The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: spherical on May 24, 2019, 08:28:23 PM
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"Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance."
I am particular interested in someone that created such text above, to explain to me the science behind such (underlined) statement.
I can push an image photons through a denser medium, for instance a glass lens, and make the object appear bigger. Your wiki statement is incorrect.
Also, what is the meaning of "because the light is refracted towards the normal"? what is "normal"?
To finish, what is the "certain distance" in kilometers that it is impossible to see through because air is not transparent?
Where all this information came from? it is the wild guessing of somebody or it is multiple times science lab tested, duplicated, recorded and published?
Please provide source evidence.
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Please propose a replacement if you think it is incorrect.
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Please propose a replacement if you think it is incorrect.
It's hard to propose a replacement for something where the meaning is unknown to begin with. What is this statement trying to convey and why:
"As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal."
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I didn't write the passage. But:
(https://www.rookieparenting.com/wp-content/uploads/2016/05/refract-straw.jpg)
In the straw refraction pictures the straw magnifies. The rays start from a high density environment (water) and move into a low density environment (air). Presumably if the opposite occurred, light moving into higher densities, the straw would shrink.
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If an opposite scenario to the straw example occurred it would also suggests that the light would be bent upwards rather than downwards, which would makes sense for why the Cinema 4D simulation of the atmosphere causes light to bend upwards and not downwards.
https://www.youtube.com/watch?v=RkDqdoINhYI (https://www.youtube.com/watch?v=RkDqdoINhYI)
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I didn't write the passage. But:
(https://www.rookieparenting.com/wp-content/uploads/2016/05/refract-straw.jpg)
In the straw refraction pictures the straw magnifies. The rays start from a high density environment (water) and move into a low density environment (air). Presumably if the opposite occurred, light moving into higher densities, the straw would shrink.
Sorry Tom, the object appears deformed by the shape of the denser medium, not only water, but the glass.
In optics study, it is the shape of the different medium density that refracts the photons, not only the density itself.
You can have a very tick glass at your window, if it is a flat plate, no deformation would be noticed on the external image for an internal observer.
You are using the shape of the glass to induce the thought of size change just based on density, not true.
There are plenty of scientific optical explanation about this on the internet, that you can replicate at home, if you want or need, I can point some to you.
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Sorry Tom, the object appears deformed by the shape of the denser medium, not only water, but the glass.
Here is a polar bear behind a flat plane of reinforced glass:
(https://homeschoolsciencegeek.files.wordpress.com/2016/03/6551371_orig.png?w=250&h=348)
The body of the Polar Bear seems magnified compared to the size of its head.
Others:
(http://www.melinweb.com/wp-content/uploads/2017/11/refraksi-sample-1.jpg)
(https://s-media-cache-ak0.pinimg.com/originals/6f/7f/6b/6f7f6b4d949dc4528aea13ec42f7819d.jpg)
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Sorry Tom, the object appears deformed by the shape of the denser medium, not only water, but the glass.
Here is a polar bear behind a flat plane of reinforced glass:
(https://homeschoolsciencegeek.files.wordpress.com/2016/03/6551371_orig.png?w=250&h=348)
The body of the Polar Bear seems magnified compared to the size of its head.
Others:
(http://www.melinweb.com/wp-content/uploads/2017/11/refraksi-sample-1.jpg)
(https://s-media-cache-ak0.pinimg.com/originals/6f/7f/6b/6f7f6b4d949dc4528aea13ec42f7819d.jpg)
These are the opposite of what the wiki says if I even remotely understand what the wiki is trying to say:
"As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal."
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The light isn't going from your eye to the polar bear. The light is starting off in the water (dense) and going into the air (less dense). Magnification occurs.
Presumably with the opposite scenario shrinkage would occur.
I don't have any pictures from polar bears underwater taking pictures of people through the glass, unfortunately.
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The light isn't going from your eye to the polar bear. The light is starting off in the water (dense) and going into the air (less dense). Magnification occurs.
Presumably with the opposite scenario shrinkage would occur.
I don't have any pictures from polar bears underwater taking pictures of people through the glass, unfortunately.
Great, so what is the wiki trying to convey again? I know you didn't write that one, but I don't even know what to propose as the context seems to be absent.
