Obviously, if two premises contradict each other, something is wrong, but nothing in his proof has contradicted itself.
P1: Light takes time to get to the eye.
P2: Light is at the eye instantly.
Light flows.
No, it moves in straight lines at c. Water flows.
The only thing that is at the eye instantly is the light that is reflected onto our photoreceptors.
That's nonsense. Reflected light is at the reflecting object, in the instant of its reflection, and then takes time to travel from there to the eye.
No, you're missing the concept entirely.
Light is reflected off the object.
At which instant, the light is "at the object", right?
What are you talking about?
At the instant that a given photon is reflected off an object, that photon is "at the object", and is some distance from the eye.
Right?
And we know that (in your own words):
If it is not at the eye in that instant, we won't be able to see the object. You are still looking at this from the point of view of afferent vision, but what I'm trying to get you to see is that if we see the object, the light has to be at the eye.
So it follows that at the instant that that photon reflects off the object, it is not at the eye (because we just noted that it is at the object); And therefore, as "it is not at the eye in that instant, we won't be able to see the object" as it is in that instant; Instead, we will see it as it was at some earlier instant, when the photons that were "at the object"
then have arrived at the eye
now.
In other words, we see the object as it was in the past.
If the light is switched off, the photons at the lightsource the instant before it is switched off will travel to the object (taking time to do so); Then will reflect off the object, and travel to the eye (taking more time to do that), and will therefore be "at the eye" allowing us to see the object for a brief time after the light goes out.
And the reverse is also true. When the light is switched on, the photons at the lightsource the instant after it is switched on will travel to the object (taking time to do so); Then will reflect off the object, and travel to the eye (taking more time to do that), and will therefore not be "at the eye" allowing us to see the object for a brief time after the light comes on.
Instant vision cannot be possible, if everything else you say is true:
Light is reflected off the object.
If it is not at the eye in that instant, we won't be able to see the object
How is light reflected off the object unless that light is "at the object"? If it is "at the object", it is not "at the eye", and cannot be until it travels the distance between object and eye. And as we know:
peacegirl said:
light travels at a finite speed.