Go Back   Physics Help Forum > College/University Physics Help > General Physics

General Physics General Physics Help Forum

Like Tree28Likes
Reply
 
LinkBack Thread Tools Display Modes
Old Oct 5th 2019, 07:56 AM   #41
Junior Member
 
muon's Avatar
 
Join Date: Sep 2019
Location: low nuclear orbit
Posts: 20
I think the virtual ones exist. They just exist for a super-short period of time. But that's just my opinion. And sometimes they become non-virtual, as in Hawking radiation.

I don't know anything about "zero-point energy". I know space is filling with various virtual particles and that there's a "vacuum expectation value" of the Higgs field. I don't know anything about radio waves causing voltage in antennas either. All I know is that radio waves are no different than any other electromagnetic wave except for having the least energy by having the lowest frequency (longest wavelength). So if they can do something "special" electrically, I would think that the other frequencies of electromagnetic radiation could do it too
muon is offline   Reply With Quote
Old Oct 5th 2019, 12:13 PM   #42
Member
 
Join Date: Sep 2019
Location: Azores
Posts: 32
Originally Posted by muon View Post
I think the virtual ones exist. They just exist for a super-short period of time. But that's just my opinion. And sometimes they become non-virtual, as in Hawking radiation.

I don't know anything about "zero-point energy". I know space is filling with various virtual particles and that there's a "vacuum expectatiVon value" of the Higgs field. I don't know anything about radio waves causing voltage in antennas either. All I know is that radio waves are no different than any other electromagnetic wave except for having the least energy by having the lowest frequency (longest wavelength). So if they can do something "special" electrically, I would think that the other frequencies of electromagnetic radiation could do it too
Virtual particles/photons are what zero point energy is based on and they are proven to exist.

Virtual particles/photons in QED are thought to exist, but not proven, likely they do exist as you say. virtual particles in fact all particles photons etc are just quantum fluctuations/waves with varying different properties depending on what is observed.

Light from a torch or laser from photons does not induce a voltage in a antennae like a radio wave, is this because it is not polarized???.

Perhaps Individual photons arriving in waves might knock electrons into higher orbits, in a vertical antennae and not in a horizontal one.

Is a photons polarization in any way aligned to electrical polarization???
interested is offline   Reply With Quote
Old Oct 5th 2019, 12:51 PM   #43
Forum Admin
 
topsquark's Avatar
 
Join Date: Apr 2008
Location: On the dance floor, baby!
Posts: 2,857
Originally Posted by interested View Post
Virtual particles/photons are what zero point energy is based on and they are proven to exist.

Virtual particles/photons in QED are thought to exist, but not proven, likely they do exist as you say. virtual particles in fact all particles photons etc are just quantum fluctuations/waves with varying different properties depending on what is observed.

Light from a torch or laser from photons does not induce a voltage in a antennae like a radio wave, is this because it is not polarized???.

Perhaps Individual photons arriving in waves might knock electrons into higher orbits, in a vertical antennae and not in a horizontal one.

Is a photons polarization in any way aligned to electrical polarization???
First, the ZPE: It doesn't really exist.
One of the most profitable advances in theoretical physics is the idea of fields. We consider the whole Universe to be filled with these fields, photons, electrons, etc. Now, at very small scales we can approximate the fields as Quantum Simple Harmoinics Oscillators. The problem is that the QSHO has a non-zero energy in the ground state, meaning that even if there are no particles around the vacuum has energy as if there particles around anyway. Add all these little pieces up and you get an infinite answer for the energy in the vacuum. Clearly we screwed this up somewhere but no one knows how to fix it. The energy of the vacuum, the amount of energy available when nothing is there, is simply 0.

Unfortunately the public has caught on to the idea that if the ZPE value is infinite then we must be able to get some energy out of it. But how do you get to the energy when it's already bottomed out? No one has yet observed negative energies.

