What about a telescope aimed at the horizon?

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29silhouette

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Re: What about a telescope aimed at the horizon?
« Reply #150 on: January 28, 2014, 10:04:14 AM »
Yes, it depends on those factors because the horizon for an observer with an unaided eye is not as distant as the horizon for an observer with an optical device.  If the ship is moving away from the observer, eventually it WILL disappear.  UNLESS you INCREASE your magnification.  No, I have never tried it myself.
So no actual experience with any of this.  Noted.

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  I use the knowledge I have in my brain already.  ;D
Is this why we're still waiting for that simple 2D diagram of how a tennis ball starts disappearing across a living room floor?  Or why you were so confused about the 'Earth's tilt' diagrams from your other thread?

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This is why 29's photos above are not valid.  He didn't zoom in enough to see the entire ship.
The photographer did zoom in.  Nothing changed.  The bottom half was still obscured.  Zooming in further would not have changed that.

Re: What about a telescope aimed at the horizon?
« Reply #151 on: January 28, 2014, 10:06:11 AM »
It's a pity because if you tried, you'd be quite a bit shaken in your beliefs.  I disagree.
But because it's unlikely that you will go out and try it in the coming hours :-), let's move on a little bit. A ship is hard to see in the distance because all we can rely on are the reflected light rays coming through the atmosphere. So, what about the sun that, we all agree about that no doubt, has enough light to be visible from quite some distance? Have you ever tried this little experiment I started with, lying down flat, jumping up when it settles and see it settle once more?
I don't have to.  I already know that visible distance increases with height. The sunset is the exact same illusion as the ship.  If you had a strong enough lens, you could watch it move away from you and all the way back around to you.

Re: What about a telescope aimed at the horizon?
« Reply #152 on: January 28, 2014, 10:12:20 AM »
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This is why 29's photos above are not valid.  He didn't zoom in enough to see the entire ship.
The photographer did zoom in.  Nothing changed.  The bottom half was still obscured.  Zooming in further would not have changed that.
Oh YOU didn't take those photos?  Then you know nothing about the photographer's camera and settings, do you?  Well he probably had a Fixed Focal length.  You're one to talk about not having experience.  You admitted you aren't a professional photographer.
http://www.photomodeler.com/kb/entry/65/

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #153 on: January 28, 2014, 10:23:01 AM »
I already know that visible distance increases with height.

That's hardly a correct answer. Sunset is not a linearly gradual phenomenon. You see the sun for many hours and then, in the course of a couple of minutes, it disappears completely, very suddenly when compared to its previous display. What you say about my experiment can only be explained in two ways within the confines of your beliefs:

First version: visibility is not gradual. There is a specific distance where visibility suddenly changes from visible to invisible. When you follow the setting sun, you can see it up to the very end. Then come a couple of seconds during which time the sun completely disappears (although you can still see light reflections for quite a few minutes, so this version somehow implies that the visiblity of the sun already ceased while the visiblity of its emitted light still prevails).

Second version: just at the time of the sunset, the sun suddenly changes its position and instantly jumps much farther, out of your visibility range (however, just like in the first case, you can still see light reflections for quite a few minutes).

Pick the one you like better.
« Last Edit: January 28, 2014, 10:30:54 AM by reofcourse »

Re: What about a telescope aimed at the horizon?
« Reply #154 on: January 28, 2014, 10:38:10 AM »
Neither version.  In your model, if the sun is not seen at sunset or sunrise, there would be no residual light.  The Earth would BLOCK it.  There is though...because even though the sun has been visually compressed by the horizon to where you no longer see it, the light still travels for miles until it gets dark.  Now all you REs, tell me how light bends in your model because that is what light has to do if it moves below the curvature of the Earth.  Remember, I'm talking about how light is still visible even when the sun itself is not.

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inquisitive

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Re: What about a telescope aimed at the horizon?
« Reply #155 on: January 28, 2014, 10:42:58 AM »
Neither version.  In your model, if the sun is not seen at sunset or sunrise, there would be no residual light.  The Earth would BLOCK it.  There is though...because even though the sun has been visually compressed by the horizon to where you no longer see it, the light still travels for miles until it gets dark.  Now all you REs, tell me how light bends in your model because that is what light has to do if it moves below the curvature of the Earth.  Remember, I'm talking about how light is still visible even when the sun itself is not.
Look up atmospheric optics.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #156 on: January 28, 2014, 10:46:45 AM »
Remember, I'm talking about how light is still visible even when the sun itself is not.

