sobota 14. ledna 2012

Is wifi in bedroom dangerous?

Comparison of electromagnetic emissions:


Source Position Average Maximal
WiFi Access point 31 cm from head 0.1 mW/kg 4 mW/kg
Apple iPhone 3G 3 cm from head 13.9 mW/kg 1300 mW/kg
Allowed limit 250 mW/kg 2000 mW/kg
Human in your bed 1000 mW/kg 2000 mW/kg

That means that WiFi typically emits less than 1% of an iPhone.
See pubmed for the source. The emission from a human body is calculated from Planck's law.

Global warming

Why people like to believe in global warming caused by emissions of carbondioxid?
Because people don't like, when they can't control things or at least explain them.

Why people like to listen to stories about global warming?
Because kids enjoy morbid fairy tails. And global warming is a blockbuster fairy tail for adults.

Does global warming really exist?
Since Vaclav Klaus, a man who hates ecologists, accepts the existence of global warming, global warming is a reality.

Is global warming caused by people?
Global warming is nothing new. It happens all the time. The last big warming happened during the transition from ice age to what we have now. These changes of temperature are natural, periodic, bigger and faster, than what we experience nowadays. See plot of temperature in the past & presence.