#AtoZChallenge Archives – Page 9 of 51

March 31, 2026March 31, 2026

You Are Here (Castro Valley)

Fast Facts

Castro Valley, California
Long/Lat: 37.41 N/ 122.05 W
Population: ~66,000
Size: 17 sq mi
Avg temp in April: 66 F / 18.9 C
Median income: $145,000
Ethnicity: 33% White/33% Asian/20% Latino
Main industries: Healthcare (big hospital) / Bedroom community

If we’re going to learn about small countries in our A to Z Challenge which starts tomorrow, April 1st, then we need some context. I know we need to know Where, but we need a little bit more. There’s no value in learning names, dates and places by themselves, no Who, When, or Where without learning Why and What? Geography is useful in comparison. I thought that one logical way to provide that context was to start with my home town. Then, I can tell you how many Castro Valleys there are in … well, you’ll see.

Alameda County is the middle of the Bay, Castro Valley is kinda middle of Alameda county. Drawing by Arkyan.

Castro Valley is a small enclave nestled in the East Bay Hills of Northern California, not the coastal range, but the second range of rounded, golden hills. It’s halfway between Berkeley and Fremont, partway between the Bay and the Tri-Valley region, about equidistant from San Francisco and from San Jose. We’re that little town people pass on their way to somewhere else. However, it’s the 4th largest unincorporated town in California and in the Top 30 across the U.S. We don’t want to be incorporated. We’ve voted on it twice; we don’t want a mayor or a police force, thanks, very much, just a really good library.

April 30, 2025May 6, 2025

Z is for Zodiac

Modern Zodiac wheel. Graphic by Pearson Scott Foresman.

I’ve always been interested in astrology. I used to be able to calculate birth charts by hand, before apps could do it. I am also familiar with numerology, read palms, and interpret tarot cards. I often did tarot readings at corporate off sites. They were wonderful for discussing team strategy; people open up and speak their minds. I was also peppered with questions about why a person who did finance and math for a living was so knowledgeable about occult practices.

They shouldn’t have been surprised. Ancient astrology was heavily dependent on math and scientific measurement. Historians often find it quaint that astrology and astronomy were taught together, but to ancient Sumerians and Egyptians, this was like statistical analysis, using data to make predictions. Where today we might apply theories of random walk, Keynesian economics, or monetary policy–given that we are a society fueled by capitalism–in 2500 BCE, the ancients generated predictions based on interpretations of the night sky. Across multiple societies, astrologers were key advisors to the king-emperor-leader, in the same way that Cabinet members function today. Will the harvest be bountiful? Will the attack on a rival neighbor be a success? Should we apply tariffs? What actions should we take to maintain celestial harmony?

The zodiac might be easily dismissed as simple superstition. Yet, for all our modern access to information and expertise, our predictions aren’t necessarily more accurate. Economists disagree, and economic results don’t always follow predictions. Political polls seem no more conclusive than a newspaper horoscope. Meanwhile, today’s horoscopes bear very little connection to the horoscopes generated three thousand years ago, which were mathematically calculated based on that day and that person, not simple platitudes.

The cultures of ancient Mesopotamia, Egypt, China, Greece, and others paid close attention to the night sky and acted accordingly. Their view also linked the activities of the constellations, along with the sun, moon, and planets, to the seasonal climate of their environment. Weather was everything, and weather came from the heavens, which meant it was affected by the stars. Just as ancient cultures defined their calendar, months, and seasons, they also organized the heavens into the zodiac.

April 29, 2025April 30, 2025

Y is for Yellow

Horse painted at Lascaux caves, @ 20,000 ya. Photo courtesy of the French Ministry of Culture.

I have to confess this up front: nobody calls it yellow. All the anthropologists and archaeologists call it ochre, which can be red or yellow. They spell it ochre, too, and that confuses the dictionaries. Also, humans don’t see yellow. Technically, I shouldn’t be writing this post, but I’m a rebel! I’m going to do it anyway. Because our ancient ancestors used color, and we should talk about how and why.

In today’s post on the color Yellow, we’ll talk about what yellow in particular and color in general meant to ancient cultures. We’ll see how the Greeks created an entire system that mirrored cave paintings in France. We’ll address who had access to what color and how that played a part in where and when. Humans could see rainbows, but they could not universally reproduce them.

I have just two posts (and a summary) left, and while I am starting to flag, I’m excited about this post and how close the finish line appears. So today’s questions include: