Light, Waves, Particles etc

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Re: Light, Waves, Particles etc

#141  Postby Teuton » Oct 09, 2011 9:56 pm

twistor59 wrote:But those conceptual reasons can't carry much weight because according to some formulations of the holographic principle, space may be essentially two dimensional and the 3rd dimension may not be fundamental. If space is two dimensional then objects which occupy it may be at most two dimensional.


"Susskind and 't Hooft stressed that the lesson should be general: since the information required to describe physical phenomena within any given region of space can be fully encoded by data on a surface that surrounds the region, then there's reason to think that the surface is where the fundamental physical processes actually happen. Our familiar three-dimensional reality, these bold thinkers suggested, would then be likened to a holographic projection of those distant two-dimensional physical processes.
If this line of reasoning is correct, then there are physical processes taking place on some distant surface that, much like a puppeteer pulls strings, are fully linked to the processes taking place in my fingers, arms, and brain as I type these words at my desk. Our experiences here, and that distant reality, would form the most interlocked of parallel worlds. Phenomena in the two—I'll call them Holographic Parallel Universes—would be so fully joined that their respective evolutions would be as connected as me and my shadow."


(Greene, Brian. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. pp. 260-1)

So, according to the holographic model, all the 3D things existing in the "shadowy" bulk world are unreal projections of the real physical (information) processes taking place on the 2D boundary world.

The holographic model obviously presupposes that surfaces as 2D boundaries of space regions are real physical things. For if they are not, there cannot be any real physical (information) processes taking place on them.
Well, it all depends on your conception of space. Most physical models and theories are based on the assumption that space is fundamentally composed or made up of 0-dimensional space points. Given this conception, 2D boundaries are real parts of space as surfaces of 3D regions which are composed of points just like regions.

But I doubt that this conception is true, thinking it more plausible that points, lines, and surfaces of or in space are but mathematically abstracted limits which aren't physically real, aren't concrete physical things.
(My approach to physical space/spacetime is holistic rather than atomistic.)
If I'm right, then the holographic model is an ontological nonstarter because it operates with fictional things: two-dimensional physical things.


"boundary. The boundaries of extended objects may be thought of in two ways: as limits or as thin parts. Limits of the object have fewer dimensions than it has itself: a three-dimensional brick has surfaces without thickness; the edge where two faces meet is a one-dimensional line; the corner where three faces meet is a point. An enduring event like a kiss has a beginning and an end without duration. There are also inner boundaries, like the half-way point in the flight of an arrow. Boundaries in this sense raise many ontological questions. Do they really exist or are they mathematical fictions? Are they parts of their objects, or of the surroundings, or neither? Alternatively, boundaries are simply 'thin' parts of the same dimensionality as their wholes. At stake is whether the highly successful mathematics of continuous structures, like the real numbers, which treat extents as composed of extensionless points, truly depict reality."

("Boundary," by Peter Simons. In A Companion to Metaphysics, 2nd ed., edited by Jaegwon Kim, Ernest Sosa, and Gary S. Rosenkrantz, 155. Malden, MA: Wiley-Blackwell, 2009.)
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Re: Light, Waves, Particles etc

#142  Postby twistor59 » Oct 12, 2011 2:39 pm

On subject of the "are virtual particles actually physical entities" discussion that was taking place a few pages back, Matt Strassler has just posted a beautifully clear exposition of what virtual particles are/are not. I urge anyone who things that real paticles interact by tossing virtual thingies back and forth to read it.
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Re: Light, Waves, Particles etc

#143  Postby zaybu » Oct 14, 2011 12:59 am

twistor59 wrote:On subject of the "are virtual particles actually physical entities" discussion that was taking place a few pages back, Matt Strassler has just posted a beautifully clear exposition of what virtual particles are/are not. I urge anyone who things that real paticles interact by tossing virtual thingies back and forth to read it.


Okay, so he has an aversion for the word "particle" and calls it a "ripple". Big deal.
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Re: Light, Waves, Particles etc

#144  Postby Teuton » Oct 14, 2011 1:08 am

zaybu wrote:
Okay, so he has an aversion for the word "particle" and calls it a "ripple". Big deal.


It is, ontologically speaking, because to say that particles are ripples or waves is to reduce them to properties (attributes) of fields and thus to deprive them of their ontological status as objects or substances.
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Re: Light, Waves, Particles etc

#145  Postby twistor59 » Oct 19, 2011 2:17 pm

zaybu wrote:
twistor59 wrote:On subject of the "are virtual particles actually physical entities" discussion that was taking place a few pages back, Matt Strassler has just posted a beautifully clear exposition of what virtual particles are/are not. I urge anyone who things that real paticles interact by tossing virtual thingies back and forth to read it.


