Units Of Measure

[steve_bank]

Greek and Eroman units of measure

Greeks and Romans probably had their equiv ants of our NIST. Fraud in business and trade was undoubtedly an issue as it can be today.

The needs for cionnerce and trade crteated a demnd for standards, and scienceis based on units of measure. Development of science was always tied to profit and military technology.

SI is more sophisticated, but the basic principle is the same. Establish basic standards and create subdivisions and multiple.

There has been talk in the past about defunding NIST, utter ignorance of impertinence of standards to commerce.

Ancient Greek units of measurement - Wikipedia

en.wikipedia.org

Ancient Greek units of measurement varied according to location and epoch. Systems of ancient weights and measures evolved as needs changed; Solon and other lawgivers also reformed them en bloc.[citation needed] Some units of measurement were found to be convenient for trade within the Mediterranean region and these units became increasingly common to different city states. The calibration and use of measuring devices became more sophisticated. By about 500 BC, Athens had a central depository of official weights and measures, the Tholos, where merchants were required to test their measuring devices against official standards.[citation needed]

Ancient Roman units of measurement - Wikipedia

en.wikipedia.org

Time in Ancient Greece: Clocks, Divisions, Days | Early European History And Religion — Facts and Details

europe.factsanddetails.com

Julian Jaynes, a Princeton psychologist, contends that people living when the “ Iliad” was written (the 8th century B.C.) had little awareness of time. The epic poem he says was about people who "did not live in a frame of past happening, who did not have 'lifetimes' in our sense, and who could not reminisce." Concepts of time developed when language advanced to the point where people could describe the past in terms of personal experience. Zeno of Elea, a fifth century B.C. Greek philosopher, was the first man to ponder over the fact that any unit could be subdivided endlessly. [Source "The Enigma of Time" by John Boslough, National Geographic, March 1990]
The 24 hour day, in the words of one historian, "was the result of Hellenistic modification of an Egyptian practice combined with Babylonian numerical procedures." The Egyptian used sun dials and came up with the idea of hours. These hours, in turn, were organized using Babylonian arithmetic which grouped numbers in denominations of six rather than ten (no one knows for sure why the Babylonians selected six). [Source: "The Discoverers" by Daniel Boorstin]

The word "hour" comes from the Latin and Greek words for “season” or “time of day.” It described a twelfth of the period of sunlight or darkness. Minutes (derived from a Latin word for "small part”) were used to divide the region between lines of latitude and mark locations on a circle during ancient times long before they marked time. It wasn’t until perhaps the 13th century, when the mechanical clock was invented, that minutes were used to divide an hour into sixty units. Seconds were not included until the 16th century when clockmaking technology was significantly improved.

Sundials didn't measure 60 minute hours. Instead they divided the daylight into 12 hours of equal length. Greek sundials looked like inside of the bottom half of a globe. On one side was the pointer that created the shadow and on the other side were lines curving up the side of the globe. These curving lines marked off the hours and compensated for the changing of the sun's position with the seasons. The length of the hours varied from about 45 minutes in the winter time to 75 minutes in the summer. The Greeks called sundials "Hunt-the-Shadow." The Tower of the Winds in Athens had sundials on four sides, which meant an observer could tell the time at any time of the day on three sides of the tower. [Source: "The Discoverers" by Daniel Boorstin,∞]

The ancient Greeks had no weeks, nor names for the different days. They followed a 12 month calendar similar to the one used by Babylonians with 29 and 30 day lunar months and a 13th month added on the seventh of thirteen years to ensure that the calendar stayed in sync with the seasons. By contrast, the ancient Egyptians used a 365-day calendar. Each Greek city state added the thirteen month at different times to mark local festivals and suit political needs. A complex system of "intercalculating" was employed to decide on meeting times between citizens of different states and to make arrangements for the pick-up and delivery of goods. [Source: "The Discoverers" by Daniel Boorstin,∞]

The Romans developed the idea of the week and gave names to the months. They had an eight-day week which they later changed to seven. By the A.D. third century Romans divided the day into only two parts: before midday “(ante meridiem” A.M.) and after midday (“ post meridiem” P.M.). Someone was in charge of noticing when the sun crossed the meridiem since lawyers were supposed to appear before noon. Later the day was dived into parts: early morning, forenoon, afternoon, and evening and eventually followed a sundial that marked "temporary" hours.

