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I was gonna ask... is that for real? How does it spin up to 11 MILLION RPM? That seems crazy.

It's a joke. The sig figs at the end is a clue, along with complete physical implausibility.

((1 mm)^2) * 1 gram * (((183 339 * 2 * pi) / second)^2) = 1 326.99551 joules

It would have 1300J of rotational energy if there was only 1 gram of spinning mass at 1 mm distance.

Not just the sigfigs, the juxtaposition of the word "about" with the excessive sigfigs. Combining a word indicating imprecision with excessive sigfigs is a very common American idiom to convey exaggeration. (Probably other places too, but I don't have firsthand experience with them.)

Richt, that needs further investiagation, Almost seems to be made up by the author.

Normal rpm's for a spin welder are <3000.

Datasheet: https://www.sonics.com/site/assets/files/2949/spin-welder.pd...

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