Sciencemadness Discussion Board

Heisenberg Uncertainty principle

GreenD - 8-3-2012 at 09:39

I read this article with equal interest and confusion;

Apparently (and it doesn't quite explain sufficiently why) we do not disturb what we observe! A very important, perhaps paradigm shifting discovery

http://www.scientificamerican.com/article.cfm?id=heisenbergs...

Yet, the heisenberg uncertainty principle of dpdx > h/4pi is still, of course, valid.

Can someone clear up what is going on here?

neptunium - 8-3-2012 at 11:02

it looks to me that they verified the law by experimentation i dont see a contradiction in the article..

GreenD - 8-3-2012 at 11:04

Quote: Originally posted by neptunium  
it looks to me that they verified the law by experimentation i dont see a contradiction in the article..


From what I read all I can tell is that their observation of particles did not "collapse" the wave function - the particles were in fact in both states at once while being observed.

Which - is a violation of what heisenberg's conjecture was.

phlogiston - 8-3-2012 at 13:13

Wavefunction collapse is an old-fashioned view anyway. I think the concept quantum decoherence more closely describes what happens.

The wiki page is quite informative, but this guy's page greatly helps to grasp the concept on a more intuitive level.

GreenD - 8-3-2012 at 13:22

Quote: Originally posted by phlogiston  
Wavefunction collapse is an old-fashioned view anyway. I think the concept quantum decoherence more closely describes what happens.

The wiki page is quite informative, but this guy's page greatly helps to grasp the concept on a more intuitive level.


Reading it now - but from my original post - are they saying that they observed "shrodingers cat" dead and alive at the same time?

kavu - 8-3-2012 at 13:47

Such groundbreaking new information on quantum mechanics, especially the experimental sort, is much more complex than Schrödingers cat or a wavefunction collapsing. I have not yet taken QM 1 and 2 and only know some of the outmost basic stuff. All I can say is that providing a non-mathematical form of the new discovery is very very difficult even for the people working in the business.

watson.fawkes - 8-3-2012 at 14:24

The preprint of the original article is available at arxiv.org: Experimental demonstration of a universally valid error-disturbance uncertainty relation in spin-measurements.