HF radio reflects off the ionosphere's F-layer, located about 100-200 miles up. To get from Chicago to Frankfurt requires several hops between the ionosphere and the earth's surface. The hop length is one or two thousand miles.
Satellites such as Starlink operate in low earth orbit at about 350 miles, significantly above the F-layer. Also, they introduce repeater delay when they relay a data packet. To get from Chicago to Frankfurt would require relaying the packet thru multiple satellites. So, greater distance (even if passed by laser between satellites) plus repeater delays.
Also note that satellites in LEO are the only option. Geosynchronous satellites are completely out of the game due to the much greater distances involved.
"Encrypted" is too strong a word. But the code talkers needed a way to represent English that didn't have a natural Navajo equivalent.
So they developed a vocabulary of 411 Navajo words to stand for common military terms. E.g., BESH-LO, which is Navajo for "iron fish", meant "submarine".
The vocabulary included a phonetic alphabet to represent the 26 English letters. E.g., the three Navajo words MOASI, TLA-GIN, and BA-GOSHI all represent English words beginning with C (cat, coal, cow). So, they could spell out arbitrary English words not in their vocabulary.
It was secure against an enemy that lacked Navajos and probably didn't even know what language was being spoken or if they were intercepting some weird form of audio scrambling. But, if the Japanese had been able to translate the messages to English, the code would probably not have survived cryptanalysis for long.
It's not really secure as such. It's a simple replacement cipher theoretically speaking. An adversary with enough time will easily be able to figure out what each word means by association of known plaintext.
However it sounds like they were mainly used in heavy combat conditions where the enemy didn't have recording equipment for later analysis. So in that scenario specifically (but in that alone) it was pretty secure.
Yes, for the parts that needed to be distinctly translated from English, it was a cipher. However, it IS a language, with it's own grammar and vocabulary. They could have an entire conversation with none of the cipher bits...
If you've ever gone to a foreign country, you know you will have zero idea what anyone is saying for quite a long time. They knew as long as they kept the messages short enough, nobody was going to learn it from immersion.
There are still ancient languages that nobody have deciphered, despite having copious samples to choose from. I don't think it's as simple as you're making it out to be.
See, for example, his video on microwaving frozen hamsters back to life[0], in which he interviews the 101-year-old J. E. Lovelock, the scientist who did the work back in the fifties.
Right below the author's comment, "Regardless of a grid’s size, the current flowing through it oscillates in perfect synchrony, at exactly the same frequency, throughout the whole grid," he presents a map of Western Europe's regional groups. I notice that Finland, Sweden, Norway, and Iceland comprise the Nordic Regional Group.
Iceland? There is a lot of water between Iceland and the other three nations in its group. Is Iceland's power indeed synchronized with the other three? If so, why does it need to be?
Below the map, the author includes a link crediting the Wikipedia article on power grids[0], which includes maps of other regions in the world.
Perusing the map for North America, I notice another noncontiguous regional group, namely the Alaska group. Most of Alaska is off the grid (or, more accurately, on a collection of local grids too small to be named). The named group includes a slice of the interior extending northward from Anchorage towards Fairbanks and a separate noncontiguous area containing Juneau. I have the same question, are the two sub-regions synchronized?
The map for Europe is a map of organizational/bureaucratic boundaries within the ENTSO-E; the world map on that page correctly omits regions not connected to the big synchronized grids.
Norway to Faroe Isles and Faroe to Iceland are about the same distance individually as the electrical links between the UK and Norway and UK and Denmark, so I don't see why not. The north atlantic is a little deeper, but that's probably not much of an increase in distance all considered - a couple of km at each end at most.
It's not useful for mag tape or wire recordings, but archaeologists have available a technique that can date artifacts like campfires, pottery kilns, and burned out adobe houses within the last 10,000 years.
It's called archaeomagnetic dating[0]. It turns out that heated ferromagnetic materials, such as magnetite, capture the magnitude and direction of the earth's magnetic field as they cool down through the Curie temperature[1]. That allows an investigator to ascertain the direction of magnetic north the last time a likely sample was heated above the Curie point. Over time, magnetic north changes with respect to true north.
The Library of Congress claims† to host 21 petabytes of digital content. That would take†† a little over a minute and a half to send over the link described in the article, assuming, of course, that the content has been put in a ready-to-send form.
From 1897 to 1953, New York City operated a pneumatic tube mail transport system. It consisted of 27 miles of tubing connecting 23 post offices and carried 95,000 letters per day, amounting to 30% of the city's mail volume. The canisters were two feet long and eight inches in diameter and could carry 600 letters.[1]
Jams were a bear. Crews would travel the route of the tube and check air pressure at test points every two blocks where the tube surfaced. When they found a drop in pressure at a test point, they would try to free the stuck canister by injecting extra pressure. If that failed, they would have to dig up the street.[2]
In the early 2000s, parts of the network were repurposed to run fiber optic cable.
Satellites such as Starlink operate in low earth orbit at about 350 miles, significantly above the F-layer. Also, they introduce repeater delay when they relay a data packet. To get from Chicago to Frankfurt would require relaying the packet thru multiple satellites. So, greater distance (even if passed by laser between satellites) plus repeater delays.
Also note that satellites in LEO are the only option. Geosynchronous satellites are completely out of the game due to the much greater distances involved.
Radio ham blog post discussing HF propagation: