Photons and determinism, part 2

[bennyboy]

Okay, so photons "experience" no passing of time. In other words, in the relative framework of a photon, whatever it's leaving and whatever it arrives at are brought together to a zero distance-- i.e. they share the same point.

Now, let's say that a photon leaves a very distance star, perhaps 1000 years away, and travels through gas clouds and (let's say in this case) the atmosphere of at least one planet, before arriving at my eye. The question is this-- could ANYTHING happen in QM, any kind of butterfly effect, which could change the final destination of that photon? Could any QM effect cause a buttefly effect which subtly affects the path of the photon?

The answer must be no. No time has passed for that photon in its long journey, so it was always going to arrive at my eye, and no matter what happens in its journey, this is written in stone. I think from this that we can conclude that IF relativity is correct, then the universe MUST be entirely 2-way deterministic (i.e. QM events must also be deterministic, because no butterfly effect can possibly exist which can interfere with an event that is timeless in any frame of reference). So this means that even though the photon left its distant star 1000 years ago in our time, and passed through that planetary atmosphere say 500 years ago, the state of that atmosphere was already (pre-)determined: it was truly inevitable.

Does this argument seem unsound to anyone?

[Surgenator]

Okay, so photons "experience" no passing of time. In other words, in the relative framework of a photon, whatever it's leaving and whatever it arrives at are brought together to a zero distance-- i.e. they share the same point.

The framework of a photon is an invalid framework. Naively interpreting the physics equation will give a no passing of time. However, the equations don't work in the photon framework, thats why they're invalid.

The question is this-- could ANYTHING happen in QM, any kind of butterfly effect, which could change the final destination of that photon? Could any QM effect cause a buttefly effect which subtly affects the path of the photon?

No, conservation of momentum forbids it. It would have to interact with something else. Possibly the virtual particles it might come across.

The answer must be no. No time has passed for that photon in its long journey, so it was always going to arrive at my eye, and no matter what happens in its journey, this is written in stone.

Wrong reason but semi correct answer. It matters if it interacts with anything else along its journey.

I think from this that we can conclude that IF relativity is correct, then the universe MUST be entirely 2-way deterministic (i.e. QM events must also be deterministic, because no butterfly effect can possibly exist which can interfere with an event that is timeless in any frame of reference).

False. The wavefunction is deterministic (that is why we can make predictions with QM), but the observations are not deterministic but probabilistic. In your photon example, there is probability the photon will not interact with your eye. Butterfly effect is back in business.

So this means that even though the photon left its distant star 1000 years ago in our time, and passed through that planetary atmosphere say 500 years ago, the state of that atmosphere was already (pre-)determined: it was truly inevitable.

Does this argument seem unsound to anyone?

500 years in the atmosphere!? How thick was that atmosphere? Plus, a photon is destroyed when it interacts and a brand new photon is emitted (assuming scattering).

Also, pre-determined is a hasty conclusion. It is just one photon that made into your eye. How many other photons started at the same trajectory that made it to your eye?

[vorlon13]

Gravity will deflect the photon and depending on the geometry, alter it's energy.

If the destination is further from the center of the galaxy (or closer) there would be a small change due to that. The source and destination points probably won't be at equal 'depths' in their respective gravity wells.

[Surgenator]

Gravity will deflect the photon and depending on the geometry, alter it's energy.

AHHHHHH, how could I possibly forget about gravity. :pulls-hair-out:

A passing by gravitation object can deflect the photon from your eye.

[bennyboy]

Okay, so photons "experience" no passing of time. In other words, in the relative framework of a photon, whatever it's leaving and whatever it arrives at are brought together to a zero distance-- i.e. they share the same point.

The framework of a photon is an invalid framework. Naively interpreting the physics equation will give a no passing of time. However, the equations don't work in the photon framework, thats why they're invalid.

Why invalid? Is this special pleading, or is there a reason why it is considered an invalid framework?

500 years in the atmosphere!? How thick was that atmosphere? Plus, a photon is destroyed when it interacts and a brand new photon is emitted (assuming scattering).

I mean that 500 years ago, it passed through a planetary atmosphere, but you are right in this (with a headslap of my own). So if a photon enters an atmosphere on its way to my eye, I'm actually receiving a photon emitted from the last of a chain of transmissions, rather than the original photon, so I'll drop that part of the idea right now.


