Half Shadow

Goethe’s shadow.

White lamp on, red lamp on as well: the hand casts a red and a green shadow! We see colors that aren’t actually there. How can that be?

The reason for perceiving a nonexistent color lies in color contrast: the more brightly lit area around the penumbra is reddish-white. Thus, the penumbra, which is actually white, appears in the corresponding complementary color.

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Biology

Light and Shadow

Optics

Physics

Seeing

Senses

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Color Contrast Main

Color Contrast

A colored object may look different against different-colored backgrounds. In this investigation, you'll discover how colors seem to change when you place them…

dokument-Links
10173 Halbschatten DEFI

Halbschatten (10173)

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11374 Haupt

"Delta Phi"

Optical phenomenon: caustics. The surface of this object resembles that of moving water. Illuminated from above, it reflects incoming light rays in various…

11798 Detail II

3D-Shadows

Shadows gain depth. Illuminated with red and green light, a tetrahedron casts a red and a green shadow on the screen. Viewed through glasses with red and…

11976 Phänomen

847 Compass needles

Magnetic Domains. There are 847 compass needles attached to a disc. Because they are so close together, they influence each other. With a magnet, the compass…

11727 Detail

A sense of optimism

Salt crayfish follow the light and thus their food. By pressing a button on the exhibit, the viewer changes colours between two light sources, whereupon the…

10104 Detail

A Slice of Turbulence

by Ned Kahn If the crest of the wave collapsed over the surfer off Hawaii and he could bring home a slice of salami from it, he would have the original to the…

10006 Detail

Additive Color Mixing

Mixing light colors. Play with red, green, and blue light, and with their brightness. When overlapped and adjusted optimally, red, green, and blue produce…

11490 Haupt

Adhesive Air

Coandă Effect: How shape, position, and surface influence airflow. The Coandă effect occurs when fluid or gas jets deviate from their original flow direction…

10515 Haupt

Aeolian Landscape

«Aeolian Landscapes» Wind shapes the landscape, just like water and ice do. As the wind sweeps over the sand surface, dune-like ripples form. When their…

10297 Haupt

After Image

Seeing the void. A powerful flash of light triggers a photochemical process on our retina. This process lasts longer than the brief light flash that…

10262 Haupt

Air Bubbles

Like dolphins: forming rings that rise. By pumping air into the glass tube filled with water, air bubbles rise. They ascend vertically. Often in a straight…

11634 Haupt

Air cushion

Inventive talent is called for here! Use scissors and tape to build objects out of paper that float on the wide air cushion. While testing and optimising, you…

11484 Air Fountain Haupt

Air Fountain

Dance with scarves. They rise and fall. Colorful scarves, moved by the airflow as if by an invisible hand. Choreography: visitors on the platform. by Daniel…

11478 Haupt

Air lift

The vacuum makes the difference. When the ball moves up the tube, the airflow is directed in such a way that a vacuum is created. How must it be directed for…

11747 Detail

Alike and unalike

The illusion of inequality. Two identical wooden arcs lie side by side. The inner one appears larger, but it isn’t. For circular arcs, the outer edge is…

10012 Haupt

All Triangels are the same

Central projection: Using various triangular shapes to cast congruent shadows onto a patterned wall with equilateral triangles.

11762 Detail

Ambiguous Figures

Clearly ambiguous. One object, two forms: “Necker cubes” belong to the category of ambiguously perceivable objects. Perceiving spatial dimensions and depth:…

10398 Detail

Angled Mirrors

Many polygons. Two mirrors positioned around an axis at various angles: a simple way to create shapes with many sides (polygons). At certain angles,…

10018 Haupt

Anti Gravity Mirror

Half a person becomes whole. Reflect the right half of the body, and there you have it: a complete person. It’s fascinating to watch them move. Can you manage…

11940 Haupt

Ants

Observe the bustling activity of ants as they move through a large enclosure performing various tasks. This is made of transparent material so that visitors…

10344 Haupt

Ascending magma

«Intrusion» Volcano in cross-section: This is what happens beneath its vent. What looks like magma is actually air-blown glass particles. They behave like a…

10030 Haupt

Aurora

A different kind of reflection. Colored filters in a mirror: why don’t we simply see their exact image? The surface of the mirror is rough. Restless,…

Bakterien als Künstler Damen

Bakterien als Künstler - Damen

Creative Microorganisms A narrow aquarium is filled with sediment from an old pond. In its various layers and under different aerobic and anaerobic…

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Bakterien als Künstler - Herren

Creative Microorganisms A narrow aquarium is filled with sediment from an old pond. In its various layers and under different aerobic and anaerobic…

10239 1

Ball in a Bowl

Particle accelerator. Hula hoop meets spinning coins: balls orbit inside the sphere. Circular movements propel the two balls onto their orbits within the…