The Math of GR (and SR)
Part 2
In Physics, in order to have a person/observer set up to make measurements on where an object is located and what time it is, he (or she) needs two things. One is a clock. That is the easy part. The second is: he needs to set up a Coordinate System. The method you all know is where you set up lines of latitude, longitude and altitude on the surface Earth. Then you have to give me these three numbers to know where something is.
If you are doing laboratory measurements, where the experiment is in a relatively small area, that would not be practical. The easiest method is to set up three perpendicular and straight rods that all meet at one point called the ORIGIN. See the picture.
This will represent "you," as an observer. When someone asks you where something is, you will use this to answer. How? First, you set up these three rods in the room. Then you hang an small ball in the room. WHERE the ball is can be answered using this procedure. (Next)
At this scale, it is easier to see that the trees are not under the influence of "artificial" gravity. It is real.
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The gravitational field around each blade of grass and tree is the same as the field around each blade of grass and tree on the surface of Earth.
Notice that if you drive on a road perpendicular to the cylinder axis, you will increase gravity driving one way and decrease it driving the other. If you drive opposite to the spin and at the radial speed, your gravitational field turns Minkowskian, and you are in a "free fall" or inertial coordinate system. That is, you and the car become "weightless."
That means this: The value of a gravity field can go from a surface-of-a-planet value to a free-fall value by a coordinate transformation among systems that are moving at a constant velocity with respect to each other.
At any instant of time, a car moving at the radial speed is in a Minkowski field, and a system at rest on the cylinder is in a planet-surface field. A ...
"Aja" is the title track of Steely Dan's 1977 album, and its meaning has been a subject of interpretation rather than a straightforward explanation from the band themselves, Walter Becker and Donald Fagen, who were known for their cryptic and layered lyrics. The song doesn’t tell a linear story but evokes a mood and imagery that fans and critics have analyzed over the years.
The word "Aja" is often speculated to refer to a person, place, or concept. One popular theory ties it to the name "Aja," which Becker and Fagen reportedly chose after learning of a Korean woman named Aja who married a friend of theirs. This fits Steely Dan’s tendency to draw inspiration from real-life fragments and transform them into something abstract. The lyrics—"Up on the hill / People never stare / They just don’t care / Chinese music under banyan trees"—suggest an exotic, serene escape, possibly a romanticized or imagined refuge from the complexities of modern life.
Musically and lyrically, "Aja" ...
"Deacon Blues" by Steely Dan, released in 1977 on their album Aja, is a richly layered song that invites multiple interpretations, blending the band’s signature irony, cynicism, and romanticism. Written by Donald Fagen and Walter Becker, the lyrics follow a narrator who seems to embrace a life of reckless abandon, yearning for a kind of mythic, self-destructive freedom often associated with jazz musicians or countercultural figures. Let’s break it down:
The title "Deacon Blues" itself is intriguing. It’s been suggested that it references football—the "Deacon" could nod to Wake Forest University’s Demon Deacons, a team whose colors are black and gold, though Fagen and Becker have said it’s more about vibe than a literal connection. "Blues" ties it to the musical genre, evoking a sense of soulful melancholy. In a 2003 interview, Fagen described the song as being about "a broken dream of a broken man living a broken life," but delivered with a sardonic twist typical of Steely Dan’s ...
