English subtitles for clip: File:Course Overview (6.002x).webm

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search
1
00:00:00,550 --> 00:00:03,060
SPEAKER 1: 6.002x, as I
mentioned earlier, is the

2
00:00:03,060 --> 00:00:06,440
first course in a typical
EE or EECS

3
00:00:06,440 --> 00:00:08,970
curriculum as it is at MIT.

4
00:00:08,970 --> 00:00:11,620
So before we start, I'd like to
spend some time discussing

5
00:00:11,620 --> 00:00:15,180
where exactly, such a circuits
and electronics course and the

6
00:00:15,180 --> 00:00:17,050
content that it teaches
fits within the

7
00:00:17,050 --> 00:00:18,310
grand scheme of things.

8
00:00:18,310 --> 00:00:20,550
We will start by trying
to understand, what is

9
00:00:20,550 --> 00:00:21,140
engineering?

10
00:00:21,140 --> 00:00:24,290
Well, engineering is the
purposeful use of science,

11
00:00:24,290 --> 00:00:27,440
where science, itself, is
the study of what is.

12
00:00:27,440 --> 00:00:29,500
In other words, it's the
study of nature.

13
00:00:29,500 --> 00:00:32,270
With engineering, we
are now focused on

14
00:00:32,270 --> 00:00:33,750
what we make of nature.

15
00:00:33,750 --> 00:00:34,640
It's what we build.

16
00:00:34,640 --> 00:00:37,720
It's how we can use science
to help humanity.

17
00:00:37,720 --> 00:00:41,080
So then, where does
6.002x fit in?

18
00:00:41,080 --> 00:00:44,100
6.002x is about the gainful
employment of Maxwell's

19
00:00:44,100 --> 00:00:47,320
equations, going all the way
from electrons to digital

20
00:00:47,320 --> 00:00:49,570
gates and op-amps.

21
00:00:49,570 --> 00:00:52,800
As I mentioned earlier, just
as engineering is the

22
00:00:52,800 --> 00:00:57,460
purposeful use of science or
nature, 6.002x is about the

23
00:00:57,460 --> 00:00:59,040
use of Maxwell's equations.

24
00:00:59,040 --> 00:01:02,230
Now, when you have nature,
that is what is.

25
00:01:02,230 --> 00:01:05,090
So you can study nature
and that is science.

26
00:01:05,090 --> 00:01:06,640
You're not allowed to
change anything.

27
00:01:06,640 --> 00:01:09,930
With engineering, you are
looking to build cool stuff,

28
00:01:09,930 --> 00:01:11,530
things that can help humanity.

29
00:01:11,530 --> 00:01:15,250
And in order to build such
stuff, we often abstract

30
00:01:15,250 --> 00:01:19,200
nature, or we abstract
what is into laws.

31
00:01:19,200 --> 00:01:23,830
And Maxwell's equations are laws
that govern the behavior

32
00:01:23,830 --> 00:01:25,500
of one part of nature.

33
00:01:25,500 --> 00:01:30,720
And 6.002x is about employing
Maxwell's equations to build

34
00:01:30,720 --> 00:01:33,080
cool systems that can
help humanity.

35
00:01:33,080 --> 00:01:37,070
Now, let's try to get a better
handle on exactly what we mean

36
00:01:37,070 --> 00:01:39,720
by looking at how
nature behaves.

37
00:01:39,720 --> 00:01:41,980
Or at least, nature
as described

38
00:01:41,980 --> 00:01:43,370
by Maxwell's equations.

39
00:01:43,370 --> 00:01:46,900
And let's see how that will lead
to building really useful

40
00:01:46,900 --> 00:01:48,410
systems that can
help humanity.

41
00:01:48,410 --> 00:01:52,970
So so let's put nature and what
is on the left-hand side.

42
00:01:52,970 --> 00:01:55,300
And on the right-hand side,
let's put down what are the

43
00:01:55,300 --> 00:01:57,280
kind of things that we
may want to build

44
00:01:57,280 --> 00:01:58,420
that will help humanity.

45
00:01:58,420 --> 00:02:01,250
So computer mice
are an example.

46
00:02:01,250 --> 00:02:06,270
Cool devices like your iPad or
your RAZR phone are useful

47
00:02:06,270 --> 00:02:09,670
devices, space shuttle,
stereo systems,

48
00:02:09,669 --> 00:02:11,909
sonar, even Angry Birds.

49
00:02:11,910 --> 00:02:14,660
So let's see, so how do we take
nature, what is available

50
00:02:14,660 --> 00:02:17,060
to us, and how do we build,
as engineers,

51
00:02:17,060 --> 00:02:18,540
really useful systems?

