The Moorish Conquest Of Spain (711 to 732)

In 711 A.D. a wave of Berber Moors crossed the straight of Gibralter and swept into Hispania. The Visigoth kingdom, which had held sway on the Iberian Peninsula for almost 300 years, was divided by a recent civil war, and had neither the leadership, nor unity to resist the invasion.

Stories of treachery by disgruntled Jews and exiled enemies of Roderic, the Visigoth king, abounded. It was even said that Count Julian, a fierce rival of the Visigoth king, had invited the Moors to help overthrow the hated Roderic, and that several important towns, including Toledo, had turned in favor of the conquerors.

In any case, the Visigoth resistance was utterly inadequate, and after making a desperate stand at the Guadalete River, the national government collapsed. Several towns resisted the invaders and were besieged, but there was no further organized resistance from the Visigoths, and within a few years the Moors had swept over most of the Iberian Peninsula.

There were a few notable Visigoth heroes however. Theodomir was a Visigoth knight who heroically fended off an army of Moors, but ultimately surrendered his town on favorable terms. Pelistes was a valiant noble who tried in vain to hold the town of Cordova, but was ultimately captured. More significant was Pelayo, who led a band of Visigoths and native Iberians north where they held out for several years in mountain fastnesses. This band of Christian refugess grew over the years, and about 10 years after the Moorish invasion successfully defended themselves from Moorish incursions at the Battle of Covadonga. This small Christian stronghold in the northern mountains eventually grew into the kingdoms of Asturias, Leon, and Castile, and Pelayo is credited with laying the seed of the Christian Reconquest of Spain.

Although the Moors met with no significant Visigoth resistance, when they ventured into territory north of the Pyrenees they encountered the more formidable Franks.

Their first defeat at the hands of the Franks was delivered by Odo, the Duke of Aquitaine, who rescued the city of Toulouse from a desperate seige in 721. The Moors were so severely defeated in this action that they did not make another attempt to invade Gaul for ten years.

When a new Moorish governor came to power in 730 however, he raised another army and prepared for a new invasion of Gaul, with the obvious ambition of conquering all of civilized Europe for the Mohammedans. The Moslem army invaded Gaul in 732, took the city of Bordeaux by storm, and obliterated Odo's army of Franks at the battle of Garonne River.

Odo escaped and sought the help of Charles Martel, the hero of the battle of Tours. This battle, which is considered on of the most significant in western history, was very hard fought and was reputed to have lasted for several days, but ended in a complete victory for the Christians and the death of the Moorish commander.

The Battle of Tours effectively ended the Muslim incursions into Gaul. The following decade saw the fall of the Umayyad dynasty altogether, and the establishment of a Moorish dynasty in Cordova independent of the Abbasid Caliph in Baghdad.

During the following fifty years, the tables turned, when a large army of Franks under Charlemagne crossed the Pyrenees into Hispania and attacked Muslim kingdoms in the region. The depredations of the Franks against the Moors ended only in 778 when a rebellion in Saxony caused Charlemagne to recall his army, but by that time, the impulse of the Moors in Spain to carry their conquests into the Frankish dominions of Gauls was permanently checked.

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Could China's "Coal Battery" Be The Answer To The Fuel Crisis?

There's no denying that coal as a fossil fuel has had a tremendous impact on the development of human society. To this day, it remains one of the most important sources of energy, with nearly 36 percent of the worldwide electricity generated using coal-based thermal power plants.

Given how long humans have used coal, we're fully aware of the ecological problems associated with it. The majority of these problems center around the most commonly used method to produce electricity from coal; by burning it. This process emits various types of pollutants into the air, and is the number one cause for coal ending up with such a bad reputation.

While engineers have steadily improved coal power plant efficiency over the decades, conventional combustion methods still wastes a significant portion of coal's energy as heat. This is why a group of scientists from China's Shenzhen University and the Chinese Academy of Engineering are trying a different method.

This group recently embarked on a study that envisions coal being used as a relatively cleaner source of energy. While still in its infancy, they have managed to refine a process called Zero-Carbon-Emission Direct Coal Fuel Cell (ZC-DCFC). This technology uses the chemical energy stored in coal to generate electricity. Not by burning it, but instead using the principles of electrochemistry.

In many ways, the ZC-DCFC process works more like a fuel cell than a conventional coal-fired power plant. What makes the development of ZC-DCFC crucial, however, is the possibility of it solving the energy and fuel security concerns faced by several countries.

Before understanding how the ZC-DCFC works, we need to understand how a traditional coal-powered thermal power plant generates power. In simple words, these power plants burn massive amounts of coal inside a furnace. The heat generated by the furnace boils water, which turns into steam. This steam then spins a turbine connected to a generator which ultimately generates electricity.

This method has been so effective, it continues to be used to this day. One major issue with this process, however, is its sheer inefficiency because it involves multiple energy conversion steps. Chemical energy becomes heat, heat becomes steam pressure, steam pressure becomes mechanical energy, and mechanical energy finally becomes electricity. If you have learned the basics of energy conversion in school, you'd realize that each of these steps results in energy loss, thereby making the entire process very inefficient.

One of the objectives of this ZC-DCFC system is to eliminate most of these stages, and in the process make electricity generation from coal more efficient. It partly archives this objective by feeding the fuel (coal) directly into a fuel cell. Inside the cell, electrochemical reactions separate electrons from the carbon contained in the coal. Those electrons then flow through an external circuit, creating an electric current that can be used to power homes, factories, or data centers. Basically, the fuel cell extracts electricity directly from the coal's chemical energy rather than generating heat first.

One of the main reasons for the ZC-DCFC tech gaining global attention is because of its potential for meeting the ever-increasing demand for electricity that doesn't produce harmful emissions. The biggest beneficiaries of this tech could be countries like China and India that possess enormous domestic coal reserves. Both these nations — despite making impressive gains in the expansion of solar and wind power — continue to burn massive amounts of locally sourced coal to produce electricity, and remain the biggest contributors to global carbon emissions.

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Nuclear-Powered Satellite Launch Aboard SpaceX Rocket

The Miami-based City Labs is all set to launch the world’s first commercial nuclear-powered satellite into orbit.

Solar panels have some challenges. When a satellite slips into the shadow of the Earth, hits a permanently dark lunar crater, or drifts into deep space, its solar arrays become useless. Batteries can step in, but they eventually die.

City Labs thinks nuclear energy could solve this persistent problem. On July 7, the company announced that its BOHR (Betavoltaic Orbital High-Reliability) satellite had secured a launch slot on a SpaceX Transporter-17 rideshare mission.

According to reports, SpaceX has scheduled the launch of its Transporter-17 rideshare mission last Tuesday, 7 July. The launch will mark a massive historic milestone. BOHR will be the first-ever nuclear CubeSat to enter orbit.

"This is a historic step for commercial nuclear power in space," said Peter Cabauy, CEO of City Labs. "BOHR demonstrates that safe, compact, and regulatory-approved nuclear power systems are ready for routine commercial deployment. This capability enables persistent, always-on payload operations that are not constrained by sunlight or battery life."

Engineered for safe handling, transportation, and integration into standard commercial launch environments, City Labs’ tritium-based power systems operate at extremely low radiation levels.

BOHR’s core technology is City Labs’ proprietary NanoTritium™ betavoltaic system, which generates continuous power from the natural beta decay of tritium rather than nuclear fission.

Compared to space-bound nuclear reactors, betavoltaic cells operate with no moving parts, no liquid electrolytes, and zero risk of fire or thermal runaway. Furthermore, as the tritium fuel naturally decays, it harmlessly transforms into helium-3, a completely stable and non-radioactive isotope.

Backed by the Department of War, NASA, and the Air Force Research Laboratory, the mission arrives at a key time for space exploration.

NASA’s Artemis program aims to establish a permanent human presence on the Moon. Therefore, the demand for continuous, light-independent power sources is skyrocketing. It could position this satellite as a pathfinder for future deep-space operations.

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The Kikkas Are Japan's Secret Jet Fighters Of WWII

Little more than a year after its destruction of the U.S. fleet at Pearl Harbor, Japan experienced a devastating setback in the Battle of Guadalcanal, which began in August of 1942 and lasted until February of 1943. The combined land and naval fighting ended with the U.S. consolidating its power in the area, and Japan on the back foot for the remainder of its time in the war.

Japan's heavy losses of invaluable assets like aircraft carriers weren't sustainable, and the United States would steadily overturn earlier Japanese gains one by one.

