I don't think space is expanding.

[Mike Helland]

The extra 30 second before "we" see the perturbation would have meant the observing radio array would have been been in the wrong place on the Earth's surface to observe it.

Whether a ten second event occurs 25 light minutes away, or 1 light year away, it's still a ten second when observed from Earth.

I thought the paper was trying to determine the shape of the asteroid.

Changing the speed of the light changes that angle.

How do you change the speed of light? Place it in a medium?

 

[Myriad]

Whether a ten second event occurs 25 light minutes away, or 1 light year away, it's still a ten second when observed from Earth.

That depends on where you try to observe it from. When occultations can be observed from the Earth's surface, it's at specific places and times.

You still haven't read the paper.

How do you change the speed of light? Place it in a medium?

You tell me. You're the one proposing that the speed of light from cosmically distant objects is slower.

 

[Ziggurat]

Here’s another problem, Mike:

According to you, photon velocity decreases while moving through space, but when it encounters matter and is absorbed and re-emitted, it resumes its original velocity of c.

If the matter that it encountered was a mirror instead of the earth’s atmosphere, then Snell’s law would apply to the reflection angle, instead of being ordinary speculation reflection.

The effect of this is that Hubble would not even be capable of focusing on distant galaxies. But it is. Ergo, the mirror is still reflecting specularly, and the incoming light is therefore at c.

 

[Mike Helland]

You tell me. You're the one proposing that the speed of light from cosmically distant objects is slower.

You could say the clock speeds up (time expands).

If expanding space doesn't blur the image, expanding time shouldn't either.

Placing the photon in a medium would be a poor approximation of expanding time.

 

[Mike Helland]

If the matter that it encountered was a mirror instead of the earth’s atmosphere, then Snell’s law would apply to the reflection angle, instead of being ordinary speculation reflection.

The photons are absorbed by the mirror and re-emitted with same energy, but d=0, v=c, and wavelength has been elongated.

Are you determining the angle based on light traveling through a medium that approximates the hypothetical deceleration?

 

[Myriad]

You could say the clock speeds up (time expands).

If expanding space doesn't blur the image, expanding time shouldn't either.

Placing the photon in a medium would be a poor approximation of expanding time.

You've stated that the velocity of light from cosmically distant objects is slower with greater distance.

That would cause the light from objects at different cosmic distances but similar directions to resolve at different angles at different times in an image taken from an orbiting camera. Correction is possible only for one distance (one incident light velocity) at a time, so most of the objects in the Hubble Deep Field images would be blurred.

They are not blurred in that way. Your claim that the velocity of light from cosmically distant objects is slower with greater distance is falsified.

 

[Mike Helland]

That would cause the light from objects at different cosmic distances but similar directions to resolve at different angles

Based on what?

Approximating a slower speed of light in a vacuum by placing the photon in a medium?

 

[Myriad]

Based on what?

Geometry and relative motion.

The type of apparatus used to measure the incident angles is irrelevant. A pinhole camera or insect-style compound eye would show the same phenomenon at sufficiently high resolution.

 

[Mike Helland]

Red line shows light going < c in a medium

Blue line is light decelerating in a vacuum.

https://www.desmos.com/calculator/f4darcvxu0

Pretty different.

 

[Ziggurat]

The photons are absorbed by the mirror and re-emitted with same energy, but d=0, v=c, and wavelength has been elongated.

Are you determining the angle based on light traveling through a medium that approximates the hypothetical deceleration?

No. I’m determining the angle based on the velocity changing upon reflection. That’s your theory. I’m telling you what the consequences would be. Energy is irrelevant to this calculation.

 

[Ziggurat]

Based on what?

Approximating a slower speed of light in a vacuum by placing the photon in a medium?

No. No approximation is needed. No medium is needed. All that is needed is a change in velocity, which is your proposal, not ours.

 

[Mike Helland]

No. I’m determining the angle based on the velocity changing upon reflection. That’s your theory. I’m telling you what the consequences would be. Energy is irrelevant to this calculation.

Ok.

Let's say there is a photon arriving with a velocity of 0.5c, and say this is in a vacuum.

Can you show how to calculate the angle?

 

[Ziggurat]

Ok.

Let's say there is a photon arriving with a velocity of 0.5c, and say this is in a vacuum.

Can you show how to calculate the angle?

Snells law. That’s all you need. And no, it doesn’t assume a medium, it only assumes a change in velocity, which is your premise.

 

[Mike Helland]

Snells law. That’s all you need. And no, it doesn’t assume a medium, it only assumes a change in velocity, which is your premise.

Let's say there's a photon at 0.5c that hits a mirror at a 45 degree angle, and this is in a vacuum.

Can you show me how you would calculate the reflection angle?

 

[Mike Helland]

"Snell's law (also known as Snell–Descartes law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air. "

"passing through a boundary between two different isotropic media,"

Yeah, that's not what's going on in the hypothesis.

 

[Ziggurat]

Let's say there's a photon at 0.5c that hits a mirror at a 45 degree angle, and this is in a vacuum.

Can you show me how you would calculate the reflection angle?

Really? You need hand holding to use Snell’s law?

sin(theta)/sin(45) = c/v = 2

sin(theta) = 2 sin(45) = 1.41

There is no valid solution. At 45 degrees, you are past the critical angle. Coherent reflection can’t even happen.

So let’s find out what the critical angle (we’ll call it alpha) is. That’s when theta = 90 and sin(theta) = 1. So

1/sin(alpha) = 2
sin(alpha) = 1/2
alpha = 30

So at 30 degrees to normal incident, it would reflect at 90 degrees to normal. No small deviation.

 

[Ziggurat]

"Snell's law (also known as Snell–Descartes law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air. "

"passing through a boundary between two different isotropic media,"

Yeah, that's not what's going on in the hypothesis.

That’s what it is used for, because other than your theory, that’s the only way the speed of light changes. But the law itself doesn’t care about the medium, only the velocity, so your setup satisfies the requirements. Which you would understand if you understood how that law is derived.

As I said before, there is just so much basic physics you don’t understand.

 

[Mike Helland]

That’s what it is used for, because other than your theory, that’s the only way the speed of light changes.

Right, and I'm suggesting another one that doesn't involve passing from one medium to another.

Just because the speed of a photon changes over distance doesn't mean we can treat it as if its in a medium and proceed as normal.

In empty space the refractive index is 1. You're treating it as > 1

 

[Mike Helland]

Really? You need hand holding to use Snell’s law?

sin(theta)/sin(45) = c/v = 2

sin(theta) = 2 sin(45) = 1.41

There is no valid solution. At 45 degrees, you are past the critical angle. Coherent reflection can’t even happen.

So let’s find out what the critical angle (we’ll call it alpha) is. That’s when theta = 90 and sin(theta) = 1. So

1/sin(alpha) = 2
sin(alpha) = 1/2
alpha = 30

So at 30 degrees to normal incident, it would reflect at 90 degrees to normal. No small deviation.

Thanks for this.

 

[Reformed Offlian]

The photons are absorbed by the mirror and re-emitted with same energy, but d=0, v=c, and wavelength has been elongated.

But not the same momentum. The mirror would emitting photons with less momentum than it received from the incoming light. You might think that light from distant galaxies are outside the domain of applicability for conservation of momentum, but surely the mirrors on the HST aren't.