Changing The Reference Frame
Every isolated unstable black hole decays rapidly to a stable black hole; and (modulo quantum fluctuations) stable black holes can be completely described (in a Cartesian coordinate system) at any moment in time by these eleven numbers:
- mass-energy M,
- linear momentum P (three components),
- angular momentum J (three components),
- position X (three components),
- electric charge Q.
These numbers represent the conserved attributes of an object which can be determined from a distance by examining its gravitational and electromagnetic fields. All other variations in the black hole will either escape to infinity or be swallowed up by the black hole.
By changing the reference frame one can set the linear momentum and position to zero and orient the spin angular momentum along the positive z axis. This eliminates eight of the eleven numbers, leaving three which are independent of the reference frame. Thus any black hole which has been isolated for a significant period of time can be described by the Kerr–Newman metric in an appropriately chosen reference frame.
Read more about this topic: No-hair Theorem
Famous quotes containing the words changing the, changing, reference and/or frame:
“The snake that cannot shed its skin perishes. Likewise those spirits who are prevented from changing their opinions; they cease to be spirits.”
—Friedrich Nietzsche (1844–1900)
“One’s condition on marijuana is always existential. One can feel the importance of each moment and how it is changing one. One feels one’s being, one becomes aware of the enormous apparatus of nothingness—the hum of a hi-fi set, the emptiness of a pointless interruption, one becomes aware of the war between each of us, how the nothingness in each of us seeks to attack the being of others, how our being in turn is attacked by the nothingness in others.”
—Norman Mailer (b. 1923)
“The common behavior of mankind is the system of reference by means of which we interpret an unknown language.”
—Ludwig Wittgenstein (1889–1951)
“In this choice of inheritance we have given to our frame of polity the image of a relation in blood; binding up the constitution of our country with our dearest domestic ties; adopting our fundamental laws into the bosom of our family affections; keeping inseparable and cherishing with the warmth of all their combined and mutually reflected charities, our state, our hearths, our sepulchres, and our altars.”
—Edmund Burke (1729–1797)