Light and inflation

[PJay_A]

If inflation in all 3d directions is faster than light than it is impossible for any two points of light anywhere at any time, correct?

Also, if the Universe is 13.7 billion years old and 46 billion ls from both ends of visible known Universe when inflation is calculated into the equation, a number very close to pi emerges when 46 is divided by 13.7. Might it be possible that light traveling 13.7 billion years ago on a 46 billion ly journey here is actually curving through space. The flat path of light we see appears so because it's not curved in 3d space, but is curved in 4d space.

Our eyes see a 3d slice of 4d space. With this understanding, many of the oddies of quantum mechanics and cosmology seem to make sense. For example, the double slit experiment does not keep I to consideration that the photon is being observed 3 dimensionally and nothing is being used to control possible extradimensional movement for when it's being measured. Such movement that we might not see but our instruments may detect will logically cause the interference patterns we see. This makes sence especially if light curves 4 dimensionally.

Also the reason why light has a constant speed and catching up to to is impossible is also because of the 4d curvature. It's actually moving diagonally on a 4d axis. So chasing it is pretty much like a dog chasing it's tail.

 

[MeteorWayne]

You are confusing inflation (which occurred only within the first second after the big bang) with expansion, that has been occurring since. The expansion exceeds the speed of light only at great distances, so there are parts of the Universe we can no longer see. But closer areas (within 13 billion LY timewise or so) we can see.

 

[dragon04]

If inflation in all 3d directions is faster than light than it is impossible for any two points of light anywhere at any time, correct?

Also, if the Universe is 13.7 billion years old and 46 billion ls from both ends of visible known Universe when inflation is calculated into the equation, a number very close to pi emerges when 46 is divided by 13.7. Might it be possible that light traveling 13.7 billion years ago on a 46 billion ly journey here is actually curving through space. The flat path of light we see appears so because it's not curved in 3d space, but is curved in 4d space.

Our eyes see a 3d slice of 4d space. With this understanding, many of the oddies of quantum mechanics and cosmology seem to make sense. For example, the double slit experiment does not keep I to consideration that the photon is being observed 3 dimensionally and nothing is being used to control possible extradimensional movement for when it's being measured. Such movement that we might not see but our instruments may detect will logically cause the interference patterns we see. This makes sence especially if light curves 4 dimensionally.

Also the reason why light has a constant speed and catching up to to is impossible is also because of the 4d curvature. It's actually moving diagonally on a 4d axis. So chasing it is pretty much like a dog chasing it's tail.

You're talking about the apparent superluminal velocity of galaxies moving away from us (red-shifted). Notice I said "apparent" because while two galaxies on "opposite ends" of the Universe appear to be moving away from each other at greater than light speeds (superluminal velocities), they're not.

You've seen the term "red-shifted". You've probably also read or heard that the Universe is expanding, and also accelerating as it expands. In part, we know that because the farther away a receeding galaxy is from us, the more "red-shifted" it is, and eventually, it gets SO red shifted that we can no longer see it.

Trust me. Light is still only moving at 300,000km/s. The "red-shift" doesn't indicate superluminal velocities, but rather the change in the frequency of the receeding light. Think about the Doppler effect in terms of sound. A train is coming at you at a constant speed, blowing its whistle... As it approaches, the pitch (frequency) of the whistle gets higher until the train passes you, and then gets lower the farther away it is from you.

That's what's happening in space only instead of a train and a whistle, it's a galaxy and light. The galaxy itself can't receed any faster than the speed of light, but the farther away it gets, the more red-shifted the light becomes and makes it appear that the galaxy is receeding at superluminal velocity.

 

[Mee_n_Mac]

You're talking about the apparent superluminal velocity of galaxies moving away from us (red-shifted). Notice I said "apparent" because while two galaxies on "opposite ends" of the Universe appear to be moving away from each other at greater than light speeds (superluminal velocities), they're not.

Actually they are. They (the galaxies) aren't moving through space at >C velocities but they are receding from each other at >C speeds. Imagine you could freeze frame the Universe for a moment and lay out a gigantic tape measure from one galaxie to another far far away. Measure the distance. Now unfreeze and let time run for a while and do the magic freeze frame again. Upon remeasuring the distance and calculating the average speed over that time interval you'd find it >C (assuming we're talking about galaxies whose redshift indicated so). Remember cosomological redshift is different from plain Doppler (red)shift. The wavelength increases because space itself got longer as the wave moved through it. IIRC the wiki on this was pretty good and will do a better job than I on the topic.

Now I don't understand what PJ_A was asking but it is possible that light from some parts of the Universe will never make it to other parts as a result of this >C expansion. Right it appears that distant parts of the Universe, that we can see now, will redshift and then become invisible (even in the radio spectrum) as time marches on.

{Now let's hope speedfreek or derek or DrR will drop on by and let me know if I've understood it correctly )

 

[SpeedFreek]

I think you are both saying the same thing in different ways.

We can see galaxies that were apparently receding from us faster than light when they emitted the light we are seeing. But they were not moving through the universe faster than c, rather then universe was expanding such that objects remain at rest in relation to the universe but the distance in between them can increase faster than c if they are far enough apart.

Distant objects are not receding from each other due to inertial movement, they are being "dragged away" from each other by the expansion of the universe. It is as if everything is "lodged" in the fabric of the universe and even though objects can interact gravitationally, if they are far enough apart for gravity to be overcome by the rate of expansion then the fabric is stretching the distance between them and with enough separation that distance can increase faster than light.