Monday, June 26, 2017

Heat Death

What is meant by “heat death”?

This is a topic that came up in class, but since it was only vaguely related to what we were actually talking about I did not take the time to explain it very well. Heat death is a theory about the ultimate fate of the universe. The second law of thermodynamics states that entropy increases over time in any closed system. In other words, available energy is always going to decrease unless there is energy being added. The earth has life, violent weather, and so on because the sun is constantly pouring energy into it, so the earth itself is not really a closed system. Meanwhile, however, the sun is slowly using up all of its energy, and one day it will burn out. Taken as a whole, the solar system is essentially a closed system (if you ignore the light, heat, and radiation that reaches us from the deep stretches of outer space). Taken as a whole, then, the universe itself is a closed system. As far as we know, the universe is using up energy and nobody out there is putting new energy into it. Therefore, the theory goes, the universe will eventually use up all the energy that is available to do work, and it will die cold and dark.

The notion of the universe as a closed system that is burning out raises an interesting question, related to the most interesting question that humans have ever asked: if the universe is constantly getting colder, and it has been in existence forever, why hasn't it burned out already? The obvious answer is that the universe has not existed forever. Scientists typically identify the Big Bang as the event that brought the universe into being. At the moment of the Big Bang event, the universe was at maximum energy. As time passes, the energy is used up, and it is decreasingly available to do work.

But what happened before the Big Bang? In a way, this is a paradoxical question. Time began at the Big Bang, and so there is no sense talking about what was there before. That does not stop people from trying to understand what could have happened. One popular theory is that there was a universe that existed before. It started with a Big Bang of its own, expanded and expanded, but then gravity slowly brought the expansion to an end, and then pulled that universe back together until it made a gravitation singularity, that then resulted in our Big Bang. According to this theory, the same fate awaits our universe, the universe that it is thus created, and so on forever.

Even though this theory is well known, possibly because it was popularized by Carl Sagan's Cosmos book series and television show, there are a couple of serious problems with it. First, there does not seem to be enough mass in the universe to get it to collapse back on itself. Maybe “dark matter,” which cannot be detected like other forms of matter, exists in sufficient quantities to allow the “Big Crunch” to take place. Second, the expansion of the universe is not actually slowing down, but accelerating! This is said to be the effect of something called “dark energy,” which scientists do not understand well. Nobody knows whether the universe is going to continue to expand faster and faster, all we have to go on is our observations, since the principle is poorly understood.

These two problems with the “Big Crunch” scenario leaves the question of how the universe has so much energy to begin with. Is there another principle that works against entropy? Some physicists believe in a steady state theory, which says that the universe as a whole does not operate by the rules of the second law of thermodynamics. There are various forms of this theory, but the proponents have not been able to observe phenomena that convincingly demonstrate their theories.

The “Big Crunch” theory connects to an interesting time travel paradox that I have been thinking about recently. Say that there is a giant war that makes it hard for the planet to sustain life. A few people, animals, and plants survive and find a way to eke out a living. Eventually civilization is rebuilt, and technology advances to a point where time travel is possible. A time traveler is convinced that it would be better if the catastrophic war had never happened, so she travels back in time to warn humanity about the cataclysmic effects of their military conflicts. Instead of doing what people usually do (continue on the road to self-destruction, only to realize after the fact that they had been foolish), they heed the warnings and destroy their extreme weapons.

The effect of this disarmament is that all the events that led to the birth of the time traveler and the creation of the time machine are erased. Of course this is a paradox, because now the warning can never come. But let's pretend that it doesn't happen. What happens instead is that the stretch of history from the time of the war up to the when the time traveler makes her trip becomes a type of “hypothetical loop.” That effect that all of those events have on the course of history is that it led to the time traveler, but other than that all of those events, people, everything that was built, made, dreamed, thought, and done is completely erased.