 

[steve_bank]

It is easy to create a sidereal water clock.

Fill a cont6ainer with water big enough to last more than one day. Drain water at a constant rate.

Use a mechanical sight to determine when a star position lines up to start and stop the clock.

Divide the sides of the container between the start and stop water levels into equal sections

Reproduce and market as the clock no home should be without ….

Create a high resolution clock for timing chariot races.

 

[Swammerdami]

The reference to Julian Jaynes is interesting. His book is a Must-Read. I still re-read it from time to time, getting a clearer picture of his genius insights.

I've had an interest in ancient measures. (Just yesterday I estimated the Sun-Earth distance as 740 stade!) 5000 years ago, Sumerians had balance scales with very tiny weights -- weights so tiny the only plausible use would be to measure valuables like silver, gold or precious spices. The Sumerian weight values followed Fibonacci's 1,2,3,5,8 while ancient Harappan weighings used 1,2,4,8,16.

The smallest Sumerian weight was 1/60 of a shekel, i.e. the weight of just three grains of barley. Interesting, I thought it is, that barley grains provided the basic definition of weight measure in ancient Sumeria, and also throughout medieval Europe: A pennyweight is 24 grains.

Speaking of AU -- the astronomical unit of about 740 stade -- this is the key scaling factor for all of astronomy! Kepler et al showed an extremely accurate map of the solar system, but had only a crude approximation to its scale! When Ole Rømer (assisted by the mathematician Christiaan Huygens) cleverly calculated the speed of light using the eclipses of Jupiter's moon, he came up with a number close to the present-day number! The biggest deviation between that 350 year-old speed of light and the number known today is NOT any flaw in Rømer's method. The error came from Rømer's need to multiply by the AU, still known only approximately then.

AU -- calculated by parallax measurements -- is the first step on the path to astronomical distance measurements. The 2nd step IIUC involves Cepheid variable stars, some of which are close enough to have distance determinable via parallax. And so on.

 

[Shadowy Man]

AU -- calculated by parallax measurements -- is the first step on the path to astronomical distance measurements. The 2nd step IIUC involves Cepheid variable stars, some of which are close enough to have distance determinable via parallax. And so on.

the second step was star clusters. Since they’re all at basically the same distance that distance can be figured out from the cluster’s H-R diagram.

 

[bilby]

Jeez, these astronomers like making things difficult. Bunnings sell really long tape measures (100m/300ft) for like $72AUD a pop.

Obviously you will also need a rocket to get into space, and a mate to hold the end against the Sun - probably best get him some oven mitts for that bit ($12.48 for a set of two, also from Bunnings) - but at least you don't need to do all the difficult sums that parallax uses.

And you get a sausage sizzle, with proceeds going to a local charity or community organisation.

 

[robnisch]

I took two years of surveying. I think this is what Mason and Dixson used. It's lasers a stuff now.
Gunter's chain.

 

[Elixir]

View attachment 51331
I took two years of surveying. I think this is what Mason and Dixson used. It's lasers a stuff now.
Gunter's chain.

There needs to be a banana for scale.
I had a guy out here about two weeks ago. He used GPS, and was done almost as quickly as you could walk the boundaries and draw a lot line adjustment. The drawing came a couple days later and was just what I needed.

 

[Swammerdami]

Mention of surveying reminded me of a paragraph in a tribute to the cleverness and bravery of one of America's very greatest of heroes.