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Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
It seems to be answering the question of why don't we see forever through the atmosphere. The air is not perfectly transparent and refraction would divert the rays over a large distance.
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Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
It seems to be answering the question of why don't we see forever through the atmosphere. The air is not perfectly transparent and refraction would divert the rays over a large distance.
Probably the easy answer is:
Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction diverts/scatters the rays over a large dense medium so it is not possible to see past a certain distance. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
Or something like that.
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It seems to be answering the question of why don't we see forever through the atmosphere. The air is not perfectly transparent and refraction would divert the rays over a large distance.
.. but if you can see a clear horizon, either on the land or on the sea, then clearly your vision is not being affected by refraction or diversion of rays.
When you run out of clear atmosphere, you see vague, indistinct stuff. On a clear day, you see a clear horizon. Therefore, you're not looking through an unclear atmosphere
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Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
It seems to be answering the question of why don't we see forever through the atmosphere. The air is not perfectly transparent and refraction would divert the rays over a large distance.
Probably the easy answer is:
Horizon Limits with Refraction and Opacity
Horizon limits are easily explained by the fact that air is not transparent and refraction diverts/scatters the rays over a large dense medium so it is not possible to see past a certain distance. As light travels through a denser medium, the object will appear to be smaller because light is refracted towards the normal. Furthermore, air is not transparent so it is not possible to see past a certain distance.
Or something like that.
Sounds fair. Lessens confusion. I changed it to what you recommended. I put a back link in the history comments so the author can refer to this thread if there is protest. It may have been written by authors on the other forum/wiki.
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It seems to be answering the question of why don't we see forever through the atmosphere. The air is not perfectly transparent and refraction would divert the rays over a large distance.
.. but if you can see a clear horizon, either on the land or on the sea, then clearly your vision is not being affected by refraction or diversion of rays.
When you run out of clear atmosphere, you see vague, indistinct stuff. On a clear day, you see a clear horizon. Therefore, you're not looking through an unclear atmosphere
I'm guessing here - The intent is to answer, ultimately, "Why can't I see the Eiffel Tower from Manhattan on a flat earth..." kind of thing. Not really about "THE HORIZON", if you get my drift.
Which begs the age old question of "Where is the horizon (on a clear day) on flat earth"? I surely don't know.
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This means that above the air is not water but vacuum
(or something that is much closer to vacuum than the air)
making the light from the Sun bend downwards, not upwards.
That way we see Sun higher than it actally is.
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Tom, when I said thick plate glass, it might confused you.
You are using the example (as below) of the bear behind a tick plate glass filled with water, and the bear is inside this medium.
This is a perfect example of "shape", like a lens.
Any angular difference from 90° from the lens of the camera, the plate glass and the position of the bear inside the pool (image incident rays of light), will change the flat shape of the object.
That is how a glass prism works, it needs the rays of light to be out of 90° angle in order for the high frequency wavelengths to bend sharper than the long wavelengths. If all the photons hit the difference density medium without any angle, no bending will happens.
On the image below, see how the violet light (higher frequency wavelength) bends more pronounced. Higher density promotes higher refractive index.
(https://www.metabunk.org/sk/prism-refractive-index.gif)
Lens magnification works the same, different angle of incidence in a different medium density, cause rays of light to bend to different directions, it can produce magnification, reduction, color separation, etc. Again, it is not density that change apparent size of an object, it is the angle.
(http://www.mstworkbooks.co.za/natural-sciences/gr8/images/gr8ec04-gd-0083.png)
A flashlight face on (90°) to the window glass will not have its light rays bent in anyway, it will enter and exit the glass (denser medium) without any refraction, the only thing that will happen is a little delay (in time) for the photons to get out of the glass.
If you bend the flashlight in certain angle to go across the window, then a certain light rays bending will happen, since the rays of light are hitting the different density medium in an angle.
Let me explain why this happen:
When face on (90°) all the wave oscillations hit the glass at the same time, even with different phases of the different wavelength. All the waves have a propagation time delayed, light speed still the same, but it has more difficult to propagate in a straight line, so photons start to colide inside the denser medium and change path, like zig-zagging in wavelength distances. The photons momentum and the alignment of the waves when hitting the medium does not allow them to change direction in a large scale, so they bounce and take a longer path to do the same straight path they had outside the glass before entering it. This longer path, same speed, means longer time to exit the medium. But as they entered the glass perpendicular, they will exit perpendicular in the same angle, no refraction happens.