52
00:02:18,540 --> 00:02:19,680
So we start with nature.

53
00:02:19,680 --> 00:02:20,670
That's what we are given.

54
00:02:20,670 --> 00:02:24,330
So what we could do is look
at how nature behaves by

55
00:02:24,330 --> 00:02:26,050
performing sets of
experiments.

56
00:02:26,050 --> 00:02:27,690
So we could perform experiments

57
00:02:27,690 --> 00:02:28,750
and build some tables.

58
00:02:28,750 --> 00:02:33,260
So as one example, in the area
that we are concerned about,

59
00:02:33,260 --> 00:02:35,410
we can measure voltages
and currents.

60
00:02:35,410 --> 00:02:40,380
So for various voltages, I can
measure currents that arise

61
00:02:40,380 --> 00:02:42,060
from those voltages.

62
00:02:42,060 --> 00:02:45,830
So I could have 4 volts and
so on and so forth.

63
00:02:45,830 --> 00:02:48,790
I can apply voltages to some
material and measure the

64
00:02:48,790 --> 00:02:50,450
current that flows through
those materials.

65
00:02:50,450 --> 00:02:53,300
In the same manner, I can
collect tables and tables and

66
00:02:53,300 --> 00:02:57,010
reams and reams of data to
characterize all kinds of

67
00:02:57,010 --> 00:03:00,150
parts of nature, and have reams
and reams of this data.

68
00:03:00,150 --> 00:03:03,450
So I could take reams of this
data, and somehow try to build

69
00:03:03,450 --> 00:03:05,850
those systems based on all those
properties of nature.

70
00:03:05,850 --> 00:03:09,210
Now, that is clearly a
herculean, if anything,

71
00:03:09,210 --> 00:03:10,340
ludicrous task.

72
00:03:10,340 --> 00:03:11,070
So what do we do?

73
00:03:11,070 --> 00:03:12,390
This is just too hard.

74
00:03:12,390 --> 00:03:14,810
And nobody sits down with reams
of data looking at how

75
00:03:14,810 --> 00:03:16,440
nature behaves and
build systems.

76
00:03:16,440 --> 00:03:17,440
What do we do instead?

77
00:03:17,440 --> 00:03:22,280
What we do, as engineers, is we
start by building laws or

78
00:03:22,280 --> 00:03:25,810
abstractions that succinctly
describe how nature behaves.

79
00:03:25,810 --> 00:03:29,470
So, for example, I can take
these measurements that I made

80
00:03:29,470 --> 00:03:31,970
of voltages and currents,
and I can say, a-ha.

81
00:03:31,970 --> 00:03:35,250
I can describe certain
materials that behave

82
00:03:35,250 --> 00:03:39,600
according to certain laws, and
write an equation, such as v

83
00:03:39,600 --> 00:03:43,880
is equal to ri, which is Ohm's
Law, that governs certain

84
00:03:43,880 --> 00:03:44,930
types of devices.

85
00:03:44,930 --> 00:03:48,190
Other phenomena are described
by Maxwell's equations.

86
00:03:48,190 --> 00:03:52,030
And these equations now, whether
it's Maxwell's, Ohm's,

87
00:03:52,030 --> 00:03:55,770
or classes of other equations,
think of these as succinct

88
00:03:55,770 --> 00:04:00,230
expressions or learning from the
reams and reams and rooms

89
00:04:00,230 --> 00:04:01,110
and rooms of data.

90
00:04:01,110 --> 00:04:04,670
So here, these equations can be
thought of as abstractions

91
00:04:04,670 --> 00:04:05,790
for those tables of data.

92
00:04:05,790 --> 00:04:09,280
And just imagine a simple law
like Ohm's Law, v is equal to

93
00:04:09,280 --> 00:04:13,130
ri, which you've learned about
in your high school advanced

94
00:04:13,130 --> 00:04:14,080
physics courses.

95
00:04:14,080 --> 00:04:18,990
Now, in one little, simple
equation v equals ri, can

96
00:04:18,990 --> 00:04:22,750
describe reams and reams of data
that govern the behavior

97
00:04:22,750 --> 00:04:24,460
of a certain class of devices.

98
00:04:24,460 --> 00:04:26,290
So we have simplified our
lives quite a bit.

99
00:04:26,290 --> 00:04:29,940
But still, trying to use
Maxwell's equations to develop

100
00:04:29,940 --> 00:04:33,670
Angry Birds, or to develop
computers and so on, is just a

101
00:04:33,670 --> 00:04:34,770
mind-numbing task.

102
00:04:34,770 --> 00:04:35,770
Just can't be done.

103
00:04:35,770 --> 00:04:36,730
So what do we do instead?

