593 reputation
212
bio website
location
age
visits member for 3 years, 6 months
seen Apr 11 at 15:29

Sep
7
comment Map Earth surface so straight line distance is great circle distance?
OK, I see it now. Because the distance from the North Pole to the equator must be EXACTLY 1/2 the distance from the North Pole to the South Pole, the entire equator must map to one point, which obviously doesn't work. This also shows you can't do it within a specified tolerance.
Sep
7
revised Map Earth surface so straight line distance is great circle distance?
sines and cosines as part of mapping
Sep
7
comment Map Earth surface so straight line distance is great circle distance?
More symbols, please. Or, better still, could you pick 3-4 specific points and show why this would be impossible? I think the proof you give works even for the straight line distance between two points on Earth, and it's obviously possible to map those in R^3
Sep
7
comment Map Earth surface so straight line distance is great circle distance?
OK, but doesn't the equator just have to map to a set of points equidistant from the poles? It doesn't have to map to the midpoint of the poles?
Sep
7
comment Map Earth surface so straight line distance is great circle distance?
First answer: but what about the Earth in 3-D. Every point on the equator is equidistant from the poles, no? In 2D this would be the perpendicular bisector. In 3D, it's a plane. In n dimensions, it's an n-1 dimensional surface, no? Second answer: what if I wanted to specify the tolerance. Is there always an 'n' that satisfies for a given tolerance?
Sep
7
asked Simple formulas rotating Earth around xyz axes?
Sep
7
asked Map Earth surface so straight line distance is great circle distance?
Sep
6
answered Why do you add +1 in counting test questions?
Aug
31
comment Inquiries around a new number system
Also octonions which have 7 imaginary units, but aren't associative.
Aug
31
comment What shape does a piece of paper make when it is pushed from the edges?
This looks like an inverse catenary to me, but I could be wrong.
Aug
26
comment How do I estimate log10 of log10 of 8 billionth element of A000670?
I'd like to get it to the nearest integer at least. When you say "use Stirling on your upper bound", could you be more explicit? I assume you're referring to a Stirling approximation, but wasn't sure. Also, are the "&E9" supposed to be "8E9" referring to 8 billion? Sorry, no offense intended, just a little hard to read your post.
Aug
26
comment How do I estimate log10 of log10 of 8 billionth element of A000670?
@RossMillikan You are correct, it's (2^n)*n!, but wouldn't that be implied by order of operations anyway?
Aug
26
asked How do I estimate log10 of log10 of 8 billionth element of A000670?
Aug
4
comment Comparing the “sizes” of square roots.
Estimating Sqrt[5] as 9/4 works (once you confirm the approximation is within 1/8 of the true value).
May
14
revised Parametric Equation for Great Circle
corrected
May
13
comment Finding a third coordinate on a sphere that is equidistant from two known coordinates
This question still confuses me. Are you saying the distance of the third point from the other two points is a parameter to problem, or that you want the third point's distance from either point to be equal to the distance between the original two points (ie, the equilateral solution suggested below)?
May
13
answered Parametric Equation for Great Circle
Apr
16
revised Domino's thin crust slicing area sans calculus (circle in squares)
added correct guide
Apr
16
comment Domino's thin crust slicing area sans calculus (circle in squares)
OK, I got it. For some reason, I was looking for right triangles with dimension 1-2-Sqrt[5], which have no superspecial properties.
Apr
16
accepted Domino's thin crust slicing area sans calculus (circle in squares)