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Topics - Scintific Method

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Flat Earth Debate / DIY Coriolis demo
« on: June 03, 2015, 05:06:45 PM »
Check out this site for a DIY Coriolis demo that anyone can do to prove the effect exists:

I would be interested to see how many FE supporters actually get off their potties and go do this! Post your results below!

Flat Earth Debate / Eötvös effect
« on: October 02, 2013, 07:31:49 PM »
It might be simplest if I just use the definition from Wikipedia:

Quote from:
The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity.

I ran across this while researching another topic, and realised that it is actually a very simple to replicate proof of three things: gravity, earth's roundness, and earth's rotation. I do not believe that this effect could exist if those three things did not exist as well.

Here's how it works: an object at rest on the surface of the earth is subject to whatever the local perceived gravity is. Hypothetically, this force could be anything: UA, gravity, whatever. For the sake of this explanation though, I'm going to have to go with current science and say that this force is the sum of local gravity and local centrifugal force resulting from the earth's rotation. As far as I can figure, no other forces could explain the effect.
So, back to our object. At rest, it has a certain weight, the product of it's mass and the aforementioned force. If we start moving this object in an easterly direction, the centrifugal component of the force acting on this object increases, reducing it's weight. If we turn around and head west, the centrifugal component decreases, increasing the objects weight.
This was reportedly observed in the early 1900's whilst gravity measurements were being performed on moving ships. The readings were lower when the ship was moving east, and higher when it was moving west. This inspired Lorand Roland Eötvös, a Hungarian nobleman who had been involved in the gravity measurements, to create a device to demonstrate the effect.

Quote from:
To demonstrate the effect, Eötvös constructed a balance with a horizontal axis, where, instead of pans, weights are attached to the end of the arms. When the balance is rotated the weight moving towards the west will become heavier, the one moving towards the east lighter and will deflect from its state of equilibrium. This proof of the earth’s rotation is perhaps of greater significance than Foucault’s pendulum experiment since it also works on the equator.

Such a device should be easy enough to construct, although care would have to be taken to ensure that the masses at each end of the arm were exactly in line with the pivot point, and that the pivot had as little friction as possible. Here's a picture of one such device:

I would like to invite discussion on what other forces could possibly explain this effect. And please, keep it credible.

Flat Earth Debate / ISS Orbital Altitude
« on: September 06, 2013, 02:45:17 PM »
A thought occurred to me the other day regarding the ISS and our ability to predict where it will be so that we can observe it.

The information I get emailed to me when a sighting opportunity comes up is actually for a town 100km South of me (as the crow flies), so for the ISS to appear within a few of degrees of it's predicted location, it must be at a significant altitude, well beyond what any winged aircraft could reach. The fact that when I see the ISS, my parents (who live 50km South-East of me, again as the crow (or Cessna ;) ) flies) can also see at close to the same viewing angles supports that.

All this tells me that the ISS's orbital altitude of ~300 miles must be true. If it were not, then there would be significant differences in the viewing angles experienced by me, my parents, and anyone else within a 100km radius of the town the predictions are given for.

Flat Earth Debate / Test the Earth's shape: Measure a mountain!
« on: July 16, 2013, 06:20:36 PM »
This is lifted from another thread with minimal editing, so it'll look familiar to some of you!

For this you need an accurate map. Now, right away, I know you'll be thinking "but the maps will have been doctored to give you the results you find". Well, if they were, this method would actually show it up with inconsistent results, but it doesn't, so you can put that thought out of your mind.

Equipment: 1 spirit level, 1 set square, and 1 ruler. You might also want something to set the spirit level up on, and some packing to level it.

Method: pick a mountain that is easily identifiable from a distance (I have a few to pick from where I am). Find a point on the map 30km away, 40km away, and 50km away (or any other largish distances, as long as you can measure them accurately. This is part of what negates any doctoring of the maps: picking arbitrary points to measure from). Set up your spirit level so that it points toward the mountain you picked, ensuring it is level. Set your ruler at a specific distance along the top of the level, standing up at right angles to it (that's what the set square is for). Sight from the edge of the level furthest from the mountain to the mountain top, and note where your line of sight crosses the ruler. The ratio of the measurement on the ruler to it's distance along the top of the level would be equal to the ratio of the mountain's height above your observation point to your distance to it (simple triangular geometry).