Now some people will speculate that history will continue now in two trajectories. The people who were left behind by the time traveler will continue in their own “universe,” while her arrival in the past creates a new trajectory that is, in effect, a different “universe.” Regardless of what happens to those people, everything that happens after she leaves is completely unknowable to the people she travels to save. Not only is it unknowable, though, it actually is a future that does not exist for those people who averted war. They eliminated that future when they chose peace over war.

This connects to the “Big Crunch” theory because, if this universe is crushed into nothingness to become a new universe, then everything that happens and in our future is a “hypothetical loop.” Not only will our existence not matter to the people of the next universe, there is no meaningful way in which we exist to those people at all, not even as a piece of their past. Time stopped and started again.

Other jobs

What would you do if you couldn't be a teacher?

I don't know. Here are some things that I would enjoy doing:

  1. Work with developmentally disabled adults. The problem with this as a career is that the pay is tragically low. There is definitely a lot of money invested by the government, parents, and others in the field, but very little of it trickles down to the people who actually work one-on-one with clients. Do you remember this past year when the minimum wage was increased, and they said that it would throw the industry into turmoil? It turns out that there are trained professionals who have been working in the field for decades who are not taking home $10 and hour!
  2. Write and perform puppet shows. I would particularly be interested in creating puppet shows that could be enjoyed by teenagers and adults. The problem with this sort of job is that I don't work well with fluid deadlines. I like daily deadlines so that I don't get too worried about whether I am doing enough work.
  3. Tech support. I have worked in this field before, and think that this is the sort of job I could actually get. The thing I liked least about working in this area is that I had to study every day to keep up with changes, and I felt that knowledge in this area is too ephemeral – you learn something only to have to replace that knowledge with something else. If I am going to study every day, I would rather study something timeless and meaningful.

The main requirements I have for a job are that I want to work with people I like on a personal level and admire on a professional level. That is why I am fortunate to work where I do.

Wednesday, June 21, 2017

Grades and Learning

Does having grades help or hurt students? (Because I heard of a school where going to class was optional and for the first two weeks students didn't go to class. After that they started going because they wanted to learn instead of being forced. I'm not sure if it's real, though.)

I have been curious about this for a long time, and I have taught classes that gave grades and others that didn't, so I have seen it from both sides.

Probably the most prominent critic of grades currently is Alfie Kohn. You might be interested in this article, in which he summarizes his analysis of the effect of grades on motivation. Kohn argues that giving grades makes students less interested in what they're learning, draws them to look for the easiest possible task, and reduces the value of their thinking. Students who are focused on getting better grades eventually come to see the grade and purpose of education, and they often lose a love of learning. Students at schools where grades are heavily emphasized, or who have parents who give them monetary rewards for grades, are more likely to cheat.

Kohn has some good insights and research to back up what he says, and I think that grades will often have a detrimental effect on students who are highly motivated to learn because of their own intrinsic curiosity. On the other hand, there are students who have low intrinsic motivation who will learn only if there is some extrinsic motivation. Since a modern classroom has students of all types of motivation, grades seem to be a necessary evil. Probably the best solution is to give grades, but not to focus on them as the sole goal of education. This is a hard balance to create, especially since parents have the central role in creating expectations, and so the school's role is limited. This summary of research has a good bibliography if you want to read further.

I used to teach non-credit classes at community college. Most of the pupils in these classes were senior citizens, but there were some younger people, too. Students are drawn to these classes for the purpose of learning, and there are no grades. I found these classes to be very enjoyable, and the students always did extra work to keep the discussions lively. If I could make a living teaching this type of class, I would enjoy it.

The difference between the students in a non-credit class and a public school setting is that the non-credit classes are completely voluntary, and the students are paying to attend. They therefore are made up of students who are intrinsically motivated. Since middle school and high school are compulsory, you have to develop the class to account for both types of students.

