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kmcguir
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Does atmospheric refraction only work at certain temperatures, distances, and shape of the object (i.e. only spheres)?
Atmospheric Refraction: Temperature, Distance, Object Shape
- Thread starter kmcguir
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In summary: This creates the conditions for atmospheric refraction to occur.In summary, atmospheric refraction can occur with any variation in the index of refraction, including changes in temperature and density. However, the larger the temperature and density differentials, the more noticeable the refraction effect will be. There is no limit to how close this can occur, but the total deflection of light rays will be greater with larger temperature and density gradients.
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berkeman
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Can you post a few links to what you are asking about? That would help us to reply. Thanks.kmcguir said:
Like this?
https://c.tadst.com/gfx/750x500/atmospheric-refraction.png?1
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berkeman
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Thread closed briefly for Moderation...
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berkeman
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Thread is re-opened after deleting a questionable reference. We can discuss the science involved in atmospheric refraction in this thread, as long as all references are to mainstream science. Thank you. 
- #5
berkeman
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Here's another example of atmospheric refraction from a Google Images search...kmcguir said:
https://i.ytimg.com/vi/-sj868IzNrk/maxresdefault.jpg
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kmcguir
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Ok, so cold and warm air are required for this to occur. Can this happen at close distances or is there a limit?
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berkeman
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All it takes is light rays traversing a change in the index of refraction at an angle.kmcguir said:
I've seen the same effect from light refracting off the hot hood of a car fairly close by. Since it involves angles, the larger the delta-n and the larger the distance, the larger the apparent visual displacement effect, no?
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sophiecentaur
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Look over the top of a hot CH radiator at a scene outside. You can often see shimmering due to the varying refraction through the turbulent mix of warm and cooler air. That refraction effect takes place right in front of you and it's more noticeable through binoculars.
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jbriggs444
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Which "this" are you talking about? Atmospheric refraction can happen with atmospheric density variations due to altitude even without a temperature difference.kmcguir said:
As for distance dependence, a particular temperature/density gradient will result in a particular curvature of light rays. At close range and a small gradient, you won't get much total deflection.
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Drakkith
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kmcguir said:
Temperature isn't directly responsible for the refraction of light through the atmosphere or any other gas. What is needed is a variation in the index of refraction. Hot air is less dense than cooler air, and thus has a lower refractive index. But since density also changes with altitude, the index of refraction of the atmosphere also increases as you get closer to the surface.
FAQ: Atmospheric Refraction: Temperature, Distance, Object Shape
1. How does temperature affect atmospheric refraction?
Temperature has a significant impact on atmospheric refraction. As temperature increases, the density of the air decreases, causing the speed of light to increase. This results in a smaller amount of refraction, leading to objects appearing closer to their actual position.
2. Does distance affect atmospheric refraction?
Yes, distance plays a crucial role in atmospheric refraction. As light travels through the atmosphere, it bends due to changes in density. The farther the object, the more atmosphere the light must pass through, resulting in a greater amount of refraction.
3. How does the shape of an object impact atmospheric refraction?
The shape of an object does not directly affect atmospheric refraction. However, the apparent position of the object may be altered due to the varying densities of the atmosphere. This is why objects near the horizon may appear distorted or displaced.
4. Can atmospheric refraction be predicted accurately?
Atmospheric refraction is a complex phenomenon that is affected by various factors such as temperature, humidity, and air pressure. While there are mathematical models and equations to estimate refraction, it is challenging to predict with complete accuracy due to the constantly changing nature of the atmosphere.
5. Is atmospheric refraction only relevant for astronomical observations?
No, atmospheric refraction has an impact on all objects that are viewed through the atmosphere. This includes not only astronomical observations but also everyday observations such as the apparent position of the sun or the shape of objects seen through a heat haze. It is a fundamental principle of optics that applies to all objects viewed through a medium with varying densities.