Look_What_I_Found

Bio-Geo

 

 

 

 

 

 

Origins

Unsung

The history of rocketry is yet to be written. To this day, rocket science is a joke
which arises in the context of ' dumb and dumber'  jokes. Indeed, there are
difficulties.

Robert Goddard(1882-1945), the first to build a liquid-fuel rocket, considered his work
in the following terms: "...the dream of yesterday is the hope of today and the reality of
tomorrow."  A German pioneer, Herman Oberth(1894-1989) was an avid reader of Jules
Verne, and came to the idea of a multi-stage rocket at 14. His phd thesis was later refused
as being too 'utopian'. This is what he had to say about the educational system:  "Our
educational system is like an automobile which has strong rear lights, brightly illuminating
the past. But looking forward, things are barely discernible."

The first true rocket, built during World War II, was a ballistic missile the - V2 - an engine of
destruction used against Allied forces. It was built thanks to Wernher von Braun(1912-1977),
a team of scientists from many countries, and the assembly-line skills of the workers of a
concentration camp, Dora-Mittelbau. The prototype picured below was painted with checker-
board squares so that the team could eye-ball it during flight to monitor if it rolled. It was
launched in 1943.

There are surely lessons to be learnt from this complex history as, today, some of the
least reasonable among us are packing their bags for Mars. It beats being stuck in traffic.

source: Wikipedia

Hail

source: Wikipedia

Tornadoes(what)

Excerpt from a Le Monde 2011 article
translation: doxa-louise

How do tornadoes form?
Tornadoes are swirling wind tunnels of extreme violence, which form

at the base of a storm cloud (cumulonimbus) and sometimes reaching the

ground. They are the result of a meeting of the cold air of the high troposphere

and warm and humid air from lower atmospheric strata. The two air masses do not

mix but roll one around the other, thus creating strong winds. In cases of variations

in the strength and direction of winds, at different altitudes - what are called

wind shearings - , the storm disturbances experience strong rotation, creating a whirl.


What is their intensity?
In general, tornadoes last ten minutes, move at the speed of the storm, between 50

and 100 kms/hour. The diameter of the vortex vaccilates between some tens and some

hundreds of meters. But in extreme cases, winds can go up to 500kms/hour and the tuba

several kilometers in length. Tornadoes can then last for hours. They are measured on the

Fujita scale, established in 1971, as a function of the damage inflicted on human constructs

more than the strength of winds. Tornadoes are thus classified as F0, which induces light

damages, up to F5, where projected débris are extremely dangerous and where winds can

rise to 500 kms/hour, with dramatic consequences.


Why do these often occur in the United States?
The United States experience every year some 1 000 tornadoes. These are formed because of

the meeting in Spring of cold and dry currents from the North Pole at some ten kilometers in

altitude, and warm and moist currents from the Gulf of Mexico, at much lower altitudes.

The presence of the Rocky Mountains, in the west, produces as well an ondulation of the Jet

Stream - a very rapid current at ten kilometers of altitude - favorable to storm disturbances

on the Great Plains.

Bernoulli Principle

How tornadoes formThe U.S. experiences the most of any country. They occur on average 1,000 times and kill 60 people per year, mostly in two regions -- Florida and the so-called "Tornado Alley," the area between the Rocky and Appalachian Mountains. But they've been recorded in all 50 states, usually between late winter and mid-summer.

No one knows what forms a tornado, but scientists agree on a few general points. The most common tornadoes come from rotating thunderstorms, called supercells.

In a supercell, the updraft of warm air rotates counter-clockwise in the northern hemisphere, reaching speeds of up to 175 mph and forcing cool air to descend. The updraft can pull cool moist air -- which would ordinarily fall from clouds -- back up into the sky. The saturated air then condenses to form a rotating wall of clouds, typically toward the back of a cloud in rain-free zones.

With enough strength, the spinning effect creates a funnel, hits the ground and creates a tornado that can last several seconds to more than an hour. Damage can range from superficial, such as roof damage from a falling tree, to completely sweeping away a structure, leaving only the foundation.

Read more: http://www.foxnews.com/science/2013/05/21/tornado-primer-earths-violent-storms/#ixzz2TyuoDpbb