Straight-edge and Compass Construction Kit

http://sciencevsmagic.net/geo/

by lygaret • 13 years ago

57 23 13 years ago

sciencevsmagic.net

anigbrowl• 13 years ago

As a member of the Geometric Cult, I love it, but when my mouse is a dot it's almost impossible to see.

pleion5• 13 years ago

I've rewritten the custom cursor CSS for the grab hand, hopefully it works now.

derleth• 13 years ago

http://en.wikipedia.org/wiki/Compass-and-straightedge_constr...

Things you can't do with this tool:

Squaring the circle: Drawing a square the same area as a given circle.
Doubling the cube: Drawing a cube with twice the volume of a given cube.
Trisecting the angle: Dividing a given angle into three smaller angles all of the same size.

Understanding why we can know that these things are absolutely impossible is an important part of understanding what formal systems mean and, therefore, the philosophy of mathematics as a whole.

OTOH, getting into arguments with people who claim to have solved those problems is a wonderful introduction to what 'crankery' means in a mathematical context.

http://www.nytimes.com/1999/02/09/science/genius-or-gibberis...

http://www.crank.net/maths.html

http://rationalwiki.org/wiki/Pseudomathematics

http://scientopia.org/blogs/goodmath/tag/cantor-crank/

http://meta.math.stackexchange.com/questions/136/how-to-deal...

IanCal• 13 years ago

Trisecting the angle: Dividing a given angle into three smaller angles all of the same size.

Unless you allow an infinite number of steps. The limit of the series 1/2 - 1/4 + 1/8 - 1/16... is 1/3 so you can get to it by repeatedly bisecting angles.

Your paper will look quite messy after an infinite number of steps however.

th0114nd• 13 years ago

AFAICT, it isn't very intuitive on how to get started. Why am I told how to undo and redo, when I'm not told how to do?

AjithAntony• 13 years ago

If the cursor was larger than a single pixel, it would make it easier to guess.

Edit: Tiny cursor in chrome. Firefox looks ok.

pleion5• 13 years ago

Hi, developer here. I'm not sure why it would give you a single pixel cursor. It should use the pointer (when you are over a point) and a grab hand (for when you are over the background).

I've probably done something a stupid way somewhere and it's not working in certain cases. What browser/os are you using?

EDIT: My chrome is okay (windows 7) but I'll check out a few others. Does the cursor always come out tiny or only in place of one of the pointer/grab hand?

siddboots• 13 years ago

Beautiful! I've had a project like this in the back of my mind for a long time. Give me the ability to define macros/subroutines, and this would be the perfect way to study Elements.

Edit: I'm a bit stuck on Circle Pack 4 in 12 moves.

pechay• 13 years ago

A compass tells you where north is. A pair of compasses is used to draw circles.

Zakharov• 13 years ago

I managed to do Circle Pack 7 in one fewer than the minimum: http://sciencevsmagic.net/geo/#0A1.1A0.0L1.1L5.5A1.5L8.0L4.5...

pleion5• 13 years ago

Well Done! As with most elegant solutions, yours is so simple that I can't believe I didn't see it earlier!

The minimum scores are from the simplest solutions I came up with during development, I was waiting for someone to best me.

davnola• 13 years ago

This is so much fun. Thanks!

thetwiceler2• 13 years ago

Somebody construct a 17-gon!

thetwiceler2• 13 years ago

http://sciencevsmagic.net/geo/#0A1.0L1.1L2.2A1.1A2.4L0.7A0.9...

Ahh! Well you can't say I didn't try. Must have accidentally hit one of the wrong points somewhere in the construction...

tfgg• 13 years ago

What does "in origin circle" in the challenges mean? I drew a triangle inside a circle and it didn't seem to recognise it.

DanielStraight• 13 years ago

I was confused at first as well. It means a circle with its center one of the original two points you are given.

At least I thought so... shouldn't this be circle pack 7 in origin circle?

http://sciencevsmagic.net/geo/#0A1.1A0.2A3.4A0.6A1.14A4.5A1....

Not detected as such.

pleion5• 13 years ago

It actually must be a circle with its centre one of the original two points AND the other point on it's edge (so it's one of the two possible first circles you can draw). Sorry that that wasn't clear enough.

jessaustin2• 13 years ago

Possible bug?

http://sciencevsmagic.net/geo/#1A0.0A1.0L1.1L4.0L5.3L2.3A6.2...

Didn't update circle pack 3, 9 moves in origin circle for me. This is the first one I've encountered that doesn't seem to work.

This is really cool!

epsylon• 13 years ago

I just can't construct the damn square in 8 steps : I always need at least 9...

Straight-edge and Compass Construction Kit

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