happyjack27 wrote:of course there are other transforms. the term "wave" is generally associated with the fourier transform.
It should not be since the basis waves are not waves that can manifest independently in physics.
if you meant to refer to a different orthogonal system, i presumed you'd likewise use a different word.
There are orthogonal systems where each wave forming the system is a possible solution of the relevant wave equation. These are then used to model other waves which are not solutions of the same boundary conditions to model so called "time-evolution". This is not physics.
but it is no matter. the point is the function is a density function that describes what is and is not the thing, and one can choose any orthogonal basis to represent that. (though some might result in singularities and what not where others don't, depending on the nature of the function)
Correct, and you even get good results, but it is still not physics. You can "create" violin music from digital code but violin music does not consist of successive arrays of zeros and ones. That is why most modern physics has become a curve-fitting exercise; and is thus paranormal, or at best virtual.
to describe how it responds to changes you'd have to write down a time-evolution equation.
Except that the "time-evolution" operator is contrived. Why not solve the Schroedinger equation to get a closed solution as a function of a time-changing potential energy for every instant in time?
my subtle philosophical differences with some of that aside, you miss my point.
I do no think so since I know pretty well the standard dogma that you are advocating and with which I disagree. The "time-evolution" operator, if indeed such a monster must exist, must first describe the change in boundary conditions with time, and
then the Schroedinger equation must be solved for each one of these intermediary boundary conditions. Perturbation theory is not a good way to do this.
and this is an altogether different thing than an atemporal expression of the state in a given basis.
Each intermediary state is an atemporal state in its own right which should be solved using the whole wave equation at that instant of time ; subject to the boundary conditions which prevail at that instant of time.
it is irrespective of the basis you choose to represent the state.
Mathematically maybe but not when you do real non-paranormal physics.
yes, of course i know that. "concern" more properly. that is besides the point. what "concerns" you; why does it "bother" you; how do you think it might be problematic; etc.
Because I am a physicist that tries to
understand nature; not just calculating it in any function space just to get an accurate fit to the measurements. If an alien has never seen a violin and analyses a compact disc he might deduce that violin music consists of digital code: But this is not the case.
i don't. they are two different pictures of the same thing.
Why is there? Because "a particle" has never been defined
the question is what is the most useful picture for the particular problem.
Yes for persons like Heisenberg and Dirac who thought that mathematics is more important than understanding and visualizing the mechanics of physics. As a physicist I reject such an attitude as being paranormal.
which thinks ma as far as an intuitive visual understanding, the particle picture is the one that most clearly and simply describes the known properties, IMHO.
Fine but if he is a physicist he must know why this approximation works for a localized wave, and not call it "a particle" which he cannot define. Try Ehrenfest's theorem and interpret it correctly as a wave with mass intensity and a center-of-mass.
i'll give you that a point is a mathematical abstraction. but in the same sense so is a 3-dimensional space,
Not true, since I can move within three-dimensional space and experience it. I cannot pick up a singular point with tweezers.
.and so is a wave.
Not true, since I can create an energy field in space and detect it.
as regards whether there are such entities in nature, however, and esp. when it comes to "singularities", i beg to differ. the event horizon of a black hole?
It is a boundary at which time stops and on the way to this boundary time alows down gradually due the increase in gravity: Where is a singularity involved?
the fusion of two nuclei?
Why is the entanglement of two waves to form a single new wave a singularity? You can do it in your bathroom by allowing two drops of water to "fuse".
beta decay?
this is not a singularity; it is a wave disentangling like a drop of water breaking up into smaller drops.
phase transition from a solid to liquid or liquid to gas (nucleation)?
That is not a singularity but the normal morphing of matter
lasers?
It is the entangling of many smaller waves to form one wave, like many droplets forming a puddle of water: Where does "singularity" comes into it?
the extinction of a species?
so the dynosuars died out at a single point in time: Wow!
the first stage of morphogenesis of an embryo?
This is to a certain extent a miracle, but now fairly well understood in terms of DNA reactions: I do not see any "singularity" in the proces
the emission of a photon by an electron?
the disentanglement of an electron wave with mass into a wave moving away at light speed c and leaving behind an electron wave with a lower mass: Where is your singularity?
the resulting light spectrum produced in spectroscopy? the list is endless...
My friend, you are confusing boundaries with "singularities". Show me the "boundary" around a single point: This is what we are talking about, not real boundaries which you for some reason want to classify as "singularities".
please. again this "i know you are but what am i." stuff doesn't do anything for me.
Please just define what you are talking about.
i fail to see the point of any of this discussion!
Yes I agree with you since I like to talk about concepts that can be defined and visualized in terms of our previous experience (this is called physics) not about "what is easy to use mathematically", or defining boundaries as "singularities" when they are not.