Alexander Graham Bell and the Photophone

Alexander Graham Bell and the Photophone While hes best known as the inventor of the telephone, Alexander Graham Bell considered the photophone his most important invention... and he may have been right. On June 3, 1880, Alexander Graham Bell transmitted the first wireless telephone message on his newly invented photophone, a device that allowed for the transmission of sound on a beam of light. Bell held four patents for the photophone and built it with the help of an assistant, Charles Sumner Tainter. The first wireless voice transmission took place over a distance of 700 feet. How It Worked Bells photophone worked by projecting voice through an instrument toward a mirror. Vibrations in the voice caused oscillations in the shape of the mirror. Bell directed sunlight into the mirror, which captured and projected the mirrors oscillations toward a receiving mirror, where the signals were transformed back into sound at the receiving end of the projection. The photophone functioned similarly to the telephone, except the photophone used light as a means of projecting the information, while the telephone relied on electricity. The photophone was the first wireless communications device, preceding the invention of the radio by nearly 20 years. Although the photophone was an extremely important invention, the significance of Bells work was not fully recognized in its time. This was largely due to practical limitations in the technology of the time: Bells original photophone failed to protect transmissions from outside interferences, such as clouds, that easily disrupted transport. That changed nearly a century later when the invention of  fiber optics in the 1970s allowed for the secure transport of light. Indeed, Bells photophone is recognized as the progenitor of the modern fiber optic telecommunications system that  is widely used to transmit telephone, cable, and internet signals across large distances.

Hyperkalemia or High Potassium

Hyperkalemia or High Potassium Hyperkalemia breaks down to mean  hyper-  high;  kalium, potassium;  -emia, in the blood or high potassium in the blood. Potassium in the bloodstream is the K ion, not potassium metal, so this illness is one type of electrolyte imbalance. The normal concentration of the potassium ion in blood is 3.5 to 5.3 mmol or milliequivalents  per  liter  (mEq/L). Concentrations of 5.5 mmol and higher describe hyperkalemia. The opposite condition, low blood potassium levels, is termed hypokalemia. Mild hyperkalemia typically isnt identified except through a blood test, but extreme hyperkalemia is a medical emergency that can result in death, usually from heart arrhythmia. Hyperkalemia Symptoms The symptoms of elevated potassium are not specific to the condition. Mainly the effects are on the circulatory and nervous system. They include: weaknessmalaiseheart palpitationshyperventilation Causes of Hyperkalemia Hyperkalemia results when too much potassium is taken into the body, when cells massively release potassium into the bloodstream, or when the kidneys cant properly excrete potassium. There are numerous causes of hyperkalemia, including: kidney diseasediabetes (leading to nephropathy)medications that affect urination (NSAIDS, diuretics, antibiotics, etc.)diseases associated with a mineralocorticoid deficiencymassive blood transfusionany major tissue damage, whether it be from injury (burns, serious wounds) or medical treatment (notably chemotherapy)excessive dietary intake of potassium-rich foods (e.g., salt substitute, bananas)intentional hyperkalemia as the last step of lethal injection, to disrupt and stop the heart Not that its highly unusual for a person with ordinary kidney function to overdose on potassium from foods. Excess potassium resolves itself if the kidneys are able to process an overload. If the kidneys are damaged, hyperkalemia becomes an ongoing concern. Preventing Hyperkalemia In some cases, its possible to prevent potassium buildup by limiting dietary intake of potassium-rich foods, taking diuretics, or ending a medication that causes a problem. Hyperkalemia Treatment Treatment depends on the cause and severity of hyperkalemia. In a medical emergency, the goal is to shift the potassium ion from the bloodstream into cells. Injecting insulin or salbutamol temporarily lowers serum potassium levels.