Cand caldura soarelui loveste campul magnetic al Pamantului, cerul de la ambii Poli este luminat de aurore. Particulele creeaza valuri electromagnetice de frecventa foarte joasa, un tip de radio natural in jurul globului. In fiecare an Steve McGreevy (inginer de sunet si pasionat in observarea acestui fenomen) se deplaseaza la Polul Nord, unde receptia este cea mai buna, isi pozitioneaza receptoarele spre cer si iata o mostra de aproape 8 minute din ceea ce se intampla acolo: Continuare
When solar flares hit the magnetic field of Earth, the skies at both poles can light up with auroras. The particles create very low frequency electromagnetic waves, a type of natural radio that can be picked up around the globe. Every year Steve McGreevy (sound recordist) heads north where the reception is best and points his receiver at the sky.
Skin color is determined by the amount of melanin, the pigment of the skin, and can create colors from blue to nearly colorless which gives the skin a reddish appearance because of the blood located just beneath. Our skin plays two key roles: to protect us from the harmful UV radiation of the sun, while still taking in enough sun to produce healthy amounts of vitamin D. Because of this need, those populations who live in lower latitudes, those closer to the equator, have adapted darker toned skin able to better protect from UV radiation, while those in the higher latitudes have lighter skin to maximize vitamin D production. Continuare