Re: The amount of times...
Hmmm, 100C is where the vapor pressure of pure water is the standard atmospheric pressure at sea level. At 1 to 1.5km of elevation, the drop in temperature at where the vapor pressure of water is equal to the ambient pressure is enough to require adjustments to recipes when baking. The more natural point for 0C would be the triple point in water. Fahrenheit's scale was 0F being the coldest achievable temperature with water ice and NaCl, with 100F being core body temperature. A real SI scale fr temperature would be eV...

For doing thermodynamic calculations, the appropriate scales are Kelvin and Rankine, and there really isn't much difference in usability between K and R as all sorts of conversions need to be done to get answers in Joules or MWHr. Another "fun" problem is dealing with speed involves Joules being watt-seconds, while vehicle speeds are usually given in statute miles, nautical miles or kilometers per hour. A fun factoid is that 1 pound of force at one statute mile per hour is equal to 2.0W (1.99W is a closer approximation).

As for feet, a fair approximation is that light travels 1 ft/nsec, too bad the foot wasn't ~1.6% shorter as a light nano-second would be the ultimate SI unit of length. The current definition of an inch, 25.4mm, was chosen in the 1920's to allow machine tools to handle inches by having a 127 tooth gear instead of a 100 tooth gear.

FWIW, Jefferson wanted to base his unit of length on a "second's" rod, i.e. e pendulum whose length would have exactly one second period when measured at seal level and 45º latitude.

Don't get me started on kilograms of thrust.

Friday 27th January 2023 06:22 GMT
IvyKing
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Re: The amount of times...
From somewhere in the later half of the 19th century to ~1920, the US inch was defined as 39.37 inches equals 1m. According a ca 1920 issue of Railway Mechanical Engineer, the machine tool industry was making a push to defining the inch 25.4mm so that by using a 127 tooth gear to replace a 100 tooth gear a lathe could be set up to produce metric and imperial threads.

One problem with converting the US to pure metric is that almost all land titles use feet, not meters. The US legal definition of a foot was 1/66 of a chain, a mile was 80 chains (66x80=5280), a section of land under the Northwest Ordnance of 1787 (passed under the Articles of Confederation, NOT the Constitution), which was 6400 square chains and the acre being 10 square chains (640 acres per square mile). The surveys for the Townships (36 sections) didn't really start until ca 1796, so if the arrival of the metric standards had not been delayed by the storm and the English, the US might have re-written the 1787 law to use metric measurements.

Another problem with the US converting to metric was Herbert Hoover's success as Secretary of Commerce in setting national standards for pipes and other hardware.

One final note about metric versus imperial is that a nautical mile is defined as 1 minute of longitude at the equator, so works well with the degrees, minutes and seconds customarily used for angles. Metric navigation would favor a decimal system for expressing angles, i.e. the gradians.

doublelayerSilver badge
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Re: The amount of times...
"Fahrenheit's scale was 0F being the coldest achievable temperature with water ice and NaCl, with 100F being core body temperature."

Wrong on both counts. On Fahrenheit's original scale, 0 was the freezing point of a solution of ammonium chloride (NH4Cl), not table salt (NaCl). As neither compound is used directly on roads, the point at which it is not useful depends on which specific salt is being used in the area, and more importantly on where the compound has been applied and whether it has been moved or not. The temperature of the human body was not 100. It was 96. Of course, neither value is considered average for body temperature (and body temperature is incredibly variable in any case, whereas boiling points of things at a specific fixed pressure is stable). This is because the modern scale abandoned both limits by instead fixing 32 and 212 as the values for water freezing and boiling, moving both of the original bounds slightly and making use of the original scale inaccurate to modern users.

Wednesday 25th January 2023 01:55 GMT
-tim
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Coat
Re: The amount of times...
In 1700 it was much easier for a scientist to calibrate a home made thermometer using ammonium chloride cooling bath and a docile dog. The temperature of boiling water required a barometer at higher altitudes and calibration tables. The human armpit temperature of about 96 allows hand drawn hash marks in repeated halves. Many very early Fahrenheit thermometer are often marked every 3 degrees.

Monday 23rd January 2023 15:59 GMT
Michael Wojcik
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Re: The amount of times...
More importantly, for Fahrenheit the reference temperatures aren't 0 and 212; they're 32 and 96. 96 minus 32 is 64. And 32 and 64 are ... stay with me here ... powers of 2.

Fahrenheit based his scale on powers of 2 so that thermometers could be graduated by successive bisection (and then reflected to extrapolate outside that range, on the assumption that the mechanism was sufficiently linear within the desired range). That's an actual engineering reason, unlike "duh humans like powers of 10". There really isn't much reason to favor Celsius.

Kelvin, of course, is the one that matters. (Yes, Rankine works too, but for some SI operations Kelvin is more convenient.)