The height of the location the measurement is taken from is important, as you will get different results from different elevations at a given distance. Another reason why this cannot be faked or doctored.

In the below diagram, the ratio of h/d should be equal to r/s if the earth is flat, and should always be that way, no matter how far away from the mountain you are.

When I did this experiment though, there was a difference between h/d and r/s, and it got bigger and bigger the further away I got from the mountain. I did some extra maths to work out where the mountain top would be for a round earth:

apparent height on a round earth = square root of ((earth's radius + h)2 - d2) - (earth's radius + altitude of your position)

When I tested the results against those calculations, they matched perfectly. Remember: maths and geometry don't care what shape the earth is; they will always tell you the truth.


Mountain (Castle Top, in the Nandewar Ranges): 1075m AMSL
Point 1 (my back yard): 30.44km from peak, 215m AMSL
Point 2 (Kamilaroi Hwy): 40.46km from peak, 205m ASMSL
Point 3 (Wee Waa levee): 55.57km from peak, 192m AMSL

Using a 1100mm baseline on the spirit level, the following apparent heights were recorded:
Point 1: 28mm
Point 2: 18mm
Point 3: 11mm
Let's be pessimistic and say they're only within 1mm either way.

Here's what they should have been for a flat earth:
Point 1: 31mm
Point 2: 21mm
Point 3: 16mm
Note the increasing difference. This is due to the mountain 'going over the edge'.

Conclusion: The data collected disagrees with FE predictions*, and almost exactly matches RE predictions. The experiment is easy to conduct, and not prone to significant error, so the results can be considered reliable.

* Rowbotham's 'perspective' has been cited as a possible cause of the results. However, a passing familiarity with geometry should be sufficient to show that this 'effect' is not responsible for the rate at which the actual measurements diverge from what they should be for a flat earth.

Interesting Note: if you use the following equation, you can work out the difference between the apparent height for a round earth and a flat earth (with respect to the diagram):

rf - rr = s * tan((d / ce) * 360 / 2)

where rf is the apparent height on a flat earth, rr is the apparent height on a round earth, and ce is the circumference of the round earth. d and ce need to be in the same units as each other, and rf - rr will be in the same units as s.

Sorry for the long post! I thought it would be best to give plenty of detail, so that others can reproduce this experiment and obtain accurate results.

I thought it might be worth creating the following image to show the difference between the flat and round earth sun motions, or rather, the apparent path and the path given by the popular, north-pole-centred-3000-mile-high-sun flat earth model.

The pink dots give the apparent position (lower) and flat earth model position (upper) for the sun at sunset on the winter solstice where I live (30° South). The yellow dots are sunset on the equinox, and the red dots sunset on the summer solstice.

The orange, green, and blue dots represent the sun's position at midday on the summer solstice, equinox, and winter solstice respectively. The dots at the top of a line represent the apparent position of the sun at these times, and the dots on the arcs represent the flat earth model position for the sun at these times.

I apologise for the lack of artistry, this was initially drawn in a 3D modelling program, and the dots added with an image editor. I wasn't really trying to make a pretty picture anyway, just something to give an idea of the relative positions of the sun at various times. Hopefully it is clear enough! Oh, and the apparent positions of the sun have been verified for my location, so no mistakes there!

Point to be debated: the difference in apparent and flat earth model locations of the sun at various times is far too great to lend any credibility to the idea of a flat earth.

Note: "Bendy light" (aka "electromagnetic acceleration") is not an acceptable explanation, as it has too many holes and has never been observed. Refraction and perspective are also unsuitable, as they do not explain the lateral or vertical difference in locations of the sun at sunset.

This publication was brought back to my attention recently, so I thought I'd express my opinion on it, starting with the first 25 "proofs".