When entering the glass in an angle, lets imagine 45° for easy understanding, the shorter path of the light wave will hit the glass first. That side of the photons will break travel speed by starting to bounce inside the denser medium before the other side of the wave that still outside the glass by the angle of penetration. The pronunciation of this "speed brake of photons travel time" depends on two variables, a) the frequency (and energy) of the penetrating photons, and b) the density difference (delta) between both mediums the photons is crossing from and to. If going from air to glass in an angle, all the photons will bend direction towards the side that hit the glass first. If going from glass to air, the bending is exactly the opposite, photons speed up travel time at the side of the wave that hits air first. High frequency waves, meaning green to blue and violet will bend more pronounced than orange to red.
(https://i.gifer.com/TyFi.gif)(https://thumbs.gfycat.com/OrangeLightAlpineroadguidetigerbeetle-size_restricted.gif)
This is exactly what happens with any glass lens, the form and shape of how the light enter and exit can produce all kinds of refraction. Knowing this, we produce lenses for our specific needs.
On the below pictures, if the observer and his camera moves right straight to 90° angle from the plate glass AND the bear, no light bending would happen, the bear will be visible as natural, no changes in image, size or position.
See, when I say "shape" it means mostly angles. Density is just the raw material, the instrument is the angle in how it is used.
On the picture below, by the position (refraction) of the bear image, I can say the observer and his camera was to the right of the 90° alignment to the glass, as if its right eye was closer to the glass. The photons of the bear image that hit the camera, came through water and glass, when they change medium, glass --> air, the right side of the waves (in the picture) exit first, they accelerate the photons travel speed and bend dramatically to their left (right of the picture), hitting the camera. As the image is composed by the width of the bear, the left side photons from the bear (in the picture) would change medium with a less pronounced angle, they are around 80cm or more to the left in the glass, so the angle they move into the air is different from the ones at the right. The angle of acceleration will be depending on such angle of medium crossing, it will be less pronounced. It works exactly as a magnifying glass, the bear may appears out of position and magnified. Here, the shape of the angles between observer, glass and bear, produces this effect.
Saying that a denser medium will magnify an object is wrong, if depends basically on the shape and angles.
By last... if you are inside that water you see no changes in the image at all, since your eyes (or camera) will make part of that medium. We, inside the bottom part of the Earth's atmosphere are deeply immersed into the denser air medium. The only effect we can see from the Sun when closer to horizon, is the reducing of the colors of faster wavelength, blues and violets (are bent first and disappear from us), this is why we see it more redish. But no change in size at all. The same "color refracting effect" can be observed on the bear below, note the more refracted image is more blueish,
(https://d2w9rnfcy7mm78.cloudfront.net/1402809/large_7773a1bbd03e52d5065e5402366a625f.jpg?1510039600)
Observe the second image, the left side of the bear (tail) produces more refraction on the glass-->air than its head, this is based on the pronounced angle from the camera to the glass, than head. Note that there is a refraction magnification that increases linearly to his tail, what proves my text above. It is not only the density, it is the angle of incidence. The bear's head, glass and camera have a better alignment to 90° than its tail.
(https://image.slidesharecdn.com/refraction-170505100217/95/refraction-9-638.jpg?cb=1493978770)
On this image below, because the half bottom part of the glass is not round, but faceted acting like a convex lens, you can even see the straw thinner, all due angles of crossing different mediums.
(https://thumbs.dreamstime.com/z/glass-water-red-straw-wooden-table-picture-iced-transparent-light-refraction-restaurant-94797996.jpg)
Optical refraction is a vast and very interesting area of study, since you can in fact test, exercise and see results on a simple kitchen table or better prepared laboratory. It is a rewarding study, the beauty of light rays and its physical properties fascinates all students. Low cost tools can teach you wonders. In all the school laboratory exercises, optics is the one that more attract students. In fact, it is a great area of work in the industry, great compensation for good professionals.