I should also say that I know of students who start school with a great deal of internal motivation, but struggles in one or two areas makes it hard for them to get exemplary grades, which causes their love of learning to deteriorate. Students like this can often start to feel like they are not valued because they repeatedly get sub-optimal grades, and it is hard to engage intellectually with a community that you feel does not value you. Evaluating students on their “sense of wonder” and “depth of inquiry” is designed to combat this deterioration, but it is hard to prevent in all cases. It would be nice if we could give grades only to those students who are not intrinsically motivated, but that is not possible.

There are also students who come to school brimming with curiosity who DO do well in school, but who attach their ego so strongly to the notion of “being an A student” that they replace their love of learning with a desire to do better than other students in the class. I hope that they get their curiosity back when they are older and are not constantly being evaluated.

I think the school you are referring to is Summerhill, which is an English school that has been around for almost 100 years. Classes there are optional, but tend to be well attended. There have been schools in many countries, including the U.S., that are based on the program. The school has supporters and detractors, but there is no denying that there have been numerous successful graduates. The reason the school is not necessarily a good laboratory for determining the best education for everybody is that it is a very expensive boarding school, and the students who are there tend to come from families that value learning enough to select a school like that. In other words, it is a selected community that does not represent the variety of students that wind up in a public school (or public charter school).

Tuesday, June 20, 2017

Why Do We Study Latin and History?

I received several questions that center around the theme of why we learn Latin or history, when very few students will use them.

Students often have a utilitarian view of education; if a class can be applied to your career, then there is a good reason for taking it – otherwise, no. For example, if you were planning to repair watches for a living, then a bezel-polishing class would be just the thing; if you were planning to be a police officer, it would be a complete waste of time. Likewise, very few students are going to “use” Latin or history (although definitely those who are going into medicine or politics clearly might), so what is the point of taking them in school?

The beauty of a liberal education is that it is not strictly utilitarian in intent. The word “liberal” comes from the Latin word “liber,” which means “free.” You would know this if you had spent as much time studying Latin as you do kvetching about taking it. In this case, a liberal education was created for “free” citizens – meaning those who are wealthy enough that they are free from having to have a vocation. Therefore, the object of a liberal education is to learn for the sake of learning, not to hone skills that a person needs in the workplace.

The subjects of Latin and history are important to free citizens because they connect us with our roots; they allow us to explore the great ideas of the past and to come to a better understanding of the foundation of our culture. They also give us a peek into the human mind. Everybody knows who Julius Caesar was, but who can tell us what he thought? What assumptions did he make about the people he fought against? What was his understanding of fate? Nobody can really think like another person, but reading Caesar in Latin can – to a certain extent – give you the ability to step outside of yourself and come closer to understanding somebody from a time far removed from our time.

The questions that a scholar of Latin and history studies are important because they give us a better perspective on truth itself, not because they are particularly useful in a specific job.

That being said, a liberal education has been shown to be a great foundation for further education in all fields. Every year graduates from our school get accepted to the most prestigious and competitive schools in the world. The upper echelons of scientists, artists, writers, mathematicians, engineers, and entertainers are populated by numerous people who have a classical foundation. The Latin Language Blog put together an interesting little list of people in various fields who studied Latin. Some of them, such as J.K. Rowling, use Latin in their work, while others merely use the intellectual tools they developed in the study of the classics and apply them in other fields.

More on Video Games

Another issue with video games that is of particular concern to educators, particularly in a liberal-arts school, is that it may affect the ability to focus on tasks that require extended focus without immediate payoff, such as reading long books. Video games can be long and involved, but they tend to be exciting throughout. Some people speculate that the brain might become accustomed to constant excitement, and therefore less able to deal with long, dry passages. I could not find any good research on this issue; so far most of what I found was speculative and not scientific.

A similar issue that comes up is “video-game addiction.” The human brain can become dependent on constant stimulation, and this looks a lot like addiction in the brain. There is a lot of research on this going on right now, and it looks like it is another reason to put a limit on the amount of time you spend playing.