1- I've flown, and this does not accurately describe my observations.
2- What experiments? Did they account for environmental variables?
3- Surveyors methods are such that curvature does not need to be accounted for in railways and canals.
4- A misconception. The Nile may only fall a foot in 1000 miles, but that is relative to sea level, not to a straight line.
5- Anecdotal. Is it the actual light being seen directly, or the beam it casts? I've seen the beam from lighthouses without seeing the lighthouse itself.
6- Failure to recognise a spherical phenomenon: gaining altitude allows one to see greater distances. This is actually evidence for a round earth.
7- There is not enough information in this anecdote to draw a conclusion from.
8- No, a model globe would be useless for navigation, as it would not be detailed enough, or convenient to use.
9- Navigational charts are not to scale at their edges, because the earth is not flat. If it were, flat charts would be to scale everywhere on the chart.
10- Nonsense. This shows a total lack of understanding of magnetic field lines and compasses.
11- See 10.
12- Again, a lack of understanding of the spherical world.
13- More misunderstandings.
14- More anecdotes and misunderstandings.
15- Ever heard of this thing called 'gravity'? It's what keeps us on the planet.
16- Found by what navigators? I never heard of anyone going twice as far at 45 degrees South as they did at 45 degrees North.
17- Theological proof? That's shaky! I could just as easily say that our Creator made the earth round with gravity to hold us on it's surface so that we would never fall off any edges.
18- Senses are not much use without reason, and reason tells us, ultimately, that we live on a globe.
19- This could do with being worded more clearly.
20- 'Up' is away from earth, and 'down' is toward it. Simple.
21- See 15.
22- Contradicting a more reputable source. Never say 'it can't be done' to the man doing it.
23- Not sure what the author is getting at here, but proof of a globular earth is all around us.
24- See 16.
25- More misconceptions, and no evidence or references to back them up.

Sorry if that's a bit of tough reading, you'll need to reference the publication itself to get those comments in context. I'm sure there'll be some discussion on this one!

Flat Earth Q&A / Sunset related observations
« on: May 16, 2013, 12:30:54 AM »
I was just outside admiring a truly spectacular sunset (sorry, no photos), and saw two things I wanted to ask the FES about:

1. A commercial jet (QANTAS by the look of the livery) was en route East to West, at cruising altitude. The sun had set by this time, and was no longer visible to me, yet the jet was brightly lit for the entire time I was watching it, starting well to the East of my location. What allows this to happen in FET?

2. Some scattered storm clouds were still around, and were lit from below with a spectacular red-orange glow. what causes this in FET? (There could be no mistake, they were definitely lit from below)

I already know the Round Earth explanations for both these observations, I'm just wondering how FET explains them?

Earth Not a Globe Chapter XIV: "Difference in Solar and Sidereal Times"

Another short section, so I'll quote it in full:

It is found by observation that the stars come to the meridian about four minutes earlier every twenty-four hours than the sun, taking the solar time as the standard. This makes 120 minutes every thirty days, and twenty-four hours in the year. Hence all the constellations have passed before or in advance of the sun in that time. This is the simple fact as observed in nature, but the theory of rotundity and motion on axes and in an orbit has no place for it. Visible truth must be ignored, because this theory stands in the way, and prevents its votaries from understanding it. What is plain and consistent with every known fact, and with the direct evidence of our senses, must be interpreted or translated into theoretical language--must be called "an illusion of our senses," and affirmed to be an apparent result only; the real cause being the earth's progressive motion round the sun in what is called the ecliptic, the plane of which is assumed to be inclined to the equator 23° 28´.

This one I had trouble making sense of. Is the author saying that the observed annual motion of the stars is due to the earth orbiting the sun? or that it's an illusion? It certainly fits with an orbital model.

Flat Earth General / Amundsen-Scott South Pole Station
« on: May 14, 2013, 02:19:47 AM »
The Amundsen-Scott South Pole Station is currently located within 100m of the South geographic pole. It has a year-round presence of staff and scientists, and observes 6 months of sunlight, and 6 months of darkness. It's primary access route is via McMurdo Station, although it could be accessed from almost any direction, and there are companies which operate tourist flights to the station during the summer. The coordinates of the station are typically given as simply 90° South.

I really can't see how this can exist on a flat earth, can you? And yet, there it is, for anyone to see and visit.

Earth Not A Globe, Chapter XIV: "Deflection of Falling Bodies"

The author makes a fuss about the lack of substantial Easterly deflection in these experiments, and about the presence of a substantial Southerly deflection, asserting that this proves the earth to have no rotational motion. But, if the earth had no rotational motion, why is there such a substantial Southerly deflection of the falling objects?

