# Fireplaces and reality

1. Mar 6, 2004

### Nath

I have a Laymans understanding of this subject but here goes...

I'm sitting now in my living room looking at the fireplace. My act of observation (photons bouncing of the electrons into my eyes) cause the wave function to collapse and create the reality of the fireplace.

I now turn my back to the fireplace and for all intents and purposes it does not exist now, since my non observation means the wave function remains un-collapsed.

I turn back again and observe the fireplace, the wave function collapses back into the reality of the fireplace.

My point is this, on turning back to observe the fireplace time and time again, why should the wave function always collapse back in exactly the same manner and produce for me the reality of a fireplace?

Is it simply that the molecules of the fire place retain a structure in which the wave function can collapse?

2. Mar 6, 2004

### LURCH

Sort-of. What you are actually observing is billions of wave functions. If your act of observation collapses all of them, causing each to fall into one of several possible states, what you see on the macroscopic scale is the average of all of these collapsed states. The most probable states will dominate with a numerical superiority equal to their probability.

So, although individual wave functions may collapse differently on separate observations, statistical probability ensures that the overall impression your eye receives will be the same each time.

NOTE:

I am a layperson also, so others might give you a more comprehensive explanation.

3. Mar 6, 2004

### Nath

Re: Re: Fireplaces and reality

I've understood this basic principle for just a couple of days. It's having a revolutionary affect on the paradigm in which I used to view the world. cannot stop thinking about it.

So we would be in agreement if I suggested that reality, as I know it, is merely chance. As write this I remember "God really does paly dice". from somewhere.

This has profound consequences - just an after thought as I type now - To"see something out of the corner of your eye" could be interpreted as an non average collapsation of the wave function? Or is it more likely a probability that its a deviant connection in the synaptic reactions of the brain? I guess I need to know the the math to put a scale on things here, but its strikes me as significant that the "corner of your eye" scenario happens more often in the dark, ie less photons avaliable in whaich to collapse the wave function, and thus reducing the likelyhood of the "average".

which now begs the question that if I have some sort of photon emmiter sending vast numbers toward the "fireplace" from a different angle then I can theoretically alter what it is I see, too the point where it could become , for arguments sake, a small rock? Or even better, I could the same thing from so many different angles so as restore the no-collapsed funtion and thus make the fireplace invisible?

This is all very very odd.

4. Apr 1, 2004

### ranyart

There is a better way of understanding this.

Sometime ago I placed the ultimate 'Thought' experiment based on reality here in PF, although it was on the original site, I do not know if it is archieved, I ll try and find it, if not I will get my original copy from my own files and place it here again.

Just been told that the original posting is on C-D rom of original PF? stay tuned and give me a chance to retrieve the post.

P.S. the original posting was called: Quantum Relativistic Mirror.

5. Apr 3, 2004

### sol2

I will have to look for it.

Just thought it looked familiar to one you had drawn?

Misner, Thorne & Wheeler (1973, Gravitation'', p. 840) object to the mirror interpretation of the Schwarzschild geometry on the grounds that: (1) it produces a sort of conical'' singularity at the crossing point of the two horizons, tK = rK = 0 (where the two red lines cross in the Kruskal-Szekeres spacetime diagram); and (2) it leads to causality violations in which a man can meet himself going backward in time.

Last edited: Apr 7, 2004
6. Apr 18, 2004

### zeta101

One thing that you must remember when talking about collapsing wavefunctions is this. You cant just say because im not looking at it the wavefunction wont collapse. Take the fireplace example...you might not be looking right at it but you can see the light reflections from the wall, and also feel the heat from the fire, which is just another form of em radiiation which your body detects (heat is infrared radiation basically). So by being in the room you cause the wavefunction to collapse. But its "worse" than that...

Also, if the information of something existance is AVAILABLE to "the universe" then the wavefunction will collapse, whether or not a human looks at the results of the measurement. This is realised by considering variations on the double slit experiment which is probably the most famously quoted and beautiful way of explaining this kind of thing.

Also, wavefunctions dont mean much to us on our macroscopic scale, they collapse almost instantly into defined values, which is why the world is a "solid" place if you get what i mean. This is because on our scale of things (ie our world is much bigger than that of an atom) the wavefunctions are so complicated and there is so much matter around that "measurements" are made all the time, and by measurements, recall that this deoesnt have to be a human looking at something or observing it...all it needs is another particle to interact with it and the wavefunction collapses, which "fixes" our macroscopic world.

Im deeply sorry if ive broken peoples illusions on things here...but the fireplace is really still there roaring away whether your looking at it or not.

7. Apr 18, 2004

### sol2

I don't think you are destroying peoples illusions:)

Along the same vein I wonder then. Could one can consider soliton production?

We can use the channel and boat for consideratin here.

As a force carrier, it might be a interesting idea then if we consider such graviational waves in the bulk, and then, call them gravitons?

Speaking about the photon in such considerations, might then move this idea from young's expeirment, to wonder then, of the dimensional significance of the bulk?

From a cosmological perspective String Cosmology has some interesting features to consider in regards to dimensional relevances?

For instance, here one might type in google.."Andrey Kratsov" and find some interesting work here about the ideas of the cosmos and how consolidation might be viewed from a dimensional perspective?

Last edited: Apr 19, 2004
8. May 21, 2004