d2jsp
Log InRegister
d2jsp Forums > Off-Topic > General Chat > Science, Technology & Nature > This Bothers Me More Than It Should
Prev12
Add Reply New Topic New Poll
Member
Posts: 12,729
Joined: May 4 2010
Gold: 2.88
Jan 23 2020 05:22pm
a circle is no real object

just assume reality doesn't exist


Member
Posts: 10,581
Joined: Mar 23 2017
Gold: 12,797.00
Warn: 20%
Jan 23 2020 05:25pm
Quote (Biceps @ Jan 24 2020 12:22am)
a circle is no real object

just assume reality doesn't exist


https://i.pinimg.com/originals/68/eb/ca/68ebca37d8cca1f598dcd42095d96a11.jpg


oh god :lol:
Member
Posts: 64,656
Joined: Oct 25 2006
Gold: 260.11
Jan 23 2020 05:53pm
Quote (Snyft2 @ Jan 23 2020 05:17pm)
it does work, you can draw a circle by chunking a square. imagine you have to draw a circle on a computer screen. you will use little squares because the screen is made of pixels. and using those you can create a circle. observe:

https://www.mathopenref.com/images/constructions/constcirclecenter2/step0.png

see, a circle :cry: ! and if you zoom in, you will see its made of little squares, so why is the total length of the circumference not 4* R but 3.14 * R :unsure: ?



exactly :cry: i need mathematical proof! something is wrong but i dont know what :wacko: !


Because pi R is for a circle. A bunch of pixels dont make a circle
Member
Posts: 1,697
Joined: Mar 16 2009
Gold: 0.00
Jan 24 2020 01:11am
Quote (Snyft2 @ Jan 23 2020 03:17pm)
it does work, you can draw a circle by chunking a square. imagine you have to draw a circle on a computer screen. you will use little squares because the screen is made of pixels. and using those you can create a circle. observe:

https://www.mathopenref.com/images/constructions/constcirclecenter2/step0.png

see, a circle :cry: ! and if you zoom in, you will see its made of little squares, so why is the total length of the circumference not 4* R but 3.14 * R :unsure: ?



exactly :cry: i need mathematical proof! something is wrong but i dont know what :wacko: !


but that is not what a circle conceptually is.
Member
Posts: 104
Joined: Jan 10 2020
Gold: 1,872.00
Feb 6 2020 09:49am
Quote (Snyft2 @ Jan 23 2020 04:17pm)
it does work, you can draw a circle by chunking a square. imagine you have to draw a circle on a computer screen. you will use little squares because the screen is made of pixels. and using those you can create a circle. observe:

https://www.mathopenref.com/images/constructions/constcirclecenter2/step0.png

see, a circle :cry: ! and if you zoom in, you will see its made of little squares, so why is the total length of the circumference not 4* R but 3.14 * R :unsure: ?



exactly :cry: i need mathematical proof! something is wrong but i dont know what :wacko: !


The key to this problem is to realize it doesn't matter how closely / many times we approximate the circle by chipping away (you'd still have wedged corners), the orthogonal lines of the approximation formed by inverting the square corners will never be tangential to the circle. You need to think conceptually, as everything on the computer screen is pixelated (i.e: made out of tiny squares). Obviously the higher resolution screen will have more "believable" circle, but it's still made out of pixels :P I remember somebody in my undergrad calculus class asking the same question to the prof and he did manage to explain it - although I didn't really pay attention / cared enough to listen lol.
Member
Posts: 90,631
Joined: Dec 31 2007
Gold: 2,489.69
Feb 6 2020 01:24pm
here's the easiest way to see how this is wrong

the distance from the center of the circle to the quadrant straight in a cardinal direction = .5

the distance to 1 corner of the square = > .5

so "taking off squares" will never get you to the profile of the circle.
Go Back To Science, Technology & Nature Topic List
Prev12
Add Reply New Topic New Poll