I Thought This Was Cool

I am working on an elementary science series right now, and I am up the point where I am looking for images to use in the first book of the series. While looking for images that were constructed using infrared light, I came across this one and thought it was really cool (click for credit):

The image is what an infrared camera sees when it looks at a snake wrapped around a person’s arm.

Remember, human eyes are not sensitive to infrared light. However, you can make cameras that see only infrared light. Generally, these cameras show you the amount of infrared light they are seeing by using a color scheme. In the picture above, for example, blue colors mean the camera is receiving a small amount of infrared light, red colors indicate a medium amount of infrared light, and yellow colors indicate a lot of infrared light.

The person’s arm “lights up” in yellow, because he or she is warm-blooded and is therefore warmer than the surroundings. Because of this, energy must flow from the person to the surroundings, and it does so mostly in the form of infrared light. As a result, the person’s arm emits a lot of infrared light. The snake, however, is not much warmer than its surroundings, because it is not warm-blooded. So it doesn’t lose much energy to the surroundings. As a result, it doesn’t emit much infrared light.

Using an infrared-sensitive camera to make such images is called thermography, and it can be used for various purposes, including seeing people in the dark.

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Amazing Ant Rafts



It has long been known that when some ants are faced with a flood, they build “living rafts” that float on the water in search of land. The earliest reference I know of to this phenomenon comes from the book Insect Architecture, which was published in 1838:1

The ants consisting of the basis of this group, lay hold of some shrub for security, while their companions hold on by them; and thus the whole colony, forming an animated raft, floats on the surface of the water until the inundation (which seldom continues for longer than a day or two) subsides.

So scientists have known about this for a long time, but how such rafts manage to float has been a mystery. You see, a single ant can float on water for two reasons: First, water has surface tension, and that tension must be broken in order for something to sink. If laid carefully on the surface of water, for example, a metal needle will float. Even though the density of the needle indicates it should sink, the water’s surface tension will keep it afloat. Second, the water-repelling nature of an ant’s outer covering (its exoskeleton) causes tiny bubbles of air to cling to it. The combination of the air bubbles’ buoyancy and the water’s surface tension keeps the ant afloat, but not by much.

Now…if I start stacking ants on top of each other, only a few of them will be in contact with the water. The water’s surface tension combined with the buoyancy of the ants that are actually in contact with the water just isn’t enough to keep the whole stack of ants afloat. Thus, something else must be going on when ants get together to form rafts.

A recent report on fire ant rafts was just published online in the Proceedings of the National Academy of Sciences, USA. It tells us what is actually going on in ant rafts, which is really quite fascinating.

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Ultrafast Underwater Traps

This video shows how the incredible traps used by bladderworts work. The narrator is hard to understand, but the video is worth watching.

When you study the living world, you can see how the Creator designed organisms to meet the needs of every ecosystem on the planet. Consider, for example, carnivorous plants. Plants form the foundation of many food webs. Using carbon dioxide and water, they convert the energy of sunlight into food for themselves, but they produce much more food than they need. As a result, they are used as a food source by many animals, which in turn are used as a food source by many other animals. Plants, therefore, are crucial to many ecosystems.

The food they make for themselves supplies plants with energy, but like all other organisms, plants need more than energy to live healthy and reproduce properly. They also need specific chemicals to build the molecules they need for survival. Most plants use their roots to absorb those chemicals from the soil. But what about places where the soil isn’t nutritious or it isn’t practical to absorb nutrients from it? Those ecosystems need plants as well, so there need to be plants that can survive in such places.

Enter the carnivorous plants. They capture and digest living organisms, but they don’t use those organisms for energy. Instead, the they use the organisms’ constituent chemicals as building blocks for all the elegant chemistry that they need to do. That way, they don’t have to absorb nutrients from the soil. Even the most barren soil can host carnivorous plants.

While all carnivorous plants are amazing in their own way, a recent study in The Proceedings of the Royal Society B has highlighted the amazing design of one type of carnivorous plant: the bladderwort (genus Utricularia).

