#interference patterns

[idlejet]

“You’re shape-shifting like a swarm of bees.”

[noosphe-re]

Radiation from a lateral quadrupole source, Daniel A. Russell, Graduate Program in Acoustics, The Pennsylvania State University

[bakerstreetirregular]

My INTP mind: *reads about interference patterns in Micheal Crichton's 'Timeline'*

Also my INTP mind: So I guess you could say Dean and Sam Winchester's actions in an alternate universe influenced Eric Kripke's mind to create Supernatural.

[dontcode]

You Live in a Simulation

[toddjdreyer]

Dynamic Interference Colors

[sensationalsegue]

“You’re in the hand of the sea. You are the pleasure of breathing it in. Within an order that does not feel, we are this insignificant disorder that feels. A thing to witness the sea.”

~ Marguerite Duras, “The Easy Life”

It’s like every fucking sentence in this book is magic; the distillation of the essence of life or something something.

[iheartvelma]

You’d think by now we’d have more of a holographic printing industry the same way we have desktop publishing or 3D printing.

We’ve slready got 3D scanning setups - imagine using a 3D model built using existing tech, and then building the classic holography table setup virtually - a raytracing render setup using a computed virtual laser, to reproduce a holographic interference pattern entirely in the computer.

Then it can print that computed holographic pattern direct to emulsion - maybe using a scanning pinpoint laser to expose the medium, similar to how film recorders for early CGI worked.

This way, you could take any scanned object, or a synthetic scene ‘diorama’ from a game or 3D design program, and output it to an actual hologram as easily as using a laser printer.

EDIT: Apparently MIT are on the case, with something called tensor holography

EDIT 2: A company called Litiholo is Kickstarting a desktop hologram printer. (h/t: @adogwithadhd)

Litiholo: Helping create the hologram engineers, entrepreneurs and artists of the future. Hologram Kits for individuals and classrooms.

[iheartvelma]

Uh, apropos of nothing, the “holography” tag is full of stuff which at best could be called “iridescent.”

And that rainbow metallic tape stuff also isn’t holographic. It just has a really fine diffraction grating layer that acts like a prism. In the lab, these sorts of materials are used to separate colour spectra. In essence the same principle applies to the structure of coloured iridescent feathers, butterfly wings, and so on.

Now holography... that is something else.

Basically it encodes a 3D image into a 2D photograph on a glass or plastic substrate, using a laser (for its coherent light) and some really interesting physics. We had a holography lab in university and I got to see several being made.

A basic setup works like this:

The beam from a laser is split with a partially silvered mirror. The first leg of the beam illuminates the object; the second leg illuminates the holographic photo plate. The interference pattern generated where the beams converge is recorded on the photo plate.

Later, when you re-illuminate the plate with the laser, it reconstructs the 3-dimensional image from the recorded interference pattern.

In essence the recorded pattern is like a kind of diffraction grating - every angle of the light that reflected off the object is encoded, so when you view it from different angles, you see only those different angles of light and the others are cancelled out, giving you the illusion that you’re seeing a 3D object. (This is why you need a laser; white light is too random to do this)

So-called “white light” holograms like the ones on your credit card don’t need a laser to be viewed. They’re made in a similar manner, but the lasers illuminate the film from the other side so that the diffraction pattern is self-decoding when light bounces through it - The printed holographic film is given a reflective backing so that white light bounces back up through the holographic layers and into your eyes. They have a rainbow appearance because of that diffraction pattern scattering white light into its component colours.

It’s this rainbow appearance that makes people confuse holography with iridescence - there’s a similar principle at work (diffraction and reflection) but a hologram is a 3D image recorded by laser light, and laser-illuminated holograms are, sadly, monochromatic.

Now here’s the part that’ll really bake your noodle. When you break a holographic photo plate, the image doesn’t disappear; each piece contains the complete image. It’s like if you had a big window and broke it into smaller ones - you can still see something outside though you might need to shift your angle.

That’s why it’s called holography, because it contains the whole information.