Resources for individual classes
(If I make any further changes, I will notify you immediately.)
A SPECIAL REQUEST FOR YOUR INPUT
Beyond the Cosmicomics stories I have assigned, if you have one or more favorites you would like me to feature in one of the last two classes, please let me know IMMEDIATELY by email (just reply [not "reply all", please] to any message I've sent you). If there are any overlaps among your favorites, I will prioritize them. I will post your suggestions immediately upon receipt (see "Stories Suggested By Students" on the class menu), so you can see what others have suggested.
Finally, if you want to improve your odds by talking with another class member about choices, but you don't know how to contact them, send your message to me and I will relay it to them (without sharing any of your personal information).
Before the 6th class, Thursday 23 October 2025,
• Please read the following stories in The Complete Cosmicomics:
-- The Light Years
-- The Spiral
Resources
• After reading The Light Years, peruse the following resources:
What did quasars turn out to be?
What is redshift? How does it tell us how fast distant objects are receding from us?
If the universe is "only" about 13.8 billion years old, and light can only travel 13.8 billion light years in that time, how can we possibly see galaxies that appear to be much more than 13.8 billion years away? Maybe the following video will help.
In news stories about discovery of the most distant galaxies, the reporter usually talks about how long after the big bang an object is being seen. They don't get into the redshifts and apparent distances from us; instead, they talk about the age of the universe at the time the light we are seeing left the object. This approach sidesteps the apparent distance and apparent recession speed, which seem impossible until you factor in the expansion of space during the travel of that light.
Puzzling sightings of very old full galaxies with elements that could only form from stars at least a few generations old, however, have upset much of what scientists thought about how soon galaxies and stars and black holes could possibly form after the big bang. New models of the early universe will need to be revised to fit this tantalizing and mysterious evidence.
• After reading The Spiral, peruse the following resources:
Here is a computer simulation that lets you look at the effects of random genetic variation, natural selection acting on the offspring that harbor these variations ("mutations").
If you get bogged down in these instructions, don't waste a lot of time. I'll help out in class.
Click the link and then follow these instructions:
- Scroll down to a black square with a Launch button at its upper left corner and Biomorph Evolve at its center.
- Click "Launch". An array of nine squares appears, each containing a tree-like pattern of connected lines. In most patterns, it's easy to find a single line (a trunk, if you will) which, by branching, produces the whole pattern. Each pattern is called a biomorph, or morph, and represents an organism whose pattern is determined by the numerical values of a handful of variables called "genes". Each gene determines a single feature, such as the number of branches, the branch angle for all branches of that morph, the length of all branches relative to first one, whether the branches ascend or descend, and other simple features. In this first screen, all morphs are given random values for all of their genes, making them highly varied.
- Click once on any morph that looks interesting to you. That morph will move to the center square, and eight similar new ones will appear around it. The central morph is the "parent" you chose, and the eight new ones are its offspring. Each offspring differs from the parent by a small change (mutation) in the value of one, or at most, two genes, so they all resemble, but are not identical to. their parent.
- The same thing happens if you now click any square: the clicked morph moves to center and produces eight new offspring, each genetically very similar to the parent in the center.
Try this. Reload the page to get a new set of random parents (see below** if you don't know how to reload a page.) See if you can evolve a species of morphs that are all very flat and wide. Start by picking the flattest and/or widest first parent, then pick the offspring that you judge to be shorter and widest, and click to make it the next parent. Repeat to make the shortest and widest morph you can.
Then try this. Reload and restart the simulation repeatedly, each time getting nine new random figures. Do you ever find any random morphs that hat are even close to being as short and wide as you can get by selection from promising parents?
You are seeing the difference between the power of random mutation with selection, versus random mutation alone. In a few generations, you can pick a property and enhance much faster than waiting for random mutation to produce it. If you have ever played gin rummy, you have seen the same kind of selection in making exchanges that improve your hand.
I will explain this simulation in class, and show some examples. If you aren't getting anywhere with this, don't waste a lot of time. I'll help out in class.
Have you ever played gin rummy? Do you see any parallels between natural selection acting on natural genetic variation versus your decisions in gin rummy and the stepwise improvement of your gin-rummy hand from a perhaps unpromising hand dealt to you to a winning hand?
••••••
** How to Reload A Web Page
On an Apple computer or iPad, pick Reload Page from the View menu, and Launch again.
On other brands, you will find a Reload command under one of the menus. On an iPhone, click the clockwise arrow on the right of the web-address line. You might have to scroll the page up or down to make the address line appear. On other phones, reloading is just as easy, but I don't have one to figure that out for you. If you succeed with reloading on a non-Apple phone, send me email with instructions and I'll put them here.