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More on Mutualism

Sweet Potato Whiteflies (public domain image)
I write and speak a lot about mutualism (see here, here, here, here, and here, for example). Not only do I find it to be incredibly fascinating, but I also think it is a clear indication that the living things we see around us have been designed. Indeed, the various ways in which two or more organisms work together to survive are often so intricate and precise it seems crystal clear to me that these mutualistic partners were made for each other.

One of the very common types of mutualism you see in creation involves microorganisms inhabiting and helping plants, animals, and people. As I mentioned in a previous post, for example, our bodies are teeming with microorganisms, and without them, we would not be nearly as healthy. Animals and plants also harbor an amazing variety of microorganisms, which help them do such diverse things as digest cellulose (in the case of termites) and resist heat (in the case of panic grass). Well, I recently came across yet another example of mutualism between an animal and a microorganism, and it adds yet another level of complexity to the process.

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Birds Use Quantum Mechanics to Navigate?

A European robin like the ones used in the study
(Click for credit)
In a previous post, I mentioned that some Christians don’t like the idea of quantum mechanics. In fact, some take great pains to fight against it, considering it a threat to a Christian worldview. Whether or not you like a theory, however, has little to do with its validity. Only the data are important, and when it comes to the data, there is overwhelming support for the validity of quantum mechanics. As a result, it’s hard to fight against it. In fact, a recent study suggests that rather than fight against it, we should marvel at how God has used it to accomplish some truly incredible things.

The study focused on how European robins sense the earth’s magnetic field. Lots of animals have been shown to be sensitive to the earth’s magnetic field, and they use it to help them navigate. In some cases, such as that of the rainbow trout, it has been shown that the animal does this with magnetite particles in a certain tissue. Those particles move in response to the earth’s magnetic field, allowing the animal to use them to orient itself.1

Migratory birds and homing pigeons have also been shown to be sensitive to the earth’s magnetic field. Magnetite has even been found in the upper beaks of such birds, which lends support to the idea that they sense the earth’s magnetic field in a way that is similar to that of the rainbow trout.2 Oddly enough, however the magnetic sensitivity of these birds is affected by light. Yellow and red light, for example, disrupt the birds’ ability to sense the earth’s magnetic field.3 This is more than a little odd, since the motion of magnetite in a magnetic field should not be affected by light.

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More Good News for the Gulf!

Oil slick from the Deepwater Horizon spill as seen by a NASA satellite (public domain image)
In September, I discussed some of the scientific findings regarding the Deepwater Horizon oil spill that spewed hundreds of millions of gallons of water into the Gulf of Mexico. Those findings were quite encouraging. They showed that the ocean’s natural “cleanup crew” was busy trying to mitigate the damage that we did to the gulf. They demonstrated that the populations of bacteria rose and fell depending on what kinds of hydrocarbons were present in the ocean. This demonstrated there was a good chance that bacteria could take care of most of the oil that was released into the Gulf.

There was one nagging problem, however. While many of the hydrocarbons that were released into the Gulf were being destroyed by bacteria, the lightest hydrocarbon (methane) seemed to be persisting stubbornly. A study of the lighter hydrocarbons in the Gulf, which was published in October of last year, showed that very little methane from the spill had been destroyed.1 In fact, one of the authors of the study said that the results indicated:

methane would persist for many, many years, if not almost a decade.2

Well, it turns out that this particular scientist (and those who agreed with him) just didn’t have enough faith in the ocean’s natural cleanup crew!

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Farming Exists at Many Levels of Creation

My previous post dealt with symbiosis, which I consider to be the most stunning example of the design that is inherent in nature. In this post, I want to discuss a specific kind of symbiosis that scientists find in Creation: farming. While many think that farming is a uniquely human activity, nothing could be further from the truth. In fact, the more we study nature, the more it seems that farming is a consistent theme throughout the natural world. This was brought home to me recently as I read a paper in the journal Nature. Before discussing the main topic of the journal article, I want to write about the various farming animals of which I am aware.

