How Would A Quantum Foam Impact The Speed of Light

[SLD]

Reading some Quantum Physics and enjoying it. One of the many ideas presented concerns the structure of space time at extremely microscopic levels. I.e. the quantum foam we’ve all heard about.



However no one seems to address how a photon navigates through this structure. Wouldn’t it slow it down? Alter its frequency? Affect it somehow? Or at least reveal its structure? Or is a photon really just way too big to be affected by it? I always thought the photon was pretty much a point particle.

SLD

 

[Bomb#20]

However no one seems to address how a photon navigates through this structure. Wouldn’t it slow it down? Alter its frequency? Affect it somehow? Or at least reveal its structure? Or is a photon really just way too big to be affected by it? I always thought the photon was pretty much a point particle.

Quantum objects, as the saying goes, travel as waves and arrive as particles. How big they are depends on how you ask the question. But in some respects a photon behaves like a wide thin pancake, with its dimensions depending on the light source. A visible light photon from Betelgeuse acts like it's a few microns front to back and a few meters from side to side, as measured by a Michelson interferometer.

But that's not to say it's too big to be affected by quantum foam. What goes on at the Planck scale can have implications far above that level.

 

[steve_bank]

In general EM theory the speed of light in a vacuum is a reference point. Light passing through any medium slows down. Materials are defined by the dielectric constant. The dielectric constant of a vacuum is 1, the dielectric constant of any material is less than 1.

Air is close to 1.

Pulse a laser into a piece of Teflon and it slows down, then speeds back up when it exits.


https://en.wikipedia.org/wiki/Relative_permittivity#Communication

EM is a wave particle duality. When it is absorbed it is seen as a particle. When propagating it is an electric and magnetic field.

 

[Sarpedon]

I imagine that the effects of the foam on photons that pass through them average out into the uncertainty we observe in the photon's path.

 

[steve_bank]

Is it like foam on top of a glass of beer?

 

[Jolly_Penguin]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

 

[skepticalbip]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

That is the question that is answered by general relativity. It is defined as a warping of spacetime.

 

[steve_bank]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

We do not know what gravity 'is'. We have models that jive with experiment and observation.

 

[Jolly_Penguin]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

We do not know what gravity 'is'. We have models that jive with experiment and observation.

Exactly. We know how it effects stuff. We know of but can't exactly explain dark matter. I have heard that gravity isn't instantaneous, so it the sun somehow magically ceased to exist the planets would not all lose its gravitational pull at the same time. Also that gravity travels at the speed of light, however that is conceptualized (is this true?).

But I don't think even the top scientists know exactly what gravity is. Which is cool because at first glance it seems like such a simple question.

 

[skepticalbip]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

We do not know what gravity 'is'. We have models that jive with experiment and observation.

Exactly. We know how it effects stuff. We know of but can't exactly explain dark matter. I have heard that gravity isn't instantaneous, so it the sun somehow magically ceased to exist the planets would not all lose its gravitational pull at the same time. Also that gravity travels at the speed of light, however that is conceptualized (is this true?).

The LIGO interferometer measurements pretty much shows that gravity does indeed travel at c.

But I don't think even the top scientists know exactly what gravity is. Which is cool because at first glance it seems like such a simple question.

'Top scientists' generally accept the theory of relativity as a reasonable description of the universe so accept that gravity is a warping of spacetime.

 

[Jolly_Penguin]

'Top scientists' generally accept the theory of relativity as a reasonable description of the universe so accept that gravity is a warping of spacetime.

But how and why? Two masses attract each other. That's all I really firmly understand about it, and that's more than most of the general public.

 

[Jimmy Higgins]

Exactly. We know how it effects stuff. We know of but can't exactly explain dark matter. I have heard that gravity isn't instantaneous, so it the sun somehow magically ceased to exist the planets would not all lose its gravitational pull at the same time. Also that gravity travels at the speed of light, however that is conceptualized (is this true?).

The LIGO interferometer measurements pretty much shows that gravity does indeed travel at c.

But I don't think even the top scientists know exactly what gravity is. Which is cool because at first glance it seems like such a simple question.

'Top scientists' generally accept the theory of relativity as a reasonable description of the universe so accept that gravity is a warping of spacetime.

I'm not certain. No one understands the tides, so if they don't understand that, how can they understand gravity?

 

[DBT]

'Top scientists' generally accept the theory of relativity as a reasonable description of the universe so accept that gravity is a warping of spacetime.

But how and why? Two masses attract each other. That's all I really firmly understand about it, and that's more than most of the general public.

Mass bends spacetime creating gravity wells, which determine the trajectories and orbits of objects?

 

[steve_bank]

I could never get my mind around quantum physics especially in relation to light. I'm not sure the top scientists truly have this solved. I think its one of those mysteries of science still to be settled, like the basic question of what exactly is Gravity and how does it work. The Gravity question is my favourite because it seems like such a simple question but winds up being very much not so.

We do not know what gravity 'is'. We have models that jive with experiment and observation.

Exactly. We know how it effects stuff. We know of but can't exactly explain dark matter. I have heard that gravity isn't instantaneous, so it the sun somehow magically ceased to exist the planets would not all lose its gravitational pull at the same time. Also that gravity travels at the speed of light, however that is conceptualized (is this true?).

But I don't think even the top scientists know exactly what gravity is. Which is cool because at first glance it seems like such a simple question.

That leads to a bigger question. What is reality? IMO the question is meaningless across all science. All we have is observation and experiment with models. There is a saying The map is not the countryside'.
.
Sometimes when driving around or go hiking we conflatd map and physical reality. To me science is a map not reality.