Or when you look for a clip art of a prism

[Borek]

splitting white light, and turns out refraction is... complicated

 

[jedishrfu]

Will the real Mr Prism please step forward?

 

[Hornbein]

Would it be possible to make a prism with a negative index of refraction?

 

[Borek]

Would it be possible to make a prism with a negative index of refraction?

https://en.wikipedia.org/wiki/Negative-index_metamaterial

(not that I understand details, I just know they exist)

 

[DrGreg]

One of those images must be a triangular hole through a large block of glass.

 

[Vanadium 50]

Would it be possible to make a prism with a negative index of refraction?

Used them - well, actually senses, but the same idea - in a freshman physics lab I taught. They are air filled, and you make the measurements in a water tank. Concave is focusing.

 

[Frabjous]

I think this is the most popular version
(over 45 million sold according to wikipedia)

 

[gmax137]

I think this is the most popular version

I read somewhere recently, that is the most widely recognized "logo" worldwide.

 

[jedishrfu]

Its sad to see that the illustrations are either poor or flat out wrong and that they got published anyway.

 

[Vanadium 50]

I read somewhere

the most widely recognized "logo" worldwide.

I'm not sure I buy that. There's some stiff competition.

 

[hutchphd]

Used them - well, actually senses, but the same idea - in a freshman physics lab I taught. They are air filled, and you make the measurements in a water tank. Concave is focusing.

I presume you meant lenses.
I recall teaching a sound lab using convex mylar helium filled balloons in air as diverging lenses.

There are general principles that make the light dispersion itself monotonic. As I recall this follows from the Kramers-Kronig relations.

 

[Vanadium 50]

I presume you meant lenses.

Yes, thanks.