Apple OpenDoc Technology Intro

https://en.wikipedia.org/wiki/Dogcow

The dogcow, named Clarus, is a bitmapped image designed by Apple for the demonstration of page layout in Mac OS. The sound she makes is "Moof!".^[1] Clarus became the archetype of surrealistic humor in the corporate culture of the original Macintosh group, particularly as the mascot of Apple’s Developer Technical Support as officially documented in Technote #31.^[1][2]

Did they have a heated conversation and holler "Dog!" "Cow!" "Dog!" "Cow!" back and forth? We may never know. But one thing is clear, Mr. Zimmerman finally gave in and said, "It's both, OK? It's called a 'dogcow.' Now will you get out of my office?"

— History of the Dogcow, Part 1^[3]

Geologic Time - A Visualization and Essay

Geologists have divided the whole of geologic history into units of varying length.  Together, they compose the geologic time scale of Earth history.  The major units of the time scale were delineated during the nineteenth century, principally by scientists in Western Europe and Great Britain.  Because radiometric dating was unavailable at that time, the entire time scale was created using methods of relative dating.  It was only in the twentieth century that radiometric methods permitted numerical dates to be added.

Here is an interactive diagram of the scale of geologic time.  Click on the right columns to zoom in, the left column to zoom out.  Data from the Geological Society of America

Structure of the Time Scale

The geologic time scale subdivides the 4.6 billion year history of Earth into many different units and provides a meaningful time frame within which the events of the geologic past are arranged.   Eons represent the greatest expanses of time.  The eon that began about 542 millions years ago is the Phanerozoic, a term derived from Greek words meaning "visible life."  It is an appropriate description because the rocks and deposits  of the Phanerozoic eon contain abundant fossils that document major evolutionary trends.

Another glance at the time scale reveals that eons are divided into eras.  The Phanerozoic eon consists of the Paleozoic era (paleo = ancient, zoe = life), the Mesozoic era (meso = middle), and the Cenozoic era (ceno = recent).  As the names imply, these eras are bounded by profound worldwide changes in life forms.

Each era of the Phanerozoic eon is further divided into time units known as periods.  The Paleozoic has seven, and teh Mesozoic and Cenozoic each have three.  Each of these periods is charactered by a somewhat less profound change in life-forms as compared with the eras.

Each of the periods is divided into still smaller units called epochs.  Seven epoch have been names for the periods of the Cenozoic.  The epochs of other periods usually are simply termed early, middle, and late.

Precambrian Time

Notice that the detail of the geologic time scale does not begin until about 542 million years ago, the date for the beginning of the Cambrian period.  The nearly 4 billion years prior to the Cambrian are divided into two eons, the Archean (archaios = ancient) and the Proterzoic (proteros = before, zoe = life).  It is also common for this vast expanse of time to simply be referred to as the Precambrian.  Although it represents about 88% of Earth history, the Precambrian is not divided into nearly as many smaller time units as the Phanerozoic.

Why is the huge expanse of Precambrian time not divided into eras, periods, and epochs?  The reason is that Precambrian history is not known in great enough detail.  The quantity of information that geologists have deciphered about Earth's past is somewhat analogous to the detail of human history.  The further back we go, the less that is known.  Certainly more data and information exist about the past 10 years than for the first decade of the twentieth century; the events of the nineteenth century have been documented much better than the events of the first century AD; and so on.  So it is with Earth history.   The more recent past has the freshest, least disturbed, and most observable record.  The further back in time. a geologist goes, the more fragmented the record and clues become.  There are other reasons to explain our lack of a detailed time scale for this vast segment of Earth history.

1. The first abundant fossil evidence does not appear in the geologist record until the beginning of the Cambrian period.  Prior to the Cambrian, simple lifeforms such as algae, bacteria, and worms predominated. All of these organisms lack hard parts, an important condition favoring preservation.  For this reason, there is only a meager Precambrian fossil record.  Many exposes of Precambrian rocks have been studied in some detail, but correlation is often difficult when fossils are lacking.

2. Because Precambrian rocks are very old, most have been subjected to a great many changes.  Much of the Precambrian rock record is composed of highly distorted metamorphic rocks.  This makes the interpretation of past environments difficult because many of the clues present in the original sedimentary rocks have been destroyed.

Radiometric dating has provided a partial solution to the troublesome task of dating and correlating Precambrian rocks.  But untangling the complex Precambrian record still remains a daunting task.

Terminology and the Geologic Time Scale

There are some terms that are associated with the geologic time sale but are not "officially" recognized as being part of it.  The best known, and most common, example is "Precambrian" -- the informal name for the eons that came before the current Phanerozoic eon.  Although the term Precambrian has no formal status on teh geologic time scale, it has been traditionally used as though it does.