[in A Plea for Captain John Brown]

As for his tact and prudence, I will merely say, that at a time when scarcely a man from the Free States was able to reach Kansas by any direct route, at least without having his arms taken from him, he, carrying what imperfect guns and other weapons he could collect, openly and slowly drove an ox-cart through Missouri, apparently in the capacity of a surveyor, with his surveying compass exposed in it, and so passed unsuspected, and had ample opportunity to learn the designs of the enemy. For some time after his arrival he still followed the same profession. When, for instance, he saw a knot of the ruffians on the prairie, discussing, of course, the single topic which then occupied their minds, he would, perhaps, take his compass and one of his sons, and proceed to run an imaginary line right through the very spot on which that conclave had assembled, and when he came up to them, he would naturally pause and have some talk with them, learning their news, and, at last, all their plans perfectly; and having thus completed his real survey he would resume his imaginary one, and run on his line till he was out of sight.

 

[Jimmy Higgins]

View attachment 51331
I took two years of surveying. I think this is what Mason and Dixson used. It's lasers a stuff now.
Gunter's chain.

...and orthophotometry. Taking pictures and resolving the surface using a little bit of on the ground survey. It is insane how far the practice has come in 20 years!

Back in college, we used a metal tape in Survey, using the ambient temp to apply corrections.

Funny how the NFL still uses the above tech.

 

[steve_bank]

The NFL needs to get with the program and go to meters instead of yards.

 

[bilby]

The NFL needs to get with the program and go to meters instead of yards.

A yard is less than 92% of a metre though, so it would reduce the number of touchdowns.

It would also require the fields to be almost ten yards (almost ten metres) longer, so some stadia would need significant remodelling, and the back row* of seats would need to be removed.










* Clarke, Dawes and Riley, 'The Games' S1E4, 1998

 

[Elixir]

A yard is less than 92% of a metre though, so it would reduce the number of touchdowns.

And first downs.
Some other rules could be changed to counter the effect, or the lines on the field could simply be re-labeled:
Instead of the 10 or 30 yard line, it would become the 9.144 meter line, or the 27.432 meter line etc. Stenciling might be a little more difficult.
But lengthening the field + endzones by 30+ feet isn’t really feasible without major structural alterations to most of the stadiums.

 

[bilby]

Instead of the 10 or 30 yard line, it would become the 9.144 meter line, or the 27.432 meter line etc. Stenciling might be a little more difficult.

This just seems like obstructionism to me. It wouldn't be difficult at all; You would just need to use smaller stencils. Could even save money!

It would also boost the flagging sales of this technological marvel from the early days of broadcast TV:
https://collection.sciencemuseumgro...d-plastic-lens-television-magnifier-1935-1965

 

[Shadowy Man]

Or they could keep the fields the same and just refer to them as meters instead of yards. Most people wouldn’t be able to tell the difference.

 

[Swammerdami]

Given the perfections of the ancient English measurements, it is really a shame that French communists inflicted their "metric" system on the civilized world. Kudos to the USA for resisting! /sarcasm

One travesty is Celsius. Do all you Celsius fiends suffer from the A/C problem? 27° is too cold, and 28° too warm. The Celsius scale just isn't granular enough. Manufacturers could solve this by deploying -- gasp! -- fractional settings, but the communist governments won't allow this. Fahrenheit is a finer scale, and doesn't need fractions.

A similar problem arises when I step on the scale to see how many pounds I've gained during the day. TWO kilograms!!? Ugh!!! I think all of you can understand that I'd much prefer to gain just two POUNDS.

And don't forget wrenches for auto repair. When an America moves abroad, he can forget his wrenches: He'll need to buy a brand-new set using multiples of the communist centimeter, instead of the inch that God intended.

Finally consider the division of a kilometer into meters. 1000 = 2³ × 5³
Whippee! 1000 is not even divisible by THREE, let alone useful numbers like 16, or the Babylonian 60. We ran 660 yards -- three furlongs -- when I was in high school. That's about 0.6 kilometers, but the popular distance in Europe is 0.5 kilometers! Did they abandon furlongs and miles because they were too lazy to run the extra 0.1 km?