Still, 1000 years in our framework is a lot of time for something to happen to our solitary little hero photon, but 0 seconds in ITS framework is obviously no time for anything to happen to it. I'd like you to explain why you don't feel this framework should be considered in philosophical arguments about determinism. Why is it "invalid"?

---

Gravity will deflect the photon and depending on the geometry, alter it's energy.

AHHHHHH, how could I possibly forget about gravity. :pulls-hair-out:

A passing by gravitation object can deflect the photon from your eye.

But I think it doesn't, because a photon cannot really be "changed," being timeless, can it?

[vorlon13]

Gamma ray photons have been proven to reduce their energy due to earth's gravity in a climb upwards of less than 50 feet.

In labs, on the earth's surface. No spacey wishy wibbly wobbly stuff at all.

---

There are 'disallowed' photons too.

As the energy decreases, the wavelength of a photon increases. Currently, photons of energy so low their wavelength is larger than our universe would be of very low energy indeed.

In the past, when the universe was smaller, the lowest allowed energy of a photon was larger. Shortly after the big bang, the lowest allowed energy would have been enormous.

[Alex K]

I don't quite understand the OP, how does chaos theory come in?

Some other thoughts -
in a medium, average propagation speed is reduced to below c by the refractive index. What does that mean for the proper time?

I still think going into the reference frame of a photon is not a mathematically valid reference frame change.

Wait! Need coffee, then brain thinking good.

[Surgenator]

The framework of a photon is an invalid framework. Naively interpreting the physics equation will give a no passing of time. However, the equations don't work in the photon framework, thats why they're invalid.

Why invalid? Is this special pleading, or is there a reason why it is considered an invalid framework?

In the relativity equations you will be dividing by zero if you go into the photon's rest frame. Thats what makes it invalid.

Still, 1000 years in our framework is a lot of time for something to happen to our solitary little hero photon, but 0 seconds in ITS framework is obviously no time for anything to happen to it. I'd like you to explain why you don't feel this framework should be considered in philosophical arguments about determinism. Why is it "invalid"?

The number of interactions that happen to the photon is independent of the reference frame. The time between two or more interactions would be spaced differently for different reference frames. Moving reference frame would see a smaller time difference between interactions compared to the stationary one. In the photon reference frame, all the interactions occurred at once which would break causality if the photon didn't get destroyed with each interaction.

---

AHHHHHH, how could I possibly forget about gravity. :pulls-hair-out:

A passing by gravitation object can deflect the photon from your eye.

But I think it doesn't, because a photon cannot really be "changed," being timeless, can it?

Imagine a photon starting on the trajectory toward your eye. Midway between galaxies, a flying black hole and photon have a close encounter. The black hole would change the trajectory of the photon.

[bennyboy]

I don't quite understand the OP, how does chaos theory come in?

The idea is that if QM actions are philosophically inderminate (i.e. not just a measurement issue but actually "random") then there would be a non-zero chance for subtle changes a la butterfly effect in fluid motion to shift gravity fields enough to subtly affect the path of the photon, and whether or not it reaches my eye.

My idea is that if time doesn't pass for a photon, then nothing can have affected its path, and that the universe must therefore be truly deterministic.

Some other thoughts -
in a medium, average propagation speed is reduced to below c by the refractive index. What does that mean for the proper time?

As Surge pointed out, that's not actually the same photon, so I had to throw out the idea of a photon actually passing through a medium.

I still think going into the reference frame of a photon is not a mathematically valid reference frame change.

Why not?

[Alex K]

I don't quite understand the OP, how does chaos theory come in?

The idea is that if QM actions are philosophically inderminate (i.e. not just a measurement issue but actually "random") then there would be a non-zero chance for subtle changes a la butterfly effect in fluid motion to shift gravity fields enough to subtly affect the path of the photon, and whether or not it reaches my eye.

My idea is that if time doesn't pass for a photon, then nothing can have affected its path, and that the universe must therefore be truly deterministic.

I see.... I'd have to think about that

I still think going into the reference frame of a photon is not a mathematically valid reference frame change.

Why not?

Because it is not a finite Lorentz transformation (not an element of the Lorentz group), it collapses the entire 3d space to a 2 dimensional surface, and time to a point.