November 2013 : Proslogion

The Plastisphere

plastic_ocean — What happens to the plastic floating in the oceans? It turns out, quite a lot! (click for photo credit)

Quite a while ago, I wrote an article about the Great Pacific Garbage Patch, which ended up being included in a book entitled Opposing Viewpoints Series – Garbage & Recycling. While the magnitude of the problem is severely overstated in nearly every popular treatment of the subject, it is a real problem. It came about as a result of the fact that some of the plastic which is not disposed of properly ends up in the oceans. A lot of that plastic gets stuck in gyres – permanent circular currents that exist in distinct regions of the seas. In most cases, once the plastic gets stuck in the gyre, it doesn’t leave.

So what happens to this plastic over time? Does it decay? Does it just float there forever? How badly is it affecting the ecosystem of the gyre? A new paper published in Environmental Science and Technology attempts to partially answer these questions. The authors sampled plastic marine debris (PMD), as well as the water in which it was floating, from several different spots in the North Atlantic. They then studied it with a scanning electron microscope (SEM), Raman spectroscopy, and DNA sequencing. The results were fascinating!

The authors found a rich diversity of microscopic organisms living on the plastic.¹ In fact, the diversity was so rich that they have decided the plastic supports its own little biological community. As a result, they call the plastic and the organisms living on it the Plastisphere. It’s probably correct to think of it this way, because the organisms living on the plastic are quite different from the ones living in the water where the plastic floats.

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An Odd View of an Old Debate

Carl Strock is a journalist-turned-columnist who recently retired from the Schenectady Gazette after 25 years of service. After he traveled to Israel and wrote some decidedly anti-Israel columns, the Gazette received numerous complaints. In response, his editor told him to stop writing about Israel for a while and submit all of his columns to her for editing. This bothered Strock, because he saw it as censorship. After continuing his columns with less frequency, he eventually retired. However, he has not stopped writing. He has a blog at the timesunion.com and has written a book, From D’burg to Jerusalem, The Unlikely Rise and Awful Fall of a Small-Town Newsman.

Why am I writing about Mr. Strock? Because in his book, he mentions a debate he had with me back in 2006. I had actually forgotten about the debate, but when a reader in Schenectady told me about being mentioned in his book, I recalled the event. I got his book and planned to read the entire thing, but it just isn’t my cup of tea. However, I did read some parts of the book, including the chapter that discusses the debate. I found his view of that event to be very odd.

Here’s what prompted the debate: Strock had written some columns in the Gazette regarding creationism and intelligent design. Since he obviously knew little about either subject, his columns provoked some rather heated responses, which he seemed to find surprising. Eventually, he tired of people pointing out his ignorance, so he said:

I will meet any of them in open forum, and we’ll see who’s ignorant of what. (p. 161)

A student who was using one of my textbooks at the time contacted me, and (of course) I agreed to meet Mr. Strock in open forum. Strock was surprised, but he agreed to the debate. I thought the debate was amatuerish but informative. Based on what he has written in his book, he obviously disagrees.

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The Bacterial Flagellum: More Sophisticated Than We Thought!

flagellum1 — This is a schematic of a bacterium's flagellum (image in the public domain).

The bacterial flagellum is a symbol of the Intelligent Design movement, and rightly so. After all, bacteria are commonly recognized as the “simplest” organisms on the planet. Nevertheless, their amazingly well-designed locomotive system has continued to amaze the scientists that study it. In 1996, Dr. Michael Behe highlighted the intricate design of the bacterial flagellum in his book, Darwin’s Black Box. While some have tried to explain it in terms of Neo-Darwian evolution, they have not come close to succeeding.
Not only is the bacterial flagellum amazingly well-designed, it is far more versatile than anyone imagined.

Some bacteria (like Escherichia coli) have multiple flagella, which makes it very easy for an individual to navigate in water. All the bacterium has to do is adjust which flagella are spinning and how they are spinning, and the single-celled creature can do acrobatics in the water. However, the vast majority of bacteria have only one flagellum. It was thought for a long time that because of this, it is difficult for them to make sharp turns in the water.

Two years ago, this thinking changed abruptly when a group of physicists from the University of Pittsburgh showed that the bacterium Vibrio alginolyticus, which has only one flagellum, can make sharp turns with ease. They showed that in order to execute such a turn, the bacterium backs up, lurches forwards, and swings its flagellum to one side.¹ The entire maneuver takes less than a tenth of a second and results in a 90-degree turn. So not only is the bacterial flagellum an exquisite “outboard motor” that propels the bacterium through the water, it is also a rudder that allows the bacterium to make sharp turns at will!

