Session Date
Lesson Topic
Escape velocities (Gravity and black holes cont.'d)
Lesson Outline
We revised escape velocities in today's class. We had already touched upon them in last Thursday's lesson, but I wanted to go into more depth, seeing as escape velocities are directly related to the mass (specifically, density) of a spherical object. They are a good benchmark for understanding gravity. I showed Jared again how to calculate the escape velocity for an object of mass, M, and radius, r. He then calculated the escape velocity for the Moon and Mars (we had calculated that of Earth last time), and together we looked at those of Jupiter, and a typical neutron star. We also looked at what the escape velocity would be if (IF! ... it will never happen!) the Earth were to become a black hole. Jared understood that in this case the escape velocity would have to be the speed of light, which is the defining feature of black holes.
Jared's math skills are very good - he has good intuition and understanding of the numbers themselves.
This class was an hour-and-a-half long, yet Jared remained focused and interested throughout. He was also eager to tell me that he had seen the movie 'Interstellar' twice since last Thursday, and understood the physics!
Jared's math skills are very good - he has good intuition and understanding of the numbers themselves.
This class was an hour-and-a-half long, yet Jared remained focused and interested throughout. He was also eager to tell me that he had seen the movie 'Interstellar' twice since last Thursday, and understood the physics!
Assignment
An short essay on the physics of black holes as portrayed in the movie 'Interstellar'
Session Minutes
90
Minutes Student Attended
90
Lesson Comments
Today was a very good class. We had to repeat some concepts from last week, but that's because it had been a full week since we last met. Jared had not completed his assignment from last week, but we worked through it together today. We spent most of the time on calculations - first I showed Jared how to work his way through an equation on escape velocities, after which he performed some calculations himself. It was very gratifying to see how his understanding of the gravitational fields of celestial objects of differing masses and densities increased with each calculation he performed. At the end he understood perfectly that the escape velocity for a black hole is the speed of light (hence the term, 'black hole').
I would like to point out two things: First of all, Jared's handling of numbers is very good - he has an intuitive understanding of math that would be nice to see developed further! He handled operations on exponents with ease, and he understood that when working with large numbers it's convenient to round them and the final result is not so different than if we had used exact numbers - a useful skill in a subject such as astronomy! Secondly, he appeared very eager to tell me that he had seen the movie 'Interstellar' twice since last Thursday, and appeared to be quite proud of himself that he understood the physics involved due to our classes! (I have yet to see the movie, but I know Kip Thorne was the main science consultant, and he's probably the most reliable source around.)
Jared also expressed an interest in relativity (partly as a result of seeing the movie) and mentioned he would like to take it as a course at some point in the future (an incentive to do well at school and go on to college??).
I would like to point out two things: First of all, Jared's handling of numbers is very good - he has an intuitive understanding of math that would be nice to see developed further! He handled operations on exponents with ease, and he understood that when working with large numbers it's convenient to round them and the final result is not so different than if we had used exact numbers - a useful skill in a subject such as astronomy! Secondly, he appeared very eager to tell me that he had seen the movie 'Interstellar' twice since last Thursday, and appeared to be quite proud of himself that he understood the physics involved due to our classes! (I have yet to see the movie, but I know Kip Thorne was the main science consultant, and he's probably the most reliable source around.)
Jared also expressed an interest in relativity (partly as a result of seeing the movie) and mentioned he would like to take it as a course at some point in the future (an incentive to do well at school and go on to college??).
Session Hours
1.50
Hours Attended
1.50
Entry Status
Review Status
Student Name(s)
Subject
School