I was listening to the New Year’s Day concert by the Vienna philharmonic and wondered who one of the composers was so used a popular song recognition app. (I expected it would make some fuzzy match on the piece and give me the name + composer). To my amazement it did give the name and composer but as played by the Vienna philharmonic in 2005 in the same location. The orchestra does not have the same members as 19 years ago, nor was it the same conductor, so it seemed the piece was matched on the acoustics of the Musikverein where they were playing, which I found astonishing.
Diffraction gratings because light is cool, and I like the pretty colors.
Not super modern but you can 3d print in a mold, or even make chocolate, and it will look “holographic.” You don’t add anything, you just manipulate the surface of the object to have tiny grooves with thickness in the nanometer range. Then light hits it and waves do their thing and we perceive a rainbow effect.
This is from a Reddit post, one of the top homemade “holographic chocolate” posts.
Presumably you could print a hologram-like portrait on chocolate, which blows my mind.
Wow that’s cool!
If it’s your thing, here’s a full on deep dive into how 3d image holograms work. I’d never really appreciated how insane it is to encode a moveable 3d volume onto a 2d surface nor how early the maths for it was developed! (method 1948, first 3d image 1962, nobel prize 1971)