Taglines

This blog has had four different taglines in the course of its history. By popular demand, here are the explanations.

1. “Join me for a party in my mind.”

This line was an inside joke among my family and friends during my first years of blogging. As one particular birthday celebration was drawing to a close, I said something to the effect of “You can send me home any time you like, but I’m going to keep partying in my mind.” The phrase stuck, and was used whenever I did or said something odd — i.e. “Been partying too hard in your mind, Josiah?” At the time, I enjoyed perpetrating the notion that I was hilarious, interesting, and above all unusual. Moreover, the phrase included the word “mind,” which I thought would give the impression that I used it frequently. I designed a custom festive theme for the tagline, and began my new lighthearted blog.

2. “Party’s over, folks. This mind’s a war zone.”

After some time, I stopped viewing myself as a source of entertainment for others — or myself. I was working very hard to excel academically, socially, and occupationally, and wanted to be taken seriously. The tagline was meant to reflect on the battleground of ideas in which I thought myself furiously engaged. I added a background image to illustrate the point.

More than that, this was a time of intense mental turmoil for me as I sorted out my relationship with God (incidentally, the background image was created using a photo of Charles Templeton), my family members, and other people. There were many conflicting options about what I should pursue in life, and which things would have to “fall through the cracks.” I was eventually able to reach some conclusions and make some decisions that I could live with. However, the effort left me extremely drained, mentally, emotionally, and even physically — which leads nicely into the next tagline.

3. “The web’s first time graveyard.”

Not feeling as if I had anything left to say, and feeling too tired to really do much serious thinking, the blog took a hiatus of sorts. The theme was a blank white background with grey text. The tagline was taken from the middle of an unfinished and almost laughably brooding poem.

Not a soul to be found in this graveyard mind,

Nought is buried here but time.

4. “Stay if you like, but don’t expect too much — yet.”

The most recent tagline reflects my quantity-based approach to getting the blog going again. My Rhetoric teacher Pat Dolan wisely told us that the only way to improve our writing was to do more writing. I’m going to take that approach. It will likely take a while for my mental and creative juices to start flowing again after stagnating for some time, so don’t expect anything too interesting right away — but also don’t rule that possibility out! I’m hoping this blog is on the upswing! :-)

My Lab

Here are some pictures of where I spend most of my time.  Enjoy them if you want to.  Otherwise, do something else.

RS232 Serial Terminal on Linux

So, let’s say that you want to talk to an embedded device over the rs232 serial port, and you want a program like Hyperterminal or Putty for Linux. You’re in luck if you have “screen”! I’m going to assume you want to talk on COM1 at 115200 baud, with no parity, 1 stop bit, 8 data bits, and no flow control:

screen /dev/ttys0 115200 cs8 ixoff

The “no parity, 1 stop bit” part is the screen program’s default, and this is not settable (as far as I know). To enter a command (like “quit”), type “Ctrl+A” followed by a colon. See the screen man page for more details.

Columbus Solution

Well, that was embarrassing… Ok, so maybe I should have seen it coming.  After all, who does GEOMETRY any more, right?  I’ll try to think up a better contest next time.  But, the good news is that I get to come up with the content of my next several posts all by myself!  So, get ready for some good ones, now. ;-)

 

Solution:

Question 1:

Simply plug in the following into the well-know chord-length formula given here.

R = radius of earth = 6378.1 kilometers
theta = s/R = 14.92 km / radius of earth

a = 2*radius of earth*sin(14.92 km /(2*radius of earth)) = 14.9199966 km =>

14.92 km - 14.9199966 km =

3.4mm

Question 1:

The distance d is actually the length of the arc that subtends the angle a that the masts make with the center of the earth:
d = r*a => a = d / r

Knowing this angle a, we can calculate h according to:
r/(r + h) = cos(a/2) =>
h = (sec(d/(2r)) – 1)*r
h = (sec((14.92 kilometers) / (2 * radius of Earth)) – 1) * radius of Earth =

4.36271238 meters

 

Question 2:

Using basic trigonometry, we have
a1 = d1/r
a2 = d2/r
b1 = b2 = (π – (a1+a2))/2 = π/2 – (d1 + d2)/(2r)

Law of sines:
(h + r)/sin(π – a2 – b2) = (w + r)/sin(b2) =>
h = sin(π – a2 - b2)*(w + r)/sin(b2) – r

Plugging in,

At this point, it is reassuring to see that this simplifies to the formula in part a if you plug in d1 = d2 and w = 0.

The answer is
((cos(((14.92 kilometers) – (400 meters)) / (2 * radius of Earth)) * ((50 meters) + radius of Earth)) / cos((14.92 kilometers) / (2 * radius of Earth))) – radius of Earth =

50.2307916 meters

Question 4:

Plug into the fresnel zone radius formula given here:
d1 = 400 meters
d2 = 2km – 400 meters
wavelength = speed of light / 2 gigahertz

sqrt(speed of light * 400 meters * (2 kilometer – 400 meters)/(2 kilometers* 2 gigahertz)) = 6.92580633 meters =>

That means you have to be that much higher than previously stated:

57.1565979 meters