A documentary about Steven Hawking
mercury
Hawking.
I was astonished to see therein that the electrons according to QM
jump from one place (not energy) to another place around the atom.
They just vanish from x1 and reappear on x2. I would have tought that
is a translators misinterpretation but there was shown an animation
picture of a classical atom and the electrons were like lamps on a
Chistmass tree just flickering here and there on a stationary orbit (I
think).
It was even stated that they can exist on 2 places at once.
I personaly think that QM somehow points to a picture like that - but
I have never seen this explicitly stated in any QM book or QFT book.
I am very suprised and need your comments.
What do you think?
P.S. This implies superluminal velocities for the electrons!?
Ilian
Oh No
of electrons orbiting the atom, but it is giving another incorrect
picture. The electron is not in any particular place x1 or x2, unless
you do a measurement to find where it is (this would require an
impossibly high resolution, but the principle is valid). If you did do a
measurement, finding the electron at x1, another measurement could not
find it at x2 if a superlumenal velocity is require to get from x1 to
x2.
In the absence of a measurement, the electron does not have any
particular position (this is a different statement from saying that it
has more than one position). If you did a measurement, it could be found
at x1 or x2.
Regards
--
Charles Francis
moderator sci.physics.foundations.
charles (dot) e (dot) h (dot) francis (at) googlemail.com (remove spaces and
braces)
M. Amin
> Thus spake mercury <il...@abv.bg>
> I think the animation is trying to break away from the incorrect picture
> of electrons orbiting the atom, but it is giving another incorrect
> picture. The electron is not in any particular place x1 or x2, unless
> you do a measurement to find where it is (this would require an
> impossibly high resolution, but the principle is valid). If you did do a
> measurement, finding the electron at x1, another measurement could not
> find it at x2 if a superlumenal velocity is require to get from x1 to
> x2.
what about the uncertainty principle?
I thought that an electron can never be at a particular place..
it's not a practical measurement problem.. it's a fundamental property
of the electron
because we can't model the electron as a geometrical point (as
classical mechanics do) but as a wave packet
there's no such thing as a "position" here.. we can just talk about
intervals.. or uncertainty
so.. no measurement whatsoever can find the electron exactly.. that's
impossible in principle.
is this right? and if not, please explain why.
thanks in advance
Oh No
Its sort of partly right, but also, I think, misleading. When we do a
measurement we always find the electron at a point up to the accuracy of
the measurement, only of course measurement is never exact.
This is distinct from the need to model the electron as a wave packet,
which is best understood in the Young's slits experiment.
Here we see the electron as wave function, but collapsing to a point
when its position is measured by the photographic plate. It is this
principle I was discussing in the context of the wavefunction of the
electron surrounding an atom, and what would happen if we could measure
its position to greater accuracy.
mercury
> Thus spake M. Amin <m.amin...@gmail.com>
>
> - Показване на цитирания текст -
After reading your post I kind of think that maybe the documentary is
right in the following way.
The wave function is probabilistic hence the electron exists
potentially everywhere in the probability cloud.
It then pops out into whatever place in the p. cloud it likes. In the
next instant it would pop out in another place.
I think QM doesnt prohibit that. Just SR is against it. (but it was
also against quantum teleportation).
So there is no one that can see these because as Francis says the WF
would collapse at one place and we wont be able to find the electron
at another place in the cloud.
So as long as the electron is unobserved it can make jumps in the
cloud.
But this brings me to the idea if it is possible using nondemolishen
measurement (the kind of Vaidman-Vaizseker) to check if it can jump so
in fact.
Ilian