The Naked Scientists

The Naked Scientists Forum

Author Topic: What do you think about the wave function collapse?  (Read 7901 times)

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #25 on: 15/08/2015 12:17:46 »
Quote from: sciconoclast
Oops: Finally got it. You were not objecting to the wave function as being a mathematical abstraction but to saying that using the term function collapse means that it is not. I guess I am the one who should read more carefully.
Ah! Finally! Thanks.

Quote from: sciconoclast
If you consider the wave function as only a tool for prediction then you are in agreement with prevailing theory.
Of course. I've known and worked with QM for 30 years now.

Quote from: sciconoclast
Please accept my apology for miss-reading you if that is the case,
Not only do I accept your apology but I commend you on offering it and the humility to do so. I highly admire people who display humility and try to do so myself when I'm wrong (which is rare but it does happen). It's very rare to see someone apologize in this forum so I make sure that the person is appreciated when they do so. So thank you and apology graciously accepted. :)

Mordeth could certainly take lessons on humility from you, that's for sure.
« Last Edit: 15/08/2015 12:19:41 by PmbPhy »
 

Offline dlorde

  • Neilep Level Member
  • ******
  • Posts: 1441
  • Thanked: 9 times
  • ex human-biologist & software developer
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #26 on: 24/08/2015 21:19:57 »
There are articles that have appeared recently with titles such as "Quantum Physics just got Easier to Understand" http://www.huffington.com/2014/12/24  . It is obvious from these titles that a new hypothesis is being presented.
Are they saying that particles effectively have complementary 'waveness' and 'particleness' properties?
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #27 on: 24/08/2015 21:39:35 »
Quote from: PmbPhy
Mordeth could certainly take lessons on humility from you, that's for sure.
I was happily proved wrong on this point recently when Mordeth apologized for something. I was highly impressed. I admire that kind of thing. My compliments to Mordeth on that point. :)
 

Offline sciconoclast

  • Sr. Member
  • ****
  • Posts: 149
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #28 on: 25/08/2015 00:39:08 »
dlorde: in answer to your question.

I believe they are saying that light exist in two superimposed states as a wave and as a particle. I also believe they are saying that if you test, or measure, for a wave you get a wave and if you test for a particle you get a particle.

This is like saying the cat in the box will be dead if you test to see if its dead and alive if test to see if it is alive. There are better answers to some of the recent experimental anomalies.

This idea has flooded the popular media and unfortunately I incorrectly jumped to the wrong conclusion that this thread was a back door attempt to introduce it.

Who knows, the concept might pan out. It wouldn't be the first time I was wrong about a new concept.
 

Offline dlorde

  • Neilep Level Member
  • ******
  • Posts: 1441
  • Thanked: 9 times
  • ex human-biologist & software developer
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #29 on: 25/08/2015 00:50:35 »
I believe they are saying that light exist in two superimposed states as a wave and as a particle. I also believe they are saying that if you test, or measure, for a wave you get a wave and if you test for a particle you get a particle.
I thought that was already accepted. They seemed to be suggesting the wave-particle superposition is a variety of quantum uncertainty - implying that the more you try to know about (measure) the wave aspect, the less you can know of the particle aspect... but hopefully a clearer explanation will emerge in time.
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2762
  • Thanked: 38 times
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #30 on: 25/08/2015 07:13:22 »
Quote from: sciconoclast
I believe they are saying that light exist in two superimposed states as a wave and as a particle.
I looked at that URL and couldn't see an article listed there with that title.

sciconoclast - If you're talking about the wave-particle duality then that's beyond the scope of this thread and I will ask you not to derail this thread with that subject.

I'll respond to your post on it but that's all; If you're referring to the wave-particle duality then that's not exactly what it means. The wave-particle duality is about particles behave either as waves or as particles but never as both at the same time. I believe what you said here is incorrect since being a wave or a particle are not two superimposed states. In fact a particle or wave is not a quantum state.

Quote from: sciconoclast
I also believe they are saying that if you test, or measure, for a wave you get a wave and if you test for a particle you get a particle.
I don't believe that's what it's saying either because I don't believe that one tests something as being a wave or particle. In doing an experiment photons, electrons etc. behave like particles or waves etc. E.g. if a light source is dim enough when it shines on an array of light detectors then only a single detector will go off at once which means that in the experiment the light behaved like a stream of photons. However the test was not designed to measure particles since the light detectors could very well have never detector single hits only but could have registered smaller and smaller amounts of light.

