IIRC. Mind, I just realised that I'm blanking on both the numbers and the title of the paper I found them in, which means that's not supported for the moment.

cralkhi wrote:I don't remember where I read this, but IIRC even at Alpha Centauri distinguishing Earth's stray signals from random natural/cosmic radio noise would be highly questionable. (At least with current observational technology.)

Louis R wrote:That would have to have been a very old text. The current limits for detecting both directed and undirected signals are much longer than that. The range of recent searches was in the 10s or 100s of parsecs, IIRC. Mind, I just realised that I'm blanking on both the numbers and the title of the paper I found them in, which means that's not supported for the moment.

Were those searches for Earth-level civilizations, though, or looking for what Kardashev I/II civilizations might be emitting?

I'm sorry, unless I can find the references I can't answer that - it's not a primary interest of mine, so I was just following up a reference in something else that made me go 'that's interesting', and now I don't even remember which computer I was using, so there aren't any notes and I can't check the cache. My recollection is that there was simply a calculation of the power required for either an isotropic or directed signal. The latter was well within our capabilities, IIRC, and the former didn't strike me as extreme, but that's all I can say.

If you're interested, BTW, there was another paper [I think it was a different paper] posted on Arxiv a few months ago that also caught my eye. The author of that one - and again, I don't have details - calculated the rate of spread of sub-light cultures at cosmological distance and the area of the sky that they could cover in a survey. Quite a lot of it, potentially, but iirc his assumption was that they would be detected by the signature of their engineering changes in their host galaxies. Which is still something we do have trouble seeing. Or identifying, at any rate.

cralkhi wrote:

Louis R wrote:That would have to have been a very old text. The current limits for detecting both directed and undirected signals are much longer than that. The range of recent searches was in the 10s or 100s of parsecs, IIRC. Mind, I just realised that I'm blanking on both the numbers and the title of the paper I found them in, which means that's not supported for the moment.

Were those searches for Earth-level civilizations, though, or looking for what Kardashev I/II civilizations might be emitting?

isaac_newton wrote:Well - lets think about the main aim of the Archangels after the war?

It is to have the church in tight control over the entire of Safehold... no little enclaves going their own way and doing an Alaxandria on them! I would have thought that they would have provided any - safe - technology that would have helped maintain that grip. So providing at least close guidance on sea going shipping whould surely have been part of that.

Also wouldn't leaving the people to develop their own shipping have fostered that 'evil spirit' of creativity that thay didn't want...

I'd argue that widespread, fast, deep ocean ships harm the Church's ability to maintain tight control more than they help it.

They have their hand picked Bishops stationed in every little city and island maintaining local control, while most of the people are concentrated on the mainland under the eyes of the heliograph system and commerce moves over restricted pathways of Church controlled (or at least overseen) canals and roads. It's fairly easy to keep an eye on who is moving around or if things you don't approve of are being shipped.

Faster more seaworthy boats do allow Church dispatch ships to get messages and people back and forth quicker between Zion and out outer islands -- which is an advantage for maintaining control. But it also allows much more shipping to happen by sea (where snugging of significant tonnage is far more practical) and the less lengthy trips, and safer travel, encourage more people to move around between ports potentially spreading heretical ideas. I'd argue the greater mobility of goods and people across the trackless ocean is a risk to the Church's control that outweighs benefit of shortening their message loop to the out islands.

Now if the Church was able to maintain a monopoly on the improved ship technologies for their dispatch boats that's a more clear advantage for them. But I don't see a good way to do that; and having a superior implementation to be envious of is a great way to spur shipbuilders into an endless series of attempts to replicate those advantages (or work around whatever proscriptions give the Church it's monopoly)


Of course as it worked out, even before Merlin, Charis was improving their boats more than the mainland was. So the Church was seeing the bad effects of increased volume and reduced transit time oceanic shipping without getting even all of the somewhat offsetting benefit of improved dispatch boat performance. Not quite a worst of both worlds, but clearly less than optimal for them.