"dendriite" <[EMAIL PROTECTED]> wrote:
>
>Is there some passive method of observing QM phenomenon?
>
>If you wanted to observe the Washington Monument by bouncing cannonballs
>off
>of it, you would change the very thing you are observing.
>
>Or am I missing something here?
That was a possible explanation until a few years ago. Experiments were done
which "erase" the information after making the observation, and things go
back to their "unobserved" state.
Example:
(1) You do the classic "two slit" experiment where you shoot a photon stream
through a beam splitter and pass it through one of two slits. You get an
interference pattern, as if the photons were acting as waves.
(2) You then try and detect which slit each photon went through by having
the half-stream aimed at slit #1 interact with an "observation" stream. The
interference pattern disappears and you get two spots.
(3) You then interact the "observation" stream with a another stream to
scramble it. Note that this is done without physically disturbing parts 1
and 2 of the experiment which are still running - you're just dealign with
an "output only" stream. Surprisingly, the interference pattern from part 1
returns.
The analogy is:
First, you shoot cannonballs in the general direction of the Washington
Monument. At certain cannon angles you hear large "thuds" which tell you
where it is, but you've also dented and tipped the monument over.
Next, you shoot canonballs in the general direction of the Washington
Monument. Simultaneously, someone starts playing a tape recording of "thuds"
at random spacings. You can no longer tell which cannon angle the monument
is at because the thuds are hidden in the noise. Oddly, though, despite the
fact that you're still hitting it with cannonballs, the monument is
undamaged.
Joshua
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com
