Europe was once a very enlightened continent, with a Pagan world view based on science. Not on politicised quasi-science, but on real science. We find evidence of this all over our mythology.
From Grîmnismâl, stanza 38, we hear talk of a shield between the Sun and the Earth, protecting the land and sea from burning up. The shield is called Svalinn («Cooler»);
38. Svalinn heitier, hann stendr sôlu fyrir,
Skjöldr skînanda goþi:
björg og brim veitek at brinna skulu
ef hann fellr î frâ.
(38. «There is one called Cooler who stands before the Sun,
a shield from the shining goddess:
the mountains I ween, and the stormy sea
will flame if he fall from thence.»)
The Earth is largely protected from the solar wind, a stream of energetic charged particles emanating from the Sun, by its magnetic field, which deflects most of the charged particles. These particles would strip away the ozone layer, which protects the Earth from harmful ultraviolet rays. Calculations of the loss of carbon dioxide from the atmosphere of Mars, resulting from scavenging of ions by the solar wind, are consistent with a near-total loss of its atmosphere since the magnetic field of Mars turned off.
So did they know that this «Cooler» protected life on our planet? That if it had «fallen down» the land and sea would «burn»? About ultraviolet rays we can learn that;
However, the entire spectrum of ultraviolet radiation has some of the biological features of ionizing radiation, in doing far more damage to many molecules in biological systems than is accounted for by simple heating effects (an example is sunburn). These properties derive from the ultraviolet photon‘s power to alter chemical bonds in molecules, even without having enough energy to ionize atoms.
If «Svalinn» falls we will (Sun)burn, and perhaps our forebears already knew – at least a thousand years ago.