WEBVTT

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YEN-JIE LEE: I decided
to include a lot of demos

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during my lectures.

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That is because I
believe to learn physics,

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you have to know how to convert
everything into mathematics.

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You want to work
on the mathematics

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and to make predictions,
and finally, you

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want to compare the predictions
to experimental data.

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Demonstrations are
particularly useful because I

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would like to show
that the mathematics we

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covered during the
classroom actually

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have a lot of consequence.

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It's actually really
to do with what

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nature does to all the physical
systems we are interested.

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So that's actually
why we first--

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usually the structure
is like this.

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We first introduce
the physical situation

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we are interested then
we use the concepts

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and the mathematics to
solve the physical system,

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and finally, the last part
is to enjoy what we have

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learned from this hard work.

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To compare our mathematical
solution to reality,

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which is actually the demo.

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So that is actually why
I introduce so many demos

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during the class, and
those, I do think,

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using those demos people
will remember more

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about the conclusion
we can actually

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get from the
mathematics instead of

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overwhelmed by a lot of
calculations during the class.

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There are so many interesting
demos which we covered.

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One of my favorite demos
is the Bell wave machine.

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First of all, it's really
a very beautiful demo.

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It is so beautiful to
see the sinusoidal wave.

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It can be produced from
this simple device.

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Secondly, you you can
actually manipulate them,

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you can connect
them to each other,

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and you can see waves
essentially bouncing

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between systems, and then
you can see the reflection

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of the traveling wave.

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It's so beautiful, and that's
actually my favorite demo

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during the class.

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I believe most of
the students are also

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interested in that
demo very, very much.