Wave-Particle Duality

[JRWASTRO]

Greetings Gentle Folk.

Without getting too deep into philosophy please may I refer you to a couple of pages from a book of my youth:

Zen and the Art of Motorcycle Maintenance

                       By

              Robert M.Persig

Relevant to this discussion are pages 40, 41 and 42

Jeremy.

[JRWASTRO]

For those who do not have the book I attach the 3 pages + 1 page from the book above.

Persig_Ghosts.pdf

It is all about ghosts and the existence  of the laws of gravity.

Jeremy

[ollypenrice]

Beware of page references.   In The Good Soldier Svejk one of the middle European armies uses a code based on a certain page of a novel. Unfortunately not all the officers receive the same edition... 

Olly

[JamesF]

I first read ZAMM when I was about fourteen or fifteen (I recall reading my dad's copy on a camping holiday in the Dordogne, oddly enough), enjoyed it greatly and have re-read it several times since though not for some years now.  This is one of a number of passages in which I believe the narrator manipulates words with the purpose of demonstrating that there may be other valid views of the world that we should consider, but I think his arguments can be fairly weak outside the realm of the narrative of the book.  Though his purpose may be one with which I agree in the "real" world, I think his reasoning doesn't stand up in this instance.

James

[Davey-T]

For those who do not have the book I attach the 3 pages + 1 page from the book above.

Persig_Ghosts.pdf

It is all about ghosts and the existence  of the laws of gravity.

Jeremy

Is it that way up cause it's in Australia or is it in two different states at once 

Dave

[PortugueseGazer]

Reading this made me feel dumb..

So, the question here is how can a wave act as a particle and a particle as a wave right?

Then someone said that it depends on the way we see it right( dumbed it down so I could understand :x )?

Much like when we see a guy at the beach staring at the horizon, some say he is gazing at the horizon, some say that he is thinking but in reality he is trying to Fart (I don't know any other word to substitute that word, sorry ).

So, we can only be certain if we ask him directly right?

In that same thought, we just need to "ask" the particle why it is behaving like that but we don't know it's "language" so we can only assume right?

"How can a particle act like a wave?"

Can't we assume that much like the ocean, that stays rather flat until some force makes it "wavy" (the wind), there is a force acting on the particle and changing its behaviour?

Sorry if I sound so dumb, I'm just trying to understand a subject my brain wasn't made to understand

[George Jones]

This stuff is so strange that it fried the CPU on my computer.

A couple of years ago, I wrote a very short Python program to demonstrate wave/particle duality to students. The program produced a screen output that built up a wavelike interference pattern photon by photon. At first, dots start appearing on a blank screen, apparently randomly distributed. As time progresses, the accumulation of dots merges into a clear interference pattern

After I got the program working, I demonstrated it to my wife (who has degrees in physics), but, while the demonstration was running, my compute shut down and tripped the breaker on the power bar.

It was all too much for my computer to handle. Luckily, it was still under warranty.

[Christopher Davenport]

So I like to think of the duality in very simple terms.

If you spray water out of a hose pipe in short bursts (like a sprinkler) it creates a stream of drops (here you observing particles in a stream), now wave the pipe nozzle left to right and it creates a wave of these particles.

Because these particles are so small we can only measure them by touching them at this point they stop acting like both and depending on the method you use to measure you either see a particle or the wave.

edit: know this is not entirely scientific ly correct but easy to visualise.

[Kropster]

In the double slit experiment, a single photo will effectively pass through both slits.

Trying to understand that is way beyond my brain, so I just accept that it is weird from a human point of view. 'End of'... as they say in East Enders.

[Macavity]

At the end of the day, are we really OK/happy/content with reducing what really is to an equation/set of numbers?

A general physics problem seems to be that there is not one, but two... more equations that describe "reality"?

http://en.wikipedia.org/wiki/T-duality

I sometimes revisit Chap 10 (Quantum Geometry) in Brian Green's "Elegant Universe". The universe can be vast

and expanding or microscopic and contracting? Somehow as human sized we can fit into either. But which is true? 

Seemingly both, but we are somehow (inherently?) biased to one by (an easier?) method of measurement - LIGHT. 

A matter of language / semantics? It's the "punch line" I always miss / seek! Or maybe simply: "It doesn't matter"? 

[JRWASTRO]

Is it that way up cause it's in Australia or is it in two different states at once  .

Dave

Very funny. I tried to think of something amazingly witty to say but somehow this has eluded me. Sorry. Ah, the cricket? No.

So this simple answer, however boring, will have to do. Senior moment if you like. I mentioned in the previous post that I had 3 pages to present but copied 4 pages so instead of blanking one page I thought that I will issue a bonus page free of charge. See, We Aussies are a generous lot but not when it comes to the Cricket.

Jeremy.

[JRWASTRO]

This stuff is so strange that it fried the CPU on my computer.

A couple of years ago, I wrote a very short Python program to demonstrate wave/particle duality to students. The program produced a screen output that built up a wavelike interference pattern photon by photon. At first, dots start appearing on a blank screen, apparently randomly distributed. As time progresses, the accumulation of dots merges into a clear interference pattern

After I got the program working, I demonstrated it to my wife (who has degrees in physics), but, while the demonstration was running, my compute shut down and tripped the breaker on the power bar.

It was all too much for my computer to handle. Luckily, it was still under warranty.

OK. Now here is a very simple algorithm that I will describe in words.