Celsius is today as much flavor-of-the-month as Fahrenheit is. The original justifications for them are no longer relevant; they're just a matter of taste.

Re: Hooray for Avoirdupois and pounds, shillings and pence
Auvoirdepois has nothing to do with pounds, shillings and pence. Precious metals are measure using the Troy system that has 20 ounces to the pound. That is why a pound of gold weighs more than a pound of feathers. 1GBP was originally worth a pound of gold hence 20 shillings to the pound.

Try Deepl:
Reindeer length is an old unit of measurement of length used when moving reindeer. Reindeer length is the distance a reindeer can travel between (reindeer) urination breaks. Reindeer cannot urinate while running, and running too long can cause them to become paralysed. The maximum distance a reindeer can run is up to 7.5 kilometres.

Re: Try Deepl:
Nobody said they couldn't urinate while flying. That's why I stay inside on Christmas Eve.

In 1793, French scientist Joseph Dombey sailed for the newly formed United States at the request of Thomas Jefferson carrying two objects that could have changed America. He never made it, and now the US is stuck with a retro version of measurement that is unique in the modern world.

The first, a metal cylinder, was exactly one kilogram in mass. The second was a copper rod the length of a newly proposed distance measurement, the meter.

Jefferson was keen on the rationality of the metric system in the US and an avid Francophile. But Dombey's ship was blown off course, captured by English privateers (pirates with government sanction), and the scientist died on the island of Montserrat while waiting to be ransomed.

And so America is one of a handful of countries that maintains its own unique forms of weights and measures. //

When the UK settled in the Americas they brought with them a bastardized version of weights, measures and currencies. A Scottish pint, for example, was almost triple the size of an English equivalent until 1824, which speaks volumes about the drinking culture north of the border.

British measurements were initially standardized in the UK's colonies, but it was a curious system, taking in Roman, Frankish, and frankly bizarre additions. Until 1971, in the UK a pound consisted of 240 pence, with 12 pence to the shilling and 20 shillings to the pound. //

The French government felt that the newly formed nation wasn't being supportive enough in helping Gallic forces fight the British in the largely European War of the First Coalition. In something of a hissy fit, the French government declined to invite representatives from the US to the international gathering at Paris in 1798-99 that set the initial standards for the metric system.

Jefferson's plans were kicked into committee and while a form of standardization based on pounds and ounces was approved by the House, the Senate declined to rule on the matter.

Mostly you don't see a difference, unless you are using set -u:

/home/user1> var=""
/home/user1> echo $var

/home/user1> set -u
/home/user1> echo $var

/home/user1> unset var
/home/user1> echo $var
-bash: var: unbound variable

So really, it depends on how you are going to test the variable.

I will add that my preferred way of testing if it is set is:

[[ -n $var ]]  # True if the length of $var is non-zero

or

[[ -z $var ]]  # True if zero length

rrsync is designed to be used as a forced command for a particular key, so it should be exactly what you want.

A forced command is set up using the command option for a key in an authorized keys file and is then always run whenever this key is used for authentication, no matter what command the client requested. But it has access to the requested command so it can for example implement a validated, restricted version of it and that's what rrsync does.

You use it like this:

command="/path/to/rrsync -wo /allowed/directory/",restrict,from="a.b.c.d" ecdsa-sha2-nistp521 AAAAE...

Access for this key is limited to rsync to the /allowed/directory/ only. The -wo (write only) option means that rsync will be only allowed to send to the remote machine, -ro would only allow reading from the remote system, giving no option would allow transfer in both directions.

On the local side when you give arguments to rsync you must give the remote path relative to the allowed directory, so on A you would do eg.rsync -options /local/path root@B: and not rsync -options /local/path root@B:/allowed/directory/.

See also https://serverfault.com/a/915842/117645

Servers on exaroton don't have a fixed monthly price. You are only charged for the time you actually use your server.

To pay for services on exaroton, you use credits, each of which is worth €0.01. After creating your account, you get 5 credits for free to test our service. //

Running a server on exaroton costs 1 credit per GB of RAM per hour. For example, if you select 4 gigabytes of RAM for your server and run it for 1 hour, you would pay 4 credits. You can choose how much RAM (2 GB to 16 GB) you want to assign to your server on the Options page. //

To save credits, it is recommended only to run your server when somebody is playing on it. To achieve this, exaroton provides you with an AutoStop feature to automatically shut down your server when it has been empty for a while and an AutoStart feature to start your server automatically as soon as somebody tries to join.

Both features can be enabled for free on the Options page. We will only charge you for the time your server is actually running.

