The Beauty of Chalk
plough.com
plough.com
I don't know... I studied theoretical math and my professors were definitely giving me a good workout trying to write down from the chalkboard.
When I took organic chemistry in a lecture hall that seated 200, the professor used larger chalk and you could easily see it in the entire hall. A regular marker would be too fine to see. I don't think that you could have a larger marker as the ink reservoir would be large and unwieldy. Plus it would probably drain rather quickly.
That entirely depends on how accurately the lecturer can throw a tiny object. IIRC some of our lecturers preferred board rubbers to the chalk itself.