Mathematics and bushcraft
- Thread starter rich59
- Start date
xylaria
Bushcrafter (boy, I've got a lot to say!)
Greg said:
Does to me too. Tipis benders archery etc were all developed without the use of Pythagoras or Newton. My first posting read like an exam question. Good on ESpy to able remember anything of what you learn in school, because IMHO most of it is pretty useless, therefore thats why it is forgotten. The human brain/eye is very good at guessing things like tradjectory and distance, esspecially when combined with experiance. I do enjoy the odd bit of mathmatics though.
xylaria said:
xylaria as an example we need a few more dimensions, but if I work off 7 feet high and a radius of 7 feet this is what I get;
Conversion from feet to metric I did like this.
7*12= total inches
total inches * 2.54= centimeters
Centimeters / 100= meters
This is the working for area.
Radius=2.1336 meters
Radius squared =4.55224896
Pi (R*R) = 14.30131189
Slant= Square root of (square of height + square of radius)
Slant=3.01736605668
Pi R S=20.2551092346
(Pi (R*R)) + (Pi R Slant) =34.5264211246
That's the end in metric, but working out panel widths along with everything else will mean that you will require a considerably larger amount than this in total as you are going to have to allow for wasteage.
xylaria
Bushcrafter (boy, I've got a lot to say!)
leon-1 said:
Therefore demostrating in the most elegant of mathematical ways why benders are easier to make:
1)Domes waste less fabric.
2)The maths is easier.
3)A 7ft radius Tipi requires 22 ft lodge poles, and benders require 6d (more old money!) withies.
4)Tescos have a 1.5m radius nylon 'play parachute' on sale for tenner, a squirt of fabsil and I can practise bender building.
Greg said:I wonder if the North American Indians worked it out like that?
Probably not, but then they did not buy materials at widths of 93 or 186cms and by the meter.
On the other hand they would have a pretty good idea on judgeing by eye, they would of known that the average elk would yield about 20 feet of hide and that approx 7 - 10 hides would probably cover an area this size (this being a relatively small tipi and not quite tall enough to be honest
).
leon-1 said:Probably not, but then they did not buy materials at widths of 93 or 186cms and by the meter.
On the other hand they would have a pretty good idea on judgeing by eye, they would of known that the average elk would yield about 20 feet of hide and that approx 7 - 10 hides would probably cover an area this size (this being a relatively small tipi and not quite tall enough to be honest
You too Clever for me!!
Thanks Stuart for the links.rich59 said:
Having now been out atlatling round a farm with mock up animals I worked out the following:-
As you creep towards your prey - stop. Measure something constant and close to your prey against your outstretched thumb (or better a ruler) "A". Then creep forward a number of paces (10 is convienient). Then take the measure again "B". It should have got bigger against your thumb or ruler.
With experience or a calculator you can now calculate exactly how far you now have to go to the target compared to how far you have just moved forward
Distance = paces moved forwards [e.g. 10] / ( B / A - 1 )
Plotting graphs is maths - without equations sometimes.
While practicing different distances for atlatl throwing I recorded the elevations of the dart above the straight line to the target needed to hit the target (well try to!). The elevations were recorded as centimetres as seen on a ruler held by my outstretched arm. For instance for one atlatl and dart pair I found:-
10 metres....0 cm elevation
15 metres....4 cm elevation
20 metres....14 cm elevation
and so on
Then I plotted a graph (looked a bit like an exponential curve) and could then read off the predicted elevations needed for other distances as encountered in a field shoot.
While practicing different distances for atlatl throwing I recorded the elevations of the dart above the straight line to the target needed to hit the target (well try to!). The elevations were recorded as centimetres as seen on a ruler held by my outstretched arm. For instance for one atlatl and dart pair I found:-
10 metres....0 cm elevation
15 metres....4 cm elevation
20 metres....14 cm elevation
and so on
Then I plotted a graph (looked a bit like an exponential curve) and could then read off the predicted elevations needed for other distances as encountered in a field shoot.
K
katiestone
Guest
rich59 said:
Effectively you were calculating basic trajectories for an object thrown from a set position. Throwing the Atlatl from diferent positions, crouching, kneeling and sitting will change the elevation of the cast, this should allow you to determine the relative drop at shorter ranges, ie;
Sitting it is 5 meters.
kneeling it is 7 meters.
Crouching is 8.5 meters.
You could also probably estimate the velocity of the dart and given a known weight of the dart could work out a number of other things.
rich59 said:
I'd say there is a major flaw here. Missing the mammoth isn't the problem upsetting it is. In which case the maths is am I too close to get away when the wounded and annoyed beast turns on me?
rich59 said:
I would have asked the guy out jogging in the African safari park recently about elephants, but he got trampled so was too close.
Wild boar? I'd guess it depends just how wild it is. If you've just grazed it with an arrow it could be pretty wild but they don't climb very well so I'd say 6' up something stout should do. If you take the precaution of standing by a suitable tree before letting the arrow go, and prestashing sandwiches and drink up the aforementioned tree, I'd say 6 seconds to drop bow and remaining arrows and to ascend to join sandwiches. Only a guess though, maybe more if fear has tightened your sphincter to paralysis levels.
Not much chance of coming across a mammoth unless it is a very big and wild boar.
