The Holographic Principle (APOD 2009 September 13)

[Star*Hopper]

Quite welcome - glad I could assist.
Your questions are answered, with this & many other aspects further visuals - tri-plane multi-level & even animations (the chess set is remarkable!)- here: http://en.wikipedia.org/wiki/Autostereogram

~*

[black mamba]

When looking at this holographic image, I can on occasion see three tea pots....two equally sized ones in the rear and a third, smaller one toward the front that is centered between the ones in the rear. Is this an unusual situation or is it commonly occuring among viewers?

[Chris Peterson]

When looking at this holographic image, I can on occasion see three tea pots....two equally sized ones in the rear and a third, smaller one toward the front that is centered between the ones in the rear. Is this an unusual situation or is it commonly occuring among viewers?

It's not a holographic image! It was really a bad choice for the editors to use this particular image if they wanted a piece on the holographic principle.

And what you're seeing is normal. It just means you've pulled your eyes a little further outwards, and are merging the next interval in the background tiling pattern.

[Czerno]

[Black Mamba:]"When looking at this holographic image, I can on occasion see three tea pots..."
Are you sure it was only tea you poured into that pot ? :=)

[Star Hopper:] "http://en.wikipedia.org/wiki/Autostereogram"
I'm still not clear about why the colored dots after reading that I'm afraid. Unless the dots serve an obfuscative function, or are purely decorative ? On the wikipedia page there are several impressive autostereograms in full color, no impressionistic dots.

Anyway... Could that technique be of use for APOD 3D pictures of, say, Martian boulders or the Space Station ?

[neufer]

It's not a Holographic image! It was really a bad choice for the editors to use
this particular image if they wanted a piece on the Holographic principle.

Holograph, n. [L. Holographus entirely autograph, Gr. "olo`grafos; "o`los whole + gra`fein to write: cf. F. Holographe, olographe.] A document, as a letter, deed, or will, wholly in the handwriting of the person from whom it proceeds and whose act it purports to be.

• ----------------------------------------------------
  The Strange Case of Dr. Jekyll and Mr. Hyde. 1886.
  
  II. Search for Mr. Hyde
  
  THAT evening Mr. Utterson came home to his bachelor house in sombre spirits and sat down to dinner without relish. It was his custom of a Sunday, when this meal was over, to sit close by the fire, a volume of some dry divinity on his reading-desk, until the clock of the neighbouring church rang out the hour of twelve, when he would go soberly and gratefully to bed. On this night, however, as soon as the cloth was taken away, he took up a candle and went into his business-room. There he opened his safe, took from the most private part of it a document endorsed on the envelope as Dr. Jekyll’s Will, and sat down with a clouded brow to study its contents. The will was Holograph , for Mr. Utterson, though he took charge of it now that it was made, had refused to lend the least assistance in the making of it; it provided not only that, in case of the decease of Henry Jekyll, M.D., D.C.L., LL.D., F.R.S., etc., all his possessions were to pass into the hands of his “friend and benefactor Edward Hyde,”
  .............................................................
  VIII. The Last Night
  
  "That is the same drug that I was always bringing him," said Poole; and even as he spoke, the kettle with a startling noise boiled over. This brought them to the fireside, where the easy-chair was drawn cosily up, and the teathings stood ready to the sitter's elbow, the very sugar in the cup. There were several books on a shelf; one lay beside the tea-things open, and Utterson was amazed to find it a copy of a pious work, for which Jekyll had several times expressed a great esteem, annotated, in his own hand, with startling blasphemies.
  ----------------------------------------------------

A Holograph is a document written entirely in the handwriting of the person whose signature it bears. The laws of various U.S. states differ as to the validity of Holographic last wills. In the 20th century, the word "Holographic" took on an additional meaning because of the invention of the photographic technique called Holography. However, images produced using this technique are called "holograms", not Holographs.

[Chris Peterson]

A Holograph is a document written entirely in the handwriting of the person whose signature it bears. The laws of various U.S. states differ as to the validity of Holographic last wills. In the 20th century, the word "Holographic" took on an additional meaning because of the invention of the photographic technique called Holography. However, images produced using this technique are called "holograms", not Holographs.

Well, thank you for informing us about this obscure and legalistic definition for holograph, but there seems to be some suggestion that the term has been used incorrectly somewhere in this discussion. If so, I can't find where that might be. The adjective, holographic, seems to be used quite correctly everywhere.

[Qev]

Oh, I believe y'all. It's just that, despite my efforts, I remain disappointed and unconvinced in the evidential sense. And how many other untested abilities might my brain be missing?

A clever trick I found which allowed me to see these for the first time was to use background reflections. Originally, I was looking at poster-sized ones behind glass, and would focus on the reflections of light-sources that were some distance behind me; this forced my eyes into the correct 'distance focus' for the autostereogram to work. You could probably arrange to have a small, bright light source a ways behind you and look at its reflection in your monitor as you view the stereogram.