As slow as possible

  Jurassic Park Theme (1000% Slower) by birdfeeder

Blue spheres

AquaGems. The patterns visible in some are reflections from the glass container.

"Fried" marbles, with internal fractures caused by rapid heating and cooling

Mandelbrot variations

Mandelbrot Pearls

Nebulabrot

Source for both images.

"Illustrations of Madness... Embellished with a Curious Plate"

Illustration of the "air loom" imagined by 18th-century paranoiac James Tilly Matthews, who believed that such a device was being used to torture him from a distance.

The full title of the 1810 book which contains this image is: Illustrations of Madness: Exhibiting a Singular Case of Insanity, And a No Less Remarkable Difference in Medical Opinions: Developing the Nature of An Assailment, And the Manner of Working Events; with a Description of Tortures Experienced by Bomb-Bursting, Lobster-Cracking and Lengthening the Brain. Embellished with a Curious Plate.

The poet's mistress

The ideal of feminine beauty in the 17th century demanded that women have the characteristics that are literally depicted in this illustration from Charles Sorel's The Extravagant Sheperd (London, 1654): teeth like pearls, eyes that sparkle like the sun, eyebrows arched like Cupid's bow, cheeks a-bloom with roses, and breasts like little globes or, as one writer put it, "little worlds of beauty."

A colored version can be found here.

Ramon Llull's theological sentence generator

The roots of artificial intelligence and digital text generation go back to the Middle Ages:

Ramon Llull’s Ars Magna provides a mechanical process for generating true statements and even proofs...
Llull provides four figures in the form of circular or tabular diagrams which recombine the elements of this table in different ways... the first figure produces combinations of absolute principles – ‘Wisdom is Power’, say. The second figure applies the relative principles – ‘Angels are different from elements’. The third brings in the questions – ‘Where is virtue final?’. The fourth figure is perhaps the most exciting: it take the form of a circular table which is included in the book as a paper wheel which can be rotated to read off results...
The kind of thinking going on here is not, it seems to me, all that different from what goes into the creation of simple sentence-generating programs today, and it represents a remarkable intellectual feat.

Llull's figure 1

Similar algorithms can be applied to produce sappy love letters or financial reports.

Vessels filled with light

These are essentially small, static versions of Lumia compositions. The light source is a Brightspot.

Three candles

These birthday-cake-type candles contain chemicals (probably some of the same ones at work here) which add color to their flames.

"...delicatessen cataract napkins of lightning chased one comp like battling fiery dragons"

A Dada-esque video based on vaguely Biblical gibberish text from a spam e-mail:

More nonsensical spam text here.

Avian phonetics

Scan from A Guide to Bird Songs by Aretas A. Saunders

The notation shows five qualities of a bird's song: time, pitch, volume, quality, and phonetics. At the top of the diagram is an indication of quality: clear, loud whistle, or harsh rattle, or the like. Below is the notation of the song in lines that are continuous or broken, of longer or shorter length, rising or falling, thicker or thinner, to indicate the line of the song and the duration of each note and the song as a whole. To the left is an indication of the musical pitch of the most prominent note or the mid point of the song. At the bottom is a phonetic transcription of the song, which, when combined with the information above, gives an indication of what the bird is saying in song.

The curves placed over these birdsong transcriptions resemble the intonation contours used to describe human speech.

Nova and Romanesco

Though this fractal resembles a fancy tiara, zooming in reveals whirling plantlike patterns reminiscent of the impressive Romanesco Broccoli.

Overturned vase and dried rose

Monarch's wing

No butterflies were harmed in the making of this photo-- I found that detached wing on the sidewalk about two years ago, and preserved it in the plastic box seen here.

Arrowhead with fossils

Arrowhead found in Kansas, sculpted from stone containing fusulinid fossil shells. Source.

Glass harmonica

This instrument is played by rubbing a wet finger along the rims of different-sized glass bowls (as one can do with a wineglass), creating different notes. Its sound (another sample here) is pleasant but vaguely unnerving. According to Wikipedia, there is a deep-seated sensory reason for this spookiness:

The somewhat disorienting quality of the ethereal sound is due in part to the way that humans perceive and locate ranges of sounds. Above 4,000 Hertz we primarily use the volume of the sound to differentiate between each ear (left and right) and thus triangulate, or locate, the source. Below 1,000 Hertz we use the 'phase differences' of sound waves arriving at our ears to identify left and right for location. The predominant timbre of the armonica is in the range from 1,000-4,000 hertz, which coincides with the sound range where the brain is 'not quite sure' and thus we have difficulty locating it in space (where it comes from), and referencing the source of the sound (the materials and techniques used to produce it).

Synthetic babbling

NETtalk is a computer model of language learning and speech synthesis, which can be "trained" to read texts aloud by associating words or letters with sounds. In this audio demo of its progress, it moves from essentially random babbling to comprehensible speech (though with odd intonations and a few mispronunciations).

Chemically enhanced flames

Toroid

If this polyhedron were made of rubber which could be stretched without tearing, it could be morphed into a donut or a coffee cup.

The Constitution as celestial mechanics

...Montesquieu insists that the English Whigs copied the new astronomy when they were creating the modern British Constitution. Referring to this in one of his essays, Woodrow Wilson drew attention to the fact that the Constitution of the United States had been made on the same principle. 'They [writers in the Federalist] speak of the checks and balances of the Constitution,' he said, 'and use to express their idea the simile of the organization of the universe and particularly of the solar system....'

From a passage on the metaphorical uses of mechanical and scientific terms during the Enlightenment, in History in English Words by Owen Barfield.

HATE BOOMERANGS

I saw those words on the sign in front of a local liberal church, and was momentarily confused about how to parse them correctly.
Analysis below the fold:

God the geometer

Medieval illustration showing God as an architect, tracing out the world with a geometer's compass.

Curiously, the cosmos in God's hand (as yet without form and void) looks rather like a Mandelbrot Set.

Turbulence

The patterns of mud swirling in this creek reminded me of the cloud bands of Jupiter-- and more tragically, of last year's Gulf oil spill.

Adorable baby trilobites

Examples of trilobite larvae, also called protaspids. Images from here.

Sea snails, monstrous and angelic

Larva of the sea angel Pneumoderma, illustrated in an 1893 natural history book

Adult sea angel, species Clione limacina

Gouldian Finch

If the Wikipedia article is to be believed, these birds are not just spectacularly colored, they're luminescent, at least in youth: "Very young birds also have blue, phosphorescent beads on the sides of their beaks to help their parents see them in the dark."