entertainment?

I was talking today to my son, about teaching college students in the US . He was told that he should be a little entertaining.
I also saw that Prof Tandon is in the news (ICM)
Some people believe that your lecture (on a scientific subject) must be entertaining --why entertaining?
Some years ago, I used to volunteer for this organisation that has a summer school in science for 9th class kids, and I heard Prof Tandon give a talk to 14 year olds on prime numbers. He was really interesting.. he held the kids (and me) spell-bound.
I think there is a great difference between entertaining and interesting.
If my students want to be entertained, they should switch on their TV, but if they want my lectures to be interesting, that's a reasonable demand. ( though some parts of my syllabus are impossible)
However, for a lecture to be interesting, one has to have some interest to begin with. Given that as a starting point, it is the duty of the teacher to make it interesting. But entertaining? No!

Though Prof Tandon's talk was like a story-telling session, I would not call it entertaining. I would call it interesting, very interesting.

I find these videos where they teach Chemistry with "you be sodium and let Jimmy here be chlorine" very silly.....you are not three years old when you are taught ionic bond - so why this role play?
I don't believe the children (12 to 14 year olds) learn ionic bond any better by this than by more conventional methods. In fact, there is a serious problem in this particular example.
Once I asked my class " If an ionic bond is formed by giving of electron directly by one atom of sodium to one atom of chlorine thus forming sodium chloride, what about the sodium chloride formed when I neutralise sodium hydroxide with hydrochloric acid and then crystallise the product? is that an ionic bond?"
The students were confused by this---- and they are in college.
I don't blame the students.
You should see the diagram the 9th class AP state school textbook has for a polarised atom...enough to confuse any child.