Exploring Ergosphere of Black Holes

Key Points

• 1Rotating black holes have an ergosphere outside their event horizon.
• 2The ergosphere is a region from which matter and energy can be extracted.
• 3The label 'ergosphere' comes from the Greek word 'ergon', meaning 'work'.
• 4It is possible to send an object into the ergosphere to accelerate it.
• 5This energy gain would translate to the black hole losing angular momentum.