What do slide rules and gunshows have in common?

[jmike314]

Grandfather was a math professor...got his slides rules when he passed. One still has the instructions. Definitely significant pieces of history as far as I'm concerned.

Heck...most kids have never seen/heard of rotary phones or black & white TV...let alone lived life without the internet, cellphones, or microwave ovens.

 

[stick4]

Ever seen a round one? That's the one my Dad used when at OSU after WWII.

 

[Pulp]

For sure they are primitive by today's standards, but we went to the moon and back on slide rule technology, so they must be pretty good.

 

[SPDguns]

HAHA. I used a ROUND slide rule in college. I got it from my dad.

 

[Dave70968]

Anybody who's a pilot has used a version of a circular slide rule in the form of the E6B flight computer. I have three of them within reach on my desk right now, plus the one on my watch.

Learn to use them, and they really are pretty slick. Very fast, and they enforce sanity checking upon you in a way that electronic gizmos can't; you have to develop a back-of-the-envelope knowledge of what the answer ought to be to use one. Such knowledge allows you to easily detect errors like, say, mixing your standard and metric units. Hey, Mars Rover Team, you listening?

 

[p238shooter]

I guess some of the posters here do not remember the "computers" we used to do all the calculations involved with our early space program including the ability to do the calculations to put the first man on the moon.

All the calculations were done with the Pickett brand slide rules. The US Government had the most advanced models that were made out of aluminum rather than wood for increased accuracy, which were not shared with the public or the rest of the world until later. Most of them less than 16 inches long.

Slide rules were the standard like the abacus in its day, very accurate and very reliable, not subject to computer glitches and power failures. I had one of the first Texas Instrument LED calculators in 1973-4 or so, poor substitute, but a neat toy, made me feel high tech, but did not give me any better accuracy for what I needed. 9V battery lasted about 2 hours.

As the previous poster noted the E6B circular slide rule flight computer was used for planning virtually all aircraft flights both commercial and all military for flights before about 1975 or so. No pilot ever left the ground without his E6B and would admit he did, like forgetting to put your pants on. It was and still is an essential flight tool for many of us. Before other means of navigation and GPS, it was a crucial flight tool. It is still used today by people who have knowledge of what can happen if your batteries or power systems fail. I have one in my flight bag for my personal aircraft. I do not leave home without it.

The E6B is a compact circular slide rule that is a full functional slide rule unit that has additional markings to facilitate quick aviation calculations, fuel burn, distance/time at certain air speeds, density altitude, etc., with an additional piece of metal that is used to figure the wind correction angle to figure how much you will likely be "blown off course", but down deep, it is just a compact circular slide rule.

For the OP, there is a "mini pocket" E6B still available from pilot shops that will do anything any slide rule will do that will easily fit into your shirt pocket, especially if you remove the wind correction addition piece if you get tired of the long stick version being in your brief case or slapping you on the leg with the clip like I had in high school.

Caution, slide rules are not advised for people that want to multiply, divide, square or square root if you can not reason that the logical answer would be 80, 800, 8000, or 8,000,000. To use it, its function presumes you have some common sense of what you are trying to calculate.

I use a torque wrench, but I have not lost the ability to feel if I think it is tight enough or not, and sometimes give it a little more after the click. Never had a bolt vibrate out, but have twisted a few rejects off during assembly.

 

[dennishoddy]

For sure they are primitive by today's standards, but we went to the moon and back on slide rule technology, so they must be pretty good.

The computers used on the moon landings were not equal to the computing power of $20 calculaters at walmart.

Imagine taking that journey with that as the thing that will save your life? Those guys were badass!

 

[p238shooter]

Wifey's uncle designed their space suits to jump around on the moon, head of the engineering dept. Slide rule was his method of computation.

 

[p238shooter]

The computers used on the moon landings were not equal to the computing power of $20 calculaters at walmart.

Imagine taking that journey with that as the thing that will save your life? Those guys were badass!

There is a term in hot roding, run what you brung. Meaning do the best you can with what you have at the time. Interestingly, we do not have the money or technology to go to the moon again. Something seems wrong here, wonder what? Dumming down comes to mind.

 

[SoonerP226]

I use a torque wrench, but I have not lost the ability to feel if I think it is tight enough or not, and sometimes give it a little more after the click. Never had a bolt vibrate out, but have twisted a few rejects off during assembly.

My dad told me that the point of a torque wrench wasn't to make sure the fastener was tight, but to make sure it wasn't over-tightened...