This was not the era of telecommunications. According to one of the opinions mentioned in the Talmud, tractate Bava Bathra p.16b, Iyov and his three friends had crowns upon which their faces were engraved . If any of them fell into trouble or sorrow the image of that person's face would sadden on all of their crowns. This was a signal that they should come to his help. As with many mysterious stories in the Talmud this too may be interpreted symbolically.
Wisdom is the crown jewel of humanity.
Wisdom is the vehicle by which we understand G-d and communicate with Him. It is only through wisdom that we can create an everlasting bond with our Creator. The capacity for wisdom is the greatest spiritual gift that we possess. The crowns that these four friends possessed is a metaphor for wisdom. The remarkable relationship that these four people shared was no ordinary one.