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.
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?
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.
In the US, we have ZIP+4, which appends an additional four digits to the five-digit ZIP code. It's mainly used by bulk mailers, as part of qualifying for reduced postage rates.
Like the British postcode, important addresses have their own ZIP+4. E.g., 20500-0001, 20500-0002, and 20500-0003 refer, respectively, to the President, the First Lady, and the White House in general.
A few years ago, the IRS came after Boris Johnson, then the mayor of London, now the PM, for taxes on the gain from the sale of his house in London. He was born in NYC, you see, making him an American citizen. He ended up paying the tax and renouncing his US citizenship.
The page reloads and re-renders with the UI changes (up-down buttons hidden and unvote link added). However, the reload takes noticeable time, and you lose your scroll location, which is disorienting.
With JS enabled, the UI changes happen instantly, and the scroll position doesn't change. The page still reloads, but the reload is directed into a new Image object which is immediately garbage, so it's off the UI timeline. But it's inexplicable bandwidth waste, nonetheless!
It seems the article's author won the 2017 Ig Nobel Prize in Physics for 'using fluid dynamics to probe the question "Can a Cat Be Both a Solid and a Liquid?"' The prize announcement[0] cites the current article.
Also relevant, down-thread, plink mentions the Bonsai Kitten[1] hoax from nearly 18 years ago now.
> Always hated the name of that store. It sounds like a euphemism for Planned Parenthood.
Back in 1994, Bezos wanted to call his new company "Cadabra," as in the magic incantation "abracadabra," but he quickly had a fresh brainstorm when his lawyer misheard the name as "Cadaver."
I have an American Express Blue Cash Preferred, with a $95 fee, and a Fidelity Rewards Visa, with no fee.
The AX card rebates 6% on groceries, 3% on gas, and 1% on everything else. The Visa pays 2% on everything else. No silly quarterly schedules on changing categories of spending.
Therefore, groceries and gas go on the AX Blue, and everything else goes on the Visa (which used to be an AX card, oops, AXP!). And, of course, both cards get paid off in full every month.
If you travel for business a lot, there are a dizzying assortment of deals. But I no longer do, so the above seems optimal for me.
>Nobody but Red Hat makes any money off the Linux kernel.
You forgot about Canonical.
But the real point is, in the wild, the Linux kernel predominates.
Every Android user is a Linux kernel user. Every Chromebook user is a Linux kernel user. Every iOS user is a Unix user. Every Google server is a Linux kernel installation.
The fact is, Linux/Unix rules. Except for the corporate desktop, where Windows predominates, at least for most (uninteresting) instances of "corporate".
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: