Notices
Results 1 to 3 of 3

Thread: Quantum Physics Thought Experiment

  1. #1 Quantum Physics Thought Experiment 
    New Member
    Join Date
    Aug 2009
    Posts
    2
    A SIMPLE THOUGHT EXPERIMENT ABOUT QUANTUM PHYSICS
    One of the most confusing and contentious elements of quantum physics is how to interpret its seemingly statistical (or some might say, random) nature. A particle's state can be said to be indeterminate until measured. The particle itself is in a so-called superposition until it is observed, at which point it collapses into a single state.
    Traditionally, it has been held that either the particle exists in multiple simultaneous states in this universe (prior to collapse) or that multiple universes exist, in each of which the particle exists in a single state. In the later case, it is less a matter of the particle collapsing then of the observer realizing which universe he or she actually inhabits.
    Neither view (either the former, the so-called “Copenhagen interpretation,” or the later, the “many-worlds interpretation”) is particularly satisfying or intuitive.
    A simple thought experiment has lately occurred to me that I think may recast the question in an interesting light. It involves a hypothetical billiard table.
    But first, let us consider a real billiard table. Because the surface, balls and pockets of the table are macroscopic objects, they behave according to General Relativity. In fact, they behave very much as Newton would expect, unless one somehow managed to accelerate the balls to a small fraction of the speed of light, which is generally not practical with a wooden cue. This is the scale that we live in and the behavior of physical objects that we find intuitive.
    Now, imagine that the billiard table represents objects on the scale of the solar system. Put a large mass--let's say a bowling ball--in the center of the table (to represent the sun). Because this particular table is constructed of elastic materials, the surface is warped by the bowling ball and any billiard balls that pass near it will be deflected by the curvature introduced in the surface of the table. On this scale, the behavior of the billiard table has gone from Newtonian to Einsteinian. The warping of the hypothetical table simulates the curvature of space-time that General Relativity posits as the underlying cause of gravity.
    So far, so good. Let us then go the other direction and imagine a billiard table at the atomic or subatomic scale.
    Now, if you believe in the Copenhagen interpretation, the balls (or the particle that they represent) should exist as a sort of statistical blur--unless someone were to observe or take measurements that would cause the ball in question to (seemingly) magically assume a specific position. If, on the other hand, you believe in the many-worlds interpretation, then we have the problem that there are a potentially infinite number of billiard tables. The question, which is answered when we observe the positions of the balls, is which of the billiard tables (universes) we ourselves inhabit.
    Both interpretations have problems. The first, as Einstein might have said, requires God to play dice instead of billiards. The second posits the existence of slightly more universes than we have any experimental reason to believe exist.
    Let us then consider the billiard table in another way. In particular, let us ask ourselves what the surface of our infinitesimal table looks like. Is it perfectly flat (like a real billiard table) or smoothly curved (like the cosmic table we considered before)? It is my suggestion that it is neither. The felt, which we all understand to represent the fabric of space-time, would, I put it to the reader, resemble more the ever-moving surface of a pond.
    I am referring, of course, to the phenomenon known as gravitational waves, which are ripples in space-time propagating from masses in motion. The type of gravitational waves most in discussion at this time are relatively high-amplitude waves hypothesized to be produced by distant, ultra-high-mass phenomena such as merging black holes. But if such relatively high-amplitude waves exist, then one must assume the presence of an entire spectrum of waves. The universe is full of mass in motion, all of it curving space-time, even as its own path is curved by space-time. As there has never been shown to be a maximum range on the effects of gravity, every mass in motion must create ripples, however small, that spread outward as what is presumably the speed of light. And these ripples must constantly interact, from one end of the observable universe to the other, causing a sort-of steady chop.
    So what does this mean for our billiard table? It means that its surface is continually being crossed and recrossed by tiny ripples. Some may be larger and some smaller, but the motion will be constant, but also--because of the incalculable complexity of the dynamics behind it--seemingly random. And how does this effect the balls on the table? Well, let us imagine that the balls are not statistical objects, but actual finite quantities existing in a single universe. Because of the shifting slope of the table (due to the ripples moving through its surface), the balls tend to roll around. They tend to stay more or less in one area, being more likely to be in the middle of that area than at the edges, but they do not stay put. Does this begin to sound familiar?
    Now, let us try to roll a ball across the table. Let us use our imaginary cue to drive the cue ball toward the eight ball. Because of the shifting surface of the table, the cue ball follows a not quite straight path. The perturbations may even out--in fact, they most often almost do--but the cue ball may end up going off course. At the same time, the eight ball may find itself on the edge of a temporary hump in the fabric and roll slightly to the side. The cue ball could conceivably end up missing the eight ball, but if the eight ball rolls back into its previous position, it would appear that the cue ball had somehow passed through it.
    Moreover, because of the shifting nature of the surface of the table, it is impossible to construct a single history that explains the current state of the balls. The cue ball could have followed multiple paths based on which configuration of the table's surface one assumes for the time of its passage. The problem is even more complicated because the cue ball's motion is not instantaneous and the table is constantly being reconfigured. Do each of these possible histories represent real alternate billiard tables in alternate universes or are they, as I would suggest, merely a failure to understand where the real complexity of the system is generated--that is, in the unquiet motion of space-time?
    I realize that it is the nature of thought experiments to over-simplify. Tables are two dimensional, whereas space-time is not. However, it is enough for me to suggest that the quasi-random behavior that has been traditionally ascribed to subatomic particles themselves is rather the effect of fluctuations in the space-time they inhabit. These fluctuations are due to processes well-understood by General Relativity and not to any special nature attributable to the particles themselves.
    I would further suggest that although we have failed (so far) to detect gravitational waves in their larger and less common form, it is possible that we observe their effects constantly (though indirectly) in the evidence of quantum dynamics.
    gulstad@altair.com


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Professor
    Join Date
    Jul 2008
    Location
    New York State
    Posts
    1,096
    Could you write a short version - maybe about ten lines?


    Reply With Quote  
     

  4. #3 what you dont understand for my opinion 
    Suspended
    Join Date
    Aug 2009
    Location
    Israel
    Posts
    272
    is that the inflation of many world ocare back in time and that faster then the speed of the inflation you mention . thanks and sory for my bad english
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •