If you saw his lectures, you will love it ;)
Haha, that got me. I always wonder how he did that. That's pretty epic!
You hold it at an angle and put a lot of pressure on it, this causes the chalk to jump up as it moves instead of stopping.
The dotted line technique is known, but what is really impressive is some of his freehand strokes. Freehand lines are straight, and what about that dotted line arc he made! Very impressive.
Oh of course, those lines!
He's a wonderful professor. I loved watching his lectures when I was in high school. Being stupid and believing that I understand relativity I emailed him a stupid question. He replied back
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