Re: Are there any subatomic particles that release no energy?

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