say that sequels are never good, but we will make the attempt ...
Thursday, October 22, 2009
Franklin Mint Vase Butterflies
3rd part of a planet, part 2
say that sequels are never good, but we will make the attempt ...
In the first part say that sequels are never good, but we will make the attempt ...
calculate the amount of energy the Earth receives from the sun But what about that energy? In a nutshell, is used to warm the Earth. Which brings us to another question before continuing: What temperature is the empty space? 
course to answer this question we must first define what it means "Empty space." Strictly speaking, the empty space there. And for various reasons: cosmology, quantum and relativistic. Re-ask: At what temperature is a region of space with no stars or other energy sources nearby?
(yes, as the oven!), Which extend in the electromagnetic spectrum between 300 MHz and 300 GHz
Alpher and R.
Hermann
, and was discovered (by accident) in 1965 by Hermann
A. Penzias and R. Wilson (Nobel Prize winners in 1978 for this work) is actually a relic of the Big Bang to the time when the universe became transparent to radiation, or put another way, when finally electrons and photons allowed to interact and electrons began to form atoms with the baryons. From that moment (about 300,000 years after the Big Bang), the photons propagate through the expanding Universe with almost no interaction (the current density is 410 photons per cubic cm.)
And since the universe expands adiabatically (by definition, the universe is a closed system), the temperature of this background radiation decreases as time progresses. The current temperature of the background radiation was measured with extreme accuracy (parts per million) and is 2.725 K, and its distribution corresponds to that of a black body at that temperature.
We finally have our answer: if the sun suddenly disappeared, and if the Earth had no nuclear processes inside, the temperature of the Earth gradually fall to reach thermal equilibrium with the background, about 2.7 K (about -270 ° C).
continued ...
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