Microbial Threats and Voyages

A research-based on the above topic:

In this paper, we’re gonna talk about Europe and what all this small continent caused.

Most of the pandemics in the past had been caused by the diseases originating in Europe. It is no surprise here. More than a billion people have died due to these diseases. Since Europeans have been colonizers in the past, they had spread their diseases to all over the world.

Let us learn about the diseases spread by this continent:

THE BLACK DEATH

  • The Black Death plague which was originally originated in China dominated Europe from 1347 to 1665. ​
  • It reached its peak in the years 1346-1356 where estimates place that around 75 million-100 million.​
  • Almost one-third of Europe perished.​

SMALL POX AND MEASLES:

  • Small Pox and Measles were the diseases that were introduced to the native population of North America brought by the Europeans.​
  • It reduce the number of native Americas by as much as 95%, killing 20 million.​
  • It was from 1509-1529

CHOLERA:

  • The third global cholera pandemic of 1852 – 1866 began on the Ganges River Delta, spreading along trade routes throughout India, and from there to Russia, China, France, England, and the United States. ​
  • In 1853–54, an epidemic of cholera broke out in London, where it claimed over 10,000 lives.​

Thank you!

DENSITY

Ever wondered why a small metal coin sinks and a big ship doesn’t?​

Oh, it’s all based on the concept of density. And the whole idea of density comes from the concept of the Archimedes principle. It is because of this principle we know why big ships float on the water, and do not sink.​

​So, what is the Archimedes principle?

Archimedes’ principle, physical law of buoyancy, discovered by the ancient Greek mathematician and inventor Archimedes, stating that any body completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant, force, the magnitude of which is equal to the weight of the fluid displaced by the body.

What is density?​

Density is a measure of mass per volume. The average density of an object equals its total mass divided by its total volume. An object made from a comparatively dense material (such as iron) will have less volume than an object of equal mass made from some less dense substance (such as water).

FLOATATION:

​When a body of density ρ and volume is completely immersed in a liquid of density, the following two forces act on the body:​

1. Weight of body, W=Vρg acting vertically through the center of the gravity.​

2. Buoyant force or upward thrust, FB = V*liquid density*g equal to the weight of the liquid displaced, acting vertically upwards through the center of the buoyancy.​

​So, in simple words we can define the Archimedes principle as: when a body is wholly or partially submerged in a liquid, buoyant force acts on it thus reducing the weight of the object which is equal to the weight of the liquid displaced.

Depending upon these formulas, there are three cases:​

  1. W > FB , the body will sink to the bottom of the liquid. This happens when the density of solid is greater than the density of the liquid.​

2. W < FB , the body will rise above the surface of the liquid to such an extent that the weight of the liquid displaced by the immersed part of the body ( i.e. upward thrust ) becomes equal to the weight of the body. The body will then float. In this case, the density of the body is lesser than the density of the liquid.​

3. W = FB , the body is at rest anywhere in the liquid. The body will float if its whole volume is just immersed in the liquid. In this case the density of the body is equal to the density of liquid.​

Therefore from the above conditions, we now know why big ships float. This is because of density. The density of the ship is much lesser or equal to that of the water.​

Thank you!