Category Archives: Materials

Superconductors? When frogs fly

levitating frogOne of the unwritten rules of physics says you can’t get something for nothing; at best, you can swing a fair exchange rate between energy in and energy out. The problem is heat:  Like an energy embezzler, it skims off the top of chemical reactions, physical systems and electrical circuits (which is why we can’t have perpetual motion machines).

Superconductors don’t break the laws of thermodynamics, but they do manage to find some fairly large loopholes. Send current through a superconducting wire, and it loses no energy to resistance. Bend the wire into a loop, and it will hold charge indefinitely. Levitate it above a magnet, and the sun will devour the Earth before it will fall.

Plus, it can levitate a frog.

What is Superconductivity?
Quiz: How Super are Superconductors?

Putting the green in nanomachines

Carbon nanotubes
Carbon nanotubes. Image courtesy Wikimedia Commons.

We tend to think of nanotechnology as the stuff of the future, but it’s already here, in hundreds of consumer products and industrial applications. As progress in this minuscule world has accelerated, concern for the environment and for public health has led to a call for green nanotechnology—approaches that accentuate the positive and eliminate the negative. In this article, we’ll take a tour of how these many approaches are playing out.

How is green nanotechnology being used?

Fearful symmetry: the beauty and power of tessellations

Irregular pentagon tessellation
Irregular pentagon tessellation. Image by R.A. Nonenmacher

We study mathematics for its beauty, its elegance and its capacity to codify the patterns woven into the fabric of the universe. Within its figures and formulas, the secular perceive order and the religious catch distant echoes of the language of creation. Mathematics achieves the sublime; sometimes, as with tessellations, it rises to art.

How tessellations work

Related Article:
Quiz: Tessellate this!

No ordinary glass of water

Grade schools teach that there are three or four states of matter—solid, liquid, gas and possibly plasma. Nature is much fuzzier than that, however. Depending who you ask, there may be more than a dozen states of matter, along with numerous substates such as glass.

Portrait of C. Austen Angell
C. Austen Angell. Image courtesy Arizona State University

Yes, glass. Scientifically speaking, glass is a highly viscous, noncrystalline substate of matter. It is like a liquid that cools without becoming crystalline. Our everyday silica glass is but one example; many substances, including metals, become glassy under the right conditions.

Physical chemists have struggled for decades to crack the true nature of glass and understand what happens at the transition to and from the glassy state. In 1995, Nobel laureate Philip Anderson called it the “deepest and most interesting unsolved problem in solid state theory.” Now, C. Austen Angell, a chemistry professor at Arizona State University believes he has translated the Rosetta Stone of glassy substances: water.

A glassy riddle: solving the mystery of water glass

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The science of setback
Angell helps solve mystery of ‘glassy’ water