Chirality in Architecture David Avnir Institute of Chemistry The Hebrew University of Jerusalem In collaboration with Dirk Huylebrouck, Department of Architecture, Sint-Lucas University   NoSIC-5: Not Strictly Inorganic Chemistry Prullans de Cerdanya, June 6 - 8, 2012

Chemists are architects

Architecture and chemistry: The Atomium (Brussels) and the BCC Body-centered cube André Waterkeyn, 1958

Geodesic dome by R. Buckminster Fuller, Washington University, St. Louis, 1954.

Achirality has been prevalent over the history of architecture Here are three icons: Menkaure's pyramid

Taj Mahal

The Empire State Building

Chirality and handedness A one slide course The main property of chiral objects – objects without mirror symmetry - is that they have two forms: a left-form and a right-form (handedness) * These left and right forms are called enantiomorphs or enantiomers * Enantiomers are different objects, but they look very similar. The similarity is because they are mirror-images of each other The difference is that they cannot coincide with each other.

A chiral object need not have a real enantiomer Regular right-handed screw Virtual left handed screw

The enantiomers of Calatrava’s Chicago-Spire model The left-handed Chicago-Spire……..…… and its virtual right-handed enantiomer

The left-handed La Défense tower model (Wilmotte et Associés, Paris) The right-handed Mode Gakuen Spiral Tower, Nagoya

Was the choice deliberate? Key question: Why was one enantiomer selected over the other possibility? Was the choice deliberate? The real left-handed model of the and its virtual right-handed enantiomer Chicago-Spire……

A screw is deliberately manufactured as right-handed. But why was the Blossoming Dubai model, (Petra architects, Greece) designed as left-handed?

Calatrava’s HSB ‘Turning Torso’, Malmö, Sweden Based on his marble sculpture, following a twisting human spine; but no clue why a left handed twist was used

Chirality is not limited to spiral, helical designs, but is a property of any structure which is devoid of bilateral symmetry IAC (InterActiveCorp) world-headquarters, NYC (Frank Gehry)

Kazuyo Sejima and Ryue Nishizawa (SANAA) 2010 Pritzker Architecture Prize Rolex Learning Center, Switzerland Museum of Contemporary Art, NYC

Guggenheim Museum, Bilbao, Frank Gehry

Is the Guggenheim Museum a left- or right-handed building? Handedness labeling is an agreed convention, not an inherent property like chirality itself Given a definition of handedness, there is at least one chiral structure the handedness of which cannot be determined under that definition

Inducing chirality in achiral structures Breaking the bilateral symmetry induces chirality Zollverein School of Management and Design, Germany, Sejima and Nishizawa

Will Alsop The public art building, West Bromwich Ontario college of art

Toyo Ito’s Hotel Realia, Barcelona

T.I.D. Tower, Tirana, Albania (2004/12) Peter Swinnen, 51N4E Architects, Brussels Which is the real façade?

Are chirality considerations relevant to architecture? Is the choice of a specific enantiomer, important?

The key argument: Diastereomeric interactions (DS) Diastereomers: * Taste differently, smell differently * Can heal or kill (Thalidomide) * Perceived differently Carvone (R): Spearmint (S): Caraway (Karwij, Kümmel)

Our biological receptor at focus: The brain * The left and right hemispheres of the brain are very unequal * Therefore, no mirror symmetry – the brain is chiral * Specifically: the brain is a chiral information receptor * Therefore, if the information – visual – is chiral, DS interactions result between the brain and the information Therefore, left and right objects must be perceived differently by the brain

Psychology of aesthetic perception “When some pictures are mirror reversed, aesthetic evaluations of them change dramatically.” “When a painting is viewed in a mirror… even the meaning can change…” “ The first major finding… was that paintings containing left-to-right directional cues were preferred…” A. M. Mead and J. P. McLaughlin, Brain and Cognition, 20, 300 (1992)

Rembrandt’s 2D-chiral preferences N. Konstom, “Rembrandt’s use of models and mirrors”, Burlington Magazine, 99, 94 (1977)

Perception as a 2D process * Perception is usually a 2D process, even of 3D objects * It is mentally difficult to check for achirality by rotation/translation Therefore: “Visual chirality” is quite rich

Are chirality considerations relevant/important to architecture? First answer: Yes, the left enantiomer and the right enantiomer of the same building may be perceived aesthetically in a different way.

Natural and urban environments/landscapes are chiral Diastereomeric interactions between neighboring buildings Toyo Ito Towers, Plaza Europa, Barcelona

Diastereomeric interactions with urban chiral environments La Défense tower model (Wilmotte et Associés, Paris)

Diastereomeric interactions with natural landscapes Objects with element of randomness are always chiral Arches Park, Utah Therefore, placing the left- or a right handed version of a building in a natural landscape, results in different DS interactions

The two DS’s of a chiral building in a natural chiral environment

Are chirality considerations relevant/important to architecture? First answer: Yes, the left enantiomer and the right enantiomer of the same building may be perceived aesthetically in a different way. Second answer: Yes - most environments are chiral, and therefore left- and right versions of the same structure, interact with it differently.

More about chirality and architecture: A touch of some additional topics

Measuring chirality

Various degrees of chirality:

Different degrees of chirality Low degree and higher degree of chirality

Resolution dependent chirality Low resolution – far away: Achiral Intermediate resolution: Chiral High resolution- very close: Achiral T.I.D. Tower, Tirana, Albania Peter Swinnen, 51N4E Architects, Brussels

Architectural aggregates and crystals A housing “crystal” Four chiral unit cells

A Soviet chiral aggregate “adsorbed” on a highway

Architectural liquid-crystal chiral phases

Is prochirality possible in architecture?

Induction of chirality by light, shadows and reflections Ronald Reagan Building, Washington, D.C.

Static vs. Dynamically induced chirality

Is (chiral) enantiomerization possible in architecture? Chiral enantiomerization of a left-hand to a right-hand glove

Dynamic chirality by illumination Enantiomerization: Dynamics may introduce a flip in handedness The enantiomerization is chiral Petronas Twin Towers, Kuala Lumpur, Malaysia

The original inventor of chiral enantiomerization

Dynamic chirality induced by motion Clockwise and counterclockwise motions are dynamic enantiomers The Seattle Space Needle revolving restaurant turns clockwise. Operators can control the rotation direction; the majority selected CW rotation!

All chiral concepts in one Summarizing example All chiral concepts in one Enantiomerization Dynamic chirality Gradual change in degree of chirality Flip in handedness A racemic mixture David Fisher, Italy, ”dynamic towers”, planned for Moscow and Dubai

Conclusion and Outlook * Chirality is a neglected major structure-characterization feature in architecture * It affects perception and the interaction of buidings with the environment * Therefore it should be embraced by cutting-edge architecture