Quote from: sciconoclast
This is like saying the cat in the box will be dead if you test to see if its dead and alive if test to see if it is alive.
In that experiment one determines the state of the cat. You don't construct experiments to see if its a dead cat or another experiment to see if its a live cat. Listen to its heart beat. If it's beating then its alive, otherwise its dead. This is like measuring an observable. You don't construct different experiments for each different value of an observable. You just measure the observable and see what its value is. E.g. measure the energy and you'll get a value of the energy. Don't construct different experiments for different values of the energy.

Note: in theory that's the case. However in practice that's not exactly correct. Take light as an example; you can't measure gamma rays in the same way that you measure microwaves.

Quote from: sciconoclast
There are better answers to some of the recent experimental anomalies.
What anomalies are you talking about?

Quote from: sciconoclast
This idea has flooded the popular media and unfortunately I incorrectly jumped to the wrong conclusion that this thread was a back door attempt to introduce it.
Never. I never ever do sneaky things in my life. I ran into people elsewhere who claimed that the wavefunction collapse was something only ignorant people talk about whereas the opposite is actually true. I was actually taking a poll on who believes what.
« Last Edit: 25/08/2015 07:16:10 by PmbPhy »
 

Offline sciconoclast

  • Sr. Member
  • ****
  • Posts: 149
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #31 on: 25/08/2015 16:37:20 »
I agree that as you say " a wave or a particle are not two superimposed states ". What I was saying is that a hypothesis is making the rounds that they are. And that I find that hypothesis to be highly unlikely.

I usually do not buy news stand science journals but I was aware of it because a colleague with a sense of humor sent those articles to me the same way he sends me cartoons.

As for what anomalies; I posted one in McQueen's post on quantum mechanics that was the experiment of the year. That would have been the thread to have discussed it. There have been some historical anomalies early on. I believe I mentioned the Chao Anomaly a couple of times.

As for your comment about detection:" never detector single hits "; I was under the impression that single photon detectors and a lasers that can generate single photons, including one that can on command, have been in use for a while.   

 
 

Offline sciconoclast

  • Sr. Member
  • ****
  • Posts: 149
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #32 on: 30/08/2015 02:27:44 »
dlorde: I am sorry I am late responding to your post; I was distracted.

You are correct that the concept of wave particle superposition as a variety of quantum uncertainty has been around for a while. Bohr and Heisenburg debated it. However, if the wave superposition is considered to be one for an actual wave ( I realize you may not be saying this ) then it is not the orthodox interpretation.

I am not the best one to present the prevailing view because I believe it is false. But, I will give it a shot anyway.

As you mentioned there are many superpositions or probabilities for a photon. One is for position. If there are multiple possible positions it is said to be a non-locality, not a wave. There are more than one function to calculate the possible positions. The wave function is the one most commonly used. for that reason light is said to have wave like properties. Being wave like is different than being a wave.

pmbphy had stated that he had encountered many people who had claimed that the wave function collapse was something only ignorant people talked about; presumably these where others working in the field. You can see from my interpretation of existing theory how they may have arrived at this. My initial answer to the proposed question may have been along this line but it was much more polite and with a good reference [ I did not realize that I was poking a hornet's nest with a stick ]. On the other hand if my interpretation is incorrect then the other assumption applies.

The statement that a clear explanation will arrive in time is right on. The current technique of observing photons in transit with energy to low to disrupt the field ( this is contradictory to existing theory on several levels ) is opening up a window into light behavior. In a few years the concepts we are currently discussing may only be foot notes to history.

"Everyone thinks they know what light is and everyone is wrong", Einstein.
 

Offline dlorde

  • Neilep Level Member
  • ******
  • Posts: 1441
  • Thanked: 9 times
  • ex human-biologist & software developer
    • View Profile
Re: What do you think about the wave function collapse?
« Reply #33 on: 31/08/2015 15:13:17 »
dlorde: I am sorry I am late responding to your post; I was distracted.
No problem; nothing important depended on it ;)

Quote
The statement that a clear explanation will arrive in time is right on. The current technique of observing photons in transit with energy to low to disrupt the field ( this is contradictory to existing theory on several levels ) is opening up a window into light behavior. In a few years the concepts we are currently discussing may only be foot notes to history.
I take it you're talking about 'weak measurements' that accumulate a statistical sample of behaviour. It does seem promising, but also seems to have its own drawbacks.

Quote
"Everyone thinks they know what light is and everyone is wrong", Einstein.
Indeed.

Thanks for the explanation. I'm happy to wait and see what comes.
 

The Naked Scientists Forum

Re: What do you think about the wave function collapse?
« Reply #33 on: 31/08/2015 15:13:17 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums