-1
$\begingroup$

Adding on to THIS question

I would like to take this question a bit further, and forgive my ignorance of the details as I have never taken any formal training on such subjects. But it's said that after observation that the photon of light that is observed becomes a particle. Not only that it becomes a particle for the entire length of its journey from source to observation.

This would mean that when we see light from a distant star we are essentially changing the output of that stars light from E/M energy to a particle and that particle has now been in existence for millions of light years as it travels its long journey.

I'm not sure where to get the answer to know if that change in state would affect anything along its path but I was thinking that if it did say fill up space then the expansion of space could be an observation of the consequence of more and more observation of light today changing the light in to photons in the past and thus, well taking up more space and pushing the space outward.

This of course would be observed today as space expanding from what it was before. light that was observed by more and more people changing more an more light in to particles that are millions of years old. So what we see is not necessarily and force from one time causing a movement but instead the butterfly effect of us making changes to the past through observation of light. So to clarify, my question into the few required components for this thought to be real the asks are:

  1. Does the state of light actually change from electromagnetic waves to a physical particle?
  2. Does that particle affect the immediate environment around it?
  3. Does this state of change then become a reality for the entire length of its journey?
  4. And finally if these questions above are true then wouldn't the effect of adding a all the light we see as space billions of light years in the past cause the viewable universe we see today to be constantly growing and expanding from the additional particles being added?

Thank you for your patience and contribution.

$\endgroup$
4
  • 3
    $\begingroup$ I am not sure what you are asking. Could you try to edit your question a bit, right now it is a wall of text with no clear conclusion. $\endgroup$
    – tuomas
    Aug 6, 2019 at 8:43
  • 1
    $\begingroup$ Observation doesn't change the past. $\endgroup$
    – safesphere
    Aug 6, 2019 at 9:01
  • $\begingroup$ "it's said that after observation that the photon of light that is observed becomes a particle" No, that's a misunderstanding. When we want to understand how light moves, we use a wave model. When we want to understand how light interacts, we use a particle model. The light itself doesn't magically switch between being a wave and a particle. $\endgroup$
    – PM 2Ring
    Aug 6, 2019 at 10:18
  • $\begingroup$ Ahhhhh OK so the explanations thus far are not statements of physical reality but rather an abstract of behavior to allow for better understanding. I had thought this would have been to easy a solution but I thought it worth some input. $\endgroup$ Aug 9, 2019 at 18:50

2 Answers 2

2
$\begingroup$

In physics the word "observe" is usually employed in a technical sense in which consciousness plays no role whatsoever. In particular, in quantum physics, there is no need to bring in the notion of consciousness or conscious reflection on what is seen. It suffices that a mark is made on a photographic film, or a particle detector registers a spark or emits a click, or whatever. For light to be "measured" it does not even require that a device deliberately constructed to measure light is used. It is sufficient, for light to be "measured" or "observed" if it merely hits an inert lump of rock and gets absorbed. Whether anybody ever notices or not is entirely irrelevant.

This type of process is going on all the time, whether or not there are any humans or other animals around, so the arrival of humans on planet Earth has not changed this aspect of what goes on in the universe.

Therefore the answer to your question is "no"; humans do not influence the dynamics of the distant universe.

Finally, the detection of light (and other types of entity) which is going on all the time does not have the type of physical consequences you are conjecturing; it would not influence the expansion of space for example. The physics underlying the accelerating expansion of the space is far from understood but it can not be explained as an outcome of the mere detection/absorption of light.

$\endgroup$
1
  • $\begingroup$ Respectfully, Its not the detection I'm saying that influences the expansion directly its the fact that, if light becomes a particle the moment it is detected and then is a particle for its entire journey where it wasn't before. It's the change of state in a backward time which implies a potential for what wasn't occupying space before now is. $\endgroup$ Aug 9, 2019 at 18:41
0
$\begingroup$

But it's said that after observation that the photon of light that is observed becomes a particle

This is wrong. At the moment, mainstream physics accepts that the underlying framework of all physical theories ( thermodynamics, classical electricity and magnetism, (maxwell's equations) etc) all emerge from the underlying quantum mechanical level ( the theory of gravity is not yet definitively quantized, but it is getting there).

Light is described by classical electrodynamics, i.e.Maxwell's equations, and the wave properties are transferring energy and momentum in space. BUT it emerges from the quantum level , where the photon is the particle which added in superposition of its wavefunction(quantum mechanics here) builds up the classical wave with its interference patterns. This can be clearly seen in this experiment, coming one photon at a time in the frames, and when a large number is gathered, instead of particles the interference pattern of classical light is seen. The wave nature of the photon is seen in the probability distribution of the photons, whereas the classical wave nature depends on energy transfer. The two frameworks (the quantum probability framework of the waves and the classical energy transfer by its waves) can be shown to smoothly join to describe the observations.

Edit after edit of question:

  1. Does the state of light actually change from electromagnetic waves to a physical particle?

As seen in the double slit experiment I linked above, light is always composed of photons in superposition , it is the multitude of photons that macroscopically is seen as classical light.

  1. Does that particle affect the immediate environment around it?

Any elementary particle, of which the photon is one, has a quantum mechanical probability of interacting with one of the known forces,To firs order a photon interacts with the electromagnetic force. If it interacts, there will be further changes to its wavefunction, i.e. probability of further interactions. It is all quantum mechanically calculable.

  1. Does this state of change then become a reality for the entire length of its journey?

Depends on the new wavefunction which gives the probabilities for the particle.

And finally if these questions above are true then wouldn't the effect of adding a all the light we see as space billions of light years in the past cause the viewable universe we see today to be constantly growing and expanding from the additional particles being added?

The questions ignore the basic quantum mechanics frame on which all classical theories rest.

The photon cannot "emerge" from the quantum realm because it is only defined in the quantum realm. In the way physics is studied it is the energy and momentum vectors that make up the universe. These may be a four vector addition of massive or massless particles and that is how the tally is kept, with energy momentum and angular momentum conservation (except for very large values where general relativity has to be invoked)

$\endgroup$
3
  • $\begingroup$ Respectfully, when the photon emerges from the quantum realm would it not then occupy space which had previously not be occupied? This would also then be true for the space unoccupied at the start of its journey. Thus, like a balloon grows with air that's added would not the space growth the addition of actual photons? $\endgroup$ Aug 9, 2019 at 18:47
  • $\begingroup$ The photon cannot "emerge" from the quantum realm because it is only defined in the quantum realm. In the way physics is studied it is the energy and momentum vectors that make up the universe. These may be a four vector addition of massive or massless particles and that is how the tally is kept, with energy momentum and angular momentum conservation (except for very large values where general relativity has to be invoked) $\endgroup$
    – anna v
    Aug 10, 2019 at 3:25
  • $\begingroup$ I'm not yet allowed to up vote but I thank you for your answer. I see the world (myself included) desperately waiting for the giant wave of understanding to finally crest before the world blows it self up. Unfortunately even for an interested mind there is so much information to decipher and interpret that even asking a question as ignorant as mine can be to scary to ask for fear of either personal embarrassment or out of respect to not waste others time. Its is for this reason that I very much love sites like this and the people who frequent them. Thanks again $\endgroup$ Aug 12, 2019 at 15:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.