Simulation News vol.1
Holistic World - The Journey for Universe,Human Baings,and Quark -
The world view changing with the number of zeros
There is the film named “Power of Ten” which was produced by Charles Eames and Ray Eames in 1977. They are the American designers who are well-known for modernly designed chairs. The theme of the film is “the relative scalability of materials in space and the effect of changing the order of scale”, and the film describes the world which changes by increasing a scale by an order of 10 to the maximum and by decreasing a scale to the minimum. It is the world with an order of one meter (10E0 meter) that we live on. On a scale of 10 km (10E4 meter), the very tall buildings and architectures become like small points. Then, on a scale of 10E14, the solar system becomes like small points. On a scale of 10 giga light years (10E24) which is the end of world we can recognize, dust-lke galaxies are sparsely distributed in the vacant space.
Further looking at smaller scales, it is the order of 10E-5 meter that cells inside hands begin to be seen, and it is the order of 10E-8 meter that a DNA begins to been seen. The world that quartz is visible is the order of 10-16 meter. Thus, a material world is composed of a superposition of many different scales from 10E-16 meter to 10E24 meter.
Nature is holistic
Earth Simulator Center has developed a new simulation method called “holistic simulation”. The holistic simulation calculates physical processes of multiple scales by applying the algorithms that are appropriate for the nature of each scale. The physical information needed to interact among each scale is communicated among processors when needed. This is the highly advanced and totally new simulation scheme, being capable of simulating a realistic world in most appropriate ways. But the concept of holistic algorithm is not a special technique, but also is the excellent technique that is capable of simulating the system of nature as it is. For example, quartz-scale dynamics itself does not always affect the scale of an earth dynamics or space physics. Instead, a nature is fundamentally a holistic world as these physics of multi-scales communicate all the necessary information when being needed in time and space.
Currently, using the method of a holistic simulation, the simulations of the aurora formation and the cloud formation are being done. Although a number of aurora-arc simulations have been done in the past, they were the simulations on a monochromatic scale.Using the holistic simulation (which is on a multi-scale), the current of energy on a macro scale and the behavior of aurora particles on a micro scale were simultaneously simulated.
Multi-scale Interaction of a Solar Wind and an Earth’s Magnetic Field, Aurora
An aurora is the radiating phenomenon generated by the interaction of an earth’s magnetic field and a solar wind. The solar wind is a plasma (the mass of ions and electrons) with one mega ton m**3 that is traveling from the sun (which is 10E9 bigger than the earth) and is continuously hitting the earth. The aurora is considered to be the radiating phenomenon in the air that is generated by the electrons extremely accelerated the interaction of an earth’s magnetic field and a solar wind. An aurora simulation requires the simultaneous evaluation of the physics of plasma (10E10 kg) and electrons (10E-31 kg). However, it is impossible even for the Earth Simulator to compute all electrons in space because of a large numbers of electrons.
The holistic simulation searches the space and time that electrons get accelerated and trace the micro-scale motion of electrons only in that time and space. Then, these effects of electron motions estimated on a micro scale do feedback to the dynamics of whole plasma on a macro scale. This extremely helps simulating physical phenomena as they are. The holistic simulation scheme extremely decreases the amount of computation and it is very meaningful in that it is capable of doing simulation with extreme accuracies by effectively using computation resources.
Simulation of atmospheric physics: From vaporization to rainfall
On the other hand, in the atmosphere, clouds have large effects on climate and weather. Water evaporates from the sea and ground, and it condenses and eventually becomes water drops. These water drops make clouds on the orders from 10E-7 meter to 10E-3 meter. However, it is impossible even for the Earth Simulator to compute all cloud particles because of its large number. Therefore, traditional numerical schemes for a cloud particle simulation have been doing simulation only by using the water amount which is assumed to eventually become a cloud, instead of including the physics of cloud particles. On the other hand, the holistic simulation only but simultaneously computes the important part of cloud particle dynamics and atmospheric dynamics, which are needed for the data communication of physical interaction between macro-scale and micro-scale. This makes the simulation of prediction more accurate.
Holistic Simulator
The EarthSimulatorCenter started the holistic simulation research program and Dr. Kusano from Hiroshima University became a group leader of this program in 2004. Currently, he and four other scientists are working on the development of algorithms that are applicable to many fields such as aurora, abnormal climatology, burning fluid, planet explosion, and material science. Furthermore, the EarthSimulatorCenter is planning the holistic simulator, as the simulator of next generations. This is the epoch-making computer system that put the architectures of actual hard wares into the algorithm of holistic simulations.
Now a further accurate future prediction is becoming a reality.
November,2005