Wait a minute, wait a minute. I'll gladly do it but let's move in an orderly fashion. We should discuss the main phenomenon first, shouldn't we? The sun itself. Let's find a plausible explanation of why the sun is visible for quite some time and then it disappears so suddenly. It has to go out of your visibility range, there is no other place it can escape to so that you won't see the massive amount of light it radiates. What happens in those few seconds around sunset? How does it transform from a setting but still very much visible Sun to invisible in a matter of seconds?
« Last Edit: January 28, 2014, 10:49:44 AM by reofcourse »

Re: What about a telescope aimed at the horizon?
« Reply #157 on: January 28, 2014, 10:49:23 AM »
Look up atmospheric optics.
Thanks.  Very informative 
"They are bent and twisted around the very rim of the Earth."
http://www.atoptics.co.uk/atoptics/sunsets.htm

Re: What about a telescope aimed at the horizon?
« Reply #158 on: January 28, 2014, 10:54:56 AM »
Wait a minute, wait a minute. I'll gladly do it but let's move in an orderly fashion. We should discuss the main phenomenon first, shouldn't we? The sun itself. Let's find a plausible explanation of why the sun is visible for quite some time and then it disappears so suddenly. It has to go out of your visibility range, there is no other place it can escape to so that you won't see the massive amount of light it radiates. What happens in those few seconds around sunset? How does it transform from a setting but still very much visible Sun to invisible in a matter of seconds?
It moves at the same speed at sunset as it does across the sky during the day.  It may seem to move faster on the horizon only because it's movement is more obvious with the Earth in it's foreground.  In the sky, you have no static objects to compare it to.

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Spank86

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Re: What about a telescope aimed at the horizon?
« Reply #159 on: January 28, 2014, 10:57:11 AM »
Neither version.  In your model, if the sun is not seen at sunset or sunrise, there would be no residual light.  The Earth would BLOCK it.  There is though...because even though the sun has been visually compressed by the horizon to where you no longer see it, the light still travels for miles until it gets dark.  Now all you REs, tell me how light bends in your model because that is what light has to do if it moves below the curvature of the Earth.  Remember, I'm talking about how light is still visible even when the sun itself is not.

You can still see at night, all night.

Unless you're under a thick tree canopy of course.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #160 on: January 28, 2014, 10:58:06 AM »
It moves at the same speed at sunset as it does across the sky during the day.  It may seem to move faster on the horizon only because it's movement is more obvious with the Earth in it's foreground.  In the sky, you have no static objects to compare it to.

OK, we agree. But still, you hasn't mentioned a word about what happens at sunset. Why does it disappear so suddenly? There is a reddish glowing something at the horizon, we all know that. But what actually happens when it goes out of sight in the last seconds of the sunset?

Re: What about a telescope aimed at the horizon?
« Reply #161 on: January 28, 2014, 11:09:28 AM »
I recommend muting this but here is an excellent video of the sun compressing as it sets.
" class="bbc_link" target="_blank" rel="noopener noreferrer">

But what actually happens when it goes out of sight in the last seconds of the sunset?
It's moving farther away from the observer.
« Last Edit: January 28, 2014, 11:14:44 AM by EarthIsASpaceship »

Re: What about a telescope aimed at the horizon?
« Reply #162 on: January 28, 2014, 11:22:55 AM »
Neither version.  In your model, if the sun is not seen at sunset or sunrise, there would be no residual light.  The Earth would BLOCK it.  There is though...because even though the sun has been visually compressed by the horizon to where you no longer see it, the light still travels for miles until it gets dark.  Now all you REs, tell me how light bends in your model because that is what light has to do if it moves below the curvature of the Earth.  Remember, I'm talking about how light is still visible even when the sun itself is not.
You can still see at night, all night.
You know, this got me to thinking....this is off topic but I just want to mention this.  If you look at images of the sun from space or check out the FULL version of Felix B's jump and notice how small the sun is.....it is TINY.  It does not emit much light at all!  So to say that it lights up an entire half of the Earth just doesn't make sense.

