In a recent thread (

https://forum.tfes.org/index.php?topic=6710.0), Tom Bishop said a couple of interesting things:

I have argued in favor of UA EA in the past when the theory was first proposed, but have since tended to prefer the theory that light travels in straight lines and that perspective is the explanation for why the view of the sun is limited, as opposed to refraction or the Universal Electro-Magnetic Accelerator (which works, but is something I now consider to be less empirical compared to other explanations).

...and...

The perspective lines meet at a finite distance, not an infinite distance as described by the Ancient Greeks. This describes why the sun appears to descent and meet the horizon a finite distance away, as opposed to an infinite distance away.

OK - so we've established that (barring the minimal effects of atmospheric refraction) Tom believes that light travels in straight lines. ("Rectilinear propagation" to use fancy-talk)

This is an important breakthrough (for me, at least).

What we're left with is this notion that the conventional concepts of "perspective lines" and "vanishing points" is somehow incorrect.

But "perspective lines" and "vanishing points" are merely a consequence of light travelling in straight lines. They are a convenience for artists and the like - but they aren't some fundamental part of physics.

So there is a contradiction in Tom's mind here...one that we should probe into.

Firstly, let's take the human eye, brain and all of that other messy stuff out of the picture. Let's not even have a lens or anything else in the way of forming an image.

Let's think about the simplest optical device imaginable...a pinhole camera.

A light-tight box with a pinhole punched in the front and a photographic plate at the back.

There are thousands of photos of sunsets made by pinhole camera enthusiasts online - here is one of them:

So we know that pinhole cameras "see" sunsets...so whatever the mechanism that Tom subscribes to has to "work" with a pinhole camera.

Looking again at that diagram:

This is how perspective works with a pinhole camera. When the tree is further away, the light coming through the pinhole makes a smaller image...right?

You can use the law of "similar triangles" to state that the height of the image on the back of the camera divided by the distance from image to the pinhole must equal the height of the tree divided by the distance from tree to pinhole.

That MUST be true if light travels in straight lines...it's elementary Euclidean geometry.

Put another way - we can come up with an equation for the height of the image:

Himage / Dimage = Hsubject / Dsubject

Where:

Dimage = Distance from image to pinhole.

Dsubject = Distance from subject to pinhole.

Himage = Height of the image of the subject on the back of the camera.

Hsubject = Actual height of the subject.

...which we can rearrange to:

Himage = Hsubject x Dimage / Dsubject

To make life easier, let's suppose our camera is one foot across. So Dimage is one foot - and all of our distances are in feet...that simplifies the equation a bit:

Himage = Hsubject / Dsubject

In English -

**the height of the image is the height of the subject divided by the distance it is from the camera**.

This is "THE LAWS OF PERSPECTIVE" in a nutshell...just a single, simple equation that depends ONLY on the fact that light travels in straight lines and Euclidean geometry - and it's a proof that any high-school student could comprehend.

It IS indisputable.

So how far away does the tree have to be to "vanish"? Well, if Himage = 0, and we know that Hsubject isn't zero then the only possibility is that Dsubject is infinite.

So right here - we have the "laws of perspective" - derived from first principles using nothing more than an old-fashioned pinhole camera and the law of similar triangles.

Sorry Tom, you can't believe in "Light travels in straight lines" *AND* your funky version of perspective without denying the most basic Euclidean geometry.

Fundamentally - if at sunset, we know that the FET sun is 3000 miles up and 6000 miles west (Hsubject=3000 miles, Dsubject=6000 miles) - then a one foot long pinhole camera would show the sun to be 6" above the horizon...not the sunset that was actually photographed with a pinhole camera.

But not matter what - Tom's notions that the laws of perspective, known since the times of the Ancient Greeks are incorrect must be untrue.

So Tom....unless you wish to change your answer about how sunsets happen - we have here definitive proof that the Earth Is Not Flat.

More fundamentally:

If the Earth is truly Flat and if sunsets happen - light CANNOT travel in straight lines, and (as explained comprehensively in my previous thread) it CANNOT be due to refraction.

So, alas, poor Tom...you're back with "Electromagnetic acceleration" - which is a truly crappy hypothesis that's going to be VERY easy to disprove. Trust me, I already have very simple evidence against that load of hogwash!

Are you now ready to admit that the world is not flat? I really think you should.