Line of Sight

Lets assume the Earth is flat.  If you took a telescope and instead of pointing it at the sky, you changed the direction to be parallel with the Earth's surface, how come you can't see a building in Tokyo, Japan when you're in San Diego, California?

Mate, I have tried this one in the debate section, and it will just end up in bitching arguments.  I know what your getting at though

1.  Are you sure you can't?

2.  Perspective

3.  Air's not perfectly transparent.

Lets assume the Earth is flat.  If you took a telescope and instead of pointing it at the sky, you changed the direction to be parallel with the Earth's surface, how come you can't see a building in Tokyo, Japan when you're in San Diego, California?

You are assuming that the horizon is located an infinite distance away. It's not.

If the horizon were located an infinite distance away that would mean that a distant ship on top of the ocean horizon would be an infinite distance away. It's not.

Hence, we see that the distance to the horizon is finite. As an analogy:

An ant has a horizon located a few inches away.

A mouse has a horizon located about six feet away.

A human has a horizon located about thirty miles away.

An eagle has a horizon located over a hundred miles away.

Ergo as we increase altitude we are increasing our vantage point. The horizon is finite, changing with our altitude. Thus, the higher we go, the farther we can see and detect.

In macro photography there is a limit to the horizon. It is usually on the range of feet depending on the height of the camera from the ground. Hence, sufficient proof that the distance to the horizon is finite, tied to the altitude of the observer.

Tom, reading what you said makes perfect sense in RE theory, but does not make sense if FE theory!

Quote

Lets assume the Earth is flat.  If you took a telescope and instead of pointing it at the sky, you changed the direction to be parallel with the Earth's surface, how come you can't see a building in Tokyo, Japan when you're in San Diego, California?

You are assuming that the horizon is located an infinite distance away. It's not.

If the horizon were located an infinite distance away that would mean that a distant ship on top of the ocean horizon would be an infinite distance away. It's not.

Hence, we see that the distance to the horizon is finite. As an analogy:

An ant has a horizon located a few inches away.

A mouse has a horizon located about six feet away.

A human has a horizon located about thirty miles away.

An eagle has a horizon located over a hundred miles away.

Ergo as we increase altitude we are increasing our vantage point. The horizon is finite, changing with our altitude. Thus, the higher we go, the farther we can see and detect.

In macro photography there is a limit to the horizon. It is usually on the range of feet depending on the height of the camera from the ground. Hence, sufficient proof that the distance to the horizon is finite, tied to the altitude of the observer.

I am not assuming the horizon is infinite.  I am, however, assuming that one can not see through an opaque object, such as a building.  If one is looking through a telescope from California to Japan, they could orient the telescope so that it is pointing directly at a building in Tokyo (assuming the Earth is flat).  I am wondering how FE explains the idea that one actually can't see a building in this scenario.

Air is not a vacuum.

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Lets assume the Earth is flat.  If you took a telescope and instead of pointing it at the sky, you changed the direction to be parallel with the Earth's surface, how come you can't see a building in Tokyo, Japan when you're in San Diego, California?

I suggest that you check out the great job Trekky did in the RE Primer on this question. It's experiment #0013.

Whats the RE Primer?

Whats the RE Primer?

Just on the links in my signature below. It's the concerted effort of a group of REers to document the arguments for RE and against FE.

Your link is broken. 

Your link is broken. 

Sorry. They took down the non-critical servers during a bad thunderstorm here. RoundEarth is back up now.

explain then how we can see Jupiter with a telescope with such detail whereas we cannot stand at the top of the empire state building and look through a telescope and see the Eiffel Tower....if the world were flat?? 

explain then how we can see Jupiter with a telescope with such detail whereas we cannot stand at the top of the empire state building and look through a telescope and see the Eiffel Tower....if the world were flat?? 

Mm, without putting much thought into it, and probably being incorrect:

"50% of the atmosphere by mass is below an altitude of 5.6 km.
...
99.99997% of the atmosphere by mass is below 100 km (almost all of it)." - Wikipedia

Because of this, along with the density of air at sea level, and the fact that it decreases with altitude, it's a lot easier to look into space; because there is less atmosphere in the way than if you were trying to look more than 100km horizontally. It will basically compound until you can't view anything through it anymore.

explain then how we can see Jupiter with a telescope with such detail whereas we cannot stand at the top of the empire state building and look through a telescope and see the Eiffel Tower....if the world were flat?? 

