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Definition of Physics

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Definition of Physics


Credit: Courtesy of NASA/JPL-Caltech
Source: http://www.jpl.nasa.gov/news/news.php?feature=560
License: CC BY-NC 3.0

This is one of several large parabolic antennas at the Goldstone complex of the worldwide Deep Space Network that Jet Propulsion Laboratory manages for NASA.  It spans 34 meters from rim to rim and stands nine stories tall.  NASA used it for years to communicate with ships and devices in solar system exploration missions such as the Mariner, Voyager, and Galileo.  When newer antennas replaced this antenna in communications use, it was converted to a radio telescope.

Definition of Physics

What is physics ?  Here is a definition you might find in a dictionary: 

Physics is the science of matter and energy and of interactions between the two.  Physics is grouped into traditional fields such as acoustics, optics, mechanics, thermodynamics, and electromagnetism, as well as in modern extensions including atomic and nuclear physics, cryogenics, solid-state physics, particle physics, and plasma physics.

This is an accurate definition, but it doesn’t really mean much to a beginning physics student, especially if he/she doesn’t know definitions for acoustics, optics, cryogenics, etc. 

Physics is the branch of science that studies the physical world using objects as small as sub-atomic particles and as large as galaxies.  It studies the natures of matter and energy and how they interact.  Physicists are inquisitive people who want to know the causes of what they see.  How does the moon move?  Why does the moon move?  Why do the stars shine?  Why do your hands get warm when you rub them together? Physicists, like all scientists, hope to find explanations that describe more than one phenomenon and offer a better understanding of how the universe works.  Perhaps physics should be defined as the search for understanding of how the universe works.


  • Physics is the branch of science that studies matter and energy and how they interact.

Image Attributions

  1. [1]^ Credit: Courtesy of NASA/JPL-Caltech; Source: http://www.jpl.nasa.gov/news/news.php?feature=560; License: CC BY-NC 3.0

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