PHIL 101: Time Edition

The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical frequency ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to  s − 1 NIST F2 and friends Imagine a single caesium atom (or "cesium" atom if you stick to the American English spelling). Imagine this atom alone, at rest, undisturbed, at a temperature of absolute zero. Counterfactually, suppose that the unpaired electron of this atom in its ground state were to be irradiated with the precise frequency of light to bump the electron from its lowest energy state into the next lowest energy state, and then that the resulting radiation released as the electron returned to its lowest energy state is recorded. Call the frequency of the resulting radiation ΔνCs. By fiat, set ΔνCs = 9,192,631,770 Hz. Since the unit Hz expresses cycles per second, this means that, by definition , the duration o...

 Dr. Nora is taking a week off blogging in order to finish grading PHIL 101 student essays. In the meantime, please enjoy Feynman playing the bongos

Just look at the future, and just imagine, when is somebody still alive that you will love?   Lately, Andri Snær Magnason has been asking people this question. He really wants us to calculate this. For instance, I am about to turn 34 this weekend (9/19/20). I don't have any children, but I do have little cousins whom I love. Here's Juliet, when she was just a very bald baby back in 2016. Let's suppose (ambitiously) that I live to be 100 years old. That's 66 years from now, so it will then be 2086. Juliet will be 70 years old (so perhaps she will live to 2126). Suppose Juliet herself has a child. If she does, I will hope to meet that baby too, and I'm sure I would love Juliet's baby just as I love her. For the sake of argument, suppose Juliet's baby is born when Juliet is 30 years old, in 2046. If that baby makes it to 100 years old also, they will live to see 2146. So it is plausible that I will love someone who will be alive in 2146.  What will the world b...

  In recent years the search for exoplanets has turned up a wealth of exciting results. The TRAPPIST project discovered a system of planets orbiting a dim red star, which with the help of the Spitzer Space Telescope, ultimately revealed seven Earth-sized planets. Three of the seven are located in the star's "habitable zone"--the region around the star in which we could reasonably expect liquid water to exist on the surface of the planets. Future scientific investigation of these planets aims to detect the signatures of atmospheric chemistry relevant to the conditions for life on these alien worlds.  Why do we care if there is, or could be, life on other planets besides our own? Brute scientific curiosity, surely. But are there other reasons? In a 1997 Scientific American article "The Search for Extraterrestrial Intelligence" , Carl Sagan and Frank Drake (of the Drake equation ), posed a question that I have heard echoed in other contexts: "Is mankind alone...

 This is a photograph (of a photograph) of me as kid, wading in the water where conch were being kept in little coral corrals next to a pile of discarded shells off the coast of Carriacou. Carriacou is a small island that is part of Grenada, where my mother conducted research for her graduate work in geography. We visited several times when I was growing up and I have many distinct memories from those visits. I remember making kites with my friends, laying in the bottom of the sailboat feeling sea sick, being gifted a beautiful mango, drawing ruins, playing make-shift cricket and getting sunburned on my 13th birthday, making drinking chocolate, another kid (a family friend) standing in front of the crashing surf yelling "Peace and love! Peace and love to all the world!", a friend arriving with a pet cat in a sack for us (with a piece of bread that had a bite taken out of it), which we named Professor McGonagall, watching my brother lose a footrace to some very fast girls, wat...

  Plato thought that doing philosophy prepares human beings to face their own deaths. He thought that in death, the human soul would be freed from the prison of the body and apprehend the true nature of things, rather than the dim shadow reality to which embodied beings are limited. During our lives, Plato argues that it is in doing philosophy that we can get the closest to truth. By following through with philosophical inquiry we can begin to see the vague contours of things as they really are, even if their true nature ultimately remains inaccessible to us while we are living. We see Plato's views on the relationship between philosophy, death, and reality in his portrayal of the death of Socrates. Socrates is not afraid of death, indeed he welcomes it. The attitude Socrates has towards death is not straightforwardly suicidal. Rather, at least in Plato's rendering, he looks forward to death as union with truth. I don't personally think about the relationship between death ...