ASTA02H3 Lecture : ASTA02 Lecture Note.docx
Document Summary
A region of space time that nothing, not even light, can escape from. The boundary of a black hole is called the event horizon. A black hole is characterized by an event horizon and a singularity in the centre. A neutron star more massive than 3m of the sun can collapse into a black hole. Adding mass to the black hole causes the event horizon to increase. Laplace and michell in the 18th century argues that a star could be so massive and so compact that the escape velocity of it is equal to the speed of light or larger. No hair theorem: black hole is characterized by only 3 main properties: mass, electrical charge, and angular momentum. Angular momentum is one of the properties that is conserved. Loss of information when anything enters a black hole: anything thrown into a black hole will lose all properties.
