Justice League: A Better World
Boom Tube is a slang expression for an extra dimensional point-to-point travel portal opened by a mother box used primarily by residents of New Genesis and Apokolips. They allow people to travel interstellar distances quickly by creating an apparent tube between two points through which people can travel. When in use a ‘tube’ coated in arcane technology appears for the user to pass through accompanied by a loud ‘boom’ noise (hence the name). The tubes need to be generated or opened by another device, commonly a Mother Box. Boom tubes are powered by the mysterious X Element, which serves as a matter threshold.
Darkseid can summon and control the Boom Tube by himself. Others need to use a Boom Tube Call Box. The Boom Tube Summoning Machine is located on Apokolips. A Mother Box is also capable of summoning a Boom Tube.