On 27 January 2014 15:30, meekerdb <[email protected]> wrote: > On 1/26/2014 12:40 PM, LizR wrote: > > It's common knowledge - well, amongst people who are interested in this > sort of thing - that an outside observer sees an infalling object get stuck > just outside the event horizon of a black hole (and then fade away as it > redshifts towards infinity) > > This was explained in a (relatively) recent "scientific american" > article using an elephant as the example. The point is that the BH creates > a superposition - the elephant is a "schrodinger's cat" which is in both > states (alive outside the BH, and dead inside). I found it fascinating that > this well known quantum thought experiment could be done for real (in > theory). > > > That's a very controversial theory though, since in the cat's (or > elephant's) frame there is notable about the horizon (per GR). Ahmed > Almheiri, Donald Marolf, Joseph Polchinski, James Sully > > http://arxiv.org/abs/1207.3123 > > and also Leonard Susskind have been proposing that there must be a > "firewall" at the horizon to prevent this kind of entanglement, because > otherwise it would violate quantum monogamy. > > > http://quantumfrontiers.com/2012/12/03/is-alice-burning-the-black-hole-firewall-controversy/ > > Hawking just delivered a somewhat cryptic paper saying there is no well > defined horizon. > > http://www.nature.com/news/stephen-hawking-there-are-no-black-holes-1.14583 > > I'm afraid SciAm has fallen into the trap of trying to compete with > "Discovery" and the tabloids. >
There is always that temptation. Almost every week "New Scientist" has a cure of cancer and an explanation of how the universe REALLY works... Yes sorry, I shouldn't have added the contraversial BH complementarity comment to the uncontentious one about what a distant observer sees. Somehow the idea of the elephant tickled my fancy... -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
