Still love your old slide rule? This guy was obsessed

[Onomea]

The Antikythera Mechanism

How about a 2000 year-old mechanical computer?

While I have very little understanding of mathematics or computing, I have long found the Antikythera Mechanism to be fascinating. Until watching the BBC video, second link below, this morning, I had assumed it to be unique.

The 2 000-year-old Antikythera Mechanism, the first analogue computer, was a bronze hand-powered device from ancient Greece filled with complex gears. It was used to predict the positions of the planets and events like lunar and solar eclipses. The machine was even used to set the dates of the Olympic Games.

Only a third of the scientific calculator had survived when it was discovered in a shipwreck off a Greek island in 1901. Ever since then, the scientific community has been trying to understand how it works and what it could have looked like...

Scientists solve mysteries of the world's oldest computer | CDE Almer'ia - Centro de Documentaci'on Europea - Universidad de Almer'ia

Six minute BBC video: Antikythera Mechanism: The ancient 'computer' that simply shouldn't exist - BBC REEL - YouTube

And if you have an hour or so: Decoding the Heavens: The Antikythera Mechanism by Jo Marchant - YouTube

Slides from lecture at the link above:

 

[oldbrownhat]

...Only a third of the scientific calculator had survived when it was discovered in a shipwreck off a Greek island in 1901. Ever since then, the scientific community has been trying to understand how it works and what it could have looked like....

It is a fascinating artifact. Given that AI-assisted imaging was recently used to "unroll" and read part of a thoroughly charred scroll from Herculaneum, who knows what they may be able to do with the Antikythera?

 

[DWalt]

Then there is the Abacus, which goes back 2500 years. I understand that they are still in wide use in many Asian countries and an accomplished user is capable of figuring faster with an abacus than by using a modern calculator. I have never tried using one. Not sure if they are good for any mathematical purpose other than addition and subtraction.

Regarding the Antikythera device, there was also an episode of the "Stranger Things" TV series about it. Basically it was a mechanical analog computer. Same principle as used for gun aiming and fire control systems on naval battleships through the Vietnam War period. Lots of mechanical gears, levers, screws, and cams, very little electronics. It took a great deal of training and practice to use one effectively, and the Navy ran out of people who knew how to do it. A similar device was the WWII Norden Bombsight, which was also a mechanical analog computer, and not nearly as precise and effective as its publicity made it out to be. The Norden Bombsight: Was it Truly Accurate Beyond Belief?

My graduate advisor in college had been a B-24 pilot in WWII. He once told me that using the Norden was not a great deal more accurate than guesswork. There was more reliance on many planes simply dropping lots of bombs in the hope that a few of them would hit the target and get results. "Pickle barrel accuracy" was nonsense when hitting within 1000 feet of the aiming point was considered more realistic.

 

[oldbrownhat]

Then there is the Abacus, which goes back 2500 years. I understand that they are still in wide use in many Asian countries and an accomplished user is capable of figuring faster with an abacus than by using a modern calculator. ...

Vancouver, B.C. has a very large Chinatown, second only to that in San Francisco, I think, and although I haven't been down there for many years, I seem to recall some of the old shops using them. I wouldn't be surprised if a few people still do.

 

[Onomea]

Re abacuses (abaci?), here's one I picked up at a flea market in Tokyo years ago. I don't know how to use it, but, I find it attractive and keep it in my library as a knick-knack.



It is not unusual at all, as DWalt notes, to see older folks using them in mom & pop businesses in Japan.

Interestingly, the abacus used by Chinese folks is different. It has two rows of beads at the top rather than the one row of the Japanese abacus.

(This made me curious, thinking about it. The difference is explained here: Difference Between Chinese and Japanese Abacus.)

 

[Exaviator]

And mine was circular, made to carry in your shirt pocket...

 

[crstrode]

I spent many months flunking out of Undergraduate Navigator Training at Mather AFB CA in the early 80's. They eventually made good on their threat of what fate would befall those who did not pack the gear to be a Navigator by making me a cop and sending me to Minot.

I had to give back my beloved whiz wheel, which was almost as painful as returning the cool red switchblade we got. I believe it is a slide rule that goes roundy-round.

If you were an AF cop in Minot, did you know of WR Brooksher?

 

[SMSgt]

And mine was circular, made to carry in your shirt pocket...

Used that a lot to check out true airspeed computers on Buffs.

 

[DWalt]

Something not seen much today are nomographs. I can't really describe them very well, other than they were graphical methods to solve equations. Most would recognize one if they saw it. For example, if you knew two variables, you could draw a line through scales to solve for the answer. I once took a class on how to construct a nomograph, but never used that information for anything. They could get quite complicated if there were more than two or three variables involved. Useful mainly for people who had no concept of algebra. For example, you could construct a nomograph to determine bullet muzzle energy and power factor from any combination of bullet weight and muzzle velocity without doing any arithmetic calculations.

 

[ZGrand]

I used a slide rule in college the first couple of years. When Texas Instruments came out with the pocket calculator, I wanted one but couldn't afford it. I instead bought a calculator at a place called Olson Electronics (long since out of business). Four functions only (add, subtract, multiply, and divide). When dealing with large numbers, it would take a few seconds to display the answer. Simpler days indeed.

 

[CajunBass]

My father was a carpenter. He never really went to school, stopping about the third grade. He could bairly read and write his name. I remember as a kid watching him at the kitchen table, painstakingly writing his name over and over. He had much better handwriting than I ever did.

