06.08.2014 Views

Classical Mechanics

Classical Mechanics

Classical Mechanics

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

The description of uniform motion leads to the calculus of variations, the description<br />

of matter leads to a discussion of vectors and tensors, and our analysis<br />

of motion requires techniques of differential forms, connections on manifolds,<br />

and gauge theory.<br />

Once these tools are in place, we derive various well-known and not so wellknown<br />

techniques of classical (and quantum) mechanics.<br />

Numerous examples and exercises are scattered throughout.<br />

[MORE HERE]<br />

Enjoy the ride!<br />

1. Physical theories<br />

Within any theory of matter and motion we may distinguish two conceptually<br />

different features: dynamical laws and measurement theory. We discuss each in<br />

turn.<br />

By dynamical laws, we mean the description of various motions of objects,<br />

both singly and in combination. The central feature of our description is generally<br />

some set of dynamical equations. In classical mechanics, the dynamical<br />

equation is Newtons second law,<br />

v<br />

F = m d dt<br />

or its relativistic generalization, while in classical electrodynamics two of the<br />

Maxwell equations serve the same function:<br />

1 dE<br />

∇ B = 0<br />

c dt<br />

1 dB<br />

+ ∇ E = 4 <br />

J<br />

c dt<br />

c<br />

The remaining two Maxwell equations may be regarded as constraints on the<br />

initial eld conguration. In general relativity the Einstein equation gives the<br />

time evolution of the metric. Finally, in quantum mechanics the dynamical law<br />

is the Schrödinger equation<br />

H ˆ = i<br />

∂<br />

∂t<br />

which governs the time evolution of the wave function, .<br />

6

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!