Monthly Archives: June 2014
It crawls… It creeps… It eats you alive!
How money or value or perhaps even The Blob grows. In the simplest of all settings, interest can be as straight forward as, I’ll loan you $10 for a hamburger today, and you pay me back $11 on Tuesday. In this case, Wimpy is taking out a loan of $10 at 10% simple interest.
That’s great for a cartoon, but it’s not the case in most real-life examples of interest. In real life, a loan you take today might accrue interest every year, month, day, or even continuously. Although the last case is one of the most interesting ones as it deals with a special number ‘e’, I just want to address the more intuitive cases.
Let’s say Wimpy is keen on that hamburger today, but he won’t have any cash until Tuesday again. This time, his usual rubes are all cash strapped as well, so poor Wimpy has to go to a formal lender. This lender is OK with the loan, but as insurance against Wimpy’s ability to pay back the loan on time, he insists on compounding interest every week.
“Let’s be clear about this Wimpy,” his loan officer says, as he walks him through the conditions. “You can have your $10 today at 10% interest. The loan is due on Tuesday, and that will come to a total of $11. If you can pay it off then, great. But if you need more time, we will be compounding the interest – that means that you will essentially be getting a new loan of $11, at the same 10% rate.”
“OK,” says wimpy and leaves his mark on the loan document.
This is exactly the right way to think about it.
- initial loan is made: $10 at 10%, due in one week.
- If the loan continues, another 10% is charged on the new total.
- Week after week, this goes on until Wimpy can pay up or he’s referred to collections and they repossess his barbershop.
Mathematically, this takes the Principal (loan amount ) and multiplies it by 10% every week.
- week 0: $10
- week 1:$10 + 10% = Principal x 1.1 -> $11.00
- week 2: ($10 + 10%) x 110% = (Principal x 1.1)2 -> $12.10
- week 3: (($10 + 10%) x 110%) x 110% = (Principal x 1.1)3 -> $13.31
This can be generalized by the formula:
Amount owed at time t = P (1 + R)t
Where P = principal
R = rate (expressed as a decimal)
T = the number of times interest is compounded
(whether its days, years, months, whatever)
(10)(1+.1)3 -> $13.31
This goes for any compounded growth.
The Blob arrived in Downingtown, PA in 1958. At first it was just something riding into town on a meteorite. But soon after, an old man touched it and got it stuck to himself. Steve McQueen comes to the rescue and gets the old fellow into town to see a doctor. Meanwhile, it becomes evident that the blob is not letting go, and is hurting terribly. Dr. Hallen decides to amputate, but before he can, the blob grows large enough to eat the old man, then a nurse, and then the doctor.
From then on, the thing just keeps growing. Let’s say it grows at a rate of about 50% an hour and use the same formula…
- hour 0: 100g
- hour 1:100g + 50% = Principal x 1.5 -> 150g
- hour 2: (100 + 50%) x 150% = (Principal x 1.5)2 -> 225g
- hour 3: ((100 + 50%) x 150%) x 150% = (Principal x 1.5)3 -> 338g
- hour 24: ——-à ->1,683,411g
You can really see how this thing gets huge fast (or at least massive, we never talked about the density of this thing).
Graphically, the blob’s growth looks like this:
One troubling thing is that this could also represent the balance on a credit card that isn’t attended to.
“It crawls… It creeps… It eats you alive!”
-Tagline, The Blob 1958
For a good explanation of interest, compound interest, and ‘e’ – check out Khan Academy’s lectures on this or this site that does a great job illustrating the difference between several types of interest.
Matting down the grass
I put on a stern voice every morning as I try to get my dog, Penny, to ‘go poop’ after her breakfast. She wanders about, obviously taking in something more than I can perceive. She circles a spot and smells intently making a slight move as if – no. That was the wrong place. She bounces away and starts mimicking a tracker again, following some invisible trail.
I imagine that I am helping her.
Despite my frustration with the dog this morning, I start doing exactly the same thing later in the day. I just arrived at the library to do a bit of quick studying (for the Chem Praxis Exam), do some research (regarding a product I am consulting on), and check email before I head over to the Enterprise Center of Johnson County (ECJC) for a lunch seminar. Because I arrived just at opening, there is nothing but space here and only a very few people. Like my dog – or like Dr. Sheldon Cooper trying to find a good movie seat, I go through the same antics.
I’ve wandered around for a while looking, then tried a few possibilities, and even now I’m sitting at what is decidedly NOT the right place.
I need to get something (other than this) done, so I think I’ll try just one more place and get to work.
In writing a quick post for one of my other blogs I came across the studio of Joanna Katchutas, who made a piece of artwork that I thought worked well with the piece. Check out that post – about the game and film, Clue, here.
Evidence of Man for Eons to Come
I don’t mean to exclude women at all, in fact, I really mean that evidence of humans show signs of lasting for eons to come, but it just didn’t sound like a title to me.
