Flat Earth?

[Albert Tatlock]

im willing to bet that the geezer who first claimed the earth was round was met with the same derision that you are getting gerry.. think you prob wasting your time trying make these fools see sense, but kudos for trying anyway

This forum doesn't even exist.

 

Wake up...and follow the white rabbit signs to the Looney Bin...and take the blue red nutter pill.

[Isaac]

I mean, why the fuck are you bothering?

 

I can understand why people get into this sort of thing. The real world can be such a damn awful place; in days gone past, people found solice and comfort in their faith, and now they look for other avenues for comfort and escape from everyday life. It's comforting to believe this world and this life is not the be all and end all, that there is more. It's a post-religious form of mysticism.

[Albert Tatlock]

The biggest conspiracy yet to unfold is that we are all made of not matter, but anti matter. And anti matter is actually matter.

 

Though this thread is made up mostly of doesn't matter of course.

[Isaac]

My post wasn't intended as a ridicule. To be honest, we've all been lied to so much over the centuries - in order to control us and suppress human potential - that it wouldn't surprise me if the world really was flat. It's unlikely, but it really wouldn't evoke surprisse. So much of our present-day social order is radical and unthinkable; it would have caused armed rebellion if introduced in previous ages, yet today people take these things for granted and can't even comprehend the thought that there might be any other way, let aone that other ways existed for 99% of human history. It's like Orwell said in 1984: Who controls the past controls the future; who controls the present controls the past. They have lied to us so much and people are so deluded about the true state of affairs, that the earth being flat or a sphere is actually inconsequential in comparison.

[Albert Tatlock]

I think he actually said it in 1948.

[Isaac]

I think

 

Try harder.

[Chinahand]

I am intrigued by willful ignorance.

 

One of humanity's triumphs is accurate navigation and it is pretty amazing that up until the 1960s when radio navigation became widespread most of it was done with sextant, chronometer and tables.

 

The tables are based on Kepler's laws, which are a direct consequence of the Newton's, well Hooke's (hee hee), inverse square law of gravitation acting on the planets and sun; fixed stars on the celestial sphere; the rotation of a spherical earth and the tilt of its axis; and the time of the observations.

 

All these are wrong ... ok approximations. Gravitation is far more complex than an inverse square law, with relativity and quantum effects messing up Newton's precision, the stars aren't really fixed on the celestial sphere, the Earth is not an exact sphere and its rotation slightly changes with glaciers' wax and wane and volcanoes shifting the mass distribution of the earth like an ice skater putting their arms in and out - pips leap; the tilt of the axis is also not fixed but drifts as Milankovitch discovered; and chronometers would always be a second or two out.

 

But all these finesses don't change the fact that you can use all of these approximations to position a plane or a ship to within a couple of miles in a thousand mile journey.

 

Science isn't divine truth - it is what will work, and trying to understand why.

 

One of the things that has really annoyed me about the various Youtube videos Gerry et al have put up, is the lies they contain. One is the idea of the dip of the horizon, which the videos claimed has never being observed. That is an absolute lie.

 

As you get higher above the Earth, the horizon appears lower in your field of view - it is no longer horizontal (90 degrees from the zenith or vertical), but lower than that. This is an important issue in navigation because your tables work out the height of the sun or a star above the horizon at sea level while your bubble sextant measures the angle from the horizontal. Unless you are at sea level these two measurements will be different, by the dip of the horizon.

 

The maths to correct for dip are pretty simple and by a fluke of units can be approximated by the dip in minutes of arc being about equal to the square root of the height in feet from sea level.

 

When aviation started to develop over the course of World War I people worried how well this approximation held, especially due to the issue which has been raised a number of times in this thread - refraction.

 

Would refraction change the dip as planes flew higher?

 

That was a serious scientific issue one which could have made navigation increasingly inaccurate.

 

Here is a 1919 report which looked at the issues facing aerial navigation and on page 131 it reports its experiments on dip. Hundreds of observations were taken and the effect of refraction examined compared to the simple theoretical approximation.

 

This 1924 report by the Bureau of standards documents best practice in Navigation and on page 290 (pdf p22) again dip is an important issue.

 

While most fascinatingly is this 1918 paper from a ship captain tasked with measuring magnetic anomolies around the world which reported the most extreme examples of refraction affecting its measurements of dip from the deck of the ship on its 10 years of surveying.

 

You cannot do navigation assuming a flat world. It doesn't work you will get hopelessly lost - a flat world would have no dip, our world does. Without accounting for the "fall away" with longitude you cannot calculate the height of the sun at noon.

 

Navigation is a wonderful example of practical, applied, science, putting simple assumptions and approximations to an end of piloting a ship or an aircraft around the world.

 

I've been lucky enough to have a go with an aviation bubble sextant, and help calculate the figures to navigate a yacht after the captain had sighted the noon day sun.

 

It is a real frustration to hear the Youtube videos simply lie, and to have those lies taken seriously by people here, but then again remembering days in my youth on a deck of a ship and finding the diligent work of sea captains nearly a century ago ... well that's enjoyable, for all Quilp's snark.

 

If people want to delude themselves there's not much to be done ... but I do try to diligently show them the evidence and encourage them to go and do the experiments for themselves.

 

There's none so blind as those who will not see.

 

[paul's got wright]

balance is required in learning. compassion in teaching. a lack of manners and common courtesy is a severe lack of intelligence x

[gerrydandridge]

A thought experiment of intuition perhaps?

 

If a skilled aircraft pilot were to fly at 100feet above the surface of the sea, or even along the Suez canal for that matter at approx 500mph, would the pilot have to take into account the curvature of the earth? The consensus curvature of the Earth would indicate that the pilot would have to constantly dip the nose of the aircraft by 2,777ft every 1 minute at such a speed.

 

Therefore if the pilot left his instruments indicating he was travelling in a straight line would he ascend over 2700ft per min (average) as the surface curved away from him?

[Chinahand]

You show yet again you don't know what down is.

[gerrydandridge]

I see what you are saying but it fly's against intuition.

[Isaac]

Pope Urban VIII must be your hero. O_o

[Mr. Sausages]

Gerry, have you ever been on holiday to somewhere in a different time zone? I have, so can confirm they exist. What's your explanation for it being night time in other parts of the world right now?

[gerrydandridge]

I double checked the figures its only 46ft for the first min, but still the average per min over an hour would be 2777

[gerrydandridge]

Probably a better way to put would be, that the pilot leaves the cockpit at 100ft above sea level and returns 1 hour later to find the plane is now 166766ft above sea level.