Second, virtual particles.
Two point Feynman diagrams generally require some particle or another to be exchanged that is never "seen" in the interaction. This particle is not observed so, by definition, is a virtual particle. The properties of virtual particles are fascinating in their own way, but there is nothing weird about the concept. If it's not observed it's called a virtual particle... end of story. And, by the way, we can have electrons (or anything else) be a virtual particle depending on the interaction we're considering, so it's not just the gauge bosons involved.

-Dan
__________________
Do not meddle in the affairs of dragons for you are crunchy and taste good with ketchup.

See the forum rules here.
topsquark is offline   Reply With Quote
Old Oct 5th 2019, 01:47 PM   #44
Member
 
Join Date: Sep 2019
Location: Azores
Posts: 32
Originally Posted by topsquark View Post
First, the ZPE: It doesn't really exist.
One of the most profitable advances in theoretical physics is the idea of fields. We consider the whole Universe to be filled with these fields, photons, electrons, etc. Now, at very small scales we can approximate the fields as Quantum Simple Harmoinics Oscillators. The problem is that the QSHO has a non-zero energy in the ground state, meaning that even if there are no particles around the vacuum has energy as if there particles around anyway. Add all these little pieces up and you get an infinite answer for the energy in the vacuum. Clearly we screwed this up somewhere but no one knows how to fix it. The energy of the vacuum, the amount of energy available when nothing is there, is simply 0.

Second, virtual particles.
Two point Feynman diagrams generally require some particle or another to be exchanged that is never "seen" in the interaction. This particle is not observed so, by definition, is a virtual particle. The properties of virtual particles are fascinating in their own way, but there is nothing weird about the concept. If it's not observed it's called a virtual particle... end of story. And, by the way, we can have electrons (or anything else) be a virtual particle depending on the interaction we're considering, so it's not just the gauge bosons involved.

-Dan
QED is based on quantum fluctuations of the vacuum is it not? The ground state exists. Space is full of particles coming into and out of existence borrowing energy from the vacuum, without violating the laws of thermo dynamics because it is re-payed very quickly.

The https://en.wikipedia.org/wiki/Cosmol...nstant_problem problem does not indicate that zero point energy does not exist. The most likely candidate for dark energy is zero point energy. I am not aware of any other mechanism that has been put forward, are you? The fact the maths does not currently stack up, means there is something fundamentally wrong with the math.

Yes there is quite a bit of literature ref electrons and feynman interactions via virtual particles. But nothing I can find ref photons interacting with virtual particles except they can be represented as two virtual particles, whose fields cancel out.

Zero point energy as a source of energy there are patents sadly no one has made one work as yet .
interested is offline   Reply With Quote
Old Oct 6th 2019, 07:34 AM   #45
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 1,060
There is nothing wrong with the maths,
But you are correct that it is clear that there is something wrong with the physics.

It must always be recognized that physics is just a model of what we observe.
We use Maths to encapsulate the model we construct.

As we expand beyond the edges of what we could previously observe
we often find that the model does not fit anymore,
and suitable modifications have to be dreamed up.

Similarly as we extrapolate the mathematical model into regions we cannot yet observe
we find that the maths gives us ridiculous results.
This is another indication that we haven't got the model completely correct.

When one moves from theory to practice,
it is not actually necessary to have a perfect model
(indeed I would be tempted to argue that a perfect model might be impossible).
However as long as you know the boundaries within which the model works well,
and don't try to use it outside those boundaries,
a perfectly working practical application can be designed and made.
interested and donglebox like this.
__________________
~\o/~
Woody is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > General Physics

Tags
fields, photons


« Need help. | - »

Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Photons and Force wad Physics 11 Jul 22nd 2017 07:31 PM
Max p.d of photons across p-n junction Immu Electricity and Magnetism 0 Apr 24th 2016 06:55 AM
Uncertainty/photons retsom Quantum Physics 2 Jul 15th 2012 06:00 AM
photons and me jamie General Physics 0 Jan 12th 2009 12:19 PM


Facebook Twitter Google+ RSS Feed