Okay, so he has an aversion for the word "particle" and calls it a "ripple". Big deal.



Well it’s a little more than that:
Matt Strassler wrote:
The best way to approach this concept, I believe, is to forget you ever saw the word “particle” in the term. A virtual particle is not a particle at all. It refers precisely to a disturbance in a field that is not a particle.


and
Matt Strassler wrote:
Physicists often say, and laypersons’ books repeat, that the two electrons exchange virtual photons. But those are just words, and they lead to many confusions if you start imagining this word “exchange” as meaning that the electrons are tossing photons back and forth as two children might toss a ball.


Hmm yeah like this animation.

They do indeed lead to many confusions, as evidenced by this physicsforums question:



I am told that the space surrounding me is filled with virtual particles, popping into and out of existence. I could believe that they exist for such short times and at such low energies that sophisticated equipment is needed to detect them. However, a collision between even 1 virtual electron and a starship going 0.99999999999999999999999999 c would have a significant effect on the ship because in the ships frame of reference the electron would have a large kinetic energy. Since all reference frames have equal claim to be "at rest", why are we not constantly bombarded by virtual particles that may be at rest relative to the afore mentioned starship, but would tear us apart?


Virtual particles popping in and out of existence :o
The poster there was quite right to ask that question given the horseshit pictures that are promulgated by the use of this sloppy terminology. Had he known how the theory is really formulated though, the question might have rather included the phrase "a collision between even 1 momentum integral and a starship going 0.99999999999999999999999999 c" :lol:
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Re: Light, Waves, Particles etc

#146  Postby starkiller » Nov 22, 2011 12:50 am

Hello,
New to this forum and I have a question. I figured this was the post to post it in.

as a particle is approaching a black hole does it accelerate?

as a particle is approaching a massive sun does it accelerate?
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Re: Light, Waves, Particles etc

#147  Postby hackenslash » Nov 22, 2011 6:15 am

Yes, as long as it has mass.
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Re: Light, Waves, Particles etc

#148  Postby cavarka9 » Nov 22, 2011 6:53 am

twistor59 wrote:


I am told that the space surrounding me is filled with virtual particles, popping into and out of existence. I could believe that they exist for such short times and at such low energies that sophisticated equipment is needed to detect them. However, a collision between even 1 virtual electron and a starship going 0.99999999999999999999999999 c would have a significant effect on the ship because in the ships frame of reference the electron would have a large kinetic energy. Since all reference frames have equal claim to be "at rest", why are we not constantly bombarded by virtual particles that may be at rest relative to the afore mentioned starship, but would tear us apart?


Virtual particles popping in and out of existence :o
The poster there was quite right to ask that question given the horseshit pictures that are promulgated by the use of this sloppy terminology. Had he known how the theory is really formulated though, the question might have rather included the phrase "a collision between even 1 momentum integral and a starship going 0.99999999999999999999999999 c" :lol:


well, but doesnt a virtual particle come in contact with a particle(particles) on the ship, if so. That particle will be lost. But the ship remains intact.Like photo electric effect.
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Re: Light, Waves, Particles etc

#149  Postby twistor59 » Nov 22, 2011 7:55 am

starkiller wrote:Hello,
New to this forum and I have a question. I figured this was the post to post it in.

as a particle is approaching a black hole does it accelerate?

as a particle is approaching a massive sun does it accelerate?


This thread was more about quantum stuff. I'll start a new one....

Edit: here
Last edited by twistor59 on Nov 22, 2011 8:47 am, edited 1 time in total.
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Re: Light, Waves, Particles etc

#150  Postby twistor59 » Nov 22, 2011 8:46 am

cavarka9 wrote:
twistor59 wrote:


I am told that the space surrounding me is filled with virtual particles, popping into and out of existence. I could believe that they exist for such short times and at such low energies that sophisticated equipment is needed to detect them. However, a collision between even 1 virtual electron and a starship going 0.99999999999999999999999999 c would have a significant effect on the ship because in the ships frame of reference the electron would have a large kinetic energy. Since all reference frames have equal claim to be "at rest", why are we not constantly bombarded by virtual particles that may be at rest relative to the afore mentioned starship, but would tear us apart?


Virtual particles popping in and out of existence :o
The poster there was quite right to ask that question given the horseshit pictures that are promulgated by the use of this sloppy terminology. Had he known how the theory is really formulated though, the question might have rather included the phrase "a collision between even 1 momentum integral and a starship going 0.99999999999999999999999999 c" :lol:


well, but doesnt a virtual particle come in contact with a particle(particles) on the ship, if so. That particle will be lost. But the ship remains intact.Like photo electric effect.


No, I don't think there will be any activity to cause Capt. Kirk to ask for a damage report.
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