Enter Plastiglomerate rock.
Science magazine explains, ” When the plastic melts, it cements rock fragments, sand, and shell debris together, or the plastic can flow into larger rocks and fill in cracks and bubbles to form a kind of junkyard Frankenstein.” Hawaii appears to have just that perfect mix of steady volcanic activity and trash-generating humans to spawn these new rocks.
Patricia Corcoran, of the University of Western Ontario in London, Canada, describes how the accumulation of plastic waste material since the 1950s has resulted in this phenomenon of plastic entering into the fossil / geologic record. The unique characteristics of Pacific Ocean create what is known as the North Pacific Gyre, that collects and concentrates waste of all kinds into an area known as the Eastern Garbage Patch. Kamilo beach, located on the southern tip of the big island, provides an excellent place for this vast amount of marine – and now human- debris to accumulate. Once this trash – including a significant amount of long-lived plastic- comes into contact with the volcanic islands of the Pacific, it has the opportunity to become fused, via the heat of the lava, with this igneous rock and sand resulting in the newly minted plastiglomerate rock which can now settle onto the sea floor and become a ‘permanent’ part of the fossil record. Perhaps these rocks will become the coprolites of our age, abundant records of our waste, for future generations to find.
It’s not just the ears. They eye’s have it too.
The Hair of the Dog post I wrote last week came from my own tendency to play depressing music when I am feeling down and how this technique does not seem to be doing me any good. According to the article I cited, this may put me in the ruminator category of folks who try to use this music to list their spirits (or at least hope that it may), but fail at escaping the downward spiral.
About the same time, I was watching Penn and Teller’s show about the BS we often believe in, but that is seldom true. In the episode I watched, they brought up the way color also feeds into our psyche making us tend to want to eat or not depending on the colors and pairings. They pointed to the ubiquity of red and yellow in fast food signs, logos and buildings to support their claim that franchises were exploiting this aspect of out brain’s wiring. The visual communication guy, a graphic art consultant, writes about this on his site, referring to it as the ketchup and mustard effect. Another design blog demonstrates how often this is used by listing a sampling of fast food logos like McDonald’s. Amongst the research journals, Satyendra Singh wrote a review of the literature supporting this conclusion for the Journal, Management Decision. Dr. Singh’s article proposes that, “managers can use colors to increase or decrease appetite, enhance mood, calm down customers, and, reduce perception of waiting time, among others.”
We would be fooling ourselves if we thought that we were not being constantly manipulated subconsciously by retailers, restaurants, and other marketers. Election campaign ads come to mind immediately) But how do you feel about this manipulation? Frankly, I think it’s just what I would expect – and moreover, exactly what I would do myself if it was my job to bring in and retain customers.
strutting and fretting
I just signed up to take the Praxis exams on Biology and Chemistry. These are content knowledge exams for those who are interested in teaching these subjects at the High School level. I’ve been teaching biology for several years and have been immersed in it for about fifteen years before that, so I’m not terribly worried about that one (although I may need to read up on some botany, as I largely ignore it in my classes – my apologies to any botanists out there.) Despite some low-level understanding of chemistry and familiarity with organic chemistry, it does worry me. There’s a lot of potential information to cover and I have about three weeks to get re-acquainted with the subject.
Why am I doing this? A good question. Because adjunct teaching is neither fulfilling (you never feel a part of something, but merely an add-on), nor rewarding (financially).
-Whoa! Wait a minute, doc. You’re not seriously thinking of teaching in a High School as a way to get paid well, are you?
No. Just paid.
Kansas has what it calls an ‘alternative pathway’ to a ‘restricted’ teaching certification. It’s designed for professionals with strong backgrounds in math and science, and are interested in a career change to teaching.
It’s heavily advertised on the radio here (at least on NPR, the non-profit, public radio station). However, most school administrators I’ve spoken with are unaware of the program.
Further, I’ve also heard that taking on educators with restricted licenses means that these teachers cannot qualify as
In order to get into the program (in addition to the classes you’ve taken in the subject’s content), you have to:
- pass these Praxis exams to prove you actually do know the content and not just a dusty piece of paper from University.
- Find a school that needs you
- Get that school to provisionally hire you
- Enroll in a program to earn your certification while you teach.
So far, I’ve signed up to take the exams and found a school that is willing to entertain the idea of taking me on so long as I can teach both biology and chemistry.
What is not entirely clear to me is whether these restricted licenses are considered ‘full’ licensure. The ‘No Child Left Behind’ Law requires all teachers to be ‘Highly Qualified’ and then defines that as:
Highly Qualified Teachers: To be deemed highly qualified, teachers must have: 1) a bachelor’s degree, 2) full state certification or licensure, and 3) prove that they know each subject they teach.
Currently, I am proceeding under the understanding that these programs do talk to one another and that the restricted licensure will not leave someone unable to meet federal demands.