The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Q&A => Topic started by: DragonXero on November 23, 2006, 10:23:08 PM
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Look, I'm not really well-versed in science, but I do know empirical data when I see it. Yes, it's interesting that light rays seem to shine down in a wide spread (though I have seen brilliant explainations for this that I'd need to look up, and it's not my argument anyway), but there's something I can't explain with the flat-earth theory. I've seen it at the beach more than once, with the naked eye and with the zoom on my camera. This isn't just the fact that the water looks to have a noticable curve when you look out at the ocean, but more to do with ships sailing out near the horizon. I've seen ships pop up and down over the horizon before. They're relatively close since I can still make out that they're ships, and see them get covered up by the water. Looks almost like they're sinking. Now, wouldn't something fade slowly as it gets further and further away if distance was the reason they disappeared?
Anyway, I may not even come back to check any replies to this, just thought I'd spark it up as a discussion topic.
I'd love to be able to take a picture of the stars moving in a circle, but I don't have an SLR, and my digital only takes a grand total of 15 seconds worth of exposure. One of the limitations of even higher-end point 'n shoots.
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The distance you can see is a function of the weather. On a clear day, you can see Calais from Dover, a distance of some 20 miles.
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The distance you can see is a function of the weather.
Not true, it is a result of the earth's curvature. The FE does not offer a valid explanation for this. Please see below for proof of a curvature:
http://en.wikipedia.org/wiki/Horizon
http://newton.ex.ac.uk/research/qsystems/people/sque/physics/horizon/
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I believe the term is "0wn3d"
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The distance you can see is a function of the weather.
Not true, it is a result of the earth's curvature.
Did you misunderstand the proposition?
Have you not noticed you can see further on a clear day, than in the rain?
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Did you misunderstand the proposition?
Have you not noticed you can see further on a clear day, than in the rain?
Yes, you can see further on a clear day than in the rain.
Do you have a point?
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Yes, you can see further on a clear day than in the rain.
Hence, the distance you can see is a function of the weather.
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Yes, you can see further on a clear day than in the rain.
Hence, the distance you can see is a function of the weather.
Unfortunately, that has nothing to do with the initial question posed... I thought you were attempting to answer it, not start a new topic in an already-defined thread.
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FFS Sara H B Ranson, just for you we will assume that it is a clear day.
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Unfortunately, that has nothing to do with the initial question posed....
Yes it does. It's the reason you cannot see an infinite distance over the sea - water wapour in the air.
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Unfortunately, that has nothing to do with the initial question posed....
Yes it does. It's the reason you cannot see an infinite distance over the sea - water wapour in the air.
Clearly it doesn't, since the initial question did not refer to infinite distances over the sea. It made reference to ships disappearing beyond the horizon and to the horizon line being curved.
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I'd really hoped for a thoughtful answer to the question. Though, in a sense, part of my question set was somewhat answered. The noticable curvature of the earth on even a perfectly clear day is explained here as being water vapor over the ocean obscuring your view. And if you know anything about three-dimensional viewing, you will recognize that sight is radial. Now, I'm not going to put too much effort into this theory (I'll leave the flowering of it to the FE'rs), but the distance you can see would be slightly lessened to the left and right of dead center. Imagine a completely dark room with a single, sharply-focussed light shining down, centered on you. All you see is white, and at the edge, black. The light's circle defines your depth of vision. You wouldn't see it as a circle looking straight ahead. It would look somewhat like the curved edge of a sphwere, I imagine. Even more so if the spotlight was enormous and you were still standing there in the center.
Of course, this is all speculation as I've never done the experiment. It'd be interesting to try. Anything to further playful debate.
Though, none of this answers the second part of my post: Why do boats appear to bob in and out of the sea at the horizon? Don't even think you can explain that one with visibility issues. I have clearly seen ships sink below the horizon line. And I damn well know they didn't fall off the side.
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Ships disappear beyond the horizon due to the fact that the earth is curved. That's precisely what I stated initially.
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Sh. Trying to get an explaination out of those who don't foolishly believe that gravity naturally makes spheres due to its omnidirectional effect. :P
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Ships disappear beyond the horizon due to the fact that the earth is curved. That's precisely what I stated initially.
