Talk:Betz mystery sphere
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Continuity
[edit]No mention of what happened to it after 1974?? - Joaquin89uy (talk) 14:56, 8 January 2024 (UTC)
Ball mass
[edit]If the ball is made from steel (assuming 7.5kg per liter) why for 10cm radius there's only 10kg? Mass for 10cm radius is over 31.4kg (4/3*PI*1000*7.5). Ok, maybe ball was empty for some reason but then, how it was made? 87.205.194.100 (talk) 20:11, 28 January 2024 (UTC)
- Hollow bearing balls are usually made in halves, and then welded together. A good weld will complete disappear when you polish it, and ball bearings are often pretty heavily polished.
- I believe there are also newer processes where the steel can somehow be formed around a plastic core. I don't quite understand how that works. I don't think that would have been available in the 1970s anyway.
- The "reason" for making them hollow is, of course, weight. As you point out, large solid steel spheres would be quite heavy, so above a certain size, it's common to make them hollow. ApLundell (talk) 03:54, 29 January 2024 (UTC)