I love studying and writing about science, especially as it relates to Christianity. However, I do have other writing interests. For example, every now and then, I write a “drama” for my church. Usually, these “dramas” are more like skits, and their purpose is to drive home a point in the pastor’s sermon. For yesterday’s service, the pastor wanted something that illustrates the fact that we are more likely to help lead people to Christ if we aren’t judgemental towards them. As I prayed and thought about what I would do, I decided to bring out the “Box of Sin.”
This is a device I use every now and again in my dramas. It is just a cardboard box that has the word “Sin” on it, but it is a great way to symbolize a person being lured into sin and becoming trapped as a result. You can use it for many different kinds of illustrations, such as the way I used it in the drama below. As with all of my dramas, feel free to use this one in any way you think will serve the body of Christ. I would appreciate a credit if you use the drama mostly as written. However, if you take the idea and make something relatively new, please don’t feel the need to credit me.
Last night I once again debated Dr. Robert A. Martin, a vertebrate paleontologist who is professor emeritus at Murray State University. The previous debate was on the broad subject of creation versus evolution. This time, the organizers of the event wanted us to narrow our discussion, so we chose to talk about dinosaurs and people. Before I discuss the debate, I want to thank Dr. Martin for participating in it. I personally think the best way to understand an issue is to hear from multiple sides, so I think debates can be extremely helpful to those interested in controversial topics. However, it is difficult to get evolutionists to participate in debates about the creation/evolution controversy. I thank Dr. Martin for being committed to education strongly enough to be an exception to that general rule!
Since Dr. Martin had the weaker position scientifically, I allowed him to choose whether to present his case first or second. He chose to go second, so I was up first. The initial activities (songs, introductions, and remarks from the organizers) made it clear that for some reason, the audience this year was overwhelmingly creationist. The previous year, creationists were in the majority, but there were many evolutionists present. That didn’t seem to be the case this year, so I started by thanking Dr. Martin for being willing to act as a lion in a den of Daniels.
I doubt that you’ll see this reported in many news outlets, but way back in 2007, Dr. Wieslaw Maslowski, a research professor in the Department of Oceanography at the Naval Postgraduate School, stated that based on his research, the Arctic would be ice-free by the summer of 2013. His prediction was based on a “high-resolution regional model for the Arctic Ocean and sea ice forced with realistic atmospheric data,” and he thought it might be a bit conservative. In fact, he said:
Our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007…So given that fact, you can argue that maybe our projection of 2013 is already too conservative.
Well, as you can see from the graph above, Dr. Maslowski’s “too conservative” prediction has failed miserably. Not only is there ice in the Arctic, there is significantly more ice than there was in 2012. Now, of course, the amount of ice is still way below the average, but it is also way above zero, the prediction that Dr. Maslowski thought might be “already too conservative.”
When I first heard about the idea that radioactive decay might vary from the smooth, constant-half-life behavior that is typically observed, I was more than a little skeptical. As a nuclear chemist, I am well aware of how much energy it takes to affect nuclear processes. Since those energies are not generally attainable except with the use of a particle accelerator, a magnetic containment system, or some other high-powered device, it seemed absurd to think that variable radioactive decay was anything other than the mad wish of those who didn’t like the conclusions of radiometric dating. However, over the years, the data have convinced me otherwise. I written a couple of posts about variable radioactive decay (see here and here), and it seems clear to me that it does happen, at least under some circumstances.
Recently, I came across another study on variable radioactive decay. It is actually a follow-up to a previous study,1, and it explores the alpha decay of uranium-232. As shown in the drawing above, alpha decay is one specific type of radioactive decay in which an unstable nucleus attempts to reach stability by spitting out two protons and two neutrons. Those four particles are bound together to form the nucleus of a helium atom, which for historical reasons is also called an alpha particle. It turns out that when uranium-232 does this, the resulting nucleus still isn’t stable, so a long series of further alpha decays occur, eventually producing lead-208, which is stable.
The authors of the study I am writing about weren’t interested in the subsequent decays. They looked specifically at the alpha decay of uranium-232. Under normal circumstances, this decay has a half-life of 69 years.* This means if I start with 200 uranium-232 atoms, after 69 years, only half of them (100) will remain. The other half will have decayed away. If I wait another 69 years, only half of those (50) will remain. In another 69 years, half of those (25) will remain. In the end, this is typically how radioactive decay works: the number of radioactive atoms ends up decreasing by half over every half-life.
