If FET is accurate, then why can't I see Mt. Everest?

Quote from: sandmanMike on April 12, 2013, 06:09:20 AM

Quote from: New Earth on April 11, 2013, 04:33:55 PM

You do not see Mt Everest because the known earth is in a form of a disc. Just like the round earth it curves just not spherically. Also a human eye can only see so far.

What is the max distance the eye can see?  Wouldn't it keep us from seeing the sun?

The sun is up in the sky, it's high and you can see through the air as it gets thinner and thinner.

Actually the cotton candy clouds limit visibility so I can safely conclude the earths mantle is made of molten shrimp.

Quote from: New Earth on April 11, 2013, 04:33:55 PM

You do not see Mt Everest because the known earth is in a form of a disc. Just like the round earth it curves just not spherically. Also a human eye can only see so far.

What is the max distance the eye can see?  Wouldn't it keep us from seeing the sun?

The eye can see as far as visible light can travel. For example, we're able to see stars which are light-years away.

Quote from: acesuv on April 12, 2013, 11:43:29 AM

Quote from: sandmanMike on April 12, 2013, 06:09:20 AM

Quote from: New Earth on April 11, 2013, 04:33:55 PM

You do not see Mt Everest because the known earth is in a form of a disc. Just like the round earth it curves just not spherically. Also a human eye can only see so far.

What is the max distance the eye can see?  Wouldn't it keep us from seeing the sun?

The eye can see as far as visible light can travel. For example, we're able to see stars which are light-years away.

But according to FET the stars are near the moon and the sun. And the RET of light years is another part of the RE Conspiracy. We can see the stars since they're so close to the earth according to FET.

That's a little alarming to hear.

Even on a very clear day visibility does not exceed 40km. Air is not perfectly clear. Air stops you seeing Everest. Or more specifically the stuff in air like water vapour and particulates.

Also the acuity of our vision limits how far a person can see. You can only make out a penny from so far, not that it is blocked by air or particles. Our vision is just not strong enough.

What is the max distance the eye can see? 

The max distance the human eye can see is 2.5 millions light-years. Andromeda Galaxy is visible with naked eye (albeit not easily) and it is at that distance.

Quote from: googleearth on April 11, 2013, 04:27:41 PM

Quote from: Thork on April 11, 2013, 02:38:10 PM

Even on a very clear day visibility does not exceed 40km. Air is not perfectly clear. Air stops you seeing Everest. Or more specifically the stuff in air like water vapour and particulates.

While I totally agree that suspended particulate does limit visibility, it is possible to see much further on very clear days. My friends and I can routinely see 150 km quite easily from an altitude of only 11000 feet, yet I can't see the small mountain range that is only 90 km away while I'm at 500 feet. On a flat earth, I should be able to see those mountains. Any thoughts on why I can't?

The air is most dense at or near the surface. The higher you get the thinner the air and the further you can see. Also the air near the surface has a much higher amount of dirt and dust in it. That's where most of the grime in it is. Air higher up is much cleaner and doesn't hold as much muck hence the reason you can see further as you gain altitude.



In a dirty city, the effect is quite marked.


Its very typical for round earthers to leap to the conclusion that something they observed must be because the earth is round. Stop blaming everything on earth being round and you'll understand a lot more about the world around you.

It's even more typical for flat earthers to rely on magic and BS to try and prove their point.

Coupling an air density graph with a photograph of a smog filled city is meaningless. On clear days, air density has an imperceptible effect on visibility over these distances . Suspended particulate, on the other hand has everything to do with it. By claiming the two are interchangeable, you are proving to us that you don't fully understand them and that you shouldn't be using them as evidence. Check your facts and do some experimentation. Visibility in clear air can and does exceed 90 km. 
   
Get out and observe a few things for yourself and you may possibly begin to understand a few things about the world around you.

The air is most dense at or near the surface. The higher you get the thinner the air and the further you can see.

Took this from sea-level.  It's 68km to that peak.

29silhouette, do you think you could measure the angular height of that peak above horizontal, and also get it's actual height above sea level for us? I have an idea for a side note

Quote from: sandmanMike on April 12, 2013, 06:09:20 AM

What is the max distance the eye can see? 

The max distance the human eye can see is 2.5 millions light-years. Andromeda Galaxy is visible with naked eye (albeit not easily) and it is at that distance.