But Emperor Hirohito would not surrender until years later, in August 1945. There remained the — albeit unlikely — possibility of shifting momentum back, as there often is in warfare. What Japan needed was a formidable weapon, and engineers were working on just that: the Nakajima Kikka (Orange Blossom) jet.

Though this secret aerial weapon wouldn't save the war for the Japanese, there's no doubt that it was an intimidating prospect (and the Axis Powers certainly had some iconic aircraft in their ranks). If the timing of its development had been different, it could well have been influential. Here's what the Nakajima Kikka could do, how it fared, and the ultimate impact it had on Japan's war effort.

Germany's Me 262 served as the inspiration for the Nakajima Kikka's exterior design. The most important trait it would have in common with the famous Messerschmitt, however, was one that was unique at the time. The Me 262 was the world's first combat jet fighter, and, after Japan's air attaché in Germany watched impressive test flights, it was determined that this was the sort of power source Japan wanted for its secretive new plane.

The project faced some huge hurdles when it began in September of 1944. The first was that, being essentially brand new, jet engines were still a novel prospect that engineers had only recently begun exploring. Japan tried to circumvent this issue with the aid of its German allies, who had shared their expertise by dispatching a package of engines, documents, and other materials dedicated to the emerging science of the turbojet, but the U.S. sank the submarine charged with delivering it across the world.

This left the Japanese with very little guidance to work from beyond a single document that made it to Japan safely. Nonetheless, Japan's Naval Air Technical Arsenal ultimately developed the Ne-20 turbojet. The engine, though experimental, was a bold and creative effort, and would become the driving force of a rather small yet — theoretically, at least — potentially impressive aircraft.

Because the Nakajima Kikka arrived late in World War II, it's impossible to say how it may have performed if it had been given more flight time and a period of learning and refinement from its creators. Even so, it's still clear from its specifications that the Orange Blossom had a lot of potential.

Two Ne-20 engines would be mounted in the aircraft, which was just short of 27 feet long and had a wingspan just shy of 32 feet, 10 inches. It weighed in at 8,995 pounds. All of this made it rather smaller than the famous Me 262, which measured just short of 40 feet long, boasted a wingspan of almost 41 feet and had a gross weight of 13,250 pounds in its Schwalbe, or Swallow, version.

The Nakajima Kikka would prove to have similar downsides to those that held the Messerschmitt back. The German aircraft suffered from the nation's material shortages and the German command's unwillingness to fully trust the turbojet, ultimately meaning that just 300 of them were used in battle during the war.

Despite its technical superiority, the Me 262 was ultimately tamed by the Allies, who used its exposure when taking off and while on the ground to target it before it could make the best of its big speed advantage. Not only did the slower Nakajima Kikka lack such a major edge, but it also didn't make it past its troubled early trial phase. A prototype model took to the air on 7 August 1945, the aircraft's only successful flight before misaligned takeoff assist rockets caused a repeat flight to be canceled abruptly.

Japan surendered on 15 August. As U.S. forces advanced across the defeated nation, they entered a Nakajima factory and observed abandoned half-built Kikkas.

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Why Not Use Satellite Phones Instead Of Smart Phones?

Smartphones are downright essential for modern life, but they weren't the first mobile phones on the market. Satellite phones (i.e., phones that send calls by communicating with Low Earth Orbit satellites) beat the first cell phones to the punch.

However, satellite phones have all but died out, and it's not just because you can use apps such as Apple TV and Nintendo Music on Android phones.

On paper, satellite phones sound more efficient. Normal smartphones route communications through entire networks of cables and cell towers, whereas satellite phones only need to bounce conversations off satellites.

However, while satellite phones indeed cut out the middleman, any call through them is prone to lag since even the closest satellites they use are thousands of miles away. Furthermore, each call is expensive. Sure, US$ 50 for an unlimited phone plan sounds like a lot, but that's US$ 50 for all your phone calls, messaging, and web browsing for a whole month. By comparison, a call on a satellite phone costs US$ 2 per minute on average, which is too expensive for most users.

The disadvantages don't stop there. While smartphones have become so small and thin that you can fit them into your pocket, satellite phones need to be large and bulky. Otherwise, their antennae (yes, they still use antennae) would be too weak to communicate with satellites.

And the icing on the cake? Satellite phones are actually illegal in some places. You can use a smartphone to call people while on vacation in, say, Cuba, but satellite phones are prohibited there.

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