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Spank86

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Re: What about a telescope aimed at the horizon?
« Reply #163 on: January 28, 2014, 11:35:57 AM »
Neither version.  In your model, if the sun is not seen at sunset or sunrise, there would be no residual light.  The Earth would BLOCK it.  There is though...because even though the sun has been visually compressed by the horizon to where you no longer see it, the light still travels for miles until it gets dark.  Now all you REs, tell me how light bends in your model because that is what light has to do if it moves below the curvature of the Earth.  Remember, I'm talking about how light is still visible even when the sun itself is not.
You can still see at night, all night.
You know, this got me to thinking....this is off topic but I just want to mention this.  If you look at images of the sun from space or check out the FULL version of Felix B's jump and notice how small the sun is.....it is TINY.  It does not emit much light at all!  So to say that it lights up an entire half of the Earth just doesn't make sense.

most images of the sun are through filters for obvious reasons.

It's also worth noting that small and very far away can be quite interchangeable in the absence of any frame of reference.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #164 on: January 28, 2014, 11:50:07 AM »
It's moving farther away from the observer.

That it does for sure. However, what interests me most is what happens in the last seconds. Up to then, it loses its brightness rather gradually. In the last hour of the day, approximately, it becomes gradually dimmer and dimmer. Still, it doesn't simply fade into oblivion at the end of the day. It is, although much less bright than during the day, is still sufficiently bright to show a nice, orange-reddish glowing object that disappears much more rapidly during the last phase than it was dimming earlier. This speeding up of the disappearing process is what intrigues me and, unfortunately, we yet failed to find an explanation for it, didn't we?

To formulate it slightly differently: why does it jump suddenly out of our visibility range when it was moving away from us steadily but nearly not as abruptly?

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Spank86

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Re: What about a telescope aimed at the horizon?
« Reply #165 on: January 28, 2014, 12:05:14 PM »
It's moving farther away from the observer.

That it does for sure. However, what interests me most is what happens in the last seconds. Up to then, it loses its brightness rather gradually. In the last hour of the day, approximately, it becomes gradually dimmer and dimmer. Still, it doesn't simply fade into oblivion at the end of the day. It is, although much less bright than during the day, is still sufficiently bright to show a nice, orange-reddish glowing object that disappears much more rapidly during the last phase than it was dimming earlier. This speeding up of the disappearing process is what intrigues me and, unfortunately, we yet failed to find an explanation for it, didn't we?

To formulate it slightly differently: why does it jump suddenly out of our visibility range when it was moving away from us steadily but nearly not as abruptly?

The only way it works is if you consider light to have a ballistic trajectory.

Or at least that refraction or other effects make it seem to.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #166 on: January 28, 2014, 12:11:20 PM »
The only way it works is if you consider light to have a ballistic trajectory.

Sorry, that still doesn't cut it for me. No matter how it goes away from me, considering that it can't disappear (I might not be able to see it if it's too far away but it's there somewhere, isn't it?), I'd very much expect to see it at least to dim back to something like the stars before I actually stop being able to see it at all. After all, stars are smaller, much less bright and I can still see them with the naked eye. What happens to the Sun that it suddenly skips all those brigthness grades between its sunset shape and the brightness (or dimness) grade of the stars and even beyond?
« Last Edit: January 28, 2014, 12:18:04 PM by reofcourse »

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Spank86

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Re: What about a telescope aimed at the horizon?
« Reply #167 on: January 28, 2014, 12:45:47 PM »
The only way it works is if you consider light to have a ballistic trajectory.

Sorry, that still doesn't cut it for me. No matter how it goes away from me, considering that it can't disappear (I might not be able to see it if it's too far away but it's there somewhere, isn't it?),

But if light had a ballistic trajectory, it could disappear.


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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #168 on: January 28, 2014, 12:57:57 PM »
But if light had a ballistic trajectory, it could disappear.

