Urban spaces that surround us are made up with steel, concrete block and glass. But what lies underneath is the flow of nature. Water flows and wind blows along the topographical undulations, and such movements have a great influence on how the architectural and civil engineering structures are laid out. An old map showing Tokyo in the 17th century, the Edo period, tells us that the city was already expanding in a dynamic spiral movement, with the castle at the core. It was at this time that the city's foundation was established.

In the course of modernization during the past hundred years, such topographical diversity and fluidity have long been lost from our vision. Because homogeneous geometric grids have overtaken. Roads and buildings compose independent spaces irrespective of the topography.

Now that we are at the end of the 20th century, remarkable development of electronic technology has wrought a new face on this megalopolis. The urban space today is immersed in an enormous amount of energy and flow of information. Like the topographical contour lines, density distribution of information now delineates yet another transient contour line. As they overlap and deviate from each other here and there, these contour lines create the urban space today. How do we adjust these two kinds of contour lines in different phases and integrate them into one space? That is the question.

The same inference applies to our physical body, because today we are clad in two different bodies: primitive physical being and virtual being.

From ancient times, the human being searched for clear water and settled near the rivers, lakes and seas. Ever since, we mantain a physical mechanism which, like a rivulet, ingests and excretes water. Today we also have a physical body in which a stream of electrons runs and which is linked to the world outside through various electronic devices. This is the virtual body which is capable of interactive communication by means of mobile phones, facsimiles or e-mail.

How we accommodate and integrate these two bodies is our challenge today. Similar challenge confronts the contemporary architecture and urban space. Why? Because we are linked with the architecture or the city via these two bodies. Architecture and urban spaces must also accommodate themselves to these two bodies. It is only natural for the primitive body to pursue physical comfort, taking shelter from rain and wind. But what sort of space does the virtual body seek?

Our physical body is continually changing, mediated by electronic technology. Development of telephones and faxes, for instance, has radically changed our concept of time. They invade our private time and space even in the small hours of the day. And rapid spread of mobile phones forces us to modify our concept of privacy. Our physical senses are being altered by these phenomenons.

Today's children are absorbed in computer games and appear to be immersed in the sphere of visual images instead of looking at them face to face. Not that they are looking at the images or facing them, but the physical body is being existent inside the sphere of visual image -there is a decisive difference between the two. Unless we acquire another virtual body, we cannot reside in this sphere.

I have a great interest in this virtual space. There, people are liberated from all sorts of constraints and are free to seek a new way of communication. Liberated from the force of gravity as we are, we can feel the delights of space floating in the cosmos.

I want to give substance to this space of virtuality, and the thought never leaves my mind. There is an abyssal gap between this virtual space and the physical space of reality, and as soon as the virtual space is given substance, it will be nothing but a reality once and for all. Because zero-gravity space cannot exist on this earth as it is. If, however, you are endowed with a physical body with which you can immerse yourself in the sphere of visual images, wouldn't it be possible then to create a space where you can physically appreciate what it is to be in zero-gravity?

Granting that this is clearly a contradiction, I still want to try and combine these two kinds of space into one. Attempts to create a gravitational space that feels like a space of zero gravity, and a real space which seems like visual images -to me, such attempts alone can bring us a new reality.

Let me introduce you a primitive prototype. This is the project called "Mediatheque in Sendai", which is currently in its planning phase. The project attempts to create an architectural complex that contains libraries, art galleries, audiovisual centers, and facilities for people with hearing and visual impairment. An open competition was held at the beginning of last year, and the selection committee adopted my proposal. The basic design has just been completed.

The project revolves around two main themes. One is the question of what a space should be like for people to feel comfortable when the two types of bodies I talked about earlier are combined. And the other is the concept and the form of a new library and art gallery in a society where new media technology is overwhelming. My solution for the first question is a very simple space structured by 12 tubular columns and seven plates. It resembles the "Domino" system of Le Corbusier that can accommodate any type of functions, but the most distinctive features lies in the use of 12 trunk-like tubes. Each tube is made of fine steel pipes and looks like an elongated bamboo basket; it is a composite structure of HP shells. Inside the structure are housed the vertical transportation means (stairways, elevators, air conditioning ducts, and various energy supply systems). But half the space is void, allowing for a natural flow of sky light from above and of air underneath. The structure has organic functions like a tree trunk or a human body. The tubes are flexible and can be of different diameters and shapes depending on the requirements of the functions inside. The seven plates are the thin and strong slabs made of sandwiched steel panels each measuring 50 m to each side. They are all of the same shape, but are capable of storing or transmitting different data in different parts. They are like floppy disks. People will stroll in the manmade forest, finding books to read and interacting with computers.

As for the second theme, all the floors in the complex are planned as media-mix spaces. The complex as a whole combines the functions of a library as well as an art gallery. One finds books, CDs and computers distributed everywhere inside the complex and allows access to old types of media such as books and movies, and at the same time equally allows access to a wide range of new media such as CDs and computers. It seems an insoluble task to finalize the basic program for the facility that introduces new media. We spent the whole last year discussing the issue with citizens and experts without reaching a satisfactory solution to all the parties. The complex is scheduled for completion in the beginning of the year 2000, but we think the discussions will have to continue till then. A public building incorporating the latest electronic technology and running a new program must, I believe, be able to change with time instead of being bound by any definite archetype.

As our physical body is born in water and is eventually reduced to water, architecture that emerges from the flow of electrons will probably be fused into the sea of information.