Author |
Topic: Photo quiz (Read 4263 times) |
|
Benny
Uberpuzzler
Gender: 
Posts: 1024
|
Do you think this relates to a Fib sequence or to something else?
The beginning of an exponential sequence?
The beginning of a polynomial sequence?
Something else?
|
| « Last Edit: Sep 20th, 2010, 2:55pm by Benny » |
 IP Logged |
If we want to understand our world or how to change it we must first understand the rational choices that shape it.
|
|
|
Noke Lieu
Uberpuzzler
pen... paper... let's go! (and bit of plastic)
Gender:
Posts: 1884
|
 |
Re: Fibonacci sequence or not?
« Reply #1 on: Sep 20th, 2010, 12:10am » |
 Quote  Modify
|
Either way, it's awesome!
|
|
IP Logged |
a shade of wit and the art of farce.
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Fibonacci sequence or not?
« Reply #2 on: Sep 20th, 2010, 2:03am » |
Quote Modify
|
Here's the approximate numerical sequence (pixel x-coordinates): 35, 43, 55, 70, 85, 107, 127, 157, 191, 235, 283, 382, 574
If we discard the last pigeon, exponential fits slightly better than quadratic; including the last pigeon neither fit very well.
Best fit is a twelve degree polynomial 
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
Benny
Uberpuzzler
Gender:
Posts: 1024
|
|
Re: Photo quiz
« Reply #3 on: Sep 20th, 2010, 2:57pm » |
Quote Modify
|
Okay, towr.
Here's another photo quiz: a parabola or a hyperbola?
http://maa.org/FoundMath/10week37.html
|
|
IP Logged |
If we want to understand our world or how to change it we must first understand the rational choices that shape it.
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Photo quiz
« Reply #4 on: Sep 20th, 2010, 3:07pm » |
Quote Modify
|
I'd go with elipse.
Although it might be something else still. But assuming it is a circle in perspective (it does say it's a circular overpass, after all), then it is not a parabola or hyperbola (it should be a closed curve ... probably).
|
| « Last Edit: Sep 20th, 2010, 3:13pm by towr » |
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Photo quiz
« Reply #5 on: Sep 23rd, 2010, 2:48pm » |
Quote Modify
|
Any true* perspective projection of a circle gives a conic (circle, ellipse, parabola or hyperbola). The curve is not closed if the circle passes behind the camera.
The one on the picture looks like a hyperbola.
*A fish-eye lens would not produce a true projection as it does not preserve straight lines. It would give other curves.
|
|
IP Logged |
|
|
|
Benny
Uberpuzzler
Gender:
Posts: 1024
|
|
Re: Photo quiz
« Reply #6 on: Sep 25th, 2010, 2:47pm » |
Quote Modify
|
on Sep 23rd, 2010, 2:48pm, Grimbal wrote:
The one on the picture looks like a hyperbola.
|
|
So, it could be a parabola.
What's the one thing we would need in the photo to make it....
(a) a hyperbola, or
(b) a parabola
Quote:
*A fish-eye lens would not produce a true projection as it does not preserve straight lines. It would give other curves. |
|
|
|
IP Logged |
If we want to understand our world or how to change it we must first understand the rational choices that shape it.
|
|
|
Benny
Uberpuzzler
Gender:
Posts: 1024
|
|
Re: Photo quiz
« Reply #7 on: Oct 8th, 2010, 1:46pm » |
Quote Modify
|
How to Slice a Bagel into Two Linked Halves
Topology problem: Modify the cut so the cutting surface is a one-twist Mobius strip.
(You can still get cream cheese into the cut, but it doesn't separate into two parts.)
Calculus problem: What is the ratio of the surface area of this linked cut to the surface area of the usual planar bagel slice?
|
|
IP Logged |
If we want to understand our world or how to change it we must first understand the rational choices that shape it.
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print