Wikipedia - Weightlessness / General Relativity
Field of reference: Physics
Description: Freely falling objects (i.e. particles moving purely under the force of gravity will "feel" no "pressure", they will not be squeezed, etc. Likewise, a free falling spce shuttle will not "feel" gravity until igniting its thrusts ... If it follows "nature" it will feel nothing. It will only start expriencing resistance once it departures/deviate from the "natural" motion, i.e. the force of gravitation. This was a key insight that led Einstein to discover the general theory of relativity (GR)
"Einstein's theory suggests that it actually is valid to consider that objects in inertial motion (such as falling in elevator, or in a parabola in an airplane, or orbiting planet) can indeed be considered to experience a local loss of the gravitational field responsible for their general motion."
| שייך לנושאים: 1-13 - חינוך אינטגרלי, -מקורות מדעיים, הטבע, 3. איזון עם הטבע |
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Berkeley University
Field of reference: Science
Description: humanity benefits from science and scientific innovations
"... And that knowledge is useful for all sorts of things: from designing bridges, to slowing climate change, to prompting frequent hand washing during flu season. Scientific knowledge allows us to develop new technologies, solve practical problems, and make informed decisions - both individually and collectively. ..."
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Dr. Jane Goodall
Field of reference: Biology
Description: altruistic behavior in nature
"Mutual grooming plays an important part in the social life of chimpanzees, and two friends, or even a small group, will sit quietly for hours searching through each other's long black hair for specks of dirt, grass seeds, or ticks.Some students of animal behavior see in this grooming activity the first beginnings of true social and altruistic behavior in the whole animal kingdom."
| שייך לנושאים: 1-13 - חינוך אינטגרלי, -מקורות מדעיים, הטבע, 2. הטבע כמערכת |
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Wikipedia - Mean Field Theory
Field of reference: Physics
Description: Multi-particle physical systems are so complex that only a very efficient approximate treatment is possible. The mean free theory describes such physical systems as individual particles evolving under the influence of an effective force, which is the combined force exerted by the rest of the system.
"Mean field theory (MFT, also known as self-consistent field theory) is a method to analyse physical systems with multiple bodies. A many-body system with interactions is generally very difficult to solve exactly, except for extremely simple cases (random field theory, 1D Ising model). The n-body system is replaced by a 1-body problem with a chosen good external field. The external field replaces the interaction of all the other particles to an arbitrary particle."
| שייך לנושאים: 1-13 - חינוך אינטגרלי, -מקורות מדעיים, הטבע, 2. הטבע כמערכת |
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Wikipedia - Principle of Min. Energy
Field of reference: Physics
Description: Closed physical systems will tend to "arrange" their sub-systems (elements) in such a way that will minimize the system's potential energy while at the same time maximize it's entropy (the level of complexity). In general, lower energy states corresponds with lower entropy, therefore keeping a balance between maximum entropy and minimum energy has some unique and interesting manifestations in physical systems.
"A closed system, on the other hand, is a system which is connected to another system, and may exchange energy, but not mass, with the other system. If, rather than an isolated system, we have a closed system, in which the entropy rather than the energy remains constant, then it follows from the first and second laws of thermodynamics that the energy of that system will drop to a minimum value at equilibrium, transferring its energy to the other system. To restate: * The maximum entropy principle: For a closed system with fixed internal energy (i.e. an isolated system), the entropy is maximized at equilibrium. * The minimum energy principle: For a closed system with fixed entropy, the total energy is minimized at equilibrium. This should not be confused with the minimum total potential energy principle which states that, at equilibrium, the total potential energy of a system with dissipation will be at a minimum, which is a special case of the maximum entropy principle."
| שייך לנושאים: 1-13 - חינוך אינטגרלי, -מקורות מדעיים, הטבע, 2. הטבע כמערכת |
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