According to the phylogenetic tree diagram, modern birds are most closely related to?
Does lightning travel from the earth to the sky, or from the sky downward? Lightning travels both ways. Lightning is a huge electrical discharge that results from vigorous motions that occur in thunderstorms. Lightning can travel from cloud to cloud, within the same cloud, or between the cloud and ground. In-cloud lightning discharges are more common than cloud-to-ground discharges and are not as hazardous. Cloud-to-ground is the best known type of lightning and it poses the greatest risk.
Cloud flashes include lightning that does not strike the ground. Instead, the lightning stays embedded in the cloud and shows up as sheet lightning or heat lightning. With heat lightning, the cloud remains too far away to hear the thunder associated with it, but thunder occurs just the same as any other lightning event.