All blackboards are gone. They were replaced during the break. (So, no chance to use this MathOverflow question on the near future.) Makes me think of T.H. Huxley’s On a Piece of Chalk (see here) and wonder what the equivalent will be in a few decades.

On the plus side, we now have computers and projection equipment on each classroom. I am using this quite a bit in my abstract algebra class. Except that, during the first few weeks, it was more often than not that the keyboard would be locked away.

Annoyed, I called OIT and asked that they please make sure it was unlocked before my class. It worked for a few days. But then, again, I found it locked.

I called again (I was charming, I am sure). So, somebody came to the classroom, looked at me, smiled. And pressed a button, to open the drawer.

Sigh.

(In my defense, the class is at 8:30 in the morning, and I’m supposed to drink less coffee these days. But still.)

(“Thanks. I’m sorry. I’m an idiot.” “Oh, no, no. It is new.” “It is a button.”)

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Have you had a chance to use a tablet+projection to replace the whiteboard? Infinite paper with infinite zoom to add additional comments in the right place is a great tool I use for taking notes, but never had a chance to use in class.

The argument you are looking for is given in Kanamori's book, see Theorem 28.15. For the more nuanced version of the lemma, see section 7D in Moschovakis's descriptive set theory book (particularly 7.D.5-8), or section 3.1 in the Koellner-Woodin chapter of the Handbook.

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This is quite hilarious (I sympathize).

Have you had a chance to use a tablet+projection to replace the whiteboard? Infinite paper with infinite zoom to add additional comments in the right place is a great tool I use for taking notes, but never had a chance to use in class.

I haven’t, but I probably should. I’ve heard Hugh Woodin uses this quite effectively teaching precalculus, of all things.