Here's the theory behind the original experiments: an object suspended at rest is moving with the earth at whatever the rotational speed is at that point on the earth; a point some distance directly below the object is moving at a slightly lower speed, due to the smaller radius of it's circle; when the suspended object is released, it retains it's slightly greater rotational speed, and falls slightly ahead (to the East) of the point directly below it. If that doesn't make sense, look into the conservation of angular momentum, it's how ballet dancers spin faster by pulling their arms in close to their bodies.

The problem I see with this is that it only covers one component of the object's motion, and the lesser one at that. There is not much difference between the speed of two points 100 feet (or even 1000 feet) apart vertically on the earth's surface, so the horizontal, East/West difference between point of release and point of impact is going to be very small.

However, as we move away from the equator there is another influence on falling objects that becomes apparent: centripetal force. As the earth rotates, everything on it's surface is subject to an acceleration towards the axis of rotation proportional to it's distance from the axis. When an object is in free fall, this force is removed, so the falling object tends to move away from the axis of rotation (like a stone from a sling, but not as dramatic!). In the Northern hemisphere, where all these experiments were conducted, that tendency is to the South, hence all the falling bodies landing to the South of their release point.

While these experiments do not provide complete proof that earth is a globe, they do provide proof that the earth is at least rotating (which, of course, the author ignores completely). If these experiments were also conducted in the Southern hemisphere, and at various latitudes in both hemispheres, then the data collected could be used to prove (or, potentially, disprove) a spherical earth.

Flat Earth Debate / ENaG Chapter XIV: "Tangential Horizon"
« on: May 07, 2013, 09:18:55 PM »
Earth Not A Globe, Chapter XIV: Tangential Horizon

Another example of collimation being misunderstood by the author. By design, the horizontal cross hair of a theodolite lines up with anything on the same level as the theodolites line of sight. So, when the horizon appears below the horizontal cross hair, that's because it is lower than the line of sight through the theodolite, not because of "collimation". Granted, this in itself is not conclusive, but I really wanted to address the latter part of this section, which relates to the observations made by Alfred Wallace on the Bedford Level (yep, that one again!).

The illustration and description from ENaG:

A, the signal on the Old Bedford Bridge; B, the telescope on Welney Bridge; and C, the central signal-post, three miles from each end. The object-glass of the telescope was 4½ inches diameter; hence the centre, or true eye-line, was 2¼ inches higher than the top of the signal B, and 3¾ inches below the top of the signal-disc at C. On directing the telescope, "with a power of 50," towards the signal A, the centre of which was 2¼ inches below the centre of the telescope, it was seen to be below it; but the disc on the centre pole, the top of which was, to begin with, 3¾ inches above the centre, or line of sight, from the telescope, was seen to stand considerably higher than the signal A. From which, three of the gentlemen immediately, but most unwarrantably, concluded that the elevation of the disc in the field of view of the telescope was owing to a rise in the water of the canal, showing convexity! whereas it was nothing more than simply the upward divergence (of that which was already 3¾ inches above the line of sight) produced by the magnifying power of the telescope, as shown in the experiment with the lens, on page 267, fig. 92.

Ignoring the assumption that the telescope was not aligned so that the centre of it's objective lens was at the same 13 feet 4 inches height as the top of the 'signal' and the centre of the disc, there is still a glaring fault in the author's reasoning. The top of the disc may have been 3¾ inches above the eye line of the telescope, which could have made the top appear higher, but with the bottom of the disc being 8¼ inches below the eye line of the telescope, the same reasoning would place the bottom of the disc substantially lower than the 'signal' on the bridge. Here is an illustration of what was actually seen through the telescope:

The top disc in this image was the one set at 13 feet 4 inches, the lower disc was actually 4 feet below it, which gives a line of sight from the telescope to the 'signal' on the other bridge about 5 to 6 feet lower at the 'signal post' than it would be on a flat earth. That's pretty conclusive I think!

Flat Earth Debate / ENaG Chapter XIV: "Theodolite Tangent"
« on: May 05, 2013, 10:34:57 PM »
This is a short one, so I'll quote the whole section.