On the surface of Earth, some people claim to see galaxies as far away as 11,000,000 light years with the naked eye. It all depends on what the light has to travel through in order to get to the eye; I'm sure astronauts are able to see much farther than people on the surface because the light doesn't need to go through the atmosphere.

...are we allowed to mention astronauts here?

29silhouette, do you think you could measure the angular height of that peak above horizontal, and also get it's actual height above sea level for us? I have an idea for a side note

picture was taken from lat 47.138601  lon -122.632159

The peak is 2085 m / 6842 ft and located at lat 47.653756  lon -123.140754

Quote from: Scintific Method on April 12, 2013, 11:16:33 PM

29silhouette, do you think you could measure the angular height of that peak above horizontal, and also get it's actual height above sea level for us? I have an idea for a side note

picture was taken from lat 47.138601  lon -122.632159

The peak is 2085 m / 6842 ft and located at lat 47.653756  lon -123.140754

Thanks! Not quite everything I was after though. When I asked for angular height, I was thinking more along the lines of "the peak is x degrees above the horizontal". I'll explain (and this is a bit of a derailment, for which I apologise): if the earth were flat, given the distance and height of the peak, the angle it would make with the horizontal would be tan^-1(height / distance) or tan^-1(2085 / 68000) = 1.756 degrees above horizontal. I expect, if you went and measured it, that the actual angle would be a bit less than that, due to the curvature of the earth.

Thanks! Not quite everything I was after though.

Your welcome.   I realized what you were thinking when I read your question and posted last night. 

I was too tired though to figure out any numbers so I just posted the elevation and locations real quick.

*In fact, just remembered I'm pretty sure my dad has a theodolite.  If he does I'll borrow it and see what I get next week.

It's possible that Thork is using MOR as his definition for "visibility".   

I'm not sure how your observation of a distant mountain is in anyway damning to a flat earth. 

On the RE view there should be a distance at which Everest is hidden behind the horizon, but it would be completely visible on a FE. Same old story really.

Assuming a perfectly clear atmosphere...

Distance from my house to Everest: 13,000km
Mt Everest height: 9km (generous)

Angular resolution of Mt. Everest from my house: 0.039666 Degrees

Angular resolution of human eye:  .9 degrees (generous)


Why would I see Mt. Everest from my house? Where do you live? Do your own math...

It's more like 0.09 degrees, the sun is 0.5 degrees of angular diameter. That means you only need 3x optical zoom to make out Everest!

It's possible that Thork is using MOR as his definition for "visibility".   

I'm not sure how your observation of a distant mountain is in anyway damning to a flat earth. 

Meteorological Optical Range?  I don't know.  Maybe he'll chime in and tell us.

True, it's not damning to FET, it's only damning to Thork's generalized claim of a person only being able to see a mere 40km.

Angular resolution of human eye:  .9 degrees (generous)

Telescopes and such. 

Quote from: Ski on April 13, 2013, 02:11:51 PM

It's possible that Thork is using MOR as his definition for "visibility".   

I'm not sure how your observation of a distant mountain is in anyway damning to a flat earth. 

Meteorological Optical Range?  I don't know.  Maybe he'll chime in and tell us.

True, it's not damning to FET, it's only damning to Thork's generalized claim of a person only being able to see a mere 40km.

Quote from: Ski on April 13, 2013, 04:38:43 PM

Angular resolution of human eye:  .9 degrees (generous)

Telescopes and such.

Speaking of telescopes, I'd like some opinions on a possible experiment. If it has already been brought up, I apologize in advance. As Ski said, the angular resolution of Mt Everest from his house, at 13 000 km, is 0.039666. This would be impossible to see without a very large telescope. My scope is a 10" dob and can only resolve to 0.04549 at best using Dawes Limit. Everest would have to be almost 20% larger for me to even see it with my telescope on a great day. Even then, I wouldn't be able to see any detail. I would only be able to make it out as a dot on the horizon and wouldn't be able to identify it as a mountain.
 
A much larger telescope with, let's say, a diameter of 33 feet, about half the distance away, sitting high above the deleterious effects of the atmosphere, at an altitude of 13 600 feet, would have absolutely no problems seeing Everest. It would stick out like a sore thumb.

I'm speaking of course of the W.M. Keck telescope atop Mauna Kea in Hawaii. From Mauna Kea the angular resolution of Everest would only be about 0.04483. While this is still out of the range of my telescope, the Keck has a resolving power of 0.0116 arc seconds and would show Everest in all it's glory. As Keck sits 13 600 feet asl and Everest peaks at 29 035, the Keck would actually be looking up over 15 000 feet toward the summit, well above any pollution and most of the atmosphere.

