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I am always amazed ...
Posted: Sat Mar 31, 2012 12:47 am
by 1over137
I am little overdue but here are the news (for those who missed that):
http://www.sciencedaily.com/releases/20 ... 173204.htm
and the video here:
http://www.youtube.com/watch?v=vCiOMQIR ... ture=share
I am always amazed when looking at interference pattern.
Re: I am always amazed ...
Posted: Sat Mar 31, 2012 8:02 am
by Byblos
Can you explain what all that means (in terms we can all understand)?
Re: I am always amazed ...
Posted: Sun Apr 01, 2012 1:34 am
by 1over137
The point is that quantum mechanics predicts that even molecules can exhibit wave-like behaviour. According to the de Broglie formula, the wave-length is proportional to 1/momentum. So, the more massive molecule is, the shorter wavelenght it has and the trickier the experiments are done.
Physicists has sent the phthalocyanine throught an ultra-thin nanograting. And what appeared on the screen was the interference pattern which shows the wave-like property of the given molecule.
These interference effects caused by matter-waves contain the mystery of quantum physics.
Re: I am always amazed ...
Posted: Sun Apr 01, 2012 1:29 pm
by Byblos
1over137 wrote:The point is that quantum mechanics predicts that even molecules can exhibit wave-like behaviour. According to the de Broglie formula, the wave-length is proportional to 1/momentum. So, the more massive molecule is, the shorter wavelenght it has and the trickier the experiments are done.
Physicists has sent the phthalocyanine throught an ultra-thin nanograting. And what appeared on the screen was the interference pattern which shows the wave-like property of the given molecule.
These interference effects caused by matter-waves contain the mystery of quantum physics.
Correct me if I'm wrong but wasn't that shown with the double slit experiment a few decades ago?
Re: I am always amazed ...
Posted: Mon Apr 02, 2012 1:17 am
by 1over137
This time they did it with molecules which were 0.1mm large. As far as I know, before, in 1999, there were experiments with buckyballs(C60) which were only 1nm large.
Re: I am always amazed ...
Posted: Mon Apr 02, 2012 4:48 am
by Byblos
1over137 wrote:This time they did it with molecules which were 0.1mm large. As far as I know, before, in 1999, there were experiments with buckyballs(C60) which were only 1nm large.
Ah, thank you. So the bottom line is that even with more mass, molecules still exhibit quantum level behavior but as mass increases more and more, quantum behavior decreases proportionality. Is this a fair statement?
Re: I am always amazed ...
Posted: Mon Apr 02, 2012 6:47 am
by 1over137
I would not say that quantum behaviour decreases. Quantum mechanics applies also for large objects. It is just harder to see the interference patern since its resolution gets worse. You hardly see the minima and maxima for larger objects. For very large we cannot see it.
Re: I am always amazed ...
Posted: Mon Apr 02, 2012 11:23 am
by Byblos
1over137 wrote:I would not say that quantum behaviour decreases. Quantum mechanics applies also for large objects. It is just harder to see the interference patern since its resolution gets worse. You hardly see the minima and maxima for larger objects. For very large we cannot see it.
Yes, that's what I meant, it becomes less and less visible. Thank you. I'm still not sure though what added value this new experiment brings, other than to state what we just did above. That's what I'm still missing.