He would drag me along on some of his jobs where I'd get to run, fetch, tote and carry. I pretty much hated it and never learned a thing about being a carpenter. To this day I can't drive a nail.

But I remember watching him a couple of times with a simple carpenters folding ruler. The kind that had a little sliding metal extension that you could use to get a precise reading (at least that what I thought it was for). He would be sliding that little piece back and forth, and I could tell he was doing something by the way he talked to himself. I wish I had thought to ask him what he was doing, but I've often since then wondered if he'd found, or been taught some way to use that ruler as a sort of a slide rule to come up with the numbers he needed to make a cut or figure how much lumber he needed. Something I had no idea about and still don't.

Sorry. No doubt off topic, but this made me think of it.

 

[Sistema1927]

I used slide rules in HS and a little in college.

My Senior year in HS, I purchased a calculator that was limited to multiplication/division/addition/subtraction, and no memory. It had an led display and terrible battery life.

While visiting us for Christmas, I showed it to my grandfather. He was not impressed. He had owned a general store that his father had opened, and told me that the only thing you needed to do math was a grocery sack and a pencil.

Attached picture of the store in 1914 with my great-grandparents standing outside.

 

[djohns6]

I have an old Ti-86 that I haven't powered up in years . Can't bear to throw it out . I guess when I die somebody will .

 

[DWalt]

You can go to a Dollar Tree and buy a pretty good scientific calculator for $1.29. I have a couple of them. I think that is an astonishing testament as to how far technology has advanced. Thing is, most people today already carry around a cell phone which has similar or better capability, so few consider buying a scientific calculator even at a giveaway price. It has been four or five years ago I bought my grandson a top-of-the-line HP scientific calculator with graphing capability at a very good price from a store going out of business. But he never used it a single time as his cell phone does all he needs. You may as well pitch your TI-86, no one will want it. Or try to sell it on eBay. I never saw much purpose in having graphing capability on a hand-held calculator.

 

[Gamecock]

I still have Dad's Post. The Frederick Post Co. NO. 1462

And my:

TI SR-16II
TI 1750-II

Like said above, I can't throw them away.

 

[noonster]

Makes me think of a joke my geometry eacher told me (Mr Adams, if you must know) im '65 or so. The punch line was "adders can multiply using a log table." REAL slip-stickers will understand it.

 

[Golddollar]

From the movie.

I just got through watching the movie "Hidden Figures" that was On Demand from DirecTV. As a number cruncher who did everything by hand and low end calculator, I was just really impressed with the story about the ladies who did all those calculations. I feel vindicated for all those years that I plotted legal descriptions without using a computer program that I could never make work.

I remember John Glenn's voyage but didn't know that it was cut short. It is good to see stories about the full details of events that occurred during my childhood.

 

[DWalt]

Curta was another mechanical calculator in wide use in the early 70's. It beat doing long hand trig calculations with a pencil and your brain.
Curta - Wikipedia

Someone else had also mentioned the Curta calculator. I saw one of those once, but never attempted to use it. Another item of extreme mechanical ingenuity which was made obsolete by the appearance of the electronic digital calculator. I checked on eBay and found several Curtas listed for sale. Prices were generally in the $1500-2000 range for those in working condition. An item I would like to find at a garage sale for $10.

I mentioned earlier about mechanical calculators. I once bought a Marchant (upper left picture of the attachment) for my lab. As I remember it was about $3K in 1965-66. Whatever the price, it was far more than my monthly pay at the time. AD ARCHIVE - SCM/Marchant Calculator Advertisement Note that the ad also shows a SCM Cogito calculator, lower right, which was one of the earliest primitive attempts at making an electronic business calculator during the mid-1960s. It actually contained a solid state microprocessor.

 

[Bekeart]

SCM Marchant Cogito 240 Electronic Calculator

I mentioned earlier about mechanical calculators. I once bought a Marchant (upper left picture of the attachment) for my lab. As I remember it was about $3K in 1965-66. Whatever, it was far more than my monthly pay. AD ARCHIVE - SCM/Marchant Calculator Advertisement

I have used, but did not remember make and model of this machine,

SCM Marchant Cogito 240 Electronic Calculator
SCM Marchant Cogito 240 Electronic Calculator | American Women's History Museum

In 1966 the engineering department had one provided for demonstration.
Probably was the 240-SR with Square Root function

As a team we tried several calculations on this NEW one and our existing mechanical calculator.
Working side by side, looking for ease of use and speed.
All was going well until:
Calculation with one set of numbers gave DIFFERENT answers from the two machines.
Each machine always gave its same answer. Just two calculators giving two different answers.
Pencil and paper yielded same number as the NEW electronic calculator,

Mechanical calculator had a service contract,
Service tech rand several test calculations and declared machine good.

We gave him the numbers for the problem calculation.
His result was the same as we had gotten.
Showed that the NEW electronic gave different answer.
He did pencil and paper - same answer as we had gotten.

Many test calculations and much later, the service tech discovered that the reason for
the machines error was r because of some worn internal part/parts.

 

[DWalt]

The square root function on the Cogito was unusual. It was sort of a brute force calculation. You would enter the number you wanted to find the square root of, then entered a second number you mentally estimated was its approximate square root. Say the number you wanted to take the square root of was 115, you might enter 11 as an approximate square root. It would take your guesswork number as a starting point and perform successive iteration calculations until the correct exact square root was determined. Sort of trial and error. Allegedly, it might take as long as 30 seconds to get an answer depending upon how good your guess was. Using a slide rule would have been far quicker, even if not as precise.