Do you remember the riddle from the Book of Veles which I mentioned in my post "Triglav , Trojan, Trinity, Trimurti, Agni":
"Jer tajna je velika, kako to Svarog biva u isto vreme i Perun i Svetovid."
Translated into English this means:
"Because it is a great secret how come Svarog (hevenly and earthly fire) is at the same time Perun (thunder and lightning) and Svetovid (Sun)."
The answer to this riddle is Triglav (three headed), Trojan (triple, trinity).
Svetovid, Perun and Svarog are just three heads, three faces, three manifestations of the one and only god, Triglav.
Now have a look at this:
This article in magazine "Nature" states that "Lightning is triggered by solar winds":
"Lightning has been around since the dawn of time, but what triggers it is still an enigma. Now, researchers propose that the answer could lie in solar particles that penetrate the atmosphere and ionize the air, releasing free electrons and leading to a massive discharge.
Thunderclouds become electrically charged from the collisions of microscopic ice particles in their midst, and from air currents that push the negative and positive charges apart. The air is a good insulator, keeping electrons from jumping back and equilibrating the electrostatic charges. But if a pathway of ionized air molecules forms that can act as a conductor between different parts of a cloud, or between the cloud and the ground, the result is a lightning bolt.
However scientists are still not sure of what initiates the formation of such a pathway. In the presence of strong enough electric fields, insulators spontaneously break down and become conductors, but experts believe that the atmosphere simply cannot reach the hundreds of thousands of volts or more required to produce a lightning. So they have been searching for alternative explanations. Researchers at the University of Reading, UK, now say that solar wind has a role.
As high-speed solar-wind particles travel through space, they can lead to localized strengthening of the magnetic field, which pushes some of the particles to even higher speeds. These so-called solar energetic particles (SEPs) — unlike other those that travel at slower speeds — have enough energy to penetrate Earth’s magnetic field and to travel through the atmosphere, down to the altitudes where thunderclouds form. There, researchers say, they could collide with atoms in the air, generating a cascade of high-energy particles. This ‘runaway breakdown’ would be sufficient to trigger lightning, says Christopher Scott, a space scientist who led the latest study."
Basically without solar winds there would be no lightning.
And without lightning there would be no Earthly fire. At least before people "stole the secret of making fire from the sky god". Originally earthly fires were a product of lightning strikes during the periods of intense sun's heat. And as we see from the above "Nature" article, lightning is a direct product of solar winds which means that Sun creates Thunder and Lightning which creates Fire.
And this is why Svetovid (Sun), Perun (Thunder and Lightning) and Svarog (fire) are One:Triglav (Three headed) one and only God.