To go along with that recent CETP trial news, here's another one for the "We don't know much about human lipid handing" file. A dietary study originally done back in the 1960s and 1970s has been (almost literally) resurrected, with data pulled out of yellowing stacks of paper, old cardboard boxes, and ancient-format computer tapes.
What it shows is that, under about the most controlled conditions possible in a large human trial (institutionalized patients being served standard meals), that replacing saturated/animal fat in the diet with vegetable-derived fats and oils provided. . .no cardiovascular benefit whatsoever. In fact, the lower the cholesterol levels of the patients, the higher their death rates. This was in over 9,000 subjects over five years, probably the largest study of its kind ever conducted, and it had only produced one (not very thorough) paper in 1989 that didn't make much of an impression. ///

READ COMMENTS

McCullough says that it was Washington and his army that won the war for American independence. “He was not a brilliant strategist or tactician, not a gifted orator, not an intellectual. At several crucial moments he had shown marked indecisiveness. He had made serious mistakes in judgment. But experience had been his great teacher from boyhood, and in this his greatest test, he learned steadily from experience. Above all, Washington never forgot what was at stake and he never gave up.” Without Washington, there would be no America.

There are many things to celebrate during our nation’s semiquincentennial celebrations, and many men to honor for their part in our country’s birth: Thomas Jefferson, John Adams, Alexander Hamilton, Benjamin Franklin, and John Hancock among them. But no one looms larger than George Washington, who today seems almost mythical. At Washington’s funeral, Henry “Light-Horse Harry” Lee famously eulogized Washington as, “first in war, first in peace, and first in the hearts of his countrymen.” In 2026, it is our duty to ensure that honorific remains as true as when it was first spoken.

A pizza place near the Pentagon received an unusual rush in orders just an hour after the US launched its attack on Venezuela. //

That would be 3 a.m. in Caracas, one hour after the US rained down airstrikes on the capital city that lasted less than 30 minutes. //

The Pentagon Pizza theory follows pizza orders surrounding the Pentagon, speculating that an increase in late nights orders for federal agents corresponds with major historical events.

In the past 20 years, there have been only nine anthrax cases in the US.

However, B. anthracis is part of the larger Bacillus cereus group, which also includes B. cereus and B. tropicus, a newly recognized species. And these species can also carry and produce anthrax toxins. Both can be found in soils, and B. cereus is considered ubiquitous in the environment.

In 2022, CDC researchers found an unexpected pattern. Since 1997, there had been seven cases of infections from Bacillus group bacteria producing the anthrax toxin—all in metalworkers. Six of the seven were welders, hence the term “welder’s anthrax,” with the remaining case in a person working in a foundry grinding metal. Of the six cases where a specific Bacillus species was identified, B. tropicus was the culprit, including in the newly reported case.

Speculating risks
It’s unclear why metalworkers, and welders specifically, are uniquely vulnerable to this infection. In their 2022 report making the connection, CDC experts speculated that it may be a combination of having weakened immune responses in the lungs after inhaling toxic metal fumes and gases created during metalwork, and having increased exposure to the deadly germs in their workplaces. //

Environmental sampling of his workplace found anthrax-toxin-producing Bacillus in 28 of 254 spot samples. //

The experts also speculated that iron exposure could play a role. Bacillus bacteria need iron to live and thrive, and metalworkers can build up excess iron levels in their respiratory system during their work. Iron overload could create the perfect environment for bacterial infection. In the teen’s case, he was working with carbon steel and low-hydrogen carbon steel electrodes.

For now, the precise risk factors and why the healthy teen—and not anyone else in his workplace—fell ill remain unknown. CDC and state officials recommended changes to the workplace to protect metalworkers’ health, including better use of respirators, ventilation, and dust control.

23 hrs
volsano
One Y2K remediation I worked on had systems from the 1960s -- crucial systems that ran the whole show.

We easily (for some definitions of the word) fixed their 1980s and 1990s stuff that used 2-digit years.

But we did not touch the 1960s and 1970s stuff that had a specialised date storage format. It was 16-bit dates. 7 bits for year. 9 bits for day of year.

It was too assemblery, too unstructured, too ancient.

And, anyway, 9-bit year counting from 1900 (as they did) was good until the unimaginably far future.

The unimaginably far future is nearly with us: 1900 + 127 = 2027.

I am waiting for the phone to ring so I can apologise, - and quote them an unimaginably large number to finish the job.

After some time, the VAX crashed. It was on a service contract, and Digital was called. Laura Creighton was not called although she was on the short list of people who were supposed to be called in case of problem. The Digital Field Service engineer came in, removed the disk from the drive, figured it was then okay to remove the tape and make the drive writeable, and proceeded to put a scratch disk into the drive and run diagnostics which wrote to that drive.

Well, diagnostics for disk drives are designed to shake up the equipment. But monkey brains are not designed to handle the electrical signals they received. You can imagine the convulsions that resulted. Two of the monkeys were stunned, and three died. The Digital engineer needed to be calmed down; he was going to call the Humane Society. This became known as the Great Dead Monkey Project, and it leads of course to the aphorism I use as my motto: You should not conduct tests while valuable monkeys are connected, so "Always mount a scratch monkey."

