I actually am not quite sure whether what I am referring to would even technically be referred to as 'holograms' per se. Basically, does anyone know whether or not the fully three-dimensional (as opposed to merely virtual three-dimensional) projecting technology seen in science fiction movies like Prometheus are possible even in principle? I'm referring to the common Sci-fi thing where a 3D image is projected seemingly into empty space/mid-air and a person can literally walk right through it without disturbing it in the least? Would that be holography or is that something else entirely?

It's been done with lasers. I'm unsure whether walking through it would be a good idea or not, though.

This is a good question. But doesn't it come about, because humans have two forward-facing eyes. Each human eye looks at the view in front, from a slightly different angle. This enables our human brain to merge the two views into a single stereoscopic, or 3D image.

 

But suppose we were another species, such as pigeons. These birds have their eyes on opposite sides of their heads.

 

This makes their eyes point outwards in completely opposite directions. So each pigeon eye, is 180 degrees apart.

This must make their eye-images so different that they can't be merged, and must remain two separate flat 2D images.

 

If so, could an intelligent pigeon, if there were one, understand what we humans mean by 3D vision, or what a hologram is?

I actually am not quite sure whether what I am referring to would even technically be referred to as 'holograms' per se. Basically, does anyone know whether or not the fully three-dimensional (as opposed to merely virtual three-dimensional) projecting technology seen in science fiction movies like Prometheus are possible even in principle? I'm referring to the common Sci-fi thing where a 3D image is projected seemingly into empty space/mid-air and a person can literally walk right through it without disturbing it in the least? Would that be holography or is that something else entirely?

 

 

If you are referring to the idea in Star Trek it requires some technologies (technobabble) that we simply don't have right now..

The simple answer is that one can stick your hand "in" a hologram and I have done it.

I put the "in" in quotes because, of course, the hologram is actually the piece of glass or whatever on which the image is recorded.

But you can put your hand where the image appears to be.

You don't feel anything special.