A low cost portable instrument known as "refractometer" measures the concentration (%) of solids in liquids, just using the ambient light refracted in the crystals, for example used to measure the percentage of sugar in soft drinks and other lab analysis. Just put few drops of the liquid under the plastic lid and see two different colors bands on the viewer, showing the percentage of solids.
(https://images-na.ssl-images-amazon.com/images/I/41nehMyVorL._SX342_.jpg)
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Lets test it. We can do an easy experiment and see whether objects magnify in a situation with no glass between the water and the air. This will tell us whether it's the glass causing the magnification.
Wonders of Science 3: Bilingual Teaching guide (https://oup.com.pk/media/teaching-guides/Wonders%20of%20Science/Teaching%20Guide%203.pdf)
p.50
(https://i.imgur.com/Ak3656D.png)
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That illustration is for Activity 3 (Seeing Double), not Activity 4 ...
Honestly, Tom had you EVER seen this document before today?
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The photograph and illustrations are used multiple times. Read the document. On p. 52 it says that water magnifies.
Put the objects into the pot. Space them out evenly.
• Cover the pot loosely with a piece of plastic wrap.
• Secure the plastic wrap with the rubber band. Gently push the plastic wrap
to make a small dip in it.
• Carefully pour water into the dip.
• Look down into the pot. The water magnifies the objects.
Deep water
Show students that pools and ponds are always deeper than they look. This is because the light rays from the bottom bend as they leave the water. This bending of the light makes the bottom of the pool or pond appear closer than it really is.
Experiment for your own self, from different angles. Water can easily magnify objects.
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Isn't the claim that water will always magnify objects? That's how the wiki reads to me. Simply providing a case where water magnifies an object isn't enough.
Fill a glass of water and wave it around in front of your face, varying distance between your face, the glass, and the object, and you'll see that water doesn't always magnify objects.
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The photograph and illustrations are used multiple times.
So what? The context of the photo you posted here, with its two coins, is clearly for the illustration of Activity 3, not 4.
They're not scattered around the document at random
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The photograph and illustrations are used multiple times.
So what? The context of the photo you posted here, with its two coins, is clearly for the illustration of Activity 3, not 4.
They're not scattered around the document at random
It doesn't matter which photo is used. The straw in the water photo is also magnified. The section is clearly describing that looking into water magnifies objects.
p.52:
Put the objects into the pot. Space them out evenly.
• Cover the pot loosely with a piece of plastic wrap.
• Secure the plastic wrap with the rubber band. Gently push the plastic wrap
to make a small dip in it.
• Carefully pour water into the dip.
• Look down into the pot. The water magnifies the objects.
Deep water
Show students that pools and ponds are always deeper than they look. This is because the light rays from the bottom bend as they leave the water. This bending of the light makes the bottom of the pool or pond appear closer than it really is.
Sciencing:
https://sciencing.com/water-magnify-things-4925557.html
Light in Water
Looking from above, an object under water appears larger than it does in air. It's not that the image the light gave our eyes is bigger. It's that the image is actually closer to our eyes, since the light is not passing straight down, but is instead bending relative to the water's surface. Light passing straight down would be perpendicular to the water's surface, like the vertical line on the letter T. A closer image looks bigger--the underwater object is magnified.
Quora:
https://www.quora.com/Why-does-an-object-appear-to-be-bigger-inside-water-when-seen-from-outside-How-does-refraction-work-in-this-case
Q. Why does an object appear to be bigger inside water, when seen from outside? How does refraction work in this case?
A. Objects in water, seen through a flat surface, do appear magnified when the eye is close to the surface. Anyone who has used a diving mask under water will be aware of this.
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If observed from the thinner medium the object submerged in the thicker medium looks bigger,
it also means that the objet in the thinner medium observed from the thicker medium looks smaller.
If that polar bear was in the air and we are in the water, it would appear smaller.
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I can make anything in any transparent medium look larger or smaller, deformed, twisted, bent, inverted, etc, viewed by another transparent medium.
It all depends on the shape of the border between both or all mediums, and the angle of incidence of the photons.
The lack of scientific knowledge about optics in general population, indeed not difficult, leads most of the population to create and believe in popular belief, not exactly facts. The popular belief is based mostly on "what you see is what you get", this kind of reason lead to several magic tricks, where optical illusion is used plenty.
