AMatterOfDegrees
A Matter of Degrees (Gino Segre)
- Average at best. Interesting part re: human fevers and life around hyrdothermal vents.
- There is no simple answer as to why our bodies maintain a constant temperature. Nor is there a complete answer to the advantage of fevers in responsce to infection.
- We know the temperature at the center of the Sun (from nus) with greater precision than that of the center of the Earth.
- We feel most confortable in external temperatures some 20 - 30 degrees below our skins temperature, bc that differential produces a comfortable rate of heat loss.
- Evaporation cools, but the process only works in the air above the skin is sufficiently dry.
- 1 calorie to raise one g of water by 1 degree Celsius, or 100 c to go from 0 to 100 Celsius. But more than 500 c are nescessary to change a gram of water at 100 C into steam at the same temperature. THis means the conversion of water to water vapor in the body is a very efficient way to cool down.
- In hydrothermal vents, sunlight is being replaced as an energy source by the sulfide-to-sulfate transition.
- Essentially all the iridium on the earths surface comes from asteroids. A measurement of the clays irr content would tell how many days it had taken for the clay to form. The clay in the layer after the great dinosaur extinction, had more than 100x the expected amount of iridium.