Skip to main content
Recently I helped Luke's classmates make geodesic domes out of newspaper, using this website:
http://www.pbs.org/wgbh/buildingbig/educator/act_geodesic_ho.html
It was very satisfactory: the kids learned about the importance of measuring accurately, keeping track of progress, and how something that looks unimpressive to begin with can be actually amazing at the end.  I was even amazed ("It works!  Math works!" I exclaimed as the kids put the roofs on) and I've done it before.

To give the kids something to look at, we made a sturdier but smaller dome out of straws. I used this website, which has a mix of complete, accurate directions and pictures and vague, inaccurate directions, as well as nice pictures of a chicken run geodesic dome:
http://sci-toys.com/scitoys/scitoys/mathematics/dome/dome.html

One important note: you actually need the following numbers of straws:
  • 90 long (7 3/4") straws, for 6 pointed stars
  • 50 short (6 1/2") straws, for the 5 pointed and partial 5 pointed stars at the bottom, and 
  • 70 medium (7 1/2") straws for connecting the edges of these stars.

The other things that are helpful is to realize that any 5 pointed star could do for the top---so to continue the design, make all the 5 pointed stars have the same configuration around it.  It also helped to look at his paper domes: those were much easier to figure out due to their color.

So here is an attempt at a picture of our dome, rather the worse for wear from being played with by elementary school children.  You can see that it really is sturdy, though: after going through through a couple car rides, being used as a tree topper, being squished through doorways (it actually goes through sideways quite nicely) and the aforementioned children, it still has its characteristic shape.

Comments

Popular posts from this blog

My hero, Helen Parr

Otherwise known as Elastigirl , a.k.a Mrs. Incredible. She is a stay at home mom ( SAHM ), she clearly feels that what she is doing is important and is willing to give up a lot to do it (remember her comment in the intro: "I'm at the top of my game! Leave saving the world to the guys? I don't think so.") But she is finding fulfillment in leading her family from day to day, in doing a hard job well. She also knows that she is very talented, and that knowledge helps her see beyond the repetitive drudgery of staying home. My favorite scene is from the deleted introduction, where she talks with a "career woman" who is of the opinion that staying home is fine for people who can't do anything else. She responds that taking care of her kid is at least as hard as saving the world, and is valuable contribution to society. The point for me is that someone has to do the job that I'm doing, and it's not something that you could pay someone to do. I see...

Why you should study the history of math

  Why you should study the history of math In the mid 1300s a fad made its way around Italy. Mathematicians would challenge each other to “mathematical duels”. They would post problems for their opponents to solve, sometimes along with their solutions in coded poetry. The winners would get support and funding from rich patrons, the losers would descend into obscurity. One such contest, between Fiore and Tartaglia, involved a new method for solving the cubic. In order to win, Tartaglia worked day and night to find Fiore’s method---unfortunately, Fiore did not do the same and only knew his own method and no others. (*Recall that the formula for solutions to quadratic equations of the form use the quadratic formula, Giorlamo Cardano---physician, philosopher, astrologer and mathematician---convinced Tartaglia to share his method and promised never to reveal it. Then Cardano figured out a more general method, and wanted to share it, but was blocked by his promises. Fortunately (for Ca...

Things that are true

"Axial tilt is the reason for the season." (Picture a globe with the northern hemisphere tilted away from the sun...) I believe this is meant to be an anti-theist slogan, although I would point out that I believe there is a reason for the axial tilt. This is a runner up to my favorite true science picture, the "Gravity Forecast." I linked to this when I was a graduate student, but the site is long since down. Picture a weather forecast graphic, but instead of clouds and temperatures, the 5-day forecast predicts 9.8 m/s^2 down. Even the idea still makes me laugh, perhaps I will reproduce it someday. Luke cut his 4th tooth today (Finally!). So far they haven't caused us too much trouble. We'll see what happens when he gets his canines.