What Day is It?

 Astro class 2025:

Regular

Goofy

Tardy

Me, Space-Time, and Cycles

         "There is no such thing as an empty space...Space-Time does not claim existence on its own, but only as a structural quality of the [gravitational] field."  - Albert Einstein, 1952 

This idea of Space & Time not really meaning anything outside of the context of gravity is something I've been trying to wrap my mind around ever since I started teaching astronomy: The ever expanding universe creating space-time as the masses separate and the meaningless of space-time outside of or before the universe ( as opposed to the Newtonian view that the stage already set and the universe plays out on that pre-existing stage).  

Before the discovery of Dark Energy (our short hand for the acceleration of the expansion of the Universe), most scientists thought the universe would end in a Big Crunch.  The story was that gravity would eventually win over the expansion and bring everything crashing together again... and maybe we could return to the Big Bang.  Such a cool idea since this eliminates the awkwardness of a one-and-done Universe with a questionable beginning and final end.

However, with Dark Energy, it appears we are doomed to the Big Chill and we will be forever haunted with the strange uniqueness of our finite-in-time Universe.

Or are we?

I recently came across this idea of Roger Penrose  (Conformal Cyclic Cosmology) that, when the Universe ends in its ultimately highest entropy state with either no mass or mass evenly distributed, Space-Time will once again be meaningless.  Highest entropy begins to look like lowest entropy and, voila, we have recovered the initial conditions of our Universe... so another Big Bang can occur.

Reversing the concept of what Space and Time are is a really powerful frame shift, is it not?  Instead of mass moving around in space and time, mass is the creator of space and time.  Once there is no interesting movement of mass, there are not relationships to have and Space and Time just fade away as meaningful concepts.

Kind of like how Who-I-Am is somehow encoding in the details of the relationships between all these atoms in my body.  It's not actually the atoms themselves, but the interesting relationships between them.  Lay out all my carbons, hydrogens, oxygens, and nitrogens in a regular array and I guarantee you that guy will not be anything like me.  Long after I'm gone though, the elements in my body can be re-used in some future self-aware sentient creature.  

"There is no such as an eternal Ken Rideout, Ken Rideout does not exist on his own.  He is an emergent property of the C H O N atoms in his body."

Freedom in a Well

"What is Freedom?" is a question my son asked of the extended family last summer for his AP Government class.

My mother had the best answer of all of us: "Freedom doesn't exist.  When you love other people, when you have responsibilities, you give up freedom."  Deep, Mom!  Freedom is just an ideal that you don't really want because you do actually want to be caught up in a web of relationships and responsibilities that give your life meaning and ground you in society.

Sure, I am in principle free to roam this Earth however and whenever I choose, but I am constrained by choice... and by gravity.

I live in a well that's inside of a well inside of another well that is itself in a large, abstract well.  

I have a family I provide for, a school I work in with its students and faculty that have certain expectations, a country that I pay taxes to and owe some measure of allegiance to, a species that I want to see thrive and survive into the future, a beautiful and delicate ecosystem of plants and animals I would also like to see thrive.  Responsibilities galore (and their incumbent limitations on my freedom).

I also live in the bottom of gravitational well created by the mass of this planet which is, in turn, nestled deeply in the well created by the Sun.  The entirety of that deep Solar well is buried within the wide well of the entire Milky Way Galaxy.  The big, fat abstract well of the Milky Way is actually loosely buried in an even fatter, wider well created by our local group of galaxies as we all fly towards each other in the midst of ever-widening ocean of receding galaxies. (So, no, it's not turtles all the way down... but it is several layers of turtles stacked on top of each other I grant you).

So, here I am: Trapped within traps within traps.  Some of my own devising and others I was born inside of.  I can despair of my Sisyphean plight, or I can go all Camus on my lot and think "Freedom is here, in my mind, as I enjoy reflecting upon the fact that I can appreciate all the wells I find myself inside of."

How's that, Mom?

Many thanks to Isabelle for the art to go with this post!

Perspective

Astronomy is a great subject to remind us how what we see and experience is often just a perspective on things rather than an actual perception of what is "out there".

Take for example, the phases of the Moon.  Do you recognize a first quarter vs. 3rd quarter Moon by which half is lit?  Well, 50% of the planet will not agree with you.  You see all those folks below the equator are looking at that same Moon more or less upside down from you:

Look at this cool time-lapse photo taken of the recent lunar eclipse from the Northern and Southern Hemispheres: (note how it goes from upper left to lower right in the North but upper right to lower left in the South)

from https://apod.nasa.gov/apod/astropix.html

I've blogged about it before in terms of the Chinese terms for the quarter moon being more about up and down than left and right, but the truth is that which half appears lit to you depends on the season and the location of the Moon in the sky and your latitude:

https://genuineideas.com/ArticlesIndex/phase.html

https://www.reddit.com/r/Nikon/comments/j7xqb2/moonrise_and_moonset_of_the_10820_waning_gibbous/

Astronomy, Bald Spots, and Witty Students

Today, in Astronomy class while reviewing the seasons and the axial tile of the Earth for a quiz tomorrow, I pulled a classic Rideout non sequitur.  

I spontaneously made the leap from how the sunlight in Antarctica never heats up that continent despite months of continual daylight to how I discovered that I had a bald spot by getting a sunburn on the top of my head while mowing the lawn.  When I ended with something like "... and then I cried in the bathroom until I felt better", the class of seniors were all looking at me a bit strangely (it is, after all, only our 6th time meeting so it was, perhaps, bit much).

To ease the transition back into the material, I looked around the room and said, "You all thought you were taking Astronomy but really this is my therapy session."  Then, without hesitation, a student in the second row (RH) calmly asks "So, this will be on the quiz tomorrow, right?"

Well played sir, well played.

Me and My Two Seniors

 (note that these events are separated by two years)

A retired teacher friend of mine does senior portraits so twice now I have had the pleasure walking around the Wellesley campus while he takes pictures of my soon-to-graduating senior.  Both times he had me jump and pose with them once:

Three Juxtapositions

From the Funny to the Sublime:

Grilling Tofu on the grill for the first time (because you want to lean into vegetarianism) but you quickly add sausage because there won't be enough to eat

Looking for a new home for my French grandmother's engraved flask and matching glasses when I remember my American grandmother's engraved end table 

Noticing this East-meets-West display at a friend's house (WW), I then ask to take a picture because it is as if someone stole an interior image from my own psyche.  Could write a whole blog post on this one, but I'll let the juxtaposition speak for itself for now.