Naked Science Forum

On the Lighter Side => Famous Scientists, Doctors and Inventors => Topic started by: SquarishTriangle on 14/06/2007 09:30:57

Title: How was the first straight line made?
Post by: SquarishTriangle on 14/06/2007 09:30:57
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?
Title: How was the first straight line made?
Post by: paul.fr on 14/06/2007 10:10:39
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.
Title: How was the first straight line made?
Post by: Bored chemist on 14/06/2007 19:19:55
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.
Title: How was the first straight line made?
Post by: kdlynn on 14/06/2007 19:58:21
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?
Title: How was the first straight line made?
Post by: Karen W. on 15/06/2007 00:48:57
That is a good point!
Title: How was the first straight line made?
Post by: another_someone on 15/06/2007 10:55:35
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).
Title: How was the first straight line made?
Post by: dentstudent on 15/06/2007 11:07:57
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?).
Title: How was the first straight line made?
Post by: dentstudent on 15/06/2007 12:34:30
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.
Title: How was the first straight line made?
Post by: Karen W. on 16/06/2007 11:20:45
How about a simple hair stretched out between two fingers!
Title: How was the first straight line made?
Post by: ukmicky on 19/06/2007 18:44:03
who is     Thales of Miletus   [:)]
Title: How was the first straight line made?
Post by: Karen W. on 19/06/2007 22:18:30
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..
Title: How was the first straight line made?
Post by: ukmicky on 21/06/2007 14:38:52
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] [;D]
Title: How was the first straight line made?
Post by: Karen W. on 24/06/2007 22:04:05
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] [;D]


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
Title: How was the first straight line made?
Post by: Pumblechook on 01/11/2008 18:16:32
Stretched bit of spiders web.
Title: How was the first straight line made?
Post by: Don_1 on 03/11/2008 13:17:15
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.
Title: How was the first straight line made?
Post by: Bored chemist on 03/11/2008 19:38:23
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.
Title: How was the first straight line made?
Post by: Make it Lady on 03/11/2008 22:34:01
The line was originally bent but it met up with some religious fundamentalists and they soon straighted it out.
Title: How was the first straight line made?
Post by: Don_1 on 04/11/2008 08:11:21
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!!!
Title: How was the first straight line made?
Post by: lyner on 14/11/2008 00:00:40
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.
Title: How was the first straight line made?
Post by: yor_on on 30/01/2009 13:39:22
quiz:

What differs a fundament from a fundamentalist?
Title: How was the first straight line made?
Post by: yor_on on 30/01/2009 18:09:07
A firm foundation
Title: How was the first straight line made?
Post by: Chemistry4me on 31/01/2009 07:31:43
You didn't give me a chance to answer [:(][:(]