This is a ball that has telescopic spring-biased members (like pogo sticks) radiating from the center. The telescopic members are covered with a flexible sphere.
I can't think of too many advantages of this ball. Maybe for playing soccer on the moon ;)-- xaviergisz, Feb 16 2008 spring ball illustration http://imgur.com/a/B1hMV [xaviergisz, Feb 16 2008, last modified Dec 14 2011] Patent US 6280356 http://v3.espacenet...C&IDX=US6280356&F=0closest I could find [xaviergisz, Feb 18 2008] Our son had a spring ball, just the springs and no covering.-- DrCurry, Feb 17 2008 We had a Spring Ball when I was up at university.-- coprocephalous, Feb 18 2008 (+) for using the phrase "telescopic members" in a sentence. Add a remote control and you'll have my $29.99.-- jutta, Feb 18 2008 Wouldn't a really low pressure ball that was somewhat heavier also be playable on the moon?-- WcW, Feb 18 2008 probably WcW, but you couldn't take it from inside the space capsule to the outside without it exploding.-- xaviergisz, Feb 18 2008 // but you couldn't take it from inside the space capsule to the outside without it exploding //
That depends how strong the outer casing is. The difference in pressure between the interior and exterior of the vessel would be (at most) one bar; many spacecraft have a much lower internal pressure. Producing a ball that could survive an effective one bar increase in internal pressure isn't rocket science. However, the ball would prove less resilient. Also, diving to save a goal in a full environment suit is probably not recommended by the manufacturers. Check on the little tab in the back of the collar before you try it.-- 8th of 7, Feb 18 2008 Me want. :)-- Thomasunde, Feb 21 2008 //The difference in pressure between the interior and exterior// - these could be the same. There'd be no need for such a ball to be air tight.
I think you might get a more ball-like-feel by maintining its shape, not from springs radiating from the centre, but between one surface section and the next. Image a ball made up of loads of triangular factes, as you might have with a CG sphere in a 3D engine. Each facet, or polygon, attempts to maintain its orientation with its three surrounding facets (again, polygons).
It wants to be a sphere, it'll always return to being a sphere, so don't bother pumping it up.-- seanbo, Jul 20 2009 random, halfbakery