Why do we call or chant the ten names of  Arjuna

when the  thunder-stroke happens ?

The  Nature consists of  six seasons (Shadrutus).

Vasanta rutu, Greeshma rutu, Varshrutu, Saradrutu,

Hemantarutu and Sisira rutu.

In the Varshrutu (Rainy season) normally it rains and rains.

 Some times it rains pouringly. It is so natural when it rains,

 in the sky the  thunder-bolts happens.

They roar like  terrible .  Every creature  fear about that.

Mostly the thunder-bolts fall on the trees and near the hill areas.

There was a epic from the Mahabharata.  In the Mahabharata,

 when the Pandavas were in the Agnatavasa Deeksha

( the Pandavas  had to  live in incognito as per the moral decesion)

 the hero Arjuna kept all his Astras (weapons) in the hollow

of  a Sameevruksha  for which one can not see them.

When their Agnatavasa is completed the Arjuna

went to that Sameevruksha  with Uttara (the son of King Virata) 

 to collect his Astras to fight against Duryodhana,

Karna etc in the war of Uttara Gograhana  and

 asked Uttara to bring the weapons from the hollow of that tree.

Then , the Uttara was afraid of bring them from the Samee Tree

as the weapons were looked like poisonous snakes. 

At that time Aruja advised Uttara to chant his  ten names ,

then Uttara  will not have any fearness and he will have courageness.

By this Arjuna’s courageous words then  Uttara did like that.

He chanted Arjuna’s ten names.

Hence the Arujan’s ten names are Arjuna, Phalguna,  Paartha,

Kireeti, Swetavahana, Bheebhatsa, Vijaya,

Krushna (this name was given by Pandavas), Savyasaachi

(He can work with both hands with the same skill) and

Dhanunjaya.

So when the thunder-bolts fall, if we call or chant

those ten names of Arjuna,  the fearness can go away.

 The Historic belief is  in some places, 

when the thunder-stroke happens, Arujuna’s

chariot’s nail (peg or screw) has fallen, so it was

  the thunder-bolt what people also believe.

When the people think like that also one kind of chanting of Arjuna itself.