Skip to comments.Quantum mechanics flummoxes physicists again
Posted on 07/24/2010 5:35:11 PM PDT by LibWhacker
A fresh take on a classic experiment makes no progress in unifying quantum mechanics and relativity.
If you ever want to get your head around the riddle that is quantum mechanics, look no further than the double-slit experiment. This shows, with perfect simplicity, how just watching a wave or a particle can change its behaviour. The idea is so unpalatable to physicists that they have spent decades trying to find new ways to test it. The latest such attempt, by physicists in Europe and Canada, used a three-slit version but quantum mechanics won out again.
In the standard double-slit experiment, a wide screen is shielded from an electron gun by a wall containing two separated slits. If the electron gun is fired with one slit closed, a mound of electrons forms on the screen beyond the open slit, trailing off to the left and right the sort of behaviour expected for particles. If the gun is fired when both slits are open, however, electrons stack along the screen in comb-like divisions. This illustrates the electrons interfering with each other the hallmark of wave behaviour.
(Excerpt) Read more at nature.com ...
Quantum mechanics and relativity are mutually exclusive theories. Both can’t be right. This is why Strong Theory must be wrong (string theory attempts to unify QM with R).
Ding! We have a winner!
What is at the core of the wave/particle duality? The fact that photons (and every other fundamental particle) is something else we still don’t grasp.
But we grasp some of it, and we’re grasping more. That’s what real science is about.
Are we 90% of the way to understanding how reality works (from a scientific view, not a theological one)? Some think so. I disagree. We’re maybe 10% of the way there.
But for most of history, we have been less than 1% of the way there...
That was AWESOME! I’ve been reading about the double slit for years but now I finally really get it!
Do you know where there is a good list of the reasons quantum mechanics is important? Like the things the study of QM has given us?
Well...I got it before but that was a great explanation to pass on. You get my meaning. ;-)
“But the most recent experiment used protons, not electrons.”
Are you positive?
To let us know we can exist in more than one place at the same time?
What amazing progress could be made if we accepted the truth of God’s word.
"And He is before all things, and by Him all things consist.
Except that in the double-slit experiment we are observing the outcome of both cases in the exact same way.
In other words, our manner of interfering in order to observe the outcome of the experiment is no different in the case that results in the wave manifestation than in the case that results in the particle manifestation. In both cases, we are observing by measuring the impact of the electrons or photons on a screen after having passed through the slit or slits, in the same way.
So the different results cannot be explained by a difference in the way we are interfering in order to observe.
I didn’t follow that. Could you elaborate on how that applies for each case? Specifically, how do you apply the notion of observation deciding the outcome, and how do you keep the act of observation completely benign, in the double-slit experiment?
I’m also interested in knowing about the “neutrality” of the slits themselves, and how they ensure that only one particle is ejected at a time, with certainty.
What I’m basically trying to clarify, is the following. The particle-wave duality of electrons is confirmed by the double-slit experiment in the following manner:
Case 1: Pass electron beam through double slit, unobserved. Result: Interference patterns on screen.
Case 2: Pass electron beam through double slit, observed.
Result: No interference pattern on screen.
What I said earlier was that the act of observation was not benign.
Case 1: Pass electron beam through double slit, after which beam strikes passive detection screen. Results on screen shows a wave-like pattern of troughs and valleys of intensity as if the electrons are interfering with each other like two sets of ocean waves.
Case 2 (close one slit): Pass electron beam through single slit, after which beam strikes passive detection screen. Pattern on screen does not show a wave-like pattern (instead, particle-like).
And interestingly, in the double-slit case, even if you slow down the electron beam so that each electron goes one at a time, the pattern that emerges on the detection screen still shows the wave-like pattern, as if the electrons as a group are interfering with each other like the two sets of ocean waves.
And may also be worth noting that God SPOKE light into existence.
Speech, to us, in human terms, is creating a wave (a sound wave). Perhaps God was giving us a small clue.
Basically what you mentioned does not have anything to do with the act of “observation” affecting the choice of what the electron wants to do, right? No hocus-pocus “electron intelligence”...
Just that the electrons produce interference patterns through a double slit, whether they are fired en-masse or one by one, and they produce a single pattern, when fired through a single slit.
Did I infer the above correctly?
In the double-slit case, we see a wave-like pattern on the screen, as if the electron beams are like two ocean waves flowing through both slits and interfering with each other.
What if we try to observe the electrons as they pass through the slits? Will we see waves passing through, or particles?
If we do that, the wave pattern collapses, and the electrons act like particles.
So in this case, when we try to observe the electron acting like a wave directly, it doesn't display the wave-like property. So arguably, this variation brings in the consideration you raised as to the act of observation interfering with the sub-atomic particle.
What it implies, essentially, is that the interfering act of observation is causing the wave function of the particles to be dissipated, and has nothing to do with any supernatural "intelligence" being displayed by the electron itself. Mostly pointing to our lack of understanding of how the wave function gets depleted by the act of interference, and that has not been explained, yet.
Arguably, but go back to the post 53 situation, and consider the case where the electron beam is slowed down so as to only emit a single electron at a time.
The single electron emitted, in a traditional way of thinking, would only pass through one or the other of the two open slits, not both at the same time.
How does it “know” at the time it passes through one such slit whether the other slit is open so as to (together with its predecessor and successor brother electrons) produce a wave pattern on the screen, compared to the case when the other slit is closed, and no wave-like result is produced?
I conclude electrons do not like slits