Laura Creighton points out that although this is told as a gruesomely amusing story, three monkeys did lose their lives, and there are lessons to be learned in treatment of animals and risk management. Particularly, the sign on the disk drive should have explained why the drive should never have been enabled for write access.

In a separate opinion, justice Kenneth Lee accused California of misleading residents in smaller counties — where the open-carry ban does not apply — about how they can lawfully carry firearms. “Our constitutional rights,” Lee wrote, “should not hinge on a Where’s Waldo quiz,” The Hill reported.

The Big Apple firefighter’s union is steaming mad over the sudden discovery of 68 boxes of Ground Zero health data following the Sept. 11, 2001 terror attacks — files they were told never existed.

The recently surfaced boxes contain thousands of pages of information on possible toxins at the Lower Manhattan site that union members said could be used to add new ailments to the list of covered 9/11-related illnesses.

Some 343 FDNY firefighters lost their lives at the World Trade Center site on 9/11 with hundreds more having lost their lives since from health-related maladies.

“They should have used that evidence and those tests to prepare for the long term health care of the people that were down there,” Andrew Ansbro, president of the FDNY United Firefighters Association said at a press conference Monday. “The decision they made was to just hide it. //

The FDNY and advocates for other first-responders have been battling for years to get more data on possible toxins at the Lower Manhattan site, which has killed about 400 people since the attacks.

Any gas can be converted into a liquid by simple compression, unless its temperature is below critical. Therefore, the division of substances into liquids and gases is largely conditional. The substances that we are used to considering as gases simply have very low critical temperatures and therefore cannot be in a liquid state at temperatures close to room temperature. On the contrary, the substances we classify as liquids have high critical temperatures (see table in §
).

All gases that make up the air (except carbon dioxide) have low critical temperatures. Their liquefaction therefore requires deep cooling.

There are many types of machines for producing liquid gases, in particular liquid air.
In modern industrial plants, significant cooling and liquefaction of gases is achieved by expansion under thermal insulation conditions.

Rockall is an uninhabited – and uninhabitable – granite islet in the North Atlantic Ocean, covering 784 sqm and claimed by the United Kingdom, despite beings some 300 miles off the west coast of Scotland.

It is perhaps most well known, of course, for giving its name to one of the sea areas named in the British Met Office shipping forecasts.

Over the years, plenty of local Cinderella stamps have appeared for British islands with a dubious postal requirement and, in some cases – such as Stroma or Staffa – no population at all.

However, when we recently came across a stamp bearing the name of Rockall – a location once described as “no place more desolate, more despairing, more awful to see in the world” – we were suitably intrigued about who might be behind such a stamp, and why.

A charity expedition
It turns out that Rockall’s sole stamp issue to date related to a charity expedition to the island in 2005, under the name “Rockall Ho!”, where a team raising funds for Mental Health Media’s MEdia initiative successfully landed on the rock on 16 June and raised the flag of the “Peoples’ Republic of Rockall”.

In doing so, they joined the fewer than 20 people who are ever confirmed to have set foot there. //

Incidentally, the Latin used in the cancellation – “Ultra Mare Usque Nusquam” – translates as “Beyond the Sea Nowhere”. A fitting motto, perhaps, for this “awful” yet intriguing lump of rock in the Atlantic, and a place now immortalised in philatelic history thanks to its sole Cinderella stamp issue.

In philately, the abbreviation signifies a postage stamp that has never been hinged or mounted, retaining its original gum. Such a stamp is considered to be in perfect, unused condition, as issued by the postal authority. An example would be a stamp carefully preserved in pristine condition since its purchase.

Stamps in this superior condition are often more valuable to collectors, particularly for older or rarer issues. Maintaining original gum is a key factor in assessing a stamp’s quality and potential appreciation. Historically, hinging was a common practice, making unhinged examples from earlier periods relatively scarce and thus more desirable. This careful preservation contributes significantly to a collection’s overall worth and prestige.

Minecraft Bedrock Edition is the version of Minecraft that powers the iPhone / Android versions (formerly Minecraft Pocket Edition), the Xbox / PlayStation / Nintendo Switch editions and the free Windows 10 Minecraft edition.

Mojang has released a dedicated server which is considered to be in alpha testing.  I have found it to be very stable and able to run on a wide variety of hardware.

This script and guide are written to help you get a robust Minecraft Bedrock dedicated server up and running in only a few minutes!

This is the standalone version.

Sets up a Minecraft Bedrock dedicated server on Ubuntu / Debian with options for automatic updates, backups and running automatically at startup.
View installation instructions at: https://jamesachambers.com/minecraft-bedrock-edition-ubuntu-dedicated-server-guide/