Il 15 Giu 2007, 11:54, marcofuics <marcofuics_at_netscape.net> ha scritto:
> On 12 Giu, 14:34, e..._at_libero.it (ernesto) wrote:
>
> > > Questo e' un meccanismo della Meccanica Quantistica non relativistica,
>
> > la meccanica quantistica non � tutta NON relativistica?
>
> Ti diro': la meccanica Q nasce proprio Relativistica:
> infatti fu con i quanti di luce che Einstein tiro' la carta sul
> tavolo, ed erano proprio i quanti di luce che hanno ispirato deBroglie
> e poi Schr. e Dirac tutti gli altri.
> Insomma la <<quantizzazione>> parte con il campo elettromagnetico, con
> la luce, che e' l'essenza della relativita'.
> Poi, la MQ non relativistica la butto' giu' Schr. perche' non era
> contento dei risultati che aveva ottenuto con la sua funzione [simile
> a Klein-Gordon] che tra l'altro era "relativistica".
>
Allora � meglio che spieghi che signirifica "meccanica quantistica
rlativistica" e "mecanica quantistica non relativstica".
E' vero ce l'effetto fotoelettrico fu la partenza di Einsein per� poi mi
pare ce non abia mai acetato la MQ. Non � cos�?
Tra l'altro leggo un articolo su informazione e buco nero che conferma na
mia antica domanda: noi dormo vedere TUTTA la materia in caduta in un BN
come congelata sull'orizzone degli eventi, ma in qusto modo se l'osservatore
eserno la vede TUTTA fuori dall'orizzonte degli eveti alora il BN non
c'�....
Bo!!!!!!!!!!!
Ecco l'articolo. Vedi se ci capusci qualcosa pi� di me!
-------------------
Black hole information loss paradox cracked
Submitted by Vidura Panditaratne on Wed, 2007-06-20 16:53.Fun |
Non-geographical | News
Physicist may have finally cracked the black hole information loss paradox
that has befuddled physicists for the past 40 years, according to an article
accepted for publication by Physical Review D, which concludes that that an
outside observer can never lose objects down a black hole.
Case Western Reserve University physicistsTanmay Vachaspati, Dejan Stojkovic
and Lawrence M. Krauss came to this conclusion after spending a year working
on complex formulas to calculate the formation of new black holes.
"It's complicated and very complex," noted the researchers, regarding both
the general problem and their particular approach to try to solve it.
The question that the physicists set out to solve is: "what happens once
something collapses into a black hole?"
If all information about the collapsing matter is lost, it defies the laws
of quantum physics. Yet, in current thinking, once the matter goes over the
event horizon and forms a black hole, all information about it is lost.
"If you define the black hole as some place where you can lose objects, then
there is no such thing because the black hole evaporates before anything is
seen to fall in," said Vachaspati.
The masses on the edge of the incipient black hole continue to appear into
infinity that they are collapsing but never fall over inside what is known
as the event horizon, the region from which there is no return, according to
the researchers.
By starting out with something that was nonsingular and then collapsing that
matter, they were determined to see if an event horizon formed, signaling
the creation of a black hole.
The mass shrinks in size, but it never gets to collapse inside an event
horizon due to evidence of pre-Hawking radiation, a non-thermal radiation
that allows information of the nature of what is collapsing to be recovered
far from the collapsing mass.
"Non-thermal radiation can carry information in it unlike thermal radiation.
This means that an outside observer watching some object collapse receives
non-thermal radiation back and may be able to reconstruct all the
information in the initial object and so the information never gets lost,"
they said.
According to the researchers, if black holes exist, information formed in
the initial state would disappear in the black hole through a burst of
thermal radiation that carries no information about the initial state.
Using the functional Schrodinger formalism, the researchers suggest that
information about the energy from radiation is long evaporated before an
event horizon forms.
"An outside observer will never lose an object down a black hole," said
Stojkovic. "If you are sitting outside and throwing something into the black
hole, it will never pass over but will stay outside the event horizon even
if one considers the effects of quantum mechanics. In fact, since in quantum
mechanics the observer plays an important role in measurement, the question
of formation of an event horizon is much more subtle to consider."
The physicists are quick to assure astronomers and astrophysicists that what
is observed in gravity pulling masses together still holds true, but what is
controversial about the new finding is that "from an external viewer's point
it takes an infinite amount of time to form an event horizon and that the
clock for the objects falling into the black hole appears to slow down to
zero," said Krauss, director of Case's Center for Education and Research in
Cosmology.
He continued "this is one of the factors that led us to rethink this
problem, and we hope our proposal at the very least will stimulate a broader
reconsideration of these issues."
If black holes exist in the universe, the astrophysicists speculate they
were formed only at the beginning of time.
------------------
sayonara! (sono in Giappone)
ernesto
--------------------------------
Inviato via
http://arianna.libero.it/usenet/
Received on Thu Jun 21 2007 - 11:12:45 CEST