Photons

[Brainee]

How is photons electromagnetic field packets? They are not electric or magnetic.

[swansont]

An changing electric field creates a magnetic field, and a changing magnetic field creates an electric field.

An EM wave happens when the oscillations induce each other. Photons are the quantized particles of that EM wave.

[Brainee]

I do not understand. Could you please explain simpler.

[swansont]

1 hour ago, Brainee said:

I do not understand. Could you please explain simpler.

Which part are you not getting, and what is the level of your understanding?

[Brainee]

What is meant by oscillating?

My level of understanding is basic only.

I also wonder what is meant by field (and electric field and magnetic field)?

[iNow]

Given your current knowledge level, maybe start with a simple dictionary, or perhaps a Wikipedia page if you’re feeling adventurous. 

[Lorentz Jr]

48 minutes ago, Brainee said:

What is meant by oscillating?

It means changing periodically, going up and down like a bouncing ball or a vibrating string.

Quote

I also wonder what is meant by field (and electric field and magnetic field)?

Electric and magnetic fields are theoretical explanations of why magnets and charged particles exert forces on each other.

Photons are both electric and magnetic. Nobody knows exactly why fields are quantized, but experimental evidence has shown that they are, and a photon is defined as one quantum of the electromagnetic field.

Edited December 10, 2022 by Lorentz Jr

[Brainee]

What is the difference between electric and magnetic fields and electromagnetic fields?

[Lorentz Jr]

When the theory of electromagnetism was first developed, it was formulated in terms of two fields. Charged particles contribute to the electric field, and magnets contribute to the magnetic field. The fields also interact with each other and with moving charges and magnets.

The current thinking is that the electric field and the magnetic field aren't really separate fields, because they look different to different observers (moving at different velocities). They're treated as aspects of a single, more complicated field that determines how light works, and it's called the electromagnetic field.

Edited December 10, 2022 by Lorentz Jr

[studiot]

On 11/22/2022 at 2:01 AM, Brainee said:

How is photons electromagnetic field packets? They are not electric or magnetic.

 

On 11/22/2022 at 2:18 AM, swansont said:

An changing electric field creates a magnetic field, and a changing magnetic field creates an electric field.

An EM wave happens when the oscillations induce each other. Photons are the quantized particles of that EM wave.

 

On 12/6/2022 at 11:42 PM, Brainee said:

I do not understand. Could you please explain simpler.

 

You first asked about packets, so let's deal with that first.

When you switch on a lightbulb, the lightbulb sends out the beginning of a pulse or stream or whatever you like to call it,  of 'light'.
When you switch it off again there is an end to the light.

That large chunk of light is a large packet in very crude terms.

Now it turns out that a stream of light is composed of very much smaller chunks of light, rather like a chunk of copper wire is composed of very much smaller chunks of copper, called atoms.
These smaller chunks of light are not atoms so they are called 'packets' and they share, with the copper atoms, the property that they are the smallest chunks of that particular type of light.

These small packets have a beginning and an end, just like the big one you generate with the lightswitch.

 

Does this help and are you ready to move on to the rest of your questions ?

 

 

 

[Brainee]

Yes.

[studiot]

 

13 hours ago, Brainee said:

Yes.

OK so here is a further analogy

 

Take a string and either tie one end to something fixed, and then take the loose end and pull it out straight.

The flick the end you are holding up and down.

You will cause the flick to travel along the string to the far end.

You can also do this without tying one end but is is ahrder to get the flick to go all the way to the other end.

 

Now here is the thing.

That flick maintains its shape and size pretty well all the way down the string.

That flick is a packet of disturbance that travels along the string.

That is what we mean by a photon being a packet, but in a way suitable for EM radiation, not exactly the same as the flick on the string.

 

One definite similarity. Both the flick on the string and the photon packet contain more energy than the undisturbed state.
So the travelling pulse (flick) is a method nature uses to tranfer energy from one place to another.

 

The next thing we need to do is to deal with fields, but I will stop there for you to digest this and to point you at your electricity question where the discussion of fields is better placed.

Then we can return to this thread and complete it.

[Brainee]

OK.