The two cultures - Art & Science, usually looked upon as two different entities, are practically one totality. The close interaction between the "two cultures" finds also attestation in the words of Cheng-Dau Lee, Nobel laureate in physics: "Both, science and art are not separated from each other. There is even a similarity between them as they help us observe nature. With the help of science we can find out routines of nature. On the other hand, by means of art we can describe the emotions of nature."

What is Science? Science to the layman is usually identified with something precise, such as mathematics or physics. Science is much easier to define in comparison to Art because it is exact, it does not depend on one's emotions, and has a very limited, but essential scope to reveal the laws of nature which govern our life every second. Many definitions for Science - the Latin for "knowledge" - are available. For example, the Oxford Advanced Learner's Dictionary (1989) and Even-Shoshan's New Hebrew Dictionary (1975) definitions are summarized as follows: Science is a systematic research in a certain subject, such as in mathematics, physics, botany, and history, organized and based on facts, observations or experiments and summarized into laws, rules and axioms. Thus, a scientist is a scholar occupied in research of a certain subject. In the Encyclopedia Britanica (1987) "Science is the knowledge of the world of nature". Campbell's (1953) definition is very interesting. He says that nature means, practically, the part of the world which man regards as external to him. Thus, "Science is that branch of pure learning which is concerned with the properties of the external world."

Other interesting questions are: What is Science for, and how is Science acting? There are two aspects of Science. First, there is a practical science, which is a body of useful and practical knowledge. In its second aspect, pure science is a branch of pure learning which aims at intellectual satisfaction. Science is not an individual experience. It is a shared knowledge based on a common understanding of some aspects of the physical or social world. Science studies laws of nature and we seek to discover laws in order to make nature intelligible to us.

What is Art? Art, like love, is a word that every one knows what it means, most of us will tell you that it is necessary, that it is also good for the soul and that they enjoy it, and that it is an activity which manifests beauty, as well. However, people will have difficulties in defining Art. The volume of definitions of art is enormous, and only a few are spelled out here. The Encyclopedia Americana (1991) elaborates as follows: "The word Art comes from Latin Ars, meaning skill ... In the broadest sense, Art embraces all the creative disciplines - literature, poetry, drama, music, dance and visual arts. However, as commonly used today, Art means the visual arts - painting, sculpture and architecture - those areas of artistic creativity that seek to communicate primary through the eye." Carta's Universal Encyclopedia (1998) and The Concentrated Hebrew Dictionary (1993) express, more or less the same: "Art is a human creation generated of one's own impulse. It is intended to stimulate an aesthetic experience, and which is accepted by others as composition of a high quality. Common subjects of Art are: painting, sculpturing, music, dance, literature, theater, cinema and their combinations." Pablo Picasso expressed once the following idea about Art: "We all know that Art is not truth. Art is a lie which teaches us how to comprehend the truth, or at least that truth we human beings are capable of comprehending." Marcel Duchamp claimed that: "A product becomes an art product if it enters a museum."

An interesting question is what does Art do to people? According to Dissanayake (1995) "Art is said to be both pleasurable and advantageous because it is therapeutic; it integrates for us powerful contradictory and disturbing feelings; it allows to escape from tedium or permits temporary participation in a more desirable alternative world; it provides encouraging illusions; it promotes catharsis of disturbing emotions, and so forth."

My understanding of what is Art has been crystallized along my scientific career and my interest in art. Art is all what affects our senses and emotions resulting from different stimuli which penetrate into our brain creating there the work of art what we eventually see or hear. These stimuli may be optical, acoustic, touch, feel, smell and others. The means for creating art, for example, paintbrush, computer, knife, telecommunication technologies, hammer, internet, etc., are immaterial.

Now, what about the interaction between Art and Science. Historically, Art did not exist as an independent genre as it does today. Great masters were well-versed in both art and science, as represented by Leonardo da Vinci. This interaction must be introduced and demonstrated in universities, and, even earlier at schools, the initial melting pot of the future generation, bearing in mind that the gap between Art and Science which has started in the 17th century became broader in the 20th century.

The Ben-Gurion University of the Negev has demonstrated a successful way for integrating the "two cultures" by establishing a Museum of Art & Science (www.bgu.ac.il/museum), the first of its kind. The museum, founded by the author of this page in 1998, displays approximately 200 non-original works of famous artists and holograms. The museum is located in the Kreitman-Zlotowski four-story classroom building which reminds the famous Guggenheim Museum in New-York. The classroom building is always crowded with students, faculty, school children of all ages, teachers and the general public, who are continuously exposed to famous art paintings and enjoy the permanent exhibition.

The underlying approach of demonstrating the interaction between art and science in the museum is based on the following duality: Art is used as a means to illustrate Science, and Science serves as an instrumentality in creating Art. This reminds what Niels Bohr said in 1926: light is not just a wave, not just a particle; it is a composite of both, a wave and a particle.

The idea of presenting an Art & Science page in PhysicaPlus Online aims at focusing our readers' attention on the frequently overlooked scientific aspects in pictures. The average viewer is generally not educated in this type of observation. Another aim is to familiarize people with art via science. It is worth noting also that in many cases the artist had no intention of demonstrating any scientific concepts in his painting; nevertheless, they are there. On the other hand, in those instances where the artist did intend to demonstrate certain scientific aspects or models, it is interesting to see how he actually achieved it.

Scientific subjects and concepts to be demonstrated are, for example, perspective, mathematical numbers, Newton's laws, black hole, symmetry, simulation, sound, light, Big Bang, gravity, zoology and botany, alternative medicine, Thermodynamics' Laws and conceptions such as entropy, internal energy, availability, work, dead state, enthalpy, equilibrium and reversible process. Combustion, closed loop, sublimation, time, Einstein's universe, fluid flow, archeology, thinking, seeing, illusion and reality, are additional examples.

Creation of art with the aid of scientific principles and tools may be demonstrated via chaos model and fractals, computer art, space sciences, weather sciences, geology, rheo-art, surface tension, as well as sonographic art. In addition, phenomena related to cognition of vision by the brain such as holusion, optical illusions, virtual motion, figure-ground, and multi-image as well as impossible objects and situations, will be demonstrated.

REFERENCES:

• Campbell, N., "What is Science?", Dover Publications, Inc., New York, NY (1953).
• "Carta's Universal Encyclopedia", Market House Books Ltd., (1998), first published 1981 by Macmillan Ltd., London (in Hebrew).
• Dissanayake, E., "What is Art for?", University of Washington Press, Seattle, WA (1995).
• Even-Shoshan, A., "The New Dictionary", Kiryat Sefer Ltd., Jerusalem (in Hebrew), (1975).
• Even-Shoshan, A., "The Concentrated Hebrew Dictionary", Kiryat Sefer Ltd., Jerusalem (in Hebrew), (1993).
• Hornby, A. S., "Oxford Advanced Learner's Dictionary", Oxford University Press (1989).
• "The Encyclopedia Americana International Edition", Grolier Incorporated (1991, vol. 2).
• "The New Encyclopedia Britanica" , Encyclopedia Britanica, Inc.(1987, vol. 1).

The museum's website: www.bgu.ac.il/museum