Toggle light / dark theme

Photo: EPNAC

TAMPA, Fla. — When Special Operations Command set out to create what would be popularly known as the ‘Iron Man suit’ seven years ago, developers assumed that the state-of-the-art in body armor would not improve much over the next few years.

That assumption led the command down a development path that would actually make the Tactical Assault Light Operator Suit resemble the comic book hero with heavy armor from head to toe and a power system and exoskeleton needed to help the operator move in the bulky suit.

Circa 2019


The development of new so-called metamaterials could lead to dramatic advances in military technology, particularly the ability to hide from sensors—even the human eye. Metamaterials, engineered composites designed to manipulate the electromagnetic spectrum, could lead to “invisible” tanks and armored vehicles, submarines undetectable by sonar, and weapons with improved seekers and guidance systems.

The big caveat though is that metamaterials are currently pretty difficult to manufacture and are still years away from full-scale production.

A new article in the October issue of the U.S. Naval Institute Proceedings outlines potential military applications for metamaterials. Metamaterials of plastic and metal and engineered in lattice-like patterns up to a billionths of a meter in scale. The result is a surface or material that can manipulate an object’s magnetic or electrical field in ways traditional building materials cannot. This allows them to alter how energy waves across the electromagnetic spectrum (visual light, radar, radio, acoustic waves, etc.) interact with them with some pretty stunning implications.

The amplitude mode is a ubiquitous collective excitation in condensed-matter systems with broken continuous symmetry. It is expected in antiferromagnets, short coherence length superconductors, charge density waves, and lattice Bose condensates. Its detection is a valuable test of the corresponding field theory, and its mass gap measures the proximity to a quantum critical point. However, since the amplitude mode can decay into low-energy Goldstone modes, its experimental visibility has been questioned. Here we show that the visibility depends on the symmetry of the measured susceptibility. The longitudinal susceptibility diverges at low frequency as Im χ σ σ ∼ ω − 1 (d = 2) or log (1 / | ω |) (d = 3), which can completely obscure the amplitude peak. In contrast, the scalar susceptibility is suppressed by four extra powers of frequency, exposing the amplitude peak throughout the ordered phase. We discuss experimental setups for measuring the scalar susceptibility. The conductivity of the O (2 ) theory (relativistic superfluid) is a scalar response and therefore exhibits suppressed absorption below the Higgs mass threshold, σ ∼ ω 2 d + 1. In layered, short coherence length superconductors, (relevant, e.g., to cuprates) this threshold is raised by the interlayer plasma frequency.

O.,o circa 2014.


Researchers in China are reporting that they’ve taken a big step towards creating a supersonic submarine. This technology, which could just as easily be applied to weaponized torpedoes as military or civilian submarines, could theoretically get from Shanghai to San Francisco — about 6,000 miles — in just 100 minutes. If all this doesn’t sound crazy enough, get this: This new advance by the Chinese is based on supercavitation, which was originally developed by the Soviets in the ’60s, during the Cold War.

As you may already know, it’s a lot harder for an object to move quickly through water than air. This is mostly due to increased drag. Without getting into the complexities of fluid dynamics, water is simply much thicker and more viscous than air — and as a result it requires a lot more energy for an object to push through it. You can experience the increased drag of water yourself next time you’re in a swimming pool: Raise your hand above your head, and then let it fall towards the water. (Or alternatively, if there are people sunbathing nearby, do a belly flop.)

Anyway, much like a small-engined car is ultimately limited by its ability to cut through wind resistance (drag), a submarine or torpedo needs insane amounts of power to achieve high velocity through water. This is why, even in 2014, most submarines and torpedoes can’t go much faster than 40 knots (~46 mph). Higher speeds are possible, but it requires so much power that it’s not really feasible (torpedoes only have so much fuel).

In light of the ongoing shift toward renewable energy technologies and the growing number of Internet of Things (IoT) devices, researchers worldwide have been trying to develop batteries that can operate more efficiently and for longer periods of time. Lithium-ion batteries (LIBs) are currently the preferred energy-storage technology for portable electronics, as they contain organic electrolytes, which typically enable high operating voltages and energy densities.

Despite their widespread use, further increasing the performance of existing LIBs could have a significant impact on their safety. In fact, these batteries contain highly volatile and flammable organic carbonates, which, if ignited, can cause considerable damage.

In recent years, researchers have made significant efforts toward overcoming these safety issues, for instance, by using additional substances or by optimizing the materials separating battery components. While some of these strategies successfully reduced the risk of the battery catching fire, as long as LIBs are made with highly flammable electrolytes, accidents may still occur.

Justin Thomas considers bidets to be “a key green technology” because they eliminate the use of toilet paper. According to his analysis, Americans use 36.5 billion rolls of toilet paper every year, representing the pulping of some 15 million trees. Says Thomas: “This also involves 473,587,500,000 gallons of water to produce the paper and 253,000 tons of chlorine for bleaching.” He adds that manufacturing requires about 17.3 terawatts of electricity annually and that significant amounts of energy and materials are used in packaging and in transportation to retail outlets.

That’s a lot of water, far more than is actually used by the bidet itself.

toto toiletLloyd Alter/ toto toilet with washlet/CC BY 2.0