Last month I did some calculations based on my birthday balloon.
http://wigtonphysics.blogspot.co.uk/2016/11/finishing-birthday-balloon-calculations.html The balloon has now been laid to rest and I took some measurements. I was wrong about the mass of the balloon. At 10.34 grams it is less than half of my estimate. Also the thickness turned out to be twice my estimate and exactly what the Internet told me it should be. So my estimate of dimensions must have been wrong!
