Lecture

A linguistics professor says during a lecture that, "In English, a double negative forms a positive. But in some languages, such as Russian, a double negative is still a negative. However, in no language in the world can a double positive form a negative." But then a voice from the back of the room piped up, "Yeah, right."
How does a mathematician lecture their child?
"If I told you n times, I've told you n+1 times..."
What do you call a cannibal that works in a university?
Hannibal Lecture.
Why was the math lecture so long?
The professor kept going off on a tangent.
After 5 hours sitting in the bar, a man was in no shape to drive, wisely left his car parked and walked home.
As he was walking unsteadily along, he was stopped by a policeman.
"What are you doing out here at 2 am?", said the officer.
"I'm going to a lecture.", the man said.
And who is going to give a lecture at this hour?", the cop asked.
"My wife." said the man.
The Surgeon Lecturer
The Surgeon Lecturer One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, "Do you have any control subjects?" The surgeon drew himself up to his full height, slammed the desk with his fist, and said, "Do you mean did I NOT operate on half the patients?!" The hall grew very quiet then. The voice at the back of the room hesitantly replied, "Yes, that's what I had in mind." Then the surgeon's fist really came crashing down as he thundered, "Of course not!! That would have doomed half of them to their death!!" God it was quiet then.... And one could scarcely hear the small voice ask: "Which half?"
At the end of the physics lecture, I asked my professor, “What happened before The Big Bang?”
He said, “Sorry. There is no time.”