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Sofishsticated Swimming

This is a glass knifefish like the one used in the study (click for credit)

Many aspects of nature are a mystery to science, and at least part of the reason is that nature has been designed so incredibly well. There are systems running in nature that are simply too complex for us to understand and, as a result, their functions remain a mystery. Not all that long ago, for example, many biologists were silly enough to actually think the human genome was mostly junk, simply because they couldn’t understand what the vast majority of the human genome does. Of course, as we have learned more about DNA, we have learned that what was once considered “junk” is vitally important (see here, here, and here, for example). Since the Encode project published its first major results, most reasonable biologists have slowly started to realize what creationists have said all along – there really isn’t much (if any) junk DNA.

Even on a larger scale, there are many aspects of nature that are very hard to understand. A recent article in the Proceedings of the National Academy of Sciences of the United States of America provides an example:¹

Animals often produce substantial forces in directions that do not directly contribute to movement. For example, running and flying insects produce side-to-side forces as they travel forward. These forces generally “cancel out,” and so their role remains a mystery.

Why would a moving animal expend energy to produce forces that are perpendicular to its motion? Those forces don’t contribute to the animal’s forward motion, and they tend to cancel each other out. As a result, they are often called “antagonistic forces.” Such forces seem like an utter waste of energy. Nevertheless, lots of animals do this. In addition, some animals exert antagonistic forces even when they are not moving in a given direction. Hummingbirds, for example, produce antagonistic forces when they are hovering over a flower.

To understand the purpose of antagonistic forces, the authors of the study examined the glass knifefish (Eigenmannia virescens). When this fish is “hovering” in the water, it uses its fins to produce antagonistic forces. It has been thought that these forces might improve the fish’s ability to control its position and orientation in the water, but no one understood how.²

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Overly Honest Moments in Science

I don’t tweet. If you have been reading this blog for any length of time, you know why. I have a hard enough time constraining my writing to a few hundred words, much less 140 characters. Nevertheless, it is interesting to see how scientists use Twitter to communicate what they are doing. For example, I recently wrote about a particle physicist who used Twitter to explain to people what was happening in the Fukushima nuclear power plant disaster. He became a bit of a celebrity as a result and has used that platform to do some serious science related to the level of radioactive contamination in Japan’s food supply.

Why in the world am I discussing a social media tool that I don’t even use? Because a reader posted a link on my Facebook page. It contains a series of tweets posted with the hashtag #overlyhonestmethods, which was started by a scientist known as “dr. leigh.” The hashtag has become a bit of a phenomenon. Essentially, scientists use it to explain the real reasons behind some of their methods.

The picture at the top of the post is a classic example of a tweet that contains the hashtag. I immediately related to it, because as a nuclear chemist, I have built a lot of systems that blew up or failed in some other spectacular way. However, when I finally got a version of the system to work, I would refer to it as “representative.” That’s just the way it is done.

If you have some time, scroll through a few of the tweets. Some of the language can be a bit foul, but the tweets give you a brief glimpse into the real world of scientific research. You might be a bit surprised at what you read!

Why Do We Have to Sleep?

sleeping3 — Scientists might finally be understanding why we need to sleep. (click for credit)

When I was doing nuclear chemistry experiments, one of my greatest enemies was the need for sleep. Those experiments required the use of a particle accelerator, and the demand for time on the accelerator always exceeded the amount of time available. This meant that each experiment was tightly scheduled for a certain amount of time, and it was almost impossible to get any kind of extension. As a result, when the particle beam was directed to my experimental chamber, every second was precious. Generally, I would stay up for as long as I could, trying to get as much as possible from the experiment. Eventually, however, I had to go to sleep and let someone else take over. I hated that. In fact, during my main thesis experiment, I stayed up for so long that I actually feel asleep in the middle of typing commands on the computer console!

Why do we need to sleep? When I ask this question to students, I generally get a response that deals with energy. Students think that sleep somehow allows us to build up our energy reserves so we can stay active and alert while we are awake. However, that’s clearly not true. Our energy comes from the food we eat. If it were just a matter of building up energy reserves, we could eat rather than sleep.

For a long time, scientists have speculated that sleep has something to do with recovery. Being awake does something to our bodies from which we must recover, and sleep takes care of the recovery process. The problem, of course, is that no one could actually say what the body has to recover from. Well, a team of researchers led by Dr. Maiken Nedergaard, a scientist at my Alma Mater, might have figured out at least one thing from which our bodies recover when we sleep.

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