I think the reason people find video games so compelling is that the tasks you complete in a game are similar to tasks you would complete in the wild. My dog loves hunting, digging, and chasing. In the wild, this is how a dog would make a living – and she LOVES it. If she could spend her whole day hunting for animals, she would.

While not all people hate their jobs, it is rare to find people who love their jobs as much as my dog loves chasing rabbits. I think that this is because our jobs are so far removed from the jobs we had when we were hunting and gathering. Video games give us a chance to do the jobs that our brains are wired to do: looking for things, running from danger, hiding, chasing, throwing, fighting, and so on.

Now, we live in civilization, and we have to adapt to more civil ways of getting by in the world. Maybe the reason our brains become “addicted” to video games is because we have a natural proclivity towards that mode of existence. Wouldn't it be cool if we could find a way to make our actual careers more similar to the careers of our “wild” ancestors?

Effects of Video Games

Do video games have any benefits for things like on-the-fly thinking?

Before I attempt to answer this question, let me say that this is an area of inquiry that is interesting to many different people for varying reasons, so there are studies updating and refining our understanding of the effect of video games coming out all the time. What I write here is provisionally based on the research I have done so far.

Moderate video game playing has numerous important benefits. The most well-researched of these benefits is an improvement in hand-eye coordination. It is most noticeable in tasks that are similar to video-game activities, such as firing a weapon and operating vehicles. Young adults who play video games are more likely to score high on military sharp-shooter tests, for example.

Another important benefit is that children who play video games learn new schools more quickly. The practice of adapting to changing situations makes the brain more flexible. This article describes neuroimaging results that show that the brains of children who play video games are better developed in areas related to learning than in children who play no video games. This has a noticeable effect on academic performance, as moderate video-game players typically do better in school.

There are also some bad effects of video games, particularly among children who play excessively. The best known of these effects is that video gamers typically are more aggressive, defiant, and report more conflicts with their peers. Excessive video game playing can also lead to social isolation.

The take-away is that video games are good, but you should limit your exposure to them. All of the positive benefits of video games seem to be available to people who play as little as an hour a week. The bad effects are seen most dramatically in children who play more than nine hours per week. So, if you can keep your gaming to a little over an hour a day, you are likely to avoid serious problems. If you do notice that you are getting short of temper, you may want to cut back a little to see if the problem stops.

Tuesday, June 13, 2017

Can Giraffes Vomit?

Can giraffes throw up?  If so, how long does it take?

A quick internet search will reveal that this is a question that numerous people can ask, but few can answer.  One of the main problems is that giraffes are very picky eaters; they take leaves one-by-one and taste them thoroughly before sending them down the neck.  Therefore, they have little reason to vomit.  That being said, they do have the physical apparatus necessary to vomit.

Giraffes are ungulates, and so they have to regurgitate their cud to re-chew it.  Ungulates do vomit occasionally, but since they have four stomachs it is most common for them to vomit from one stomach into another one.  It is much rarer for them to expel food from their first stomach into the open air for us all to enjoy.  It does happen occasionally that a deer or a cow has to spew regurgitated food out of their mouths, but this has not been observed in giraffes.  If a giraffe did have to get rid of nasty food that way, it could simply use peristalsis and hack up food and spit it out.  Since a giraffe's stomach ferments food instead of breaking it down with acid, the result would not be repulsive vomit like people spew out, but more like a chunky mass of fermented leaves and grasses.  Quite pleasant, actually.  By comparison, I mean.  Also, it would not spray forth like our puke, because the giraffe does not have the muscles necessary to violently expel their vomit like that.  There are a lot of positive perks to being a giraffe, but having the ability to spew a glorious rainbow of regurgitated food onto the heads of the members of the more altitude-challenged species is not one of them.  Sorry.

How long would it take?  Not very long at all.  If you have the time, it is possible to watch riveting videos of giraffes hacking up their food.  The cud comes up in a big wad, so you can watch it travel up the neck into the mouth.  Even with their enormous necks, the process takes between 1 1/2 seconds to about 3 seconds.