Ships disappear because water saturation of the air prevents you seeing that far.
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Ships disappear because water saturation of the air prevents you seeing that far.
That has already been refuted in the initial post:
They're relatively close since I can still make out that they're ships, and see them get covered up by the water.
Since it is stated that they are "relatively close" and that their shape can still be observed, that means they do not disappear because of eye-sight hindrance, but another reason (curved horizon). You are going around in circles.
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That'd be a fine explaination if I could see the ship gradually fading out at the horizon. Hell, it'd even work (poorly) if I saw them just blink out of view. But I SEE THEM SINK UNDER THE HORIZON LINE. Just like when the moon goes down and you see that magical white circle slowly sink below the horizon as though it's going underneath the earth.
Stop avoiding the question.
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That'd be a fine explaination if I could see the ship gradually fading out at the horizon. Hell, it'd even work (poorly) if I saw them just blink out of view. But I SEE THEM SINK UNDER THE HORIZON LINE. Just like when the moon goes down and you see that magical white circle slowly sink below the horizon as though it's going underneath the earth.
Stop avoiding the question.
I understand that's not addressed to me. :D
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Musta posted at about the same time. No, not directed at you. :P
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But I SEE THEM SINK UNDER THE HORIZON LINE.
Having worked at sea I can only say I do not think you do.
On a clear day you can see over 20 miles. That's a bit far to determine if the largest super tanker is falling or fading.
Most days you cannot see 20 miles, or even 10. So ships fade, not fall, under both RE and FE theory.
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But I SEE THEM SINK UNDER THE HORIZON LINE.
Having worked at sea I can only say I do not think you do.
On a clear day you can see over 20 miles. That's a bit far to determine if the largest super tanker is falling or fading.
Most days you cannot see 20 miles, or even 10. On most days, the ships fade under both RE and FE theory.
At this point of time you can use binoculars or a telescope; obviously a ship sinking beyond the line of horizon is governed by the same property as the sun sinking beyond the line of horizon. Thus, you only see part of it "sinking", not the entire object. In conclusion, sea vapors are still not a valid point.
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Well, what you think I've seen and what I think I've seen seem to be out of phase here.
I'll trust my eyes and binoculars and not yours on this one.
As for atmosphere, where do you live? I live in Northern California, where the water is extremely cold as it is flowing down (or out, depending on your worldview) from alaska. Now, maybe I'm remembering incorrectly, but I believe I've read that cold air provides a better medium of travel for light. So I'd venture a guess that cold air/water = Greater distance of sight.
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Well, what you think I've seen and what I think I've seen seem to be out of phase here.
I'll trust my eyes and binoculars and not yours on this one.
As for atmosphere, where do you live? I live in Northern California, where the water is extremely cold as it is flowing down (or out, depending on your worldview) from alaska. Now, maybe I'm remembering incorrectly, but I believe I've read that cold air provides a better medium of travel for light. So I'd venture a guess that cold air/water = Greater distance of sight.
Again, directed at Sara H B Ranson (I noticed he/she is a little confused on who the replies are written to).
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Well, what you think I've seen and what I think I've seen seem to be out of phase here.
I'll trust my eyes and binoculars and not yours on this one.
You should not trust me at all. You must work things out for yourself, as you've said.
So I'd venture a guess that cold air/water = Greater distance of sight.
Ice gives off water vapour, so you'll never get 100% clarity at sea. Telescopes and binoculars cannot penetrate water vapour.
I dunno what the arguments are for camels in the desert.
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I didn't say ice, I said extremely cold water. Above 0C, but still cold enough to put someone into hypothermia.
I have never been in a large, featureless desert before, so I can't attest to the same phenomena occuring there. I'd assume it does though.
And going to a large, featureless desert would certainly show an interesting amount of earth curvature, unexplainable by water mist.
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Here's an interesting view...
http://www.duck.org/flatearth/ships.asp
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Interesting but just from a quick estimate (I'd need someone with some real math skills and a lot of knowledge of physics to back this up) I would say that it's not satisfactory.
Though, at least it's a solid, real answer to my question. A refutable answer is still an answer.
Why refutable? The theory of "gravity lenses", or gravity bending light, is in reference to celestial bodies over millions of miles, and the light is bent very little even over these astronomical distances.
In fact, the theory has a lot of evidence to support it. We see certain things we really shouldn't see in space. They really should be behind other things. (sorry I'm not being too technical, can't be arsed to look up the names and such right now) Yet, we see them. The theory is that gravity is slightly bending the lightwaves/particles, which ends up letting us on Earth have a peek around the corner, so to speak.
Still, thanks for providing some kind of answer, finally. :)
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Still, thanks for providing some kind of answer, finally. :)
It's the only respectable attempt at an answer that I was able to find...
Anyone else have any links?
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Hey, you did good. It's certainly convincing at first glance. When I first hit the page I was like "well, hell, that's pretty good".
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One little note. This question is one of the reasons Aristotle first suspected something might be amiss with the flat earth cosmology. I had completely forgotten about that.
Some of the others have to do with mathematics, so I'm sure this was what started his insane rush for a round earth.
That crazy old coot with his golf cart and buffet meal ticket.
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Wait a sec... How can gravity bend the light down so that you can't see all of a ship if gravity doesn't exist? >> << >> I thought we were all just accelerating upwards at 1g.
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Wait a sec... How can gravity bend the light down so that you can't see all of a ship if gravity doesn't exist? >> << >> I thought we were all just accelerating upwards at 1g.
Fine, it's not bending down from gravity, it's bending down in our reference frame due to the fact we're accelerating. It's still complete bull.
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Yeah, but light would bounce between the icewalls some 16 time before it would even get remotely close to the ground if it started off going horizontal from the top of a mast. Let's assume the mast is 7 meters tall and our observer is 2 meters tall. So, light needs to fall roughly 5 meters for it to "disappear."
Pos(final) = Pos(initial) + Vel(Inital)*Time + 1/2*Accel*time^2
5 = 0 + 0*X + 1/2*10*X^2
5 = 5*X^2
1 = X^2
1 = X
So, it would take exactly one second to fall from the top of the mast to below this person's like of sight. Light travels at C, or roughly 8000000 meters a second. Therefore, the ship would have to be roughly 8,000 kilometers away.
The Earth's circumfrence, pole to pole... Or very close to northernhub to ice wall... Is roughly 40000 km. Thus, the ship would need to be 1/5 of the way "across" the world. I have difficulty people can see across the atlantic. ^^;;
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Wait a sec... How can gravity bend the light down so that you can't see all of a ship if gravity doesn't exist? >> << >> I thought we were all just accelerating upwards at 1g.
Fine, it's not bending down from gravity, it's bending down in our reference frame due to the fact we're accelerating. It's still complete bull.
Again, reaching well beyond my knowledge here, but I would guess that it wouldn't work the same with inertia causing the downward pull as it would with gravit causing it. Light is affected by gravity. I don't think the same can be said of inertia. Maybe I'm wrong, but I can only see two other ways of this going. The light falls off much more quickly than it could with gravity (since its initial speed, that of the earth when it was created, would be much less than the speed of the constantly accelerating earth), or the light would never fall off because its speed inexplicably keeps increasing with the earth.
Obviously the former theory is closer to what might actually happen, but I have a feeling there's some math that can easily disprove my little idea.
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Again, reaching well beyond my knowledge here, but I would guess that it wouldn't work the same with inertia causing the downward pull as it would with gravit causing it. Light is affected by gravity. I don't think the same can be said of inertia. Maybe I'm wrong, but I can only see two other ways of this going. The light falls off much more quickly than it could with gravity (since its initial speed, that of the earth when it was created, would be much less than the speed of the constantly accelerating earth), or the light would never fall off because its speed inexplicably keeps increasing with the earth.
Obviously the former theory is closer to what might actually happen, but I have a feeling there's some math that can easily disprove my little idea.
I'm not sure what you mean by "inertia" here - the distinction should really be between gravity and accelerating reference frames. However, light behaves the same way in either - this is another result of general relativity (actually it was always thought that light would appear to accelerate in an accelerating reference frame, but Einstein was the first to predict it would also accelerate in a gravitational field.)
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I was clumsily attempting to describe the behavior of light's motion in relation to a body like earth. Are you saying that light would fall off at the same distance on both models (gravity and accelerating body pushing everything at 1g)? I always thought that light was "bent" by gravity because of the electromagnetic force. I know that a gun fired on either model would end up with the bullet landing in the same place, but I didn't think light had the same properties.
Aside from the fact that it's moving at the speed of light, I thought it was also different from other particles. I mean, for one thing, it actually goes at the speed of light, continues to move at that speed (why?) and rather than stopping when it meets something of equal mass, deflects and goes in another direction at the same speed, apparently unaffected by friction.
Though I've heard of expierments where light was slowed by a huge factor, so I guess I know jack about light.
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Though I've heard of expierments where light was slowed by a huge factor, so I guess I know jack about light.
Light moves at different rates in different media. For example glass slows light more than atmosphere, and atmosphere slows light relative to it's speed in a vacuum. When people refer to the speed of light, they mean its speed in vacuum.
I was clumsily attempting to describe the behavior of light's motion in relation to a body like earth. Are you saying that light would fall off at the same distance on both models (gravity and accelerating body pushing everything at 1g)?
Yes, it would. Part of Einstein's Theory of General Relativity is that a uniformly accelerating reference frame is indistinguishable from a uniform gravitational field. No experiment can ever detect the difference between the two.
I always thought that light was "bent" by gravity because of the electromagnetic force.
No, gravity and the electromagnetic force are two very different things. Light is bent by gravity for the same reason that any other object is affected by gravity, more or less.
I know that a gun fired on either model would end up with the bullet landing in the same place, but I didn't think light had the same properties.
It does.
Aside from the fact that it's moving at the speed of light, I thought it was also different from other particles.
Oh, it certainly is!
I mean, for one thing, it actually goes at the speed of light, continues to move at that speed (why?)
(I'm going to assume we're in a vacuum to simplify matters for this explanation.) The classical explanation of why light always moves at the same velocity is a consequence of Maxwell's Equations. Light is really just vibrations in the electromagnetic field, and such vibrations propagate according to differential equations derived from Maxwell's equations, with the result that they always move at the same velocity (at least in vacuum - maxwell's equations become more complicated in different media). I'm not really sure about the quantum-mechanical explanation (it's possible that it's essentially the same, or quite different) and I don't really have a better explanation than this one.
Essentially it's always observed as moving at the same velocity, and it fits in with a consistent theory of physics, so it is so. We don't really know why it is beyond those facts.
That said, light does behave differently in a gravitational field/accelerating reference frame than ordinary matter does, because it does always move at the same speed. It bends, but does not change speed. So as the light is accelerated, it keeps moving at the speed of light, but in a slightly different direction due to the acceleration.
and rather than stopping when it meets something of equal mass, deflects and goes in another direction at the same speed, apparently unaffected by friction.
Or else is absorbed. There's no reason that it should be effected by friction. Other single particles are not affected by friction either. Friction is a large-scale phenomenon caused by the interactions of billions of atoms. Any single particle cannot by affected by friction - only large objects such as shoes or bacteria or DNA molecules* can.
*You have no idea how much of a kick I just got out of referring to 'large objects such as DNA molecules'.
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Thinking more clearly, I had already learned a lot of that stuff. Though I still wonder about certain aspects of light. I know waves and particles act differently, but it seems to me that the same effect we use on long-range satellites (slingshotting, basically) should work on ilght. In that case, I would expect any measurment of distance gained from light that's been bent by gravity should need to be slightly adjusted for this alteration of speed...
And forgive me if I'm wrong, but hasn't light been observed to have the properties of both waves and particles?
Also, to explain my notions of electromagnetic fields and such, I was under the impression that it was thought that gravity was electromagnetic like light, gamma radiation and satellite signals (which apparently don't exist. Tee hee.)
Of course, I'm pretty sure that all has to do with attempts to create a unified field theory. I say we should stick with curing AIDS and VR similar to the Matrix, without the dying etc.
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it seems to me that the same effect we use on long-range satellites (slingshotting, basically) should work on ilght. In that case, I would expect any measurment of distance gained from light that's been bent by gravity should need to be slightly adjusted for this alteration of speed...
