|MadSci Network: Physics|
What do you mean by not change? That it doesn't interact with the universe at all? Everything (of which we know) interacts with the universe-- otherwise we would have no way of knowing it existed! There are 4 fundamental forces that control everything in the universe: Force Types of particles acted on Weak Everything (quarks, leptons (i.e. electrons, muons and taus), neutrinos) Gravity Everything with mass (i.e. all but neutrinos, unless they have mass) Electromagnetic Everything with charge (i.e. everything but neutrinos) Strong Only quarks The weak for is responsible for many nuclear decays, gravity holds us all on the earth and the earth spinning around the sun, electromagnetism is responsible for most everyday actions (chemistry, friction, etc) and the strong force holds together nuclei in atoms. So all the different types of matter of which we know interact in some manner with the universe around us. To make any sort of measurement, or interact with the universe, we change the object being observed. That means that everything is changeable, and everything releases energy in some form or another. A good text on introductory particle physics is "Introduction to Particle Physics" by Griffiths. -Benn
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