Obviously in this day and age we are surrounded by examples of straight lines e.g rulers. But how did we get the first one?
2007-01-23 01:44:21 · 10 answers · asked by grokebag 1 in Science & Mathematics ➔ Engineering
First, he learned how to spell 'straight'.
2007-01-23 01:48:16 · answer #1 · answered by $Sun King$ 7 · 0⤊ 0⤋
The key word in your question is "exactly." Man got the first "exactly straight line" in his imagination - and it's still just a concept to this day. All bets went out the window when classical mechanics was displaced by relativity.
Even a laser beam bends toward the earth in an arc equal to a circle with a diameter of one light year due to the earth's gravity.
Terms such as "point", "plain" and "straight line" are concepts used, very effectively, in Euclidean geometry and we really don't find them in reality.
Obviously, a taut string, a plumb bob or laser markers are exceedingly "straight" enough for even the most complex construction or manufacturing projects in practice - but when we endeavor to travel great distances in space, the concept of "straight lines" becomes moot - even for a light beam.
2007-01-23 10:06:35 · answer #2 · answered by LeAnne 7 · 0⤊ 0⤋
There is no true straight edge, and a "ruler" is a king or queen, there is a straight edge on a rule, but that is as near possibly most people want to get.
A plumb line is a good example using simple non technical equipment, or as we all know that a straight line is the shortest distance between two points, so using a piece of string tight between two points should give you a reasonable answer, you have to ignore such things as the curvature of the earth and the effects of gravity
2007-01-23 09:56:48 · answer #3 · answered by ArskElvis 3 · 0⤊ 0⤋
We never have had a true straight line as the surface of the earth is curved
It is assumed that the neccessity arose from early building practice when blocks had to be standerd to fit.This gave frames to mould the mud blocks and straight edges became inportant
2007-01-23 10:00:51 · answer #4 · answered by aburobroy 2 · 0⤊ 0⤋
By elongated shadows of the things at the time closer to sun set or after sun rise.
Or by stretching a thin/long root of a tree, using it as a thread.
Or the people with good control on their hand and brain coordination, can draw a good straight line.
Or by grinding a stone on a smooth surface.
2007-01-24 04:58:37 · answer #5 · answered by Ishfaq A 3 · 0⤊ 0⤋
Men invented it. For millennia certain things could not be measured, and men did not know who was best. But then some bright spark said: "Uhg UG HU UG = UGHUGUU!!!"
Which means, "why don't we use a straight line like this one with standard units of measurement along the side".
Which of course led to modern civilisation and laser guided volumetric assessments etc.
2007-01-23 09:57:27 · answer #6 · answered by mince42 4 · 0⤊ 0⤋
Any string held taunt is a straight line. It doesn't need to be on a vertical line. A beam of light is also very straight if held to a low angular dispersion.
2007-01-23 10:03:42 · answer #7 · answered by Gene 7 · 0⤊ 0⤋
Stick 3 sticks in line in the ground.
Walk away and move the middle one so you can only see one stick.
Result one straight line.
2007-01-24 06:24:11 · answer #8 · answered by Anonymous · 0⤊ 0⤋
He just got a piece of linen thread and stretched it between two points. The phrase "stretched linen", or in Old English "streht linen", gives us "straight line" in Modern English.
2007-01-27 07:49:16 · answer #9 · answered by Anonymous · 0⤊ 0⤋
Wow...that questions a plum, Bob!
Hang a weight from a piece of string/twine and what have you got?
There's your answer!
2007-01-23 09:52:43 · answer #10 · answered by Jimbobarino 4 · 0⤊ 0⤋