I'm looking for a textual version of a2
that is as old as possible, among all the Greek sources. [more inside]
posted by benito.strauss
on May 12, 2014 -
Wizards of Hive,
Before I buy that 90" couch from a friend, how can I make sure I'll be able to get it up my L-shaped stairs? Sure, there are a lot of variables. But is there a tool or methodology for figuring this out ahead of time (presuming I know the depth and height of the couch too)? I don't think I have the cardboard to build a mockup.
This couch is 50 miles away and can't be returned. Thanks!
posted by baseballpajamas
on Aug 21, 2013 -
I'm drawing/painting a globe (in time lapse, so the sun appears to rise) and trying to figure out what shape, exactly, the longitude (not latitude) lines are when a globe is flattened into a circle (I know I can just trace them, but I've gotten curious). So, the outermost longitude lines are tangent to the circle, they are half-circles, and the centermost line is a straight line from pole to pole, it's the progressively flatter curves in between that I'm trying to figure out. Do they have a name? Are they catenaries? Are they the curves of progressively larger circles? How do I construct them (easily)? Example image: HERE
posted by sexyrobot
on Jul 26, 2013 -
Here’s a simple computational geometry problem. I am trying to figure out the value at an point of two line segments based off of the values at both of one of the segment’s endpoints.
The problem is that I don’t exactly know the best
way of going about finding the value at one of those points.
Here is a reference figure
(X_C, YC) = F_C
(X_D, YD) = F_D
How can I calculate the value of F_E, where F_E = (X_E, Y_E), where E is the point on the segment CD, where CD intersects with the line AB?
(Extraneous details inside) [more inside]
posted by oceanjesse
on Dec 5, 2012 -
Calling geographers: has anyone applied the idea of topological prominence to population density? [more inside]
posted by miyabo
on Apr 27, 2012 -
I'm looking for an awesome video/discussion topic that relates to street maps - something appropriate for a HS geometry course. [more inside]
posted by ch3cooh
on Jan 3, 2012 -
. What was it? Is it still online? [more inside]
posted by rivenwanderer
on Jan 3, 2012 -
Consider two rings that are intertwined. (These lie in 3-dimensional space, but when you draw it on paper it looks like a venn diagram.) In 3-dimensional space they cannot be unlinked. The questions is, if you had one more dimension, can you unlink them?
posted by gzimmer
on Jul 15, 2011 -
I'd like to be able to watch the Macy's fireworks from my dad's roof on the Upper West Side. How can I figure out if I'll be able to see them? I have some variables, heights, distances, and video... [more inside]
posted by thebazilist
on Jul 1, 2011 -
I'm writing a graphics app where I'm generating a simple gear transmission system with a variable number of gears each with variable number of teeth and placed at random orbits around each other. I generate gears in succession, placing and rotating each with respect to its parent/driver gear before moving on to the next. The problem I'm having is how to determine the initial orientation of each subsequent gear such that its teeth are properly meshed with that of its driver. [more inside]
posted by Epsilon-minus semi moron
on Oct 25, 2010 -
MathFilter: Is there a relationship between the number of dimensions in a Euclidean space and the number of regular tessellations of that space? [more inside]
posted by jedicus
on May 2, 2010 -
Math filter: How many equally sized rectangles will fit into a circle, and how should I arrange them in order to make the best-looking approximation? [more inside]
posted by brandnew
on Aug 17, 2008 -
My geometry teacher in high school in 1984 showed us this puzzle.
I was only half paying attention, but I believe the goal was to draw a line that intersected each segment only once. [more inside]
posted by mecran01
on Jan 6, 2008 -
Vector Geometry Filter: I'm working in matlab and need to transform a surface to match an arbitrary angle. I have the unit vector of the new normal (and the original normal is in the Z axis (0 0 1))...however i'm not sure how to rotate one normal to another (i know, i know, it sounds very simple really...) [more inside]
posted by NGnerd
on Oct 23, 2006 -
My room has an angled ceiling. I have measured its height at the highest and lowest points, and I have the dimensions of the room. Help me determine what height the ceiling is at a particular point on the floor, and where exactly the skylight is. [more inside]
posted by xo
on May 23, 2006 -
Programming/geometry: in a Flash program (you don't need to know Flash to answer this), I'm trying to place rectangular images at random positions on the screen. There are already images on the screen. I need to make sure that the new, randomly-placed images don't obscure the images already there. [more inside]
posted by grumblebee
on Sep 29, 2005 -
Is there a specific name for a rectangle which, if you divide it in half, the two halves have the same proportions as the original rectangle? [more inside]
posted by e-man
on Sep 27, 2005 -
I have a circular patio table with four legs. The paving stones are uneven, so it has always been difficult to set the table in place so it doesn't wobble. I move it regularly, since the shadows from the trees change, and sometimes I want shade, other times sun. I used to mark small dots on the stones so I could set it down quickly. Then I discovered something very interesting--no matter where I put the table, if I simply rotate it around its center, I can very quickly find a steady configuration. But move it from place to place, and it takes all day.
This is like the four color map theorem. It works every time, but I haven't figured out why. It might even be tricky to put this into a mathematical format. The table doesn't need to be level, and all four legs needn't be the same height or "at" the same height. The table just can't wobble.
posted by weapons-grade pandemonium
on Mar 10, 2005 -
What do you call those three-dimensional geometric novelties, consisting of eight cubes, joined to each other at one edge to form one large cube, whose pieces can be flipped around to display different images on the exterior of the large cube? What is the history of this delightful object? What are the geometric priniciples behind it?
posted by Faze
on Jan 20, 2005 -
I read Edwin A. Abbott's Flatland this weekend and really enjoyed its fiction and speculative geometry/mathematics. I guess the logical next step would be to read the unofficial sequel, Flatterland, but can any of you recommend other books that similarly twist math and fiction, or just books that explain mathematical concepts or theories to laymen such as myself in ways that are entertaining to read?
posted by Evstar
on Jan 3, 2005 -