Why did the ancient world use amphorae and how did they work?

The long pointed bottom of the typical amphora actually gave it an excellent shape for stacking against a ship’s hull, ensuring that the oil or wine within would be safe during transport. In the evolution of amphorae, they often began rounded and egg-shaped and shifted to pointed, because the long bottom of the brittle pottery … Read more

Did bleeding or bloodletting the patient in ancient times actually help any medical condition or did it make it worse?

Not unless the victim that is, patient chanced to be suffering from a hypertension crisis or an abnormal buildup of iron in addition to whatever disease the doctor thought he was treating. For example, draining 10 to 12 ounces of blood, for a start, and up to 80 ounces in all, was routinely prescribed during … Read more

Is spontaneous human combustion real or a myth?

There is no scientific evidence that any person ever spontaneously combusted, and no scientifically known means by which it could happen. In a typical case where there has been a report of a body burning unusually, a simple or at least plausible explanation is available when the case is examined in detail. A statistically typical … Read more

Did a secret Byzantine naval weapon called Greek fire exist or was it a myth?

Historians agree Greek fire existed, but debate its nature. Some credit Callinicus of Heliopolis with building fire-spouting ships that defended Constantinople from the Arabs in 673. Greek fire was described as a liquid that burned even on the sea surface, with smoke and whooshing sounds. Candidates for ingredients include petroleum, resin, and quicklime, plus an … Read more

Do tall buildings in the city need lightning rods and why?

Historically speaking, New York City is less prone to thunderstorms than many areas of the country, but the island of Manhattan is not immune to lightning. For example, the Empire State Building is struck by lightning on average about two dozen times a year. The good news for Manhattanites is that modern high-rise buildings have … Read more

Why is grain dust in elevators explosive?

Just about any organic material will explode if it is fine enough, dry enough, in suspension in air, and confined. All it takes is the fuel, oxygen, and a spark. Sugar, coal dust, wood dust, walnut hulls, the ingredients of children’s modeling dough, and some medications have also been involved in recent dust explosions. Organic … Read more

What are touch screens and how do they work?

Several kinds of technology have been used for touch screens. If the screen responds without actually being touched, it probably uses a system that has tiny infrared light emitters and detectors along the edge of the screen. When a finger interrupts the grid of beams, a computer can tell its exact position. Some screens sensitive … Read more

Why does paper especially newsprint turn yellow as it ages?

The paper is oxidizing, one of several destructive processes that affect paper. Newsprint is high in lignin, one of the main structural components of wood. When lignin is in contact with oxygen, a highly reactive chemical, the reaction changes the way the fibers reflect light, discoloring the paper. Oxidation also produces more acid, a major … Read more

Why do some kinds of cookware get very hot in the microwave?

There are two reasons why cookware may heat up excessively in a microwave oven. The first is the same effect that occurs in cooking: friction. Microwaves are rapidly fluctuating electromagnetic fields, which push on electric charges and twist naturally polarized particles like water molecules back and forth. In liquid water, this twisting leads to molecular … Read more

Why do I see more steam when I take the teakettle off the flame?

The “steam” you see is what steam engine enthusiasts call wet steam, because it contains unevaporated water as a mist within the actual water vapor, which is a colorless, odorless gas. Dry steam does not contain any unevaporated water. Steam vapor forms at temperatures above the boiling point, normally 212 degrees Fahrenheit. Visible steam is … Read more

Is being allergic to winter possible or is it a myth?

Conditions that are very like an allergy to winter are not only possible but common. Your friend’s problem could be an asthmatic reaction to exercising in the cold, or it could be an allergy to something she is exposed to in winter even more than in the traditional allergy season. It could even be that … Read more

Does holding your breath when a bus passes on the street protect your lungs from pollution?

Probably not, but more research is needed to know the degree of danger presented by the fumes emitted from diesel vehicles. Cars, trucks, and buses, especially diesel buses, emit large amounts of tiny particles that remain airborne for long periods. Because they linger, holding the breath until the bus passes is ineffective in keeping them … Read more

Why is AIDS so prevalent in Africa?

There are many theories about the high AIDS rates, especially in sub-Saharan Africa, and answers almost certainly lie in combined economic, sociological, political, and medical factors. For example, the rate of HIV infection in Botswana, the highest in the world at 35.8 percent of adults, has been linked to Botswana’s location and excellent road system, … Read more

Do rats carry and spread the rabies virus and how?

Scientists don’t know for sure, but the most likely explanation is that rats probably would not survive an encounter with an infected carnivore, and so would not be around to transmit the disease to people. It is also possible that rats may lack a means of transmitting the virus within the species, because of mouth … Read more

How Do Conservationists Predict Whether a Species Will Become Extinct?

Conservation biologists use population viability analysis (PVA), a relatively new method, to predict the viability of a species in a particular habitat. Computer modeling generates PYAs using life history data, genetic variability, and a population’s response to environmental conditions-especially disturbances-to predict viability of a species. A typical species becomes extinct within 10 million years of … Read more

What Methods Are Used To Estimate Wildlife Populations?

Since it is usually impossible, and often impractical, to count all individuals in a population, researchers use a variety of sampling techniques to estimate population densities. One method is to count the individuals in a certain area. The larger the number and size of sample plots, the more accurate the estimates. Population densities may also … Read more

Where Is the Coldest Place On Earth?

what is the coldest place on earth

So you think it’s cold where you are? Not even close. Vostok, Antarctica, had the Coldest Temperature ever recorded on Earth on July 21, 1983 at -129 Fahrenheit (-89 Celsius). The second Coldest Place on Earth ever recorded was Verkhoyansk, Russia, in February 7 1892, where it reached a chilly -90 ° Fahrenheit (-68 °C). … Read more

Where Is the Hottest Place On Earth?

hottest place in the world

So you think it’s hot where you are? Not even close. Updated 17 August 2020 Update: The hottest temperature on the planet recorded hit a new high today in Death Valley National Park, California, where the temperature reach a scorching 54.4 C (130 F). Source: https://www.bbc.com/news/world-us-canada-53788018 Previous Records 2013 In 2013, the highest temperature reliably … Read more