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Hollister (Hop) David
P. O. Box 39, Ajo, Arizona 85321
520-387-7688
hopd@cunews.info
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| Kickstarter for my new coloring book An opportunity to pre-order my new coloring book looking at conic sections, Kepler's laws, the Oberth Effect, Hohmann Transfers, Tsiolkovsky's rocket equation and other stuff related to going to space. Coloring book is $5 plus $5 shipping and handling ($10 shipping and handling if you are outside the U.S.) Hopefully this Kickstarter will help finance printing of this book. Kickstarter ends 4:30 a.m. April 13, 2020 |
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For prints of my drawings and paintings:
Hop's Prints
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Dandelin Spheres
A study of conic sections
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Specific Angular Momentum as a Bivector
A little Clifford Algebra
Asteroid Towns
Colonizing the asteroids
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Spiral Tessellations
Spiral Tessellations and a Helicoid
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Kepler Fractals
Some Koch like fractals based on Kepler's polyhedra
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Perspective Study
Including some of M. C. Escher's observations
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Curl Ups
An essay on Escher's invented animal
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Frank Zubek's Construction Blocks
Frank's Elusive Cube
Moiré Patterns
Ellipses & hyperbolas
Parabolas
Eccentricity of Conics
Circles?
Drawings of Numbers
Coefficients of (a+b)^n
ln(2)
pi/4
2/3
(pi^2)/12
Escher
Sphere Spirals
Drawings of Equations
cos(a+b)=cos(a)cos(b) - sin(a)sin(b)
& sin(a+b)=cos(a)sin(b) + cos(b)sin(a)
sin(h)/h approaches 1 as h approaches 0
(a+b)^2
= a^2 + 2ab + b^2 & (b-a)^2
= a^2 - 2ab + b^2
Angles of a
triangle total 180 degrees
Pythagorean Theorem
Areas of plane geometry figures (circle, triangle, parallelogram, rectangle)
Paper Blackhole Models
http://clowder.net/hop/etc./wormhol2.html
Quadpods
Tetrahedral Spaceships
An interesting curve
& now I know it's name
Tiles
The
Table Top Tessellations
17 Wallpaper Groups
Twistohedra
A family of polyhedra
starting with the icosohedron
Making Polyhedra with Soda Straws
Mike Patten's inexpensive and easy method of making polyhedral models
Jacob Goff
Paintings by Jacob Goff
Jacob's My Space Page
Me
A pic of my daughters & I
(taken by William Chow)
My family and the Chow family
e-mail hopspage@tabletoptelephone.com
Hop David
P. O. Box 39, Ajo, Arizona 85321
520-387-7688
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