# Hawking radiation - question **URL:** \ **Category:** Factual Questions\ **Created:** [September 17, 2011, 8:55pm UTC](https://boards.straightdope.com/t/hawking-radiation-question/596660 "2011-09-17T20:55:54Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 18, 2011, 3:31pm UTC](https://boards.straightdope.com/t/hawking-radiation-question/596660/21 "2011-09-18T15:31:30Z")
> [@Half\_Man\_Half\_Wit](#): > > I’m not sure, but isn’t generally energy conserved in asymptotically flat/static spacetimes? So we ought to have both Hawking radiation and CoE in the Schwarzschild case, no? Or am I misreading you? Yes I am saying that we ought to have conservation of energy and Hawking radiation in the Schwarzchild case and so by extension Hawking radiation should affect the mass of the black holein order to satisfy this conservation of energy. But I’m also saying the negative energy flux in to the black hole is due to the global symmetry of the spacetime ratehr than the local symmetry. btw in between the first and the second sentence of the above paragraph I read what Wald has to say on this as he does cover it in his book _General relativity_, needless to say his arguments on why there has to be a negative nergy flux in to the black hole (and he offers approximations as to what this flux should be) are considerably more robust than what I’ve offered so far ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [September 18, 2011, 3:44pm UTC](https://boards.straightdope.com/t/hawking-radiation-question/596660/22 "2011-09-18T15:44:41Z")
> [@These are my own pants](#): > > btw in between the first and the second sentence of the above paragraph I read what Wald has to say on this as he does cover it in his book _General relativity_, needless to say his arguments on why there has to be a negative nergy flux in to the black hole (and he offers approximations as to what this flux should be) are considerably more robust than what I’ve offered so far Ha, I’m actually just in the process of reading the chapter in Wald, as well… 😛 [Previous page](https://boards.straightdope.com/t/hawking-radiation-question/596660.md?page=1)