The results of the study seem to indicate that a tabletop device involving a laser and gold can end up decreasing the half-life of uranium-232 by as much as a factor of 435,494,880,000,000!2
The video above shows you the jumping prowess of a juvenile Issus coleoptratus, a species of plant hopper. As its name implies, this insect hops from plant to plant, eating sugar directly from the veins of the plant’s leaves. Believe it or not, jumping is a rather difficult way to travel, because once you are in the air, you don’t have a lot of control over your body’s movement. As a result, the jump itself is very important. Not only must it be aimed correctly, it must happen so that the body stays upright throughout the time it is in the air.
That latter task can be a bit difficult. Imagine, for example, if an insect pushes off really hard with one leg, but not very hard with the other leg. This imbalance would cause the body to start spinning in the air, which would make for horrible aerodynamics and a very difficult landing! The same thing would happen if the pushes were not timed very well between the legs. If one leg started pushing sooner than the other, the insect would once again go spinning out of control. Most jumping insects are designed to deal with this by having their jumping legs arranged on either side of the body. This gives them a larger margin of error when it comes to both the timing and the force of each leg. This is convenient, but it also inherently limits how high and far the insects can jump.
For species of insects that must jump really high and far, the legs must be right under the body. This maximizes the amount of force that goes into the jumping motion, but it also allows for only a tiny margin of error in terms of the timing and relative force of each leg. As a result, these species must coordinate their jumping legs very, very precisely.
It has long been known that the species of jewel wasp pictured above (Nasonia vitripennis) can mate with another species of jewel wasp (N. giraulti), but the male offspring die in their larval stage. This, of course, keeps the species separate. Scientists have always assumed that the death of the male larvae must have something to do with an incompatibility between the two species at the genetic level. However, a recent study indicates that’s not true. The real reason the males die off is because their bacteria are incompatible with them.
Each species has bacteria living in its gut, helping it digest food, fight off infection, etc. However, the actual mix of bacterial species is different in each wasp species. When male larvae that came from the interbreeding of the two species were given antibiotics to kill off those bacteria, the larvae were able to survive. They weren’t incredibly healthy, but they were as healthy as purebred wasps that also had no bacteria living inside them. However, when bacteria from either species were introduced back into the larvae that came from interbreeding, they died! In the end, then, the males don’t die because of genetic incompatibilities. They die because of bacterial incompatibilities. As ant taxonomist Dr. Corrie Moreau commented:1
I would never have predicted that…We were blown away.
So in some way that we don’t currently understand, the bacteria that live in the gut of these two species of jewel wasps so fundamentally affect their development that the wasps cannot survive unless they are compatible with a specific mix of bacteria. Interestingly enough, this isn’t the only case of bacteria affecting the development of an animal.
As if I have not been harping on this enough, I have a new book out. It’s called Science in the Beginning, and it’s an elementary science course that uses the days of creation as reported in Genesis to introduce scientific concepts. The course is very hands-on, with an experiment or activity in every lesson. One of the homeschooled students who field-tested the course, Ryan McFall, has been kind enough to allow me to show pictures that were taken while he was performing some of those experiments. This one is about diffusion.
First, soak an egg in vinegar for a day or so:
The vinegar will slowly react with the calcium carbonate shell of the egg, turning it into a salt (which dissolves in water) and a gas (which bubbles away). In the end, you are left with an egg that has no shell:
One of the features of the mammalian brain is a structure called the hippocampus. Since the brain is split in half, every mammal has two hippocampi, one on each side, as illustrated in the drawings of the human brain above. These structures are very important for the formation of memories as well as spatial navigation. The reason I am telling you all this is because an incredibly interesting study was just published in the journal Cell, and it uses the aftereffects of the atomic bombs (both their use and testing) to pin down the specifics of how many new brain cells people make in their hippocampi throughout their adult life.
At one time, it was considered a rather strong scientific fact that adult mammals do not produce new neurons (the cells that make up the basic building blocks of the nervous system). For example, An Introduction to Neural Networks (a textbook published in 1995) puts it this way:1
In mammals, although not in many other vertebrates, central nervous system neurons have an important peculiarity; they do not divide after a time roughly coinciding with birth. When a neuron dies, it is not replaced.
Prentice-Hall’s textbook, Exploring Life Science (published in 1997), tells us what this means for people:2
All the neurons you will ever have were formed by the time you were six months old.
We now know that such statements are incorrect. In a variety of mammals that have been studied, adults produce new neurons in the olfactory bulb (a part of the brain used in the sense of smell) and the hippocampus.3 This new study uses a technique that shows adult humans produce a significant number of new neurons in their hippocampi, but they probably don’t produce new neurons in their olfactory bulbs.