 Here a random placement of dots results in a very recognisible pattern:

Set-up of the algorithm: 

1.  Place / draw 3 points on the apexes of an equilateral   triangle , p1(x1,y1) , p2(x2,y2) and p3(x3,y3) 

 or any other type of triangle but an equilateral triangle looks good.

2. Now place a fourth point p4 (x4,y4) anywhere, at random.

This point may be inside or outside the triangle at any distance  from the triangle.

The algorithm:

1. Choose, at random, one of the 3 points  p1, p2, or p3 . 

2. Determine  the distance L  between this point and p4 and

calculate  the co-ordinates  of the point , pn(xn,yn)  that is at L/3 from this randomly chosen point. 

3. Plot point pn(xn,yn) on the screen and set x4 = xn and y4=yn . We now have a new point p4

goto step 1

This is the algorithm and with about 10,000 iterations  the picture is very detailed and needs explaining.

Jeremy.

[George Jones]

This is the algorithm and with about 10,000 iterations  the picture is very detailed and needs explaining.

But then my computer would probably blow a gasket. 

[ollypenrice]

With our terms 'wave' and 'particle' are we not trying to do what Ptolemy and (ironically) Copernicus were trying to do with circles? That is, trying to make something that was not a circle out of circles? They did, in fact, have the term ellipse in their lexicons but, for all the good this did them, they might as well not have done so.

I very much doubt that that we already have a term for what manifests itself variously as wave or particle but I wouldn't rule out the possibility that we might. Given the length of time it took to identify the ellipse, that is...

Feynman, if I understand him aright, wondered what might be waving and concluded that it might be probabilty. I'm not a physicist and might have got this round my neck but if this is correct then it forges a link between terms which we maybe don't have and terms which we do. I come at these problems from a background in language rather than maths. You'll have to make allowances!

lly

[m1dlj]

I don't think current English has any suitably descriptive terms. Other languages? Possibly, who knows. If we were to choose something, is it not likely that it too would need to be reconsidered, as theories improve?

We have good working models of these things, which enable us to understand and predict their behaviour. However, ideas in one language, don't alway have a meaningful translation in another, and many concepts expressed using mathematics, are difficult to articulate in English. Some get through: tell someone that energy and matter are interchangeable, and it's likely they'll say "oh you mean e=mc² ". Perhaps some shorthand for a relativistic wave equation will one day resolve the wave particle debate.  

What I find fascinating, is not that language is inadequate for describing the natural world, but that it may be no coincidence that mathematics is perfectly suited to it.

Ray

ps Does the word 'noumenon' ever get used in this context, or has it been well and truly philosophically trashed?

Sketch found on UOregon.edu

  

[ollypenrice]

Ah yes, why does maths work so well? I once asked that question on here. It's a tough one.

Olly

[Earl]

Language is key, we are tought it, yet really dont understand it, take lawyers for example  they make up a language out of a language then make poeple pay them to translate but still argue what the translation means in real terms and then you have to pay them another pile of money to try and get them to agree on what the language is saying today, tomorrow they might disagree again.

I think Mathematics is the same I think its a best aproximation with current knoweleged tool, particles dont understand Maths, we make models to explain how they work, then when it all get really complicated we ant get the models to talk to each other anymore and need to make up some new maths to fix it.

Dont get me wrong here I do get that maths is fundamental in lots of ways, but it is still just a man made tool which looks to fit the tool slot until someone goes finds something new and it needs tweaking again.

However we alll need some form of common ground where we can express all this "stuff" and we call it Language, and its not really the perfect tool, but its all we have.

[NickK]

Maths, too, has a fundamental flaw - definition of the mathematics from the concept.

Maths boils down to:

a. The defined maths equates to true - thus giving a valid model.

b. The defined maths equates to false - thus giving a valid model but negative.

Now the flaw - how good are humans generating maths? In addition - maths doesn't generate new maths (i.e. meta-maths) and hence when using maths it's based on a toolkit that itself may be flawed in missing the critical point due to it's approach on precision and accuracy - often because it's the human that has selected the maths to be applied..

The wrong maths can still satisfy points a and b but miss the Nobel prize..

[Kropster]

Once you study maths even a little, you soon come across problems it is very bad at describing.

Chaos, the 3 body problem, non-linear equations..... lots of 'real world' stuff, basically.

[Cath]

I see Maths as the best method we currently have for predicting the outcome (ie the present state), I certainly don't see Maths as being the only way though.

We could describe say an electric motor using Maths, but I wouldn't say the Math equations are particularly good at creating an image in the minds eye of what an electric motor actually looks like or how it came into being or how it's used etc.

But then, we as a spieces have only really just begun to climb the near vertical and endless learning curve of what it all may or may not actually be. And to throw another spanner in the works, everything we have so far come up with is based totally on how we are viewing it all (which includes all the flaws found within such a limited view point).

It's no wonder we are finding it difficult to express/convey what ever it is we are and are a part of using nothing but letters and numbers (language?).

[Physicist13]

Just to say that dont even try to get your head around wave/particle duality!!!...or collapsing wavefunctions for that matter!

P

[JB80]

....or even the universal wavefunction. 

[Earl]

I can handle making a cuppa tea. this set the world to rights

Seriously If I had my time again a) I would of eaten better b ) followed apath in education, I love this stuff but my life has not taken that path.

[Macavity]

You may (or may not) change the universe just by rubbing yer diamonds?

But one should not necessarily condemn... [http://youtu.be/ASZWediSfTU]

[Ganymede12]

Sorry to drag this back up and give people headaches!

I think I've heard (correct me if i'm wrong) that an electron, given the choice of multiple paths, will somehow take all of them. How?