While there is some argument about the obscuring effect of looking through over a thousand miles of dense atmosphere, I suggest that you're basically correct in your challenge.

Trekky did a fantastic job, with the concerted effort of several REers, in documenting this challenge in the RE Primer Experiment #0013. I hope you'll read the write-up and review the great photographs. See my signature to get your copy of the current RE Primer.

The compounding effect of the dense atmosphere would also explain why even though the Earth is spherical, that you can't view stars directly above the horizon line, but can see it further above, as the density decreases.

The compounding effect of the dense atmosphere would also explain why even though the Earth is spherical, that you can't view stars directly above the horizon line, but can see it further above, as the density decreases.

Sorry, but that's wrong. You can see stars on the horizon. You need great observing conditions, though. I've seen stars below eye-level on the horizon on Maui. I've seen stars on the horizon over the Gulf of Mexico in Florida and Cozumel.

Now you're right that for most people and places you can't see low stars. It's not so much an effect of atmospheric density as it is light pollution.

Sorry, but that's wrong. You can see stars on the horizon. You need great observing conditions, though. I've seen stars below eye-level on the horizon on Maui. I've seen stars on the horizon over the Gulf of Mexico in Florida and Cozumel.

Now you're right that for most people and places you can't see low stars. It's not so much an effect of atmospheric density as it is light pollution.

Well, density, particles in the air, still obstruction. Although, I'd be interested if you have any pictures of stars directly on or above the horizon line. My short search yesterday didn't yield any results. 

There is a process astronomers use to help get rid of the distortion of light due to the atmosphere.  It is called Adaptive optics.  They point a laser in the direction they want to look at and a computer can somehow alter the image the astronomers get back to make it clearer.  It significantly increases the picture quality.  Now, the first person that knows an astronomer with this technology, or the first person that makes seven figures a year that reads this, please try and use this technology and see if we can see a building on the "other side of the world" (according to REers).  The Earth is round.

Quote from: Gulliver on August 23, 2007, 01:25:16 PM

Sorry, but that's wrong. You can see stars on the horizon. You need great observing conditions, though. I've seen stars below eye-level on the horizon on Maui. I've seen stars on the horizon over the Gulf of Mexico in Florida and Cozumel.

Now you're right that for most people and places you can't see low stars. It's not so much an effect of atmospheric density as it is light pollution.

Well, density, particles in the air, still obstruction. Although, I'd be interested if you have any pictures of stars directly on or above the horizon line. My short search yesterday didn't yield any results. 

Already done. See: My Post.

There is a process astronomers use to help get rid of the distortion of light due to the atmosphere.  It is called Adaptive optics.  They point a laser in the direction they want to look at and a computer can somehow alter the image the astronomers get back to make it clearer.  It significantly increases the picture quality.  Now, the first person that knows an astronomer with this technology, or the first person that makes seven figures a year that reads this, please try and use this technology and see if we can see a building on the "other side of the world" (according to REers).  The Earth is round.

How could firing a laser that eventually gets stopped by the air let you see farther?  If the light doesn't get to you, the light doesn't get to you.

I should have been more accurate. Being at near sea-level, stars will not appear (at least I haven't seen them) directly on or above the horizon line. Those pictures seem to be taken at significant altitude, and the second one seems to be more so vertical than horizontal.

Quote

Lets assume the Earth is flat.  If you took a telescope and instead of pointing it at the sky, you changed the direction to be parallel with the Earth's surface, how come you can't see a building in Tokyo, Japan when you're in San Diego, California?

You are assuming that the horizon is located an infinite distance away. It's not.

If the horizon were located an infinite distance away that would mean that a distant ship on top of the ocean horizon would be an infinite distance away. It's not.

Hence, we see that the distance to the horizon is finite. As an analogy:

An ant has a horizon located a few inches away.

A mouse has a horizon located about six feet away.

A human has a horizon located about thirty miles away.

An eagle has a horizon located over a hundred miles away.

Ergo as we increase altitude we are increasing our vantage point. The horizon is finite, changing with our altitude. Thus, the higher we go, the farther we can see and detect.

In macro photography there is a limit to the horizon. It is usually on the range of feet depending on the height of the camera from the ground. Hence, sufficient proof that the distance to the horizon is finite, tied to the altitude of the observer.

I laughed.

Which side are you supposed to be on again?

It's hard to tell if Tom is a troll or not. Or if he's atheist or not.