So there are 5280 feet in a mile. 5280 = 2⁵ × 3 × 5 × 11.
Nicely divisible by 60, or even 32 for those who like binary. Who could ask for better? You want divisibility by SEVEN????

I'm sure there will be complaints about the 11. Might not 10 be better? Google is your friend!

The perch or rod, as it was also known, was a traditional Saxon land measure and survived into the twentieth century. It had originally been defined as the total length of the left feet of the first sixteen men to leave church on Sunday morning.

In those days church-going Saxons wore dress-up shoes with large heels and large toes on Sunday. This beautiful distance (2⁴ Sunday feet) was later codified as eleven half-ulna; and there are exactly 40 U.S. survey rods to a surveyor's furlong. (Never mind the tiny difference between the U.S. survey inch, and the communist "International" inch.)

It was the measurement of proper Sunday God-worshiping apparel that introduced the extra 11/10 multiplier. The 11 is thus a celebration of God's glory.

It was a simple pleasure to split an English pound three ways in the olden days: Each drinker owes six shillings and eight-pence. Have you ever watched three American tourists try to split a 1 Euro bill in Europe?

 

[bilby]

27° is too cold, and 28° too warm.

27°??? What are you, a lizard?

23° is comfortable. At 27° I would be melting down so badly that Jane Fonda would be making alarmist movies about me.

 

[Swammerdami]

I praise Thailand as a holiday destination but -- Warning! -- when you first step outside you may be aghast at the heat. ("Airline? It's too hot here. Change my return ticket; I'm going home TODAY!")

27° is too cold, and 28° too warm.

27°??? What are you, a lizard?

23° is comfortable. At 27° I would be melting down so badly that Jane Fonda would be making alarmist movies about me.

I thought of altering the numbers to avoid this predicted complaint.
But "Honesty is the best policy."

I'm not sure why 27° seems quite comfortable for me. Is it because the cool air is directed toward me? Is it because of the years I've spent in the Land of Smiles without A/C at all? Is it because I'm often half or wholly naked?

I do set the car's A/C to about 22° but that's almost irrelevant as I control the driver's coolness with other controls, especially fan speed.


ETA. In future I think you should show contrition for calling me a lizard by answering at least one of my questions, e.g.

It was a simple pleasure to split an English pound three ways in the olden days: Each drinker owes six shillings and eight-pence. Have you ever watched three American tourists try to split a 1 Euro bill in Europe?

 

[robnisch]

If I recall, a mile was based on 1000 paces of a Roman soldier. Mille-mile.
The first thing we did in surveying was know your pace. Very useful for finding old monuments.
And power company said you should not set the A/C below 73F. Why?

 

[steve_bank]

If I recall, a mile was based on 1000 paces of a Roman soldier. Mille-mile.
The first thing we did in surveying was know your pace. Very useful for finding old monuments.
And power company said you should not set the A/C below 73F. Why?

Really a question?

Keeping AC at or above 73F lowers demand for electricity.

 

[steve_bank]

Celsius sets the freezing point of water at 0 degree and the boiling point 100.
Fahrenheit is 32F and 212F,.

The difference between boiling and freezing for C is 100-0 = 100.
For F it is 212 - 32 = 180

Scaling to 100 graduations on say a 1 foot glass mercury thermometer degree C has a restitution of 1 and F 1.8.

Put a glass thermometer in boiling water and scratch a line atthe mercury level. Put it in an ice water mixture and mark the low point.

Make 100 subdivisions. On one side 1 degree per division the other 1.8.

A stirred ice water mixture is considered very close to 0C and is used as a reference point for checking and calbrting sensors. At typcal room temperures and low altutudes boilng water is the other refernce point..



Comfortable room temperature is taken to be about 70F which is about 21C.