November 2016 : Proslogion

Antarctic Ice Still a Mystery

A German ship (The Gauss) in Antarctic Ice, in Antarctic Ice, as seen from a balloon in 1901. (credit: National Oceanic and Atmospheric Administration/Department of Commerce) — A German ship (The Gauss) in Antarctic Ice, as seen from a balloon in 1901.
(credit: National Oceanic and Atmospheric Administration/Department of Commerce)

Ice in the Arctic has been on a shaky-but-steady decline for the past 25 years, perhaps even longer. Many point to this decline as evidence for global warming. If that were the case, however, ice in the Antarctic should be declining as well, but it isn’t. A recent scientific paper that attempts to put Antarctic sea ice in historical context states this problem succinctly:

In stark contrast to the sharp decline in Arctic sea ice, there has been a steady increase in ice extent around Antarctica during the last three decades, especially in the Weddell and Ross seas. In general, climate models do not to capture this trend and a lack of information about sea ice coverage in the pre-satellite period limits our ability to quantify the sensitivity of sea ice to climate change and robustly validate climate models.

In other words, the computer models that are based on our understanding of global climate predict that global warming should be causing a decline in both Arctic and Antarctic sea ice. However, that’s not what’s happening, at least according to the satellite record, which has been around for a little over 35 years. As a result, the authors of this paper decided to do something innovative: attempt to find out how much ice was in the Antarctic roughly 100 years ago.

How did they do it? They examined the logbooks of explorers who attempted to reach the South Pole during the Heroic Age of Antarctic Exploration, which took place from the late 1800s to the early 1900s. Using those logbooks, the authors were able to produce what seems to be a fairly accurate map of the edge of Antarctic sea ice during that time period. However, these data don’t help to resolve the conflict between the Arctic ice record and the Antarctic ice record. In fact, they seem to amplify the problem.

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The Latest Numbers on Homeschooling From The U.S. Department of Education

Homeschooled students building a trebuchet (click for credit) — Homeschooled students building a trebuchet
(click for credit)

Roughly every four years, the United States Department of Education produces a report of statistics related to homeschooling. Their 2016 report, which covers statistics from 2012, was recently released, and it contains some interesting results that I think are worth discussing. Before I do that, however, it is important to note the limitations of this report.

Since each state has its own laws regarding home education, it is very difficult for the federal government to track homeschooling families. As a result, the estimates regarding the number of homeschooled students is probably low and the sample that was studied is probably not totally representative of the homeschooling population. Also, the detailed statistics are based on a survey called the “Parent and Family Involvement in Education Survey.” Of the more than 17,000 students covered in that survey, only 397 were homeschooled. Thus, the statistics are based on a relatively small sample of students. Nevertheless, some of the results are worth noting.

First, the report tries to adjust its results to take into account the fact that it can’t track all homeschooling families. Based on the data and the subsequent adjustments, the report estimates that there were 1,773,000 students being homeschooled in 2012. This did not include students who were being temporarily homeschooled (because of a long-term illness, for example). This translates to roughly 3.4% of the population, which represents a doubling of the percentage of homeschooled students in 1999 and an 18% increase from the time of the previous report (2007). Needless to say, then, homeschooling is becoming more common.

Before I give you the next interesting statistic, I want you to think about the answer to the following question:

Are homeschooling parents generally more or less educated than the rest of the population?

I have heard people suggest both answers to that question. Some view homeschoolers as people who do not value “real” education, so they are less educated, on average, than the rest of the population. Others view homeschoolers as those who value education more than the rest of the population, so they are more educated. Based on this survey, the education level of homeschooling parents is roughly equivalent to that of the rest of the population. 25% of homeschooling parents have a Bachelor’s degree, while according to the U.S. Census Bureau, 32% of U.S. adults have one. 18% of homeschooling parents have a graduate or professional degree, compared to 12% of U.S. adults. Only about 2% of homeschooling parents don’t have at least a high school degree, compared to about 12% of U.S. adults.

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Radiation Probably Did Harm the Apollo Astronauts

The astronaut in this Apollo 17 photo was probably harmed by the radiation to which he was exposed on his voyage.

The earth has been magnificently designed for life. Amongst its amazing contrivances for nurturing and protecting living organisms, its magnetic field shields its surface from most of the high-energy radiation to which it is exposed. If it weren’t for this protective shield, life as we know it could not exist on earth. So what happens when people venture beyond that protective shield? A recent paper in the journal Scientific Reports attempts to answer that question by studying astronauts. While it suffers from the unavoidable weakness of using a very small group of individuals, the results presented in the paper are very interesting.

The researchers who wrote the paper examined five women and 37 men who had spent some time in space. All five women and 30 of the men experienced low-earth orbit, while seven of the men were a part of the various Apollo missions that went to the moon. These astronauts were compared to three women and 32 men who have been trained as astronauts but have never gone into space. Both of those groups were also compared to the U.S. population of the same age range. Specifically, the researchers were looking for the mortality rates among the astronauts, as well as what caused their deaths.

What they found was that the astronauts who never went into space were less likely to die from cardiovascular disease and other common ailments (such as cancer) than the rest of the population in the same age range. This makes sense, since health is one of the factors used to choose astronauts, and their training keeps them healthy. However, they were more likely to die from accidents than the rest of the U.S. population. Once again, this makes sense, since being an astronaut is a dangerous line of work.

However, when the astronauts who never went into space were compared to the Apollo astronauts, there was one striking difference.

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The Reviews (At Least Some of Them) Are In!

If you haven’t been reading this blog for a while (and didn’t notice the ad on the right), you might not know that I have written a new high school chemistry course: Discovering Design with Chemistry. My previous course, Exploring Creation with Chemistry, Second Edition, was updated by different authors, and I didn’t like the result. Consequently, I thought it necessary to write a new course so that home educated students could have a scientifically accurate, user-friendly, up-to-date resource with which to study chemistry at the high school level. I already discussed the user-relevant differences between my old chemistry course and my new one, so I won’t rehash that. Instead, I want to share some reviews and comments the new course has received.

I will start with the most recent one, which comes from a teacher who is facilitating classes that use the book. She discusses the fact that my old chemistry course prepares students very well for chemistry at the university level, and then she says:

Wondering about Dr. Wile’s new Chemistry text? We’re about 1/3rd of the way through the text at two class day programs. There are new experiments, which are a great addition to the topics. The topics go a little more in depth and are in a different order than the previous edition.

I highly recommend his new textbooks, including his new elementary series which I’ve taught to 5th/6th grade students for over a year now.

I am really glad that she mentioned the new experiments, because I think they are the main reason to use my new chemistry course instead of a used copy of my old chemistry course. The old chemistry course is still a good one, but the experiments in the new course are significantly better. If you would like to see some of them, this student is posting videos.

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