April 2019 : Proslogion

You Just Never Know What Will Inspire a Student

Spoons used as resistors in series (left) and in parallel (right).

In my high school physics course designed for homeschooling, I cover the standard topics that are considered important in preparing a student for university-level physics. One of those topics is resistance in electrical circuits. Unless you are dealing with exotic substances at very low temperatures (superconductors), all materials that conduct electricity resist the flow of electrons to some extent. A good conductor has a low resistance; a poor conductor has a high resistance. The amount of resistance in an electrical circuit and the voltage of the power source determine the amount of current flowing through the circuit, so it is important to be able to calculate a circuit’s overall resistance.

When resistors are connected so that the electricity must flow through each one of them, we say that the resistors are hooked in series. Notice how the spoons are connected in the left-hand photograph above. If I hook a battery up to the handle of the right-hand spoon and the head of the left-hand spoon, electricity would have to flow through both spoons to get from the negative side of the battery to the positive side. That tells you the spoons are hooked together in series.

When resistors are connected so that electricity has a “choice” about which resistor to travel through, we say that the resistors are hooked up in parallel. Notice how the spoons are connected in the right-hand photo above. If I were to hook a battery to the handle and head of the bottom spoon, the electricity would only have to travel through one of the two spoons to go from the negative side of the battery to the positive side. That tells you the spoons are hooked together in parallel.

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No, Scientists Did Not “Partially Revive” Pig Brains!

One conception of a pig’s brain being kept alive outside the body. (modified from the linked image)

As anyone who reads my blog knows, I have a rather low opinion of science “journalism.” In my experience, most science “journalists” know little about journalism and even less about science. As a result, what they publish is often so misleading that it just adds to the level of scientific ignorance that is already shockingly prevalent in today’s society.

As a result, I was pleased to find that two different readers sent me two different articles about a recent experiment involving dead pig brains. They were both justifiably skeptical of what the articles were saying, and they asked my opinion. I am happy to oblige. The worst of the two articles can be found at Big Think. It is entitled “Yale scientists restore brain function to 32 clinically dead pigs.” It then goes on to say:

The image of an undead brain coming back to live again is the stuff of science fiction…But like any good science fiction, it’s only a matter of time before some manner of it seeps into our reality. This week’s Nature published the findings of researchers who managed to restore function to pigs’ brains that were clinically dead. At least, what we once thought of as dead.

None of this is true. The researchers have accomplished something that overturns the current scientific consensus about the survivability of neurons (the “workhorse” cells of the brain). They also might have developed a technology that will significantly improve drug testing, but they haven’t even come close to restoring brain function!

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Best Evidence Yet for a Black Hole!

Four images of the center of M87 constructed from data collected by eight radio telescopes on four different days. The bar represents an angle of roughly 14 billionths of a degree, and the circle represents the resolution of the system.
(click for credit)

In 1796, Simon Pierre LaPlace predicted that there are objects in the universe which are so massive that light cannot escape them. As a result, they would be “invisible” to us. These objects have become known as black holes. More than 100 years later, Einstein published one of the most successful theories of modern science: General Relativity. A year later, Karl Schwartzchild used Einstein’s equation to define a black hole and calculate its radius, which is now known as the Schwarzschild radius. While black holes captured the imagination of many scientists, Einstein himself did not like them. In fact, in 1939, he published a paper that attempted to show they cannot exist.

Over the years, however, several lines of indirect evidence have supported the existence of black holes. For example, astronomers can measure the speed of objects in orbit around other objects. The speed of the orbiting object indicates the mass of the object being orbited. In the center of a nearby galaxy charmingly named “M87,” there is a disc of hot gas that is orbiting so quickly that the mass of what is being orbited must be three billion times the mass of our sun. However, the size of the object is, at most, the size of our solar system. Those measurements are consistent with Schwartzchild’s description of a black hole.

Of course, it’s always possible that the speed measurements are wrong, or that there is a very massive object that is consistent with what we think a black hole might be but isn’t actually a black hole. Thus, we need some other means by which to analyze the object. That’s where the Event Horizon Telescope (EHT) comes in. Despite it’s name, it is not a single telescope. It is a combination of eight different telescopes that are found in different geographic locations. Those telescopes examined the center of M87 for several days, and their data were combined together to produce the images seen at the top of this post. They are exactly what one expects those telescopes to detect if the center of M87 is a black hole. Thus, as the title of this post indicates, they represent the best evidence to date for the existence of a black hole!

Now while these images are excellent evidence for a black hole at the center of M87, it is important to know what they are and what they are not.

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Robert Rowlett, Homeschool Graduate and Deputy Attorney General

I recently wrote about Hayley Bower, a homeschool graduate who earned a degree in Engineering Physics. When I interviewed her for that article, I also interviewed her boyfriend, Robert Rowlett. He is just as impressive as Hayley, but in a completely different way. He was homeschooled for thirteen years, kindergarten through 12th grade, and he had a very traditional experience. Unlike most homeschooled students, he didn’t get together every week with other homeschoolers in a co-op setting. Instead, he learned on his own and was entirely taught at home. His only co-op experience was teaching a co-op class.

By the time he was in high school, his parents noticed that he took after his grandfather, who had been a chancery court judge in Tennessee for 25 years. As a result, they signed him up for a homeschool speech and debate team. Initially, he found the public speaking experience nerve-wracking, but he got over that pretty quickly. As he told me:

It didn’t take six months of competing [in debate tournaments] and it became my entire high school…It’s what I loved doing, and I did it all the time.

Not surprisingly, the class he taught at co-op was a speech and debate class.

As you would expect from someone who loves speech and debate, he wanted to be an attorney. He decided to major in biology at Anderson University and then go to law school. As time went on, however, he found that the biology program was largely focused on preparing students for the medical profession, so he switched majors to political science. He ended up graduating in three and a half years magna cum laude as a member of the AU Honors Program. His B.A. is in political science with a minor in biology.

The semester before Robert graduated, an AU chemistry professor asked him to speak to a group of six incoming freshman who were recent homeschool graduates. The professor wanted Robert to share his thoughts on the transition from homeschooling to university. Guess who was one of those incoming freshmen? Hayley Bower! That’s how they met. So you could say that homeschooling is what brought them together.

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