What other reasons would Everest not be visible through the Keck telescope if the earth was flat? So far the only thing I can think of would be cirrus clouds. However, ground based observation would easily confirm or deny their presence at the time. Any other thoughts of what else could spoil the view?

You'd need a day free of weather. No dust, moisture, turbulence, etc for a stretch 13,000km.  It seems, erm, unlikely....

Yep. It would be difficult but not impossible. We have shortened the distance from 13 000 km as it's only 7 000 km from Hawaii. And luckily smog rarely ventures above 7 000 feet even on those nasty, sticky, humid days. I have seen it as high as 9 000 but only a couple of times in 20 years. Turbulence is definitely a factor but we can easily tell when the air is steady by watching the contrails of aircraft. While a lot would have to come together, it's still a possibility.

What if we used the Okayama Astrophysical Observatory on Mt. Chikurinji in Japan? We would be cutting the distance to about 4 500 km.

As mentioned above, angular resolution of the human eye is about four to six arc minutes or 0.07-0.10 degrees, not 0.9 - if it was 0.9 we wouldn't be able to see our moon during the day. Bright objects against a dark background that are much smaller in angular size than our eye's resolution can be seen as well (easily visible stars are in the range of only 1.5 × 10^-5 degrees).

You'd need a day free of weather. No dust, moisture, turbulence, etc for a stretch 13,000km.  It seems, erm, unlikely....

But possible!  And all you need is a $20 telescope from Wal-Mart (the muggsybogues1 special). Find a way to take a picture and the prize is yours!  I will personally donate $5,000 if a 3rd party can verify a picture of Everest from 13,000kms away.

...I'm pretty sure my dad has a theodolite.  If he does I'll borrow it and see what I get next week.

Sweet! It'll be interesting to see what you get.

As mentioned above, angular resolution of the human eye is about four to six arc minutes or 0.07-0.10 degrees, not 0.9 -

Good catch - pretty sloppy of me. Yet, Everest would still be irresolvable.

Quote from: Ski on April 13, 2013, 10:20:53 PM

You'd need a day free of weather. No dust, moisture, turbulence, etc for a stretch 13,000km.  It seems, erm, unlikely....

But possible!  And all you need is a $20 telescope from Wal-Mart (the muggsybogues1 special). Find a way to take a picture and the prize is yours!  I will personally donate $5,000 if a 3rd party can verify a picture of Everest from 13,000kms away.

Excellent. I'll eagerly await a day when there is no weather, humidity, dust, etc in between me and the Himalayas....

Quote from: neimoka on April 13, 2013, 11:13:39 PM

As mentioned above, angular resolution of the human eye is about four to six arc minutes or 0.07-0.10 degrees, not 0.9 -

Good catch - pretty sloppy of me. Yet, Everest would still be irresolvable.

Actually, the angular resolution of the normal, unaided human eye is about 1 arc minute (sometimes better), not 4-6.  Come on Ski, even Rowbotham got that one right. 

Quote from: Ski on April 14, 2013, 08:57:50 AM

Quote from: neimoka on April 13, 2013, 11:13:39 PM

As mentioned above, angular resolution of the human eye is about four to six arc minutes or 0.07-0.10 degrees, not 0.9 -

Good catch - pretty sloppy of me. Yet, Everest would still be irresolvable.

Actually, the angular resolution of the normal, unaided human eye is about 1 arc minute (sometimes better), not 4-6.  Come on Ski, even Rowbotham got that one right. 

Do you have a source for one arc minute resolution? Not to argue about it, just curious, as sources I've seen cite at least a couple arc minutes.

Do you have a source for one arc minute resolution? Not to argue about it, just curious, as sources I've seen cite at least a couple arc minutes.

Although there are several variables that can affect resolution, one arc minute is the generally accepted answer.
http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/Introduction/visualacuity.htm

This wiki page has a picture of Mt Mckinley from 100 miles away, it's near the bottom.


http://en.wikipedia.org/wiki/Mount_McKinley

Quote from: 29silhouette on April 13, 2013, 08:40:00 AM

...I'm pretty sure my dad has a theodolite.  If he does I'll borrow it and see what I get next week.

Sweet! It'll be interesting to see what you get.

Found out it's not a theodolite.