Mirages - Sixty Symbols

What causes mirages? More physics explained at http://www.sixtysymbols.com/

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Science & Technology

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• Mirage

[SpikeZeek]

i like how most replies are an elaboration and possible correction of what the last person said

[SpikeZeek]

@jeffshubert because you are standing at a fixed point, as soon as you move so would change of these other light streams, your brain takes the seperate images from your eyes and tries its best to add depth and percetion. and a better question is can these streams be broken up to produce a hologram or even a spectrum?

[jeffshubert]

Given the other streams of light that are present, why wouldn't the composite image be rendered due to the principle of superposition?

[ghelyar]

@ricktbdgc the flipped image effect is because the refracted light does not all come from the same place. You can visualise this better by taking the graph at around 5:50 in the video, adding a second light source further away and drawing another parabola from the new source to the existing sink.

[Mrjesse451]

@Richy15251 Light can and does slow down. There are several circumstances where light travels slower than usual. One of these is an experiment being conducted where light traveling through a super cooled liquid(I think its a liquid) and then shot by a laser beam will actually slow down to speeds where we can actually use it practically to send and receive data.

[subsystems]

@jonahansen Furthermore, what is forcing the path to be parabolic as he clearly states? Parabolic paths by definition require a constant acceleration. The entire field of optics relies on light rays that travel in straight lines through different mediums and change directions as the refraction index changes. Never have I seen any parabolic formulas for light paths used, only straight paths. I can imagine a hyperbolic path where the 1st approximation is the light paths along the asymptotes.

[subsystems]

@jonahansen I understand what you are saying but the professor is saying the light will bend to, in a sense, "seek out the path of least resistance". This cannot be entirely true because light going around an object would be the path of least resistance instead of striking the object. If what he were saying were correct, we would always be able to observe objects placed behind other objects, always.

[jonahansen]

@subsystems Well, actually he is right. There is a good set of videos by the Vegas trust that show Richard Feynman explaining quantum electrodynamics, the theory that governs this behavior, for which he and other got the Nobel prize. In there, he explains how it works in that theory, where all paths are given equal weight, and one sums up all the paths for the light - in many simple cases much cancels out, making it possible to do the calculation. In this case involving refraction , mirrors, etc

[ElectricSheep10]

Very interesting :)

[subsystems]

I respectfully don't think the professor's description is correct. Lights rays radiate in many directions. Placing a solid object between the object and the observer will not cause the light to seek the path of least resistance and go around the object. It will be blocked.

Mirages are caused when light refracts as it passes from colder air across a sharp boundary to significantly warmer air.

I think he meant hyperbolic instead of parabolic.