What does that even mean - — Harry Hindu

That the clock on them goes in two directions. Sometimes one direction, sometimes the other. The clock goes to and fro.

Not all particles are virtual. Virtual just means fluctuating in time with all possible values of energy and momentum. Real particles only go forward (or backward) with fixed E and p.

You repeat what you already said. In fat even. Why they don't go forwards or backwards in time? They even fluctuate in time.

I have brain damage — Agent Smith

You should thank God on your knees!

The clock is the time. Virtual particles form a clock, a pendulum. How do you know a pendulum goes forwards or backwards in time? You don't. Likewise for a normal clock. Without symbols or agreed direction, a clock can go forward as well as backwards. A clock itself has no time direction. That's what naive realists do. Assigning a direction in time to the clock.

Imagine being an electron. A virtual one. You travel on all possible paths, with all possible values of E and p, forward and backward in time, at the same time. A real electron does the same, but only forward in time and with fixed E and p (or corresponding t and x, their conjugates, obeying uncertainty relations).

Like I said, time is an illusion — Harry Hindu

Time an illusion? They must have something wrt to change to. Space or time.

Yeah, I never understood how scientists could say that processes are reversible - as if while the rest of the universe moves forward, some other processes could move backward in time. — Harry Hindu

That's where virtual particles come in. Their name is a misnomer. They go back and forth in time all the time. Before real particles came into existence, there were only these VPs.

Gotcha!

Right of the fat, quote, list, picture, and link...

Isn't there an @ on top of the comment space? With all the other symbols?

How can every possible path be traversed by the 'same' particle in an instant of time? — universeness

That's exactly why hidden variables are invented! How can a particle have a probability to be here or there? Where is it then?

I ama member... press the @, and fill in the name you wanna link: @universeness

The idea of a wave 'amplitude,', if so, an amplitude must take time to form an it forms in a direction from rest to up (in the case of a crest) or rest to down (in the case of a trough). Does this marry with the proposal of 'rest up to crest as current to future' and 'rest down to trough as current to past?' — universeness

I'm not sure I understand. You mean time going forwards and backwards in a wavefunction, depending on the position in the wavefunction?

It's a bit hard to visualise, because we are used to particles going forward in time with definite position and energy, mutually related. If energy is zero then momentum squared is $-m^2$, according to $E^2-p^2=m^2$, and this relation doesn't hold for virtual particles. They can have independent values to fit the boundary conditions of two asymptotically free particles. In other words, if the two incoming particles have specified E and p, as the outgoing ones, the virtual particle adjusts to fit these values. It could also adjust to other values. All have certain amplitudes to occur. Qft calculates these scattering amplitudes by means of Feynman diagrams.

Carlo Rovelli is great. He's something else, like Smolin. Must be his "Italian blood". All particles need interaction to identify themselves. By interaction they can show their quantum numbers. Which is almost equivalent to their charges. There are leptons and quark numbers. But these are not thought to be fundamental. Which is naturally the case in preon theory. There are only three kinds of massless charges in that theory. All moving within the space sauce of hidden variables.

I cannot understand EugeneW, so I don't think an explanation of what I mean is going to come from him.
— noAxioms

He has been quite patient with me when I have demonstrated my limited knowledge of physics. He has demonstrated his deeper grasp of the topic and has not 'dismissed' me as 'not worth his efforts.' As a retired school teacher myself, I appreciate and celebrate his approach and passion for physics and I prefer it to the more pretentious and unwarranted, almost sad, aloof attitudes of other members of this forum, be the thread philosophical, scientific, religious or political. Thankfully, such attitudes are also in the minority on this forum. — universeness

Thank you @universeness ! That's good to hear!

A wavefunction, in relation to qft, can be considered as a temporal cross section of a particles free field. A particle litterally travels on all possible pathways through spacetime. All paths have a probability, and are taken at the same time. In hidden variables theory, they hop from one to the other. No wonder these variables are non-local, and I have never understood why the fact that there are no local hidden variables is such a big deal. That's exactly what they don't have to be. In that theory, the wavefunction is a physical entity. Its squared, that is. It's a wavefunction because it's derived from the same equation as a real wave equation.

Real particles have a direction in time. They move forward in time. A virtual particle goes forwards, backward, forwards, backwards, forwards, etc. This fluctuation is often popularized as a pair, a particle-antiparticle pair, created and annihilating each other, while in fact there is just one eternal particle (seen from the collective of real particles going forward).

DOES NOT COMPUTE! = APORIA! — Agent Smith

Exactly! Being in aporiaticalistic state means being unable to compute. We're all Aporians, living close to Ignorantia. Gnosis of Philo has had his cynosure days, ruling from the hierarchy apex.

Wtf????

How do you know this to be the case? — 180 Proof

I'm part of reality. Wtf are D-Kers? Is it a D-cherry?

