quarta-feira, abril 26, 2006

Hoje ... de Outros Tempos

Talvez a última lição da História, neste dia holocáustico!

Que, conjuntamente com outras efemérides de hoje que não tenho de as recordar
( 26 de Abril
- de 1860. Morte do duque da Terceira, marechal do Exército, político liberal. Tinha nascido em 1792.
- de 1937. Aviões alemães, a Legião Condor, bombardeiam a cidade espanhola de Guernica, no País Basco.
- de 1946. É criado o MUD Juvenil.
- de 1986. Acidente na Central Nuclear ucraniana de Chernobyl) - retirado do Portal da História,
apesar de apontá-las, é a última marca da estupidez humana, quando sabe que a nossa capacidade para evitar os riscos da aventura em que nos lança a inteligência não é directamente proporcional à nossa capacidade para os interpretar, descodificar e, assim, instituir a aprendizagem com a qual poderemos não permitir a repetição deste tipo de erros! Não digo mais nada. Apenas reproduzo o que hoje tirei do Google. Vale a pena!

Roentgens
To begin our journey, we must learn a little something about radiation. It is really very simple, and the device we use for measuring radiation levels is called a geiger counter . If you flick it on in Kiev, it will measure about 12-16 microroentgen per hour. In a typical city of Russia and America, it will read 10-12 microroentgen per hour. In the center of many European cities are 20 microR per hour, the radioactivity of the stone.
1,000 microroentgens equal one milliroentgen and 1,000 milliroentgens equal 1 roentgen. So one roentgen is 100,000 times the average radiation of a typical city. A dose of 500 roentgens within 5 hours is fatal to humans. Interestingly, it takes about 2 1/2 times that dosage to kill a chicken and over 100 times that to kill a cockroach.
This sort of radiation level can not be found in Chernobyl now. In the first days after explosion, some places around the reactor were emitting 3,000-30,000 roentgens per hour. The firemen who were sent to put out the reactor fire were fried on the spot by gamma radiation. The remains of the reactor were entombed within an enormous steel and concrete sarcophagus, so it is now relatively safe to travel to the area - as long as we do not step off of the roadway.......

The map above shows the radiation levels in different parts of the dead zone. The map will soon be replaced with a more comprehensive one that identifies more features.

It shows various levels of radiation on asphalt - usually on the middle of road - because at edge of the road it is twice as high. If you step 1 meter off the road it is 4 or 5 times higher. Radiation sits on the soil, on the grass, in apples and mushrooms. It is not retained by asphalt, which makes rides through this area possible.