The leafcutter ant cuts leaves to feed a fungus it farms. (Public domain image)
Probably the most famous example of an animal farmer is the leafcutter ant. There are more than 40 species of this ant, and they are found in the forests of South and Central America. If you are in such a forest, look down at the ground. You might see what appears to be small leaves “walking” along the forest floor. If you look more closely, however, you will see that they are being carried by ants. The ants cut leaves and carry them back to their mound, but they do not eat the leaves. They use the leaves to grow a fungus, and they eat that fungus. Not only do they cultivate the fungus, they also protect it by culturing a species of bacterium along with the fungus. The bacterium produces antibiotics which prevent the growth of organisms that are pathogenic to the fungus!1

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Microbial Me

Bacteroides trichoides, one of the many species of bacteria that live in the human intestine (CDC image)
One of the most fascinating aspects of the biological world is the phenomenon of mutualism – two or more different species living together so that each organism benefits. I have blogged about this topic before (here, here, and here), and I discuss it quite a bit in my science texts. Technically, it is a subcategory of symbiosis, where two or more organisms live together. If all organisms benefit from this living arrangement, we call it mutualism. If one benefits and the others are not harmed, we call it commensalism. If one benefits and another is harmed, we call it parasitism.

Many scientists consider mutualism (and symbiosis as a whole) to be a fairly uncommon thing in nature. Sure, you can find some organisms that help each other out from time to time, but overall, nature is about organisms “battling it out” for survival. Nothing could be further from the truth! While organisms do compete against one another in nature, they also help each other quite a bit. As George D. Stanley, Jr wrote a few years ago in the journal Science:1

Symbiosis is the most relevant and enduring biological theme in the history of our planet.

Indeed, symbiosis (and mutualism in particular) is incredibly common throughout creation, and nothing makes that more apparent than a study of the microbiological communities that live in each one of us.

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If You Thought Some of My Other Posts Were Geeky…

A tortoiseshell cat helps explain genetics in light of X-inactivation. (Click image for credit)
A few posts back, I commented on some experimental genetic results that throw a real monkey wrench into the generally-accepted view of the evolution of gender. Part of that post dealt with the concept of X-inactivation, the process by which one of a woman’s X chromosomes is inactivated so that she has no more functional X chromosomes than a man. A commenter known as jsilverheels then asked an excellent question, which I attempted to answer.

All of that discussion related to chromosomes, dominance, recessiveness, etc. got me thinking about sex-linked inheritance. It’s a common subject taught in high school biology, and it is something I discuss in my biology textbook. However, X-inactivation seemed (in my mind) to contradict something that is routinely taught in most high school biology courses. I searched the web for an answer to this apparent contradiction, but to no avail. No matter what kinds of keywords I used, I couldn’t find an article that addressed this particular problem.

As a last resort, I ended up E-MAILing my sister-in-law. My wife is brilliant, and she comes from a family of brilliant people. Her oldest sister is not only an accomplished molecular biologist, she is also a dedicated college professor. I knew she would have the answer to this question, but I hate to bother people who are busy doing such productive things. Nevertheless, I really wanted an answer, so I broke down and sent her the question. Not surprisingly, she answered it straightaway. I thought I would blog about it, mostly so I would remember it later on.

WARNING: If you thought what I have posted before was geeky, you probably won’t like what appears below the fold!

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Should I Feel Stupid FOR Running or Just AFTER Running?

Runners in the Zurich Marathon of 2008. Click Image for credit.

An infrequent but enjoyable commenter (Black Sheep) recently asked a question that I thought I would answer with a post. The relevant portion of the comment is:

A friend and I are always puzzled by the way our bodies, or rather minds, react after a run. This really only tends to happen when we do longer runs, like when we were training for a half marathon. After we finish, whether it be a race or just a training run, we feel completely stupid…why the diminished mental capacity?

Some might argue that a person who wants to do such a long run is actually starting out with a diminished mental capacity. However, there is actually a very good reason for why you can feel stupid after a long run, even if you started with a keen mind. You will find the answer below the fold.

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