1
00:00:05,580 --> 00:00:09,630
YEN-JIE LEE: Before people
take 8.03 class, especially

2
00:00:09,630 --> 00:00:12,810
my version, most
of the students may

3
00:00:12,810 --> 00:00:18,930
think uncertainty principle
is actually completely related

4
00:00:18,930 --> 00:00:20,980
to quantum mechanics.

5
00:00:20,980 --> 00:00:23,520
So actually it is
actually not the case.

6
00:00:23,520 --> 00:00:27,180
Actually, uncertainty
principle almost have nothing

7
00:00:27,180 --> 00:00:29,770
to do with quantum mechanics.

8
00:00:29,770 --> 00:00:35,370
It has to do with just the
wave description we employ

9
00:00:35,370 --> 00:00:37,680
when we describe the system.

10
00:00:37,680 --> 00:00:39,390
So that's actually
one of the big thing

11
00:00:39,390 --> 00:00:42,960
which you will learn from 8.03.

12
00:00:42,960 --> 00:00:48,420
The other thing which
people will learn a lot more

13
00:00:48,420 --> 00:00:52,780
is actually that before
they come into the class,

14
00:00:52,780 --> 00:00:57,450
they may think it's almost
impossible to understand

15
00:00:57,450 --> 00:01:00,300
infinitely number of
coupled oscillators.

16
00:01:00,300 --> 00:01:05,280
And it turns out that there
is a very systematical way

17
00:01:05,280 --> 00:01:10,500
you can actually make use
of simple symmetry argument,

18
00:01:10,500 --> 00:01:13,410
and that you can
actually greatly simplify

19
00:01:13,410 --> 00:01:18,000
complicated system, like
infinity long system.

20
00:01:18,000 --> 00:01:20,870
So it is actually not
an impossible task,

21
00:01:20,870 --> 00:01:23,600
and then everything can
be actually understand,

22
00:01:23,600 --> 00:01:29,270
using the concept of symmetry,
which we introduce in 8.03.