By saying that "it can't disappear" I didn't mean I would always see it. I meant that it couldn't actually cease to exist or move away from its actual physical position. The sun stays above the horizont, just goes too far for us to be able to see it, right? But its general direction five minutes after sunset couldn't be radically different from its direction five minutes before that time, couldn't it?
« Last Edit: January 28, 2014, 01:14:42 PM by reofcourse »

Re: What about a telescope aimed at the horizon?
« Reply #169 on: January 28, 2014, 03:02:20 PM »
most images of the sun are through filters for obvious reasons.
Not the ones taken from cell phones on helium balloons.  You must be talking about the close ups that show it in colors other than white.  The sun in Felix B's jump was white.
« Last Edit: January 28, 2014, 03:08:33 PM by EarthIsASpaceship »

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Scintific Method

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Re: What about a telescope aimed at the horizon?
« Reply #170 on: January 28, 2014, 03:23:59 PM »
Interesting to see where this conversation has ended up since this comment was made:

Then why is it that the sun at sunset is the same (measurable) size as at midday, and too intense to look at, then 5 minutes later is completely out of sight?
That has nothing to do with this topic.

So, just before dawn, the sky grows brighter and brighter thanks to Rayleigh Scattering, then the sun rises. As soon as the sun becomes visible, it is too bright to look at directly with any comfort (assuming clear conditions). It remains about this bright for the entire day (12 hours on average), until it sets, at which time it is still too intense to look directly at safely until it has completely vanished (which happens in a matter of minutes or seconds, depending on your latitude). I still have yet to see a plausible explanation of how this can happen on a flat earth.
Quote from: jtelroy
...the FE'ers still found a way to deny it. Not with counter arguments. Not with proof of any kind. By simply denying it.

"Better to keep your mouth shut and be thought a fool, than to open it and remove all doubt."

Re: What about a telescope aimed at the horizon?
« Reply #171 on: January 28, 2014, 03:59:19 PM »
Sorry, that still doesn't cut it for me. No matter how it goes away from me, considering that it can't disappear (I might not be able to see it if it's too far away but it's there somewhere, isn't it?), I'd very much expect to see it at least to dim back to something like the stars before I actually stop being able to see it at all. After all, stars are smaller, much less bright and I can still see them with the naked eye. What happens to the Sun that it suddenly skips all those brigthness grades between its sunset shape and the brightness (or dimness) grade of the stars and even beyond?
It's good that you are interested enough to ask these questions.  Before I explain what I think happens, let me ask this.  Have you ever seen the sun on the horizon through one of those huge telescopes the observatories use?

Re: What about a telescope aimed at the horizon?
« Reply #172 on: January 28, 2014, 04:02:29 PM »
So, just before dawn, the sky grows brighter and brighter thanks to Rayleigh Scattering, then the sun rises. As soon as the sun becomes visible, it is too bright to look at directly with any comfort (assuming clear conditions). It remains about this bright for the entire day (12 hours on average), until it sets, at which time it is still too intense to look directly at safely until it has completely vanished (which happens in a matter of minutes or seconds, depending on your latitude). I still have yet to see a plausible explanation of how this can happen on a flat earth.
No, the sun is MUCH dimmer on the horizon.  And yes, you're right about the topic changing.  That happens when people continue to ask questions off topic.

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29silhouette

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Re: What about a telescope aimed at the horizon?
« Reply #173 on: January 28, 2014, 10:42:36 PM »
Oh YOU didn't take those photos?
A keen eye for the obvious you have there.  'Pitdroidtech' being the name in the quote and all.

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Then you know nothing about the photographer's camera and settings, do you?  Well he probably had a Fixed Focal length.
Or he probably didn't.  He claimed different magnifications for the pictures he took (a lot more than the four I posted).  I don't remember if he stated what camera was used.  Probably a higher-end point and shoot with a fixed lens and high power optical zoom, as he mentions 1x, 8x, and 28x, vs 55mm, 100mm, or 300mm... unless he actually bothered with converting it.  I might go back and check tomorrow.

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You're one to talk about not having experience.
I've looked at 'sinking' ships and such before with various levels of magnification.  Have you? "No", you say?  Then I guess I have more experience.

