Each week, I devote part of my Sunday to reading.  I tend to accumulate a lot of saved links on Facebook during the week, and I like to try to keep up with what fellow writers are posting here on WordPress.  At the end of my reading day, I like to put up a post to draw my readers’ attention to a few articles I found to be of particular interest.

Here’s what I enjoyed this week:

Wendelstein 7-X achieves world record for fusion product

by Isabella Milch, Max-Planck-Institut für Plasmaphysik

Fusion power has long been the veritable holy grail of energy.  By utilizing the same form of power generation found in stars, a fusion reactor could provide incredible amounts of power in a manner far cleaner and safer than any current large-scale methods.  Of course, while fusion power is highly effective, it’s also very difficult to accomplish: achieving a stable fusion reaction require sufficient current and heat to convert a stream of hydrogen into plasma.  Thus, for decades the problem with fusion power has been negative output: more energy is put into the system to produce the reaction than is put out by the reaction itself.  While we’re still a long way from making fusion power plants a reality, Isabella Milch of the Max Planck Institute wrote this week about a major step toward that goal.

Decades of research into fusion energy have produced no less than a half dozen means of achieving a fusion reaction.  While the tokamak, a toroidal design pioneered by Soviet researchers in the 1950s, is regarded as the standard today, in recent years the Max Plank Institute has been experimenting with an older concept: the stellarator.  Unlike a tokamak, a stellarator forgoes symmetry in favor of versatility: by not conforming to a rigid geometric design (instead taking the form of a wandering loop), a stellarator can be fine-tuned to manage the plasma stream.

The Planck Institute’s test reactor, the Wendelstein 7-X, is a stellarator, and its design has allowed researchers to sculpt each of the system’s electromagnets to optimize the plasma stream.  The results released this week suggest their approach is paying off: the Wendelstein 7-X set world records for both temperature and plasma pressure within a stellarator, while also mitigating particle leakage.  As creating a stable, positive-energy fusion reaction requires pressure and temperature conditions that mimic those within a star, this represents a major step forward, and suggests the stellarator holds promise as a design for use in power plants.

Researchers create world’s smallest ‘computer’

by Katherine Mcalpine, University of Michigan 

Lately, the scientific community has seen something of an arms race in computing, as teams of researchers continue to produce smaller and smaller computers.  The latest, announced this week by the University of Michigan, measures only 0.3 mm to a side; that’s smaller than a grain of rice.  And as the university’s own Katherine Mcalpine wrote this week for TechXplore, the continued shrinking of computers has raised a lot of questions.

With such small systems, virtually everything we know about building a computer changes.  While these tiny computers can communicate wirelessly, because conventional radio antennae don’t work on such a small scale, they communicate instead through visible light, sending signals with an LED.  However, the LED itself can pose a problem: in order to receive information, the computer is housed in a transparent casing, allowing incoming signals to reach photosensitive components within.  Because of its small size, even its own LED signaling device can interfere with its ability to communicate.  Researchers were also required to virtually reinvent the process of designing circuits, as with such a small device even a minuscule current can become noise.

Interestingly, some of the questions raised by these devices have become almost existential.  For instance: what, exactly, is a computer?  This question was raised by the team at Michigan, in relation to a competing design produced by IBM.  Unlike their design, the IBM system is incapable of storing information without power.  When the system is turned off, all data is lost.  When we turn off our personal computers, on the other hand, the data remains stored on drives, independent of power source.  So, can a device that functions like a computer but cannot store data without a current actually be considered a computer?

Questions aside, the potential applications of such tiny computers are vast, especially in medicine.  Recent research suggest there may be a connection with tumor growth and cell temperature.  Such a small computer could be used as a temperature sensor, implanted directly into a tumor to assess the effectiveness of cancer treatments.  Researchers have also suggested using the computers as pressure sensors in the treatment of glaucoma.  Indeed, it appears we’re still just scratching the surface in this emerging subclass of computers.

The Maya civilization used chocolate as money

by Joshua Rapp Learn, Science

In this fascinating article, Joshua Rapp Learn of Science reports on recent research that suggests the Mayans may have used cacao beans as currency…and that climate shifts affecting the availability of cacao may have led to their civilization’s downfall.

It’s widely-known that the Mayans were very fond of chocolate.  Chocolate was almost universally enjoyed by the Mayan people, who consumed it primarily as a hot beverage (likely similar to champurrado, a chocolate-based form of atole, which is still consumed in Mexico today).  As such, chocolate was prized, and the fermented cacao beans used to produce champurrado were extremely valuable (the Spanish Conquistadors were known to pay workers in cacao beans).

Like most early civilizations, the Mayans generally eschewed established currency in favor of barter.  Maize (corn) was the staple crop of the Mayan civilization, and as such was among the most valuable commodities in barter, though Mayan transactions could also include tobacco, woven cloth, precious stones, and of course chocolate.  However, a recent study by Joanne Baron, an archaeologist with the Bard Early College Network, suggests that over time chocolate rose to prominence.  While studying murals and ceramics from throughout the Mayan period, they noticed that cocoa beans began to feature more and more prominently in works of art depicting commerce.  Eventually, they found murals depicting Maya kings receiving vast quantities of cacao beans; far more than the palace would likely consume.  This suggests that, at some point, fermented cacao beans were essentially used as currency, with each bean being treated as a sort of coin.

While some researchers remain skeptical, Baron argues that this could explain the sudden downfall of the Maya civilization.  As she points out, cacao was prized partly because it didn’t grow well near Mayan cities, and was highly sensitive to drought.  It’s long been known that the sharp decline of the Mayan civilization coincided with a period of intense drought.  Baron suggests the sudden collapse could have been due not to crop failures, but rather to the sudden scarcity of the bean that had become the basis of Mayan commerce and economic power.

Knowledge is power.  Take a little time out to read each day.  It’s your window into the world around you. – MK