Light does not "travel" (split from Travelling light...)

[Dr.Krumpet]

Essentially though, if you logically think about it.. light does not "travel" its a rate of propagation. and i'm not into conspiracies.. however it makes much more sense! 🤔

[Bufofrog]

19 minutes ago, Dr.Krumpet said:

Essentially though, if you logically think about it.. light does not "travel" its a rate of propagation.

Are saying a photon from the sun does not travel to earth?  Is this a semantic thing around definitions of terms?

[Dr.Krumpet]

1 minute ago, Bufofrog said:

Are saying a photon from the sun does not travel to earth?  Is this a semantic thing around definitions of terms?

If you can give me an EXPLANATION to what a photon is, NOT a DEFINITION.. then I'll gladly answer your question.😀

[Strange]

1 hour ago, Dr.Krumpet said:

Essentially though, if you logically think about it.. light does not "travel" its a rate of propagation. 

Of course it travels. We can measure its speed and even see it as in the examp,e above or: 

 

[Bufofrog]

43 minutes ago, Dr.Krumpet said:

If you can give me an EXPLANATION to what a photon is, NOT a DEFINITION.. then I'll gladly answer your question.😀

How can you make statements about light of you do not know what a photon is? 

My question was a fair question, I am disappointed that you won't answer it.

[Strange]

46 minutes ago, Dr.Krumpet said:

If you can give me an EXPLANATION to what a photon is, NOT a DEFINITION

Can you define the difference between an EXPLANATION and a DEFINITION? Or maybe just explain it.

Also, how is that relevant? Light travels from the Sun to the Earth whether you take a classical or a quantum view of it.

[studiot]

16 hours ago, Dr.Krumpet said:

Essentially though, if you logically think about it.. light does not "travel" its a rate of propagation. and i'm not into conspiracies.. however it makes much more sense! 🤔

I think the original question about Jedi like light beams has been well answered.

But the issue of propagation has been less well explained.

 

It is easiest to talk of light as a wave for this since we can then talk of a wavefront.
(It is also possible to ignore the dual nature of light)

When light is emitted it spreads out as a (wave) front.
That front travels at the local 'speed of light' in th medium of transmission (which may be a total void).

The entire space between the emitter and the front and the emitter (ie behind the front) contains light (ie is illuminated) until the emitter stops emitting.
When the emitter ceases darkness spreads at the same rate at the wavefront, as does any change to the light intensity.

Edited January 16, 2020 by studiot

[swansont]

16 hours ago, Strange said:

Can you define the difference between an EXPLANATION and a DEFINITION? Or maybe just explain it.

Seconded.

 

A photon is a quantum of EM radiation. Is that a definition or an explanation? I say it's both. As an explanation it requires you to be familiar with some physics, but by raising the issue you have implied that you have that knowledge.