I just can't shake the oxymoronic sense of the term "non-physical reality" proposed in the OP, and therefore the 6 pages of mostly incoherent gibberish which has followed. — 180 Proof

It's oxymoronic and gibberish only when you speak a language which uses the word reality as a synonym for physical world. Reality contains more than what physics tells us though. The non-psychal reality is an epiphenomenon. It's contingent to or emerging from magic reality. If I love Suzan, where is the physical reality of that feeling. It's a wise comment made by forum member godmustbeanatheist (if there are more gods they might be theists in love).

Objects are countable and finite. 1 object, 2 objects, 3 objects, 4 objects, 5 objects, 7 objects, ... ad inf. Or the other way round: 1 object, 1/2 object, 1/2 object, 1/3 object, 1/4 object, 1/5 object, 1/6 object, 1/7 object, ... ad 0. And then there are all numbers in between.

Together they form an infinite continuum to move in. Space is the only real infinity.

"Aporia, the black-veined whites or blackveins, is a genus of pierid butterflies found in the Palearctic region."

Amaaaazing....

I don't wanna talk to you! — Agent Smith

???????????????........

Wtf are D-kers?

A philosopher then is just a student, an eternal pupil, alway learning, but never, ever completing the process of absorbing information and processing that into knowledge and, ultimately, wisdom. — Agent Smith

You mean a philosopher is a computer? A computer has no understanding. Without understanding no knowledge. Understanding means being what you wanna understand. Learning is being. Understanding is learning is being. But why doing this eternally?

Don't forget the use of aporia by our beloved leaders...

"Can it really be, my fellow partisans? Were they truly considering this? Did it actually cross their minds? My mouth fell open wide, sweet comrades! It cannot be. It will not be!! It won't be!!! Brothers, in aaarms!!!!"

Haha.

Who said I heard my name 180Booze? I defend those who don't understand... according to you. They might understand after all...

is this mathematical modeling or something that actually happens?
Oscillate in time in what sense? Current/past or current/future — universeness

"In Feynman's language, such creation and annihilation processes are equivalent to a virtual particle wandering backward and forward through time"

So, a virtual particles have no direction in time. They just go up and down. Since the beginning of time and before.

A VP is an imaginary simulation of a real particle. :smile: — Gnomon

So is a real particle... :wink:

It's their behavior in time and their energy-momentum relation that's pretty virtual. But still real...

And if they are just mathematical constructs (integrals over 4-momentum of e^ip, a virtual propagator), consider the mathematical structures real.

You've been speaking of locality before, and now there's hidden variables, used only by interpretations which abandon locality. — noAxioms

Locality and non-locality can co-exist. Only the hidden variables are non-local.

It's like the shell game — noAxioms

It's not like the shell game.

The only blame of this conflict lies on those producing weapons. These are the direct cause for the misery.

There are no hidden variables in RQM, and humans do not play any preferred role. — noAxioms

How do you know there are no hidden variables? It's the only solution that solves the problems, and the nature of space.

Many seem to know some (textbook) physics but, as this thread amply shows, very few demonstrate that they actually understand the speculative implications of major physicists' rival — 180 Proof

Especially you... Tedious indeed... :fire:

None of this seems not at all relevant to my comment quoted above. — noAxioms

None seems not at all relevant? So all seems relevant?

It depends how you view the wavefunction. In the standard Copenhagen view it's a mathematical aid. A complex function in Hilbert space. The square, a real number, represents the probability of finding a particle. Contrary to a dice, this probability has no determining substrate. That's the difference with etymological chance, where chance is due to lack of knowledge. The standard says there is nothing to know.

The other approach, which I use here, is that there is a layer of determination beneath the chance: hidden variables. These are real features. The wavefunction describes them. So the particle has a well determined position but hops around in space due ti the hidden variables. You could say the hidden variables are the space-sauce around the particles. If there is no interaction, the particles get lost in space.

. So, some physicists will confidently assert that a VP is just as "real" as an ordinary particle. I guess they mean that a non-physical bit of mind-stuff is mathematically interchangeable with a physical speck of matter. — Gnomon

If you mean that a VP is a non-physical bit of mind stuff I disagree. The real and virtual particle are just as real. Every real particle is a virtual particle is part of a virtual particle that propagates forward in time with well defined momentum and energy (obeying the relativistic energy-momentum relation). I think the mind stuff is not the particle but that what's inside of it.

Our first meeting with infinity — Agent Smith

Can we meet infinity? If we've reached it we can always walk further. It will always stay ahead of us. That's why the female mind comes close to infinity.

What's your avatar? I love it!

So do you mean all interacting wavefunctions (which produce actual waveform disturbances yes?) in the Universe collapse? — universeness

Rìght!

Yeah, definitely the white flag from me for now. — universeness

Let me put it in a different way. Consider a single virtual photon. Represented as a single circle in a Feynman diagram. One of the quantum "bubbles" (wrongly imagined in popular science to be a short appearance of a particle and its antiparticle). The virtual particles dont go in one time direction. They oscillate in time. Constantly and everywhere. Electrons couple to them. They "break" them open and from a circle they become a line (in Feynman diagrams) between two vertices (with associated vertex factors which quantify the coupling strength).