A
thunderbolt or
lightning bolt is a symbolic representation of
lightning when accompanied by a loud
thunderclap. In
ancient Hellenic and
Roman religious traditions, the thunderbolt represents
Zeus or
Jupiter (etymologically 'Sky Father'), thence the origin and ordaining pattern of the universe, as expressed in
Heraclitus' fragment describing "the Thunderbolt that steers the course of all things". It is the same in other Indo-European traditions, for example the
Vedic Vajra.