[SquarishTriangle (OP)]

Not a lot of things in nature have perfectly straight line edges.

So, does anyone know or have any ideas on how the first template for a straight line (eg. a ruler of some sort) would have been produced, in order for other straight lines to be made from it?
And how would someone evaluate if what they had made really was straight?
How would you go about doing it if straight objects did not yet exist, and you were responsible for creating one?

What I was thinking, involved hanging a weight on a piece or string and somehow going from there...but that's as far as I got. Any ideas?

[paul.fr]

good question, squarish. I dont know the exact first straight line, but these links are quite informative and interesting.

http://kmoddl.library.cornell.edu/tutorials/04/
http://www.worthingtonsharpe.com/Mechanisms.htm
http://historical.library.cornell.edu/cgi-bin/cul.math/docviewer?did=Kemp009&seq=5

your idea of a weighted string, is used already, it is called a plumb line. have you ever watched a brick layer at work? they use a line to keep their bricks level. a tiler will use a line coated in chalk, pull the line, let go and this leaves a chalk line in the wall.

one of my other jobs, was that of a foreman joiner. we used squares and premade straight edges of metal, also you eventually can look down a length of timber (with experiance) and tell if it has a straight edge.

another way to make a straight line on a piece of timber without using rulers or suchlike, is:

assuming you have a straight edge, hold a pencil between your thumb and finger at an angle. then just run the pencil tip down the wood, this gives a lovely straight line.

[Bored chemist]

Well, I know part of the answer for the next dimension up.
The same problem happens with flat plates- how do you know if you have something truly flat?
The answer is that you get 3 roughly flat plates and gring them repeatedly against one another.
With just 2 plates you could grind them to fit together but they might be curved- parts of the surface of a sphere. But if you have 3 and any pair fit together in any combination then they must all be flat.

[kdlynn]

you said something about the first device used to make the first straight line... but wouldn't the thing you were tracing actually be the first straight line?

[Karen W.]

That is a good point!

[another_someone]

Not a lot of things in nature have perfectly straight line edges.

I would suggest that in nature there is nothing that ever absolutely matches a simple geometric shape; so there is nothing that ever matches an exact straight line.

Th only relevant question would be what was the first technology to draw a line of a given length that does not deviate from a theoretical straight line by more than a given amount.

A lot depends on how long you are looking to project the line.  Roman roads were fairly straight, if one is judging on a fairly large area, but on a small scale, they would be far less straight than the line you could draw by simply running a pencil along the side of a tout string (but nobody was using strings that were hundreds of kilometres long).  At an even smaller scale, you can get a very straight line along the edge of a crystal (depending on the crystal you are using).

[dentstudent]

Not a lot of things in nature have perfectly straight line edges.

I would suggest that in nature there is nothing that ever absolutely matches a simple geometric shape; so there is nothing that ever matches an exact straight line.

What about rays of light from the sun? If you look at light passing through a forest canopy, for example, the rays look like crepuscular rays through clouds, and would be as near to parallel as would make little difference (though how to draw them?).

[dentstudent]

How about this?

http://staff.science.uva.nl/%7Eleo/cinderella/peaucellier.html

It's similar to Paul's http://www.worthingtonsharpe.com/Mechanisms.htm, but perhaps a bit clearer.

[Karen W.]

How about a simple hair stretched out between two fingers!

[ukmicky]

who is     Thales of Miletus   []

[Karen W.]

Here is a link! Seems he was a
Greek Philosopher and Scientist Born in 624 BC in Miletus Asia Minor now (Turkey)! Died in 346 BC in Miletos, Turkey.
Was somewhat of a mathematician..

[ukmicky]

Here is a link! Seems he was a
Greek Philosopher and Scientist Born in 624 BC in Miletus Asia Minor now (Turkey)! Died in 346 BC in Miletos, Turkey.
Was somewhat of a mathematician..

Thales was probably the first known scientist and engineer and is known for his advanced application of geometry which requires straight lines.


The Romans were also good at creating long straight lines they used a device called a gromer for creating long and very straight roads.

Ps Karen
According to your dates above Thales lived to a ripe old age of 278   [:I] []

[Karen W.]

Here is a link! Seems he was a
Greek Philosopher and Scientist Born in 624 BC in Miletus Asia Minor now (Turkey)! Died in 346 BC in Miletos, Turkey.
Was somewhat of a mathematician..

Thales was probably the first known scientist and engineer and is known for his advanced application of geometry which requires straight lines.


The Romans were also good at creating long straight lines they used a device called a gromer for creating long and very straight roads.

Ps Karen
According to your dates above Thales lived to a ripe old age of 278   [:I] []

LOL... And this internet Encyclopedia of philosophy says 62?E to 546BCE And that the ates are debatable!! LOL BUt here is the link.. I find it all amusing..

http://www.utm.edu/research/iep/t/thales.htm

So michael.. how old does this link make him! lol! THE OTHER LINK DEFINELY SITED THE OTHER DATES.. hee hee hee hee  lETS SEE... lol......HMMMMMM....ABOUT 78 YEARS OLD... I BET I MADE A TYPO EH MICHAEL!!!!! lol Thanks for the catch.. I better find that other link! LOL

[Pumblechook]

Stretched bit of spiders web.

[Don_1]

The ancient Egyptians used water to level ground prior to building. A mudbrick wall constructed around the area to be developed was filled with water. Anything protruding above the water would be removed. This went on over a number of lowering water levels until the whole ground was flat.

[Bored chemist]

A piece of folded paper or leaf? If it was paper, perhaps it was the original death certificate of this thread. November 1 is a day late for necromancy.

[Make it Lady]

The line was originally bent but it met up with some religious fundamentalists and they soon straighted it out.

[Don_1]

The line was originally bent but it met up with some religious fundamentalists and they soon straighted it out.

Judging by the Revelations of some 'religious' individuals, I would say you may have this arse-about-face, that the line was straight until it was found by the religious, who bent it!!!

[lyner]

Making the first straight edge was one thing - how do you think they cut the first high quality thread to make a thread cutting lathe?
I read that it involved taking the pith.

[yor_on]

quiz:

What differs a fundament from a fundamentalist?