#ScribePost Luke 23.1-23.3

Sorry about the lateness of this scribe post; it totally slipped my mind over fall break so my bad.

I’ll be covering the class from Tuesday (10/11) and the class from today (10/17) in this Scribe Post.

Tuesday (10/11)-

We started off today by watching a few YouTube videos, one of which we had already watched at the beginning of the year in class.

1. “7 Billion, National Geographic Magazine” was the first one that we watched. This video is all about modeling human population growth exponentially and the threats of over-population to our planet.

Here is the URL: http://www.youtube.com/watch?v=sc4HxPxNrZ0

2. The next video that we watched, “7 Billion People: Everyone Relax!” was a video response to the previous one which argued that human population growth is in fact best modeled after a linear, not exponential, growth rate and that our populations rapid increase is really not that much of a problem because we will reach a carrying capacity, go down, and then be back at 7 billion in 75 years. So, essentially, everything’s fine, everyone chill out. Here is the URL: http://www.youtube.com/watch?v=iodJ0OOdgRg
3. The third video, “Distilled Demographics: Deciphering Population Pyramids,” dealt with population pyramids, obviously. I think that Jojo just turned the sound down and spoke over this video. I had a little trouble finding the video online because all I had in my notes was “Population Pyramid,” so I’m not certain if this is the right video, but I believe so. Here is the URL: http://www.youtube.com/watch?v=sSoSYm4AOls

We didn’t just watch videos in class, we also started in on chapter 23. Here are my notes from that part of class:

Chapter 23.1-

• This formula is used to model population growth: A = P(1+r)^n
• Population growth is an exponential, as opposed to a linear growth rate
• r=rate of natural increase = birth rate / death rate
• P = population
• M = carrying capacity
• Growth rate = r(1-(P/M))
• When solving A = P(1+r)^n r=growth rate not the r that equals the rate of natural increase

We also did some classwork and here is that:

Page 849 Questions: #3 & 5

3. 1.7% = r = .017 25 = n 3,617,000,000=P

P(r+1)^n = 5,595,104,568

5. 818,000,000 = P n = 24 r = .024

P(r+1)^n = 1,284,497,816

Today, Monday (10/17)-

Today we went further into chapter 23, clarifying some confusion to do with the Growth Rate. To clarify any conclusion:

Growth Rate = r(1-(P/M))

If you’re confused about the variables in this equation, see the notes from 23.1 from the previous section of this Scribe Post.

We spent most of class today dealing with Chapter 23.3, here are my notes:

23.3: Nonrenewable Resources

• Nonrenewable resources are resources that cannot be renewed (I know, shocking, but try to bear with me)
• The usage of non-renewable resources can be modeled through this formula:
• A=d(((1+i)^(n)-1)/i))
• The static reserve is the time the resource will last with a constant rate of use.
• Supply / Use à S/U
• The exponential reserve is the time that resource will last given constant use that increases geometrically with the population.
• S=supply, U=Use, r=rate of usage, n=exponential reserve à n=(ln(1+(S/U)r))/(ln(1+r))

The next scribe is Kenan!

Kenan is out of the country and so if he is not back by tomorrow's class the next scribe will be Sarah!