IF a spirit-level or a theodolite is "leveled," and a given point be read on a graduated staff at the distance of say 100 chains, this point will have an altitude slightly in excess of the altitude of the cross-hair of the theodolite; and if the theodolite be removed to the position of the graduated staff, again leveled, and a back sight taken of 100 chains, another excess of altitude will be observed; and this excess will go on increasing as often as the back and fore sight observations are repeated. From this it is argued that the line of sight from the theodolite is a tangent, and, therefore, the surface of the earth is spherical. The author has made experiments similar to the above, and found it to be as stated; but the cause is not that the line of sight is a tangent, but the same "collimation" as that referred to in the section on "Spherical Excess."

So, despite having seen evidence of curvature himself, the author again dismisses it as being a result of what he calls "collimation". Theodolites would not be much use if they were as inaccurate as the author implies, and collimation is actually a part of ensuring that accuracy, not a cause of inaccuracy.

This one had me shaking my head.

Chapter III of Earth Not a Globe deals with the axial and orbital motion of the earth. This could get a little bulky, so bear with me.

Axial Motion.

The chapter starts out with a lengthy description of what supposedly happens when a ball is thrown vertically up from a moving platform, such as a ship or train. The trouble starts when the assumption is made that, on reaching the highest point of it's flight, the ball stops moving forward:

 "...and now, as the two forces will have been expended, the ball will begin to fall, by the force of gravity alone, in the vertical direction..."

This assumption may have been based on a poor understanding of ballistics, or a poor understanding of Newton's laws of motion. We now know that a projectile follows a more parabolic path, and the x component of it's motion is reasonably preserved throughout it's flight, decaying only slightly due to drag.

Anyway, this incorrect assumption led to the assertion that a cannon ball, fired vertically and having a time in the air of 28 seconds total, should fall some 8400 feet to the West of the cannon from which it was fired if the earth were rotating. What actually happened was that the ball fell close to the cannon, sometimes even striking it. Here is the illustration from the book:

compare this to a normal ballistic trajectory:

As can be seen, the projectile continues to move in the x direction even when falling. This means that the whole experiment was pointless, as it was unable to reveal anything about whether the earth was rotating or not. Such was also the case with other examples given in this section.

Orbital Motion.

This entire section ignores the fact that stars can be seen to move seasonally in our sky. A constellation that is visible overhead at, say, 10pm in the middle of June, is not visible in the sky at all at this time in December.

There is some mention of annual parallax, but it is dismissed as being no more than an illusion. I suspect this would have been due to the poorer quality of telescopes and measuring equipment at the time, as we are now able to measure with great precision the distance of stars using annual parallax. In fact, there is even a unit of measurement defined for the purpose: the parsec.

Ok folks, your turn!

Flat Earth Debate / ENaG Chapter XIV: "Spherical Excess"
« on: May 05, 2013, 12:16:49 AM »
On reading through Earth Not a Globe, I've spotted a few misunderstandings and faulty assumptions. I plan to start up individual threads on some of these, so that they can be discussed and, hopefully, clarified.

I've decided to start with the section on spherical excess, found here.

Spherical excess is the theory behind the 'triangle with three 90 degree angles' thought experiment, which has been proposed on this forum before. This experiment is a bit impractical, due to the distances involved, but "...the excess of three spherical angles above two right angles..." has been observed and recorded on smaller scales already.

Rowbotham contends that this excess is due to collimation, which he mistakenly compares to refraction: "...the influence of refraction or "collimation" in their instruments...". Apparently, he did not know that collimation is "the accurate adjustment of the line of sight of a telescope". Even then, if there were an error present in the measurements being made, it would be either left or right, but always the same way, and always the same amount, which would mean that the angles would still be accurately measured, and any excess found would be real.

So, given that spherical excess has been accurately measured as long as 150 years ago, despite Rowbotham's assertions to the contrary, I would consider it a reasonable contribution to the evidence supporting a round earth.

What are your thoughts?

Searching the forums, I found this thread - Question about lines of latitude - which has remained unanswered for 7 years, and just wanted to ask a related question:

If the earth's circumference at the equator is ~40,000km, at what latitude is it's circumference 20,000km? The North pole centred FE map would indicate that this would occur at 45 degrees, the bipolar FE map does not allow for a circumference measurement at the equator, so is useless, and RET would dictate that this circumference would be found at 60 degrees.

This is not an impossible task, so has anyone found an answer?

