Saturday, March 17, 2012

Seeking Sphericity


Did you know that the most perfectly smooth and accurate spherical object ever created by human kind was a 1.5" diamter piece of fused quartz (glass)? 

I did, and so did Wikipedia (This round is a draw, Internet)! 

It's true, this little marvel of modern material engineering was made by NASA for use in "Gravity Probe B". Gravity Probe B was one of the most remarkable, elaborate, and ultimately triumphant examples of experimental physics that confirmed Einstein's assertions about effects of gravity on space-time. It also has nothing to do with rest of the content of this blog post, except for the part about glass spheres. 

This past Monday, just before becoming horribly ill (again), I spent the evening in the hot shop making a whole bunch of little glass spheres. At the end of the night, just before 1:00am, I thought that the process might make some good internet. So, I propped my camera on a brick and shot this video outlining the process of making a "perfect" glass sphere out of hot glass, by hand. In this case, "perfect" is being used quite subjectively, but you get the point (You win this round, NASA)!
Check it out: 


3 comments:

Anonymous said...

fantastic! great way to start my Saturday.

Nick said...

Nice video Niels,
I have a design that calls for a black glass sphere. I assume this process can be done with colored glass as well. Is there a minimum size you can get to by this process? I'm not settled on a size yet, but when the time comes, I may just have to recruit you (or NASA).

nielscosman said...

Thanks Nick,
There is a minimum size that's probably around the diameter of a penny or dime. The max for the tools that I have is close to the size in the video. I only have two ring tools that are about 1.5" and 2.5" however smaller tools could always be improvised out of tubing. I could probably make little marble using a 1/2" copper pipe. Of course, at that size you'd probably be better off finding somewhere that sells black marbles. As for color, you can do the same in any color, it just adds time to the process.
Cheers,
Niels