18 – The Badness of Death, Part III; Immortality, Part I

18 – The Badness of Death, Part III; Immortality, Part I

By |

Podcast: Play in new window | Download (Duration: 50:34 — 46.3MB) | Embed

Subscribe: Email | RSS

The discussion of the badness of death continues by asking whether it is bad that we do not exist before our birth. The views of a number of contemporary philosophers, such as Tom Nagle, Fred Feldman, and Derek Parfit, are introduced. Then Professor Kagan turns to the subject of immortality. Would it be desirable to live forever, and if so, under what circumstances one might enjoy such a prolonged existence? The lecture concludes with Bernard Williams’ take on immortality which posits that no kind of human life can continue to be enjoyable and attractive for eternity.

17 – The Badness of Death, Part II: The Deprivation Account

17 – The Badness of Death, Part II: The Deprivation Account

By |

Podcast: Play in new window | Download (Duration: 51:36 — 47.2MB) | Embed

Subscribe: Email | RSS

This lecture continues to explore the issue of why death may be bad. According to the deprivation account, what is bad about death is the fact that because one ceases to exist, one becomes deprived of the good things in life. Being dead is not intrinsically bad; it is comparatively bad and one is worse off only by virtue of not being able to enjoy the things one enjoyed while alive, such as watching the sunset, listening to music, and discussing philosophy.

15 – Supermassive Black Holes

15 – Supermassive Black Holes

By |

Podcast: Play in new window | Download (Duration: 47:37 — 43.6MB) | Embed

Subscribe: Email | RSS

The lecture begins with a question-and-answer session about black holes. Topics include the extent to which we are sure black holes exist in the center of all galaxies, how massive they are, and how we can observe them. The lecture then turns to strong-field relativity: relativistic effects that are unrelated to Newtonian theory. The possibility of testing predictions of the existence of black holes is discussed in the context of strong-field relativity. One way we might learn about black holes is through observation of the orbit of the companion star in an X-ray binary star system. Through this we can estimate the mass of the compact object. The lecture ends with an explanation of how astronomers find black holes, and how Professor Bailyn was able to discover one himself.

16 – Dying Alone; The Badness of Death, Part I

16 – Dying Alone; The Badness of Death, Part I

By |

Podcast: Play in new window | Download (Duration: 49:50 — 45.6MB) | Embed

Subscribe: Email | RSS

Professor Kagan puts forward the claim that Tolstoy’s character Ivan Ilych is quite the typical man in terms of his views on mortality. All of his life he has known that death is imminent but has never really believed it. When he suddenly falls ill and is about to die, the fact of his mortality shocks him. In trying to further access how people think about death, Professor Kagan explores the claim that “we all die alone,” presents a variety of arguments against it and ends by considering whether the primary badness of death could lie in the effects on those who are left behind.

14 – Pulsars

14 – Pulsars

By |

Podcast: Play in new window | Download (Duration: 48:40 — 44.6MB) | Embed

Subscribe: Email | RSS

Professor Bailyn begins with a summary of the four post-Newtonian effects of general relativity that were introduced and explained last time: precession of the perihelion, the deflection of light, the gravitational redshift, and gravitational waves. The concept of gravitational lensing is discussed as predicted by Einstein’s general relativity theory. The formation of a gravitational lens can be observed when light from a bright distant source bends around a massive object between the source (such as a quasar) and the observer. Professor Bailyn then offers a slideshow of gravitational lenses. The issue of finding suitable astronomical objects that lend the opportunity to observe post-Newtonian relativistic effects is addressed. The lecture ends with Jocelyn Bell and the discovery of pulsars.

15 – The Nature of Death (cont.); Believing You Will Die

15 – The Nature of Death (cont.); Believing You Will Die

By |

Podcast: Play in new window | Download (Duration: 44:15 — 40.5MB) | Embed

Subscribe: Email | RSS

The lecture explores the question of the state of being dead. Even though the most logical claim seems to be that when a person stops P-functioning he or she is dead, a more careful consideration must allow for exceptions, such as when one is asleep or in a coma. Professor Kagan then suggests that on some level nobody believes that he or she is going to die. As a case in point, he takes Tolstoy’s famous character Ivan Ilych.

13 – Stellar Mass Black Holes (cont.)

13 – Stellar Mass Black Holes (cont.)

By |

Podcast: Play in new window | Download (Duration: 49:01 — 44.9MB) | Embed

Subscribe: Email | RSS

Class begins with clarification of equations from the previous lecture. Four post-Newtonian gravitational effects are introduced and discussed in detail. The first of these is the so-called Perihelion Precession, which occurs when the major axis of a planet’s elliptical orbit precesses within its orbital plane, in response to changing gravitational forces exerted by other planets. Secondly, deflection of light is described as the curving of light as it passes near a large mass. Gravitational redshift is explained as a frequency effect that occurs as light moves away from a massive body such as a star or black hole. Finally, the existence and effects of gravitational waves are discussed. The lecture closes with a brief history of the 1919 eclipse expedition that made Einstein famous.

14 – What Matters (cont.); The Nature of Death, Part I

14 – What Matters (cont.); The Nature of Death, Part I

By |

Podcast: Play in new window | Download (Duration: 47:18 — 43.3MB) | Embed

Subscribe: Email | RSS

The suggestion is made that what matters in survival is the future existence of someone with a personality similar to one’s own. Professor Kagan then turns to the question, “what is it to die?”. In answering this question, attention is first drawn to the bodily and mental functions that are crucial in defining the moment of death.

12 – Stellar Mass Black Holes

12 – Stellar Mass Black Holes

By |

Podcast: Play in new window | Download (Duration: 49:42 — 45.5MB) | Embed

Subscribe: Email | RSS

One last key concept in Special Relativity is introduced before discussion turns again to black celestial bodies (black holes in particular) that manifest the relativistic effects students have learned about in the previous lectures. The new concept deals with describing events in a coordinate system of space and time. A mathematical explanation is given for how space and time reverse inside the Schwarzschild radius through sign changes in the metric. Evidence for General Relativity is offered from astronomical objects. The predicted presence and subsequent discovery of Neptune as proof of General Relativity are discussed, and stellar mass black holes are introduced.

13 – Personal Identity, Part IV: What Matters?

13 – Personal Identity, Part IV: What Matters?

By |

Podcast: Play in new window | Download (Duration: 48:53 — 44.8MB) | Embed

Subscribe: Email | RSS

The personality theory is revised to state that the key to personal identity is having the same personality provided that there is no branching, that is, provided there is no transfer or duplication of the same personality from one body to another. Similar “no branching” requirements are added to the other theories as well. At the end of class, Professor Kagan suggests a shift from thinking about the survival of the soul in terms of “what does it take to survive?” to “what is it that matters in survival?”