From Tausami's thread in Q&A:

We get this video a lot, so I thought I'd make an easily found thread debunking it. If a mod could sticky this that would be awesome.

1. Other planets are round

According to Flat Earth Theory, the Earth and other planets are not really the same type of celestial body. To put it another way, which I'm sure everyone everywhere will take offense to, the Earth is different.

2. Time Zones

This is the first of a trend in this video, in which Henry (the host of MinutePhysics, for those not subscribed) assumes that the Flat Earth is exactly the same as the Round Earth in every way except for shape. The sun works in a manner similar to a spotlight in Flat Earth Theory, which is why time zones exist. When the Sun isn't pointing overhead, it's nighttime.

3. The Coriolis Effect

Once again, Henry is making assumptions. There are a few differing opinions about this, as Flat Earth Theory is not a unified theory. Some people doubt the existence of Coriolis as anything more than a theorized force, as the evidence for it is largely contrived. Others have various explanations for it, such as the Shadow of the Aetheric Wind theorized by myself.

4. Triangles

This is little more than conjecture. It is literally impossible to perform this experiment on the scale required.

5. The Sun

Henry is assuming again. The Sun's apparent movement is caused by the Sun actually moving. As for Eratosthenes's famous experiment to measure the diameter of the Earth, that assumes a Round Earth. If we assume a Flat Earth, the same experiment gives us the distance to the Sun.

6. Stars Change

Another assumption. This time, he's assuming that FE geography is just a Mercator map. It's not. The Earth is a disk centered around the North Pole, which would provide the same effect.

7. Magellan

Again, the Earth isn't in the shape of a Mercator map. That would be silly. Magellan and many others simply made a circle around the disk of the Earth.

8. The Horizon

This is just a perspective effect. First of all, apparently large waves will obscure apparently small objects. Therefore, looking out long distances over water you will of course be unable to see land on the other side. In addition, refraction has an effect. Some flat Earthers theorize an electromagnetic acceleration which appears to bend light upward.

9. Eclipses

Eclipses are caused by the sun going behind the moon, or vice versa. It's that simple. Once again, Henry is assuming everything is exactly the same.

10. Photographic Evidence

Most photographic evidence actually demonstrates what we would expect to see on a disk shaped, flat Earth: a circle with little to no apparent curvature. Add in camera distortion, and that's our explanation for low Earth photos. As for photos like the famous Blue Marble, that the space agencies of the World are involved in a conspiracy is depressingly obvious if you look at the evidence.


I'd appreciate it if you didn't respond to this thread, or if a mod locked it. It's not up for discussion. This is just to let newcomers know that they can't 'destroy FES with a single video' as so many hope to. It's not that easy. Sorry.

Seriously, this isn't a debate thread. If you want to debate it, feel free to make a new thread. I'm not responding to questions or concerns in this one.

1. Okay, it's possible you're right. Not very likely, but possible.

2. Again, possible, but not very likely (and very hard to explain as simply as on a round earth).

3. Have you ever studied meteorology? Or been hit by a hurricane or cyclone? Or fired a projectile over very long range (such as long range target shooting, or artillery)? The Coriolis Effect is very real, and the evidence is far from contrived.

4. This is not an impossible experiment, just a bit impractical for anyone without a substantial amount of money to spend on it.

5. It's pretty much impossible for the sun to move in such a way as to both fit in with FET and match observed motions. And no, 'bendy light' just doesn't make any sense, so is not an acceptable explanation. Also, repeating Eratosthenes's experiment with various distances between the two points will give various distances for the sun if you assume a flat earth, but consistent measurement of the circumference if you assume a round earth.

6. No, a flat earth will never produce the same effect, it is pretty much impossible. And again, 'bendy light' is not an acceptable explanation.

7. Possible, certainly.

8. Perspective? Seriously? SMH

9. "...or vice versa." I've never seen the moon go behind the sun. Lunar eclipses only occur during a full moon, when the sun and moon are furthest apart.

10. "Most photographic evidence actually demonstrates what we would expect to see on a disk shaped, flat Earth..." Sooo, are they actual photos (and videos) taken from space? or very good forgeries? Make up your mind! Oh, and in case you missed it, photos are flat anyway. That doesn't mean that a photo I take of my car shows my car to be a cardboard cutout, it just means that the photo can't show everything about it's subject.