Optics is a scientific field most unknown and "distorted" in the popular knowledge, even being really easy to grasp and understand.
I believe the great responsible for that is how little it is explored in school, at home and at 99% of the regular jobs.
Several online training optical labs and exercises help to start to understand how things really works:
https://www.newpathonline.com/free-curriculum-resources/virtual_lab/Mirrors_and_Lenses/10/8,9,10,11,12,13,14/1911 (https://www.newpathonline.com/free-curriculum-resources/virtual_lab/Mirrors_and_Lenses/10/8,9,10,11,12,13,14/1911)
https://ricktu288.github.io/ray-optics/simulator/ (https://ricktu288.github.io/ray-optics/simulator/)
Very good:
https://phet.colorado.edu/sims/html/bending-light/latest/bending-light_en.html (https://phet.colorado.edu/sims/html/bending-light/latest/bending-light_en.html)
A pack of simulations:
https://ophysics.com/l.html (https://ophysics.com/l.html)
This is a very numeric and adjustable, for advanced optics students:
https://arachnoid.com/OpticalRayTracer/ (https://arachnoid.com/OpticalRayTracer/)
A very simple optics test to find out how much you know:
https://www.proprofs.com/quiz-school/story.php?title=light-practice-test-- (https://www.proprofs.com/quiz-school/story.php?title=light-practice-test--)
This is very good to start to understand optical concepts:
https://www.miniphysics.com/ss-ray-diagrams-for-converging-lens.html (http://ttps://www.miniphysics.com/ss-ray-diagrams-for-converging-lens.html)
One of the first "wow" about understanding light, image refraction and reflection, is when you compare light with radio frequencies. On the old AM radio you tune one station and you have a voice, sound, song, etc, it is almost complete, whole, you can be listening to it for hours without losing any bit of information, considering the reception is good and your own language. On light image, it is like tuning to a thousand different frequency radio stations at the same time, each one transmitting a part of that image, if you see (hear) just one transmission it will be very difficult to grasp about the total final image. It will be like seen a monkey just observing the violet band of light its body reflects, you will not understand it. You need more frequencies, more stations, only by seen (hearing) several stations at the same time you will start to grasp the final image.
A simple example of few "radio stations" carrying different part of the final image, based on CMYK filters:
(https://static1.squarespace.com/static/537c9f82e4b031913f8e5d37/t/541366e0e4b014031cfce9b2/1401193014238/?format=1000w)
This is why optics field become very important in the late 20th century, when the industry and scientific development realize they could understand better the composition of matter by just tuning few selected of those "radio stations", and observing certain frequencies of light instead of everything at once. Chromatography became popular in the scientific area. You can burn a piece of anything and observe the gases resulting on the flame and identify almost 100% its chemical composition. You can analyse all signals "transmitted by those hundreds of radios" from the light reflected by a planet and identify most of the gases on its atmosphere.
There are much more under this rug than discussing about a straw inside a cup with water, or the light bent over the ocean moisture denser medium, and the first impression you have, without understanding it deeply.
And that, it is just studying plain fixed density and optical refraction index of materials, like water, glass, crystals, etc, but now there are materials with gradient index of refraction, creating a total new field of study and work, light can bend in a variable way.
https://en.wikipedia.org/wiki/Gradient-index_optics (https://en.wikipedia.org/wiki/Gradient-index_optics)
Think about this: You go to a brain neurosurgeon and explain to him about a certain recent headache. You try to tell him what you think it is, about the skull bone, nerves, veins and arteries, muscles and try to make your medical knowledge become important to him. The surgeon will keep listening to you, will make a magnetic resonance imagine recording and evaluation, then will prescribe a single aspirin to help dissolve a tinny cloth you have in a non important artery. As a matter of fact, the cloth dissolves by itself and you never had the headache anymore. Obviously you think your knowledge and talk helped a lot the doctor decision, without your info he would not be able to find and fix your problem. Do you really think your very superficial and popular distorted knowledge of the human anatomy and works will dramatically change the 30 years of experience and hundreds of surgeries, thousands of analyzed MRIs of such doctor and his team?
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You can also limit the effect of diffraction/magnification through a medium by simply adjusting the aperture. Or in a human's case, the amount of dilation:
(https://i.imgur.com/aMxWZtG.png?1)