Today’s New Reason To Believe

Editor’s note: Today we present an article by guest scholar Katie Galloway

Geckos and Mussels Inspire New Wet/Dry Adhesive

The Bible declares that nature reveals God’s workmanship from the beasts of the fields to the stars of the sky. Job implores, “But ask the animals, and they will teach you, or the birds of the air, and they will tell you; or speak to the earth, and it will teach you, or let the fish of the sea inform you. Which of all these does not know that the hand of the LORD has done this?” (Job 12:7-9). Scientists have begun to draw from this well of knowledge by studying designs in nature to inspire solutions to engineering challenges.

Recently, scientists set out to design an improved reversible wet/dry adhesive inspired by mussels and geckos.

Geckos adhere to surfaces with footpads made of foot-hairs called setae that are subdivided into nanoscale spatulae (hair tips). Adhesion is promoted through weak secondary bond forces such as van der Waals interactions and capillary forces.

Previous work on gecko-foot mimetic nanoadhesives demonstrated that the number of reversible cycles that retained adhesion were limited. Wet conditions nearly obliterated adhesion.

In nature mussels readily solve the wet adhesion problem by secretion of specialized proteins containing a high amount of 3,4-dihydroxy-L-phenylalanine (DOPA). DOPA is known to impart increased interfacial adhesion strength when added to natural and synthetic adhesives and to remain reversibly adhesive after many cycles.

Researchers speculated that combining the two naturally derived designs could lead to a reversible wet/dry adhesive with increased strength and longevity. Gecko-mimetic nanoscale pillar arrays were cast from polydimethylsiloxane (PDMS). The pillars were coated with a thin layer of poly(dopamine methacrylamide-co-methoxyethyl acrylate) (p(DMA-co-MEA)), a polymer designed for low-water solubility and high DOPA content. These properties are thought to be important in the adhesive mussel proteins.

The combination of these two adhesive technologies—to create an adhesive termed ‘geckel’—increased the wet adhesion strength per pillar fifteen times over previous gecko-mimetic designs. Geckel also maintained reversibility over many adhesion cycles. Compared to flat designs coated with p(DMA-co-MEA) alone, geckel demonstrated robust performance.

Success that results from the reverse-engineering of natural designs demonstrates that natural systems are endowed with specialized knowledge from which even the most intelligent biological designers can benefit. The engineering solutions found in nature reveal a highly creative and intelligent Designer who endowed his creation with unique properties to function in diverse environments.

The Creator instilled a natural curiosity within humans to explore creation and has commissioned humanity to seek knowledge through understanding nature. Not only does this search bring innovative technologies to society, but it also brings us closer to realizing what the animals already know: “…that the hand of the LORD has done this.”

Kenneth Richard Samples

Watching Ken Burns’s new documentary on PBS about World War II led to, of all things, an apologetics epiphany on my part.

I have been a student of the Second World War since my early childhood. Because my father was an American combat soldier during the war (fighting in Europe against the German army), studying the war caused me to ask the big questions of life—especially questions about God, evil, and the unfolding of human history. It is difficult to study the bloodiest war in human history (resulting in the deaths of 50 to 60 million people) and not ask deep philosophical questions. Historian Stephen Ambrose has even called the Second World War “the greatest catastrophe in history.”

One question that I have been turning over in my mind for probably two decades is: Why was my father’s generation able to overcome so many obstacles and accomplish so much good? America’s “greatest generation” was able not only to overcome a terrible economic depression, but with the help of their allies they were able to decisively defeat two of the mightiest military powers in history. And they started out facing great military disadvantages such as a tiny military force, little military hardware (tanks, planes, etc.), and a decimated navy after the Japanese attack on Pearl Harbor. Yet within the span of four short (though terrible) years America stood triumphant.

America not only helped defeat Nazi Germany and Imperial Japan, it also singularly provided the finances and technology to rebuild these nations, as well as the rest of shattered Eastern Europe. So successful was the Marshall Plan (an economic plan to rebuild Western Europe), that just a couple of decades after the war ended both Germany and Japan boasted robust economies that challenged America in terms of gross national product. And the American World War II generation leaders created a military coalition (NATO) that protected the Western world from the powerful threat of Soviet expansionism and inevitably defeated Russian communism.