Flat Earth Debate / Another hitch with bendy light?
« on: March 26, 2013, 08:06:09 PM »
It's reasonably well know that you can determine your latitude by taking a measurement off the sun. There's even a page about it in the wiki. Thing is though, for this to work in a flat earth model, light has to do some pretty funky bending.

I'm going to use the circular, north pole centered FE model, with the sun at an altitude of 3,000 miles, as this seems to be the most commonly used model, and all measurements are based on the position of the sun at local midday on the equinox unless stated otherwise.

For an observer on the equator, the sun appears directly overhead. This is fine, it fits in with everything.

For an observer at 22.5 degrees latitude, the sun should appear to have an angular elevation, relative to the horizon, of 67.5 degrees for the latitude shot to work, which it does. But, in the FE model, it's actual angular elevation is ~63.4 degrees. Okay, so maybe we can explain the 4.1 degree difference with bendy light. Let's continue.

For an observer at 45 degrees latitude, the sun appears to have an angular elevation of 45 degrees. Again, as it should be. Um, except that this means that light is bending back again from it's 4.1 degree deviation before. Hmm. Never mind, push on.

For an observer at 67.5 degrees latitude, the sun appears to have an angular elevation of 22.5 degrees above the horizon. In the FE model, it's actual angular elevation would be ~33.7 degrees above the horizon, so now we have an 11.2 degree deviation the other way. WTF? Anyway, let's finish the data set.

For an observer at 90 degrees latitude (the North pole, or the Southern equivalent), the sun appears to be setting (or rising) for the entire day, as it is partially obscured by the horizon. But in the FE model, it's actual position would be ~26.6 degrees above the horizon. Now we have a 26.6 degree shift!

Like I said, some pretty funky bending! Of course, the straight line distances to the sun may have some influence, so I'll leave you with some calculated FE data (for the model used in this example) which someone more mathematically minded can have some fun with.

Latitude: 0, Apparent Angular elevation of sun (AAE for the rest of this data): 90, Actual: 90, Distance: 3,000 miles
Latitude: 22.5, AAE: 67.5, Actual: 63.4, Distance: 3,354.1 miles
Latitude: 45, AAE: 45, Actual: 45, Distance: 4,242.6 miles
Latitude: 67.5, AAE: 22.5, Actual: 33.7, Distance: 5,408.3 miles
Latitude: 90, AAE: 0, Actual: 26.6, Distance: 6,708.2 miles

Oh, wait, that's not all! It's not just latitude shots at midday, but sunsets as well. For someone at the equator, the sun would be about 8485.3 miles away (line of sight) when it appears to set, with an actual angular elevation of 19.5 degrees, which means that light has to change direction a second time! If you head down to 45 degrees South latitude, the sun is 10,816.7 miles away with an actual angular elevation of 15.5 degrees when it appears to set.

If anyone can explain how that works in FET, I look forward to it! Especially if the explanation is supported with working formulas.

EDIT: I just realised, it gets even worse! If you were at the South pole (or the FE equivalent thereof) at midnight on the summer solstice, the sun would be nearly 20,000 miles away, at an actual elevation of 8.8 degrees, but an apparent elevation of 23.5, AND on the opposite side of the North pole, which should be in darkness!

Of course, RET covers all of this quite gracefully and without any convoluted BS explanations.

Flat Earth Debate / I can disprove FET with a stick.
« on: March 15, 2013, 11:21:53 PM »
...and so can you! Get a stick, stand it vertically (it must be vertical, a plum-bob can help with this) somewhere away from shadows, and measure from the base of the stick to the end of the stick's shadow at midday (this must be local midday, as measured by the sun's position, not just by a clock).
If you are close to the equator, travel away from it (north or south, whichever is 'away') a good distance, say 500km (or 300 miles), and repeat the above procedure.
Travel the same distance again, and repeat the measurement.
Now, using some fairly basic trig, you will find that the numbers don't work for a flat earth model. Here's the math:
The tangent of each angle = length of each shadow divided by length of stick.
The angle can then be found from trig tables, or using a calculator (or you can sit down with a protractor and make your own trig table).
What you will find, is that angle 1 minus angle 2 = angle 2 minus angle 3. This is only possible on a round earth.

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