Go Back   Physics Help Forum > Physics Forums > Philosophy of Physics

Philosophy of Physics Philosophy of Physics Forum - Philosophical questions about our universe

Like Tree1Likes
  • 1 Post By Fox333
Reply
 
LinkBack Thread Tools Display Modes
Old May 6th 2017, 01:03 PM   #1
Member
 
Join Date: Apr 2017
Posts: 46
Time and Photon

Time has a direction. We can't return back in time. Space doesn't have a direction, we can move in it in any direction we want. Time is moving, space is static. For us.

Let's look at a photon, which moves along the X axis. It can't move backward this axis, just like we can't move backward in time. It carries information about its source, but any new information from the source can't reach it. So, the source seems to not exist for the flying photon. Just like our past doesn't exist for us anymore. So, the X axis for the photon is like the time axis for us.

But "our" time is kinda static for the photon. All the events from its appearing to disappearing are simultaneous for it. So, one of the space axis (let's say, X) and the time axis are swapped for a photon.

Does it make sense?
mattlock likes this.

Last edited by Fox333; May 14th 2017 at 10:14 AM. Reason: grammar mistakes
Fox333 is offline   Reply With Quote
Old May 6th 2017, 02:37 PM   #2
Senior Member
 
Join Date: Nov 2013
Location: New Zealand
Posts: 510
Time is different. We can remember the past but can't forsee the future. However we can see both up and down, left and right and forward and back spatial directions.
kiwiheretic is offline   Reply With Quote
Old May 7th 2017, 01:14 AM   #3
Member
 
Join Date: Apr 2017
Posts: 46
@kiwiheretic, you're right. Time is different for us. We can remember the past, cause the past affected us some ways. The events from the past formed memories in our brains. The memories exist in our brains in the present. But we can't send any signals to the past.

What about a massless object, let's say a photon, flying to us from the Sun? It has a kind of "memory" cause it has a piece of information about the Sun. But this information is valid only for the moment of its emission. Leaving the Sun, the photon left it forever. The Sun can't affect the photon after its emission. Even is the Sun explodes and ends its existence it will have no influence on the photon. From the perspective of the photon, the Sun ended its existence just after the emission! It just became the photon's past. The axis, along which a photon moves is "different" for it, as the time axis different for us.

Last edited by Fox333; May 10th 2017 at 11:46 AM. Reason: grammar
Fox333 is offline   Reply With Quote
Old May 10th 2017, 11:56 AM   #4
Member
 
Join Date: Apr 2017
Posts: 46
I feel like adding a question to this small essay.
I expected many "this is wrong" answers, cause I've noticed many disproves under posts with alternative views on physics. But this didn't happen with my post.

So, are there any flaws in my reasoning?
Fox333 is offline   Reply With Quote
Old May 10th 2017, 01:05 PM   #5
Senior Member
 
Join Date: Nov 2013
Location: New Zealand
Posts: 510
I think you are referring to the arrow of time.

If you watch this video from about 35 minutes into it:



I presume you are referring to a particles "memory" in the sense that you could run the laws of physics backwards and reconstruct their history.

I also found this short video interesting although not entirely on your topic (but a consequence of it):



It seems to be a law that information should be conserved (along with momentum and energy) and this had led to some paradoxes, notably what is termed the information paradox:

(short video)
kiwiheretic is offline   Reply With Quote
Old May 10th 2017, 01:25 PM   #6
Member
 
Join Date: Apr 2017
Posts: 46
kiwiheretic, yes.
I brought myself to a conclusion (just a hypothesis), that there is no universal arrow of time. Every particle has it's own one. They all cross in co-called "singularity". That is probably related to the space expansion. So, a photon's arrow of time lies in our "usual" space.

Thanks for the video, I'll try to understand them, although my understanding of spoken English isn't that good. If there are any question arise I'll ask you
Fox333 is offline   Reply With Quote
Old May 10th 2017, 02:45 PM   #7
Senior Member
 
Join Date: Nov 2013
Location: New Zealand
Posts: 510
I think what they mean by arrow of time is that the universe becomes more disorderly over time. The video about Maxwell's demon shows that (sort of). If we have two chambers, one of hot molecules and another of cold molecules and then the chamber partition is removed then over time hot molecules intermix with cold molecules and reach thermal equilibrium. We don't see the reverse happening although in theory it could (according to the Nova video posted earlier).

Have a look at this Eugene Khytoransky video with some english subtitles:


Last edited by kiwiheretic; May 10th 2017 at 02:49 PM.
kiwiheretic is offline   Reply With Quote
Old May 11th 2017, 01:31 AM   #8
Member
 
Join Date: Apr 2017
Posts: 46
@kiwiheretic, I'm aware about this classical principles, like 2nd thermodynamics law and entropy. Maxell's demon needs some energy anyway, just to be able to see the molecules and handle them.
What I'm really interested in what lies beyond classical physics and standard model.

Answering your question about "memory of a particle". No, I didn't mean turning laws of physics backward. I mean this: our memory isn't the ability to see the past, it's just information that is kept in our brains. A photon also keeps some information about its source. Indeed, all we know about the Sun we know it from photons, emitted by our star. Leaving its source forever, a photon keeps a piece of information in the form of its frequency.

Last edited by Fox333; May 11th 2017 at 11:27 AM.
Fox333 is offline   Reply With Quote
Reply

  Physics Help Forum > Physics Forums > Philosophy of Physics

Tags
photon, time



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
What is a photon? Anonymous General Physics 8 Jul 23rd 2017 06:53 AM
Photon Parvez Quantum Physics 21 May 22nd 2012 08:38 AM
photon emissions? stevie c Quantum Physics 5 May 31st 2010 01:18 PM
photon flux newer Nuclear and Particle Physics 1 May 5th 2010 12:31 PM
mass of photon binayakafle Nuclear and Particle Physics 7 Dec 27th 2009 04:19 AM


Facebook Twitter Google+ RSS Feed