Hadean is another informal term that is found on some versions of the geologic time scale and is used by many geologists.  It refers to the earliest interval (eon) of Earth history -- before the oldest-known rocks.  When the term was coined in 1972, the age of Earth's oldest rocks was about 3.8 billion years.  Today that number stands at slightly greater than 4 billion, and, of course, is subject to revision.  The name Hadean derives from Hades, Greek for underworld -- a reference to the "hellish" conditions that prevailed on Earth early in its history.

Effective communication in the geosciences requires that the geologic time scale consist of standardized divisions and dates.  So, who determines which names and dates on the geologic time scale are "official"?  The organization that is largely responsible for maintaining and updating this important document is the Interanl Comittee on Straigraphy (ICS), a committee of the International Union of Geological Sciences.  Advances in teh geosciences require tha tthe scale be periodically updated to included changes in unit names and boundary age estimates.

For exmaple, the geologic time scale shown in 

Neil Freeman's Fake is the New Real

The Website is HERE

Hackbright Music Class Project

Two Women in STEM Articles - NYT & The Atlantic

Women in Cryptocurrencies Push Back Against 'Blockchain Bros' - NYT

"Women always question if they're qualified," one female cryptocurrency investor said.  "But look at these clowns around us."

The More Gender Equality, the Fewer Women in STEM

Though their numbers are growing, only 27 percent of all students taking the AP Computer Science exam in the United States are female. The gender gap grows worse from there: Just 18 percent of American computer-science college degrees go to women. This is in the U.S., where many college men proudly describe themselves as “male feminists” and girls are taught they can be anything they want to be.

Meanwhile, in Algeria, 41 percent of college graduates in the fields of science, technology, engineering, and math—or STEM, as it’s known—are female. There, employment discrimination against women is rife, and women are often pressured to make amends with their abusive husbands.

So what explains the tendency for nations that have traditionally less gender equality to have more women in science and technology than their gender-progressive counterparts do?

According to a new paper published in Psychological Science by the psychologists Gijsbert Stoet, of Leeds Beckett University, and David Geary, of the University of Missouri, it could have to do with the fact that women in countries with higher gender inequality are simply seeking the clearest possible path to financial freedom. And typically, that path leads through STEM professions.

The issue doesn’t appear to be girls’ aptitude for STEM professions. In looking at test scores across 67 countries and regions, Stoet and Geary found that girls performed about as well or better than boys did on science in most countries, and in almost all countries, girls would have been capable of college-level science and math classes if they had enrolled in them.

But when it comes to their relative strengths, in almost all the countries—all except Romania and Lebanon—boys’ best subject was science, and girls’ was reading. (That is, even if an average girl was as good as an average boy at science, she was still likely to be even better at reading.) Across all countries, 24 percent of girls had science as their best subject, 25 percent of girls’ strength was math, and 51 percent excelled in reading. For boys, the percentages were 38 for science, 42 for math, and 20 for reading. And the more gender-equal the country, as measured by the World Economic Forum’s Global Gender Gap Index, the larger this disparity between boys and girls in showing science to be their best subject. (The most gender-equal countries are the typical snowy utopias you hear about, such as Sweden, Finland, and Iceland. Turkey and the United Arab Emirates rank among the least equal, according to the Global Gender Gap Index.)

The gap in reading “is related at least in part to girls’ advantages in basic language abilities and a generally greater interest in reading; they read more and thus practice more,” Geary told me.

What’s more, the countries that minted the most female college graduates in fields such as science, engineering, or math were also some of the least gender-equal countries. Stoet and Geary posit that this is because the countries that empower women also empower them, indirectly, to pick whatever career they’d enjoy most and be best at.

“Countries with the highest gender equality tend to be welfare states,” they write, “with a high level of social security.” Meanwhile, less gender-equal countries tend to also have less social support for people who, for example, find themselves unemployed. Thus, the authors suggest, girls in those countries might be more inclined to choose STEM professions because they offer a more certain financial future than, say, painting or writing.

Modernizing the New York City Subway

“People know that the system is old, but I don’t think they realize just how old it is… in our system, it’s not just the architecture that’s 100 years old. It’s a lot of the basic technology, as well. The infrastructure is old.”

From the MTA in New York City, this is CBTC: Communications-Based Train Control, an astounding behind-the-scenes video about the technologies running the NYC subway system. Get a gander at West 4th Street station’s electromechanical relays, a pre-1930s technology that’s no longer supported by anyone but the MTA themselves. Plus, learn about their multi-decade plan to modernize the traffic control system, and see the Corona Subway Maintenance Shop, temporary home of the new CBTC-equipped subway cars.

As Service Delivery Division VP & Chief Officer Wynton Habersham explains, Communications-Based Train Control provides constant, centralized data about a train’s location, direction of travel, and speed, a leap forward from the safe but less precise fixed block signaling of the current system. The MTA invested seven years into converting the L train (14th Street – Canarsie Local) to CBTC, and is currently working on the 7 line (the Flushing local and express).