The speed of light is always the same, regardless of the relative speed of source and emitter. If we bounce a light signal off an object, the distance to that object is half the total transit time, scaled by the speed of light. You will get the same value for distance if you use a really long meter stick to measure it.
Also, to explain my notions of electromagnetic fields and such, I was under the impression that it was thought that gravity was electromagnetic like light, gamma radiation and satellite signals (which apparently don't exist. Tee hee.)
While there are attempts to unify gravity with electromagnetism, no testable solution has been proposed. At this point in time, the only similarity between gravity and electromagnetic fields is that changes in those fields propagate through space at the speed of light.
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See http://theflatearthsociety.org/forums/viewtopic.php?t=6680 for another explanation of the ship example.
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Here's an interesting view...
http://www.duck.org/flatearth/ships.asp
That, my friend, is HORSESHIT.
The mass of the Earth is NOT ENOUGH to bend light in ANY measurable way. Even the sun can only bend light by a FRACTION of a degree. Only large galaxies / black holes can bend light in a directly observable fashion.
This blatant mutilation of scientific theories is the reason Flat-Earthers will NEVER be accepted. Get your act together, all of you.
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Light is NOT bent directly by gravity.
The force of gravity = GMm/r^2
G = Constant of Gravitation
M = mass of object 1 (planet or whatever)
m = mass of object 2 (in this case, a photon)
r = distance between objects
it requires two masses, and since light has no mass, gravity cannot exert a force on light.
Einstein's Theory of General Relativity states that "Matter bends spacetime" much like a bowling ball on a rubber sheet. The light is bent by the distortions in spacetime caused by a sufficiently large mass, i.e. a galaxy. Gravity does NOT exert a force on light.
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Only large galaxies / black holes can bend light in a directly observable fashion.
Not really, a brown dwarf is enough for microlensing.
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Light is NOT bent directly by gravity.
The force of gravity = GMm/r^2
G = Constant of Gravitation
M = mass of object 1 (planet or whatever)
m = mass of object 2 (in this case, a photon)
r = distance between objects
it requires two masses, and since light has no mass, gravity cannot exert a force on light.
Einstein's Theory of General Relativity states that "Matter bends spacetime" much like a bowling ball on a rubber sheet. The light is bent by the distortions in spacetime caused by a sufficiently large mass, i.e. a galaxy. Gravity does NOT exert a force on light.
I like your selective, patch-work explanation.
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Explain it then!
Since you obviously know something that I don't, maybe you could share it with the class. Instead of posting sarcastic comments, enlighten us!
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Pick a theory. What is gravity? Is it a force that only acts on objects with mass, or is it the acceleration of objects due to the curvature of space?
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Explain it then!
Sorry, I'm losing track of the conversation. Which bit do you need explained?
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I thought you were an engineer? Shouldn't you know that?
Gravity is a force exerted on an object with mass. Mass is believed to curve spacetime, according to General Relativity. This curving effect would produce a gravitational attraction towards a large body.
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Light is NOT bent directly by gravity.
The force of gravity = GMm/r^2
G = Constant of Gravitation
M = mass of object 1 (planet or whatever)
m = mass of object 2 (in this case, a photon)
r = distance between objects
it requires two masses, and since light has no mass, gravity cannot exert a force on light.
Einstein's Theory of General Relativity states that "Matter bends spacetime" much like a bowling ball on a rubber sheet. The light is bent by the distortions in spacetime caused by a sufficiently large mass, i.e. a galaxy. Gravity does NOT exert a force on light.
I like your selective, patch-work explanation.
Explain it then!
Since you obviously know something that I don't, maybe you could share it with the class. Instead of posting sarcastic comments, enlighten us!
Pick a theory. What is gravity? Is it a force that only acts on objects with mass, or is it the acceleration of objects due to the curvature of space?
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Gravity has no effect on light.
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Gravity has no effect on light.
bullshit! gravity bends light around objects. this is particulary evedent around massive objects. check out this article from wikipedia.
http://en.wikipedia.org/wiki/Gravitational_lensing
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I stand corrected.