Where Traditional Physics StopsWe're about to move into the modern age of physics. In the early 1800's, scientists began examining the basis of matter, space, and time. Sometimes it gets very confusing, but the big idea is that Newton's physics describe about 90% of the way things work in the universe (mechanics). His ideas start to break down when you talk about ideas such as objects moving at the speed of light, the inside of atoms, extreme temperatures, and when the objects are huge (like galaxies interacting with each other).
Into the AtomThe original idea of atoms developed by Niels Bohr showed a structure based on various shells and a center area called the nucleus. The electrons were found in those shells while the protons and neutrons were found in the nucleus. There are other ways to look at the structure of atoms (you may have heard of "spdf"), but we're going to stick with the classic view for many of our discussions. This view of the structure of an atom was one of the foundations for modern physics.
Into the UniverseAlbert Einstein also played a large part in modern physics. He developed formulas that described the way matter and energy were related. Just about everyone has heard of the formula E=mc^2. That formula explains how energy is related to mass. The idea found its way into the study of fission reactions, and it was proved that enormous amounts of energy were stored in even one atom of a substance.
Current StudiesEven now, scientists are still testing the boundaries of physics and the laws of physics. Only a few years ago a new state of matter was created. The Bose-Einstein condensate was theorized decades ago, but scientists have only recently been able to create it in a lab. Every day astronomers are studying space and learning how black holes and galaxies interact. Stephen Hawking is one of the more famous scientists working in that field. Our point is, there is still much to discover.
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Einstein’s Cosmic Speed Limit (NASA/GSFC Video)
Useful Reference MaterialsEncyclopedia.com (Astrophysics):
Encyclopædia Britannica (Scope of Physics):