In an interview where he discussed his new film, The War, Ken Burns offered an answer to my enduring question. He said that what made the difference for the American World War II generation was that they were all in a boat with their oars in the water and they were all rowing in the same direction. Whites, blacks, Hispanics, native Americans, men and women were all united in defending America and defeating the forces of fascism. Americans, in effect, put aside their differences to a certain degree to accomplish an absolutely necessary goal.

Now the apologetic epiphany: What would happen if Christians were able to cooperate with each other to this degree? What if believers in Christ made it their goal to seriously work together to combat the great challenges of our time?

Think of the impact on our culture if conservative Christian denominations put aside their secondary doctrinal differences and cooperated with each other to accomplish mutually agreed upon goals. What would happen if even the members of local church congregations all got in a boat and decided to row “together” to accomplish important goals? How about if individual families really cooperated to make a difference?

And what would be the result if old-earthers and young-earthers who both embrace biblical inerrancy and Christian orthodoxy were able to respectfully cooperate with each other? Especially at a time when a seemingly growing number of people think that religion is a poisonous agent in the world.

I’m personally going to be giving this epiphany a great deal of thought and prayer. For I long to be part of a country, a church, an apologetics organization, and a family that cooperates in order to accomplish necessary and noble goals.

For more on a call for Evangelical Christians to effectively cooperate, see John M. Frame, Evangelical Reunion: Denominations and the One Body of Christ (Grand Rapids: Baker, 1991).

Astronomers have discovered over 250 planets outside of our solar system residing in over 200 different planetary systems. However, all of these extrasolar planets exhibit characteristics that would eliminate the possibility of another planet residing in the same planetary system that could possibly support advanced life for a brief time or even primitive life for a long time.

Why does the solar system appear to be unique? Many astronomers have suggested that the solar system is different because it formed in a manner very different from the extrasolar planetary systems so far discovered. For such a claim to be held as fact, though, astronomers need to develop a model for the formation of extrasolar planetary systems. Researchers could then confirm the model through observations, demonstrate what is different about the manner in which the solar system formed, and show which features in the solar system’s formation make the solar system appear unique. Such a quest may also uncover several more design features in the solar system that make it suitable for the support of life.

Theoreticians have recognized that all of the large extrasolar planets either orbit close to their stars or manifest significantly eccentric (noncircular) orbits. That observation led them to conclude several years ago that these planets must have formed far enough away from their stars that they could accrete substantial amounts of gas and subsequently suffered substantial inward migration as they interacted with the dust and rocks that remained in the star’s protoplanetary disk. However, astronomers could not match theoretical models with the statistics of extrasolar planet characteristics. These difficulties informed the theoreticians that their models were too simplistic.

A breakthrough has been achieved through the work of Philip Armitage, an astronomer at the University of Colorado. He inserted into a protoplanetary disk model the mass loss from photoevaporation caused by the light emitted both by the star and nearby bright stars. He also accounted for “viscous evolution,” that is, allowance for changes in the viscosity of the protoplanetary disk.¹ His model produced results that matched not only the distribution of extrasolar planet distances from their stars but also the distribution of extrasolar planet masses.

Such a good fit between theory and observations implies that the mechanisms for the formation and evolution of extrasolar planets are well-enough understood to justify certain deductions about the solar system’s extraordinary formation history. Armitage’s model, though it explains quite well the characteristics of the 200+ extrasolar planetary systems, is not able to explain the solar system’s features (an ensemble of distantly orbiting gas giant planets with near-circular orbits combined with large rocky planets with stable near-circular orbits, with one of those rocky planets manifesting all the features that life requires) without the introduction of exceptional fine-tuning.

The formation of the solar system either implies this exceptional fine-tuning or it implies the solar system formed through some exotic and unique process. Either way, it adds to the already overwhelming evidence that the solar system must have been supernaturally designed for the support of life and of human beings in particular.

1. Philip J. Armitage, “Massive Planet Migration: Theoretical Predictions and Comparisons with Observations,” Astrophysical Journal 665 (August 20, 2007): 1381-90.