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You admitted you aren't a professional photographer.
Again you shock us with your ability to point out the obvious.  Indeed, I never claimed to be a 'professional' photographer.  I consider a photographer to be someone who knows all aspects of photography and has a camera capable of a wide range of shots in a wide range of conditions, but that's just my opinion.  I know enough to get by, and could get some good shots with a DSLR after some minor experimenting as I already know what basically needs to be set for what, but I don't own a DSLR.  I've taken some delayed exposure shots, star trails, etc, but it was with an older 35mm SLR.  I know a few people who are 'photographers', and they know a lot more than me and have way better cameras.  I also know people who have point and shoots, but don't even know the difference between optical and digital zoom, what macro is or how to use it, or even how to turn their flash on or off and how to hold it steady to make the most of natural lighting, etc etc, but they consider me a borderline pro when I'm explaining this stuff to them.

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http://www.photomodeler.com/kb/entry/65/
Yep.


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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #174 on: January 29, 2014, 02:49:31 AM »
It's good that you are interested enough to ask these questions.  Before I explain what I think happens, let me ask this.  Have you ever seen the sun on the horizon through one of those huge telescopes the observatories use?

Yes, I have. Although it was decades ago and there were significant advances in this area, today I can see a multitude of images taken by the more powerful telescopes of today. And I have absolutely no problem in accepting photographic evidence with the same amount of proofing force as my own individual experience (not without criticism, of course, but I learned to differentiate). I never subscribed to conspiracy theories, especially not those that claim that facts that can easily be verified by practically anybody on the planet can be massively falsified. There are some areas of life where, even if I don't believe in those conspiracies, the fact remains that although mass falsification is very unlikely, at least it's not logically impossible. In the case of the shape of the Earth, it is impossible.

Still, I'd be very much interested to hear your answers to the actual questions I asked.

Re: What about a telescope aimed at the horizon?
« Reply #175 on: January 29, 2014, 07:45:57 AM »
Can you describe it?  Did they already have the sun in the scope for you to view?  How long were you able to watch the sun on the horizon?  What did it look like?  If sunspots can be seen on the sun through a cell phone/digital camera, I suspect you could see solar flares and details that resemble the solar satellite images.

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Novice

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Re: What about a telescope aimed at the horizon?
« Reply #176 on: January 29, 2014, 07:53:08 AM »
A naked eye observer has an angular resolution of approximately 1 arcminute. This observer sees a ship on his horizon. That ship is sailing away from him and starts to disappear from view, hull first, until it finally disappears altogether. This is touted as being proof of the World’s curvature.

If the ship is restored to view by use of a telescope at the same altitude as the observer’s eye then it is not proof at all.

In the following video, posted again by EarthIsASpaceship,
" class="bbc_link" target="_blank" rel="noopener noreferrer">

The naked-eye observer corresponds to the time of 24s into the video, when the ship appears on the horizon. Watching to the end of the video, we see the ship disappear ‘over the horizon’, hull first. Proof? No, because the rest of the video clearly shows that the horizon is taken far further away by use of a zoom lens. The same effect is clearly seen with the other ship (or rig), to the right of the main ship.

The disappearing ship (hull first) is therefore no proof of the World’s alleged rotundity. We can surely all agree on that one?

"I should rather be right and stand alone than run with the multitude and be wrong." C. S. de Ford.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #177 on: January 29, 2014, 07:56:31 AM »
Can you describe it?

Hardly after all these years and I met way too many other sun photos since to be able to tell what I saw back then for sure. It must have been something about the sunspots for sure because sun activity and radio wave propagation was a hot topic then.

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reofcourse

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Re: What about a telescope aimed at the horizon?
« Reply #178 on: January 29, 2014, 08:03:28 AM »
The disappearing ship (hull first) is therefore no proof of the World’s alleged rotundity. We can surely all agree on that one?

No, unfortunately, we can't agree on that one. Because, just like I already mentioned it earlier, there is absolutely no need to check this out both with and without zooming, and make comparisons. It is of absolutely no importance what you can see with the naked eye and whether your eyesight is good or bad in this respect. You would be completely free to observe the movement of the ship fully and totally with an already zoomed camera (telescope, whatever) and still see the phenomenon. Actually, it would be more than recommended to do so because, I repeat, this is not a question of eyesight.

Re: What about a telescope aimed at the horizon?
« Reply #179 on: January 29, 2014, 08:11:47 AM »
The horizon will forever increase as long as the scope increases.  Therefore, the horizon is relative.