104
00:04:36,730 --> 00:04:39,270
So remember, we have engineers,
and our goal is to

105
00:04:39,270 --> 00:04:42,040
build these systems at the end
that will help humanity.

106
00:04:42,040 --> 00:04:46,170
So what we will do is we will
make some assumptions that you

107
00:04:46,170 --> 00:04:47,780
will see in the rest
of this lecture.

108
00:04:47,780 --> 00:04:50,840
And by making certain classes of
assumptions, we will build

109
00:04:50,840 --> 00:04:53,310
what is called the lumped
circuit abstraction.

110
00:04:53,310 --> 00:04:56,090
Now, the lumped circuit
abstraction, we have a set of

111
00:04:56,090 --> 00:05:00,100
lumped elements, or discrete
elements, such as resistors,

112
00:05:00,100 --> 00:05:03,960
capacitors, voltage sources,
inductors, transistors like

113
00:05:03,960 --> 00:05:06,720
the MOSFET switches, and
so on and so forth.

114
00:05:06,720 --> 00:05:10,790
So now, other than using
equations and equations, we

115
00:05:10,790 --> 00:05:13,900
build some abstractions and
build some discrete devices

116
00:05:13,900 --> 00:05:15,890
that we shall use in
building systems.

117
00:05:15,890 --> 00:05:18,840
Now, we could take these simple
devices and go ahead

118
00:05:18,840 --> 00:05:19,620
and build computers.

119
00:05:19,620 --> 00:05:20,780
But nobody does it that way.

120
00:05:20,780 --> 00:05:23,660
When you build a computer,
such as a modern

121
00:05:23,660 --> 00:05:26,450
microprocessor, such a
microprocessor might have 10

122
00:05:26,450 --> 00:05:27,950
billion elements in it.

123
00:05:27,950 --> 00:05:31,960
There's no way we can sit around
dealing with resistors

124
00:05:31,960 --> 00:05:35,630
and MOSFETs in quantities of 10
billion, and individually

125
00:05:35,625 --> 00:05:37,205
build systems using that.

126
00:05:37,200 --> 00:05:40,580
So what we do is, again, apply
the process of abstraction.

127
00:05:40,580 --> 00:05:42,590
We abstract out the behavior of

128
00:05:42,590 --> 00:05:43,870
collections of these elements.

129
00:05:43,870 --> 00:05:47,170
And the next abstractions we
will make in this course is

130
00:05:47,170 --> 00:05:49,150
the simple amplified
abstraction.

131
00:05:49,150 --> 00:05:51,420
We learn a lot more about
this as we go on.

132
00:05:51,420 --> 00:05:55,230
This amplifier may have dozens,
if not hundreds of

133
00:05:55,230 --> 00:05:57,280
these lumped elements
inside them.

134
00:05:57,280 --> 00:05:59,990
But then we will go and continue
to work with those

135
00:05:59,990 --> 00:06:03,970
amplifiers, which are abstract
conglomerates of a lot of

136
00:06:03,970 --> 00:06:04,630
these elements.

137
00:06:04,630 --> 00:06:08,850
So at this point, life can take
a couple of turns once we

138
00:06:08,850 --> 00:06:10,740
build a simple amplifier
abstraction.

139
00:06:10,740 --> 00:06:14,030
So one thing we could do from
there is use that to build

140
00:06:14,030 --> 00:06:16,680
what we call the operational
amplifier abstraction.

141
00:06:16,680 --> 00:06:20,250
And then, using that, we can
build even more complex

142
00:06:20,250 --> 00:06:21,760
system, such as filters.

143
00:06:21,760 --> 00:06:26,260
Filters are able to process data
in various ways and give

144
00:06:26,260 --> 00:06:29,820
us a set of outputs that might
suit our purposes in

145
00:06:29,820 --> 00:06:31,590
engineering certain classes
of systems.

146
00:06:31,590 --> 00:06:35,190
Then we build the next level of
systems, analog subsystems,

147
00:06:35,190 --> 00:06:38,500
such as oscillators, modulators,
RF amplifiers,

148
00:06:38,500 --> 00:06:39,850
power supplies, and so on.

149
00:06:39,850 --> 00:06:44,630
And then, those would be used
in systems like the space

150
00:06:44,630 --> 00:06:46,470
shuttle, or phones, and
things like that.

151
00:06:46,470 --> 00:06:50,710
So that is one whole set of
directions that we can take.

152
00:06:50,710 --> 00:06:53,460
Think of that as the
analog direction.

153
00:06:53,460 --> 00:06:57,440
But we can take a second
direction, that is along the

154
00:06:57,440 --> 00:06:59,150
lines of the digital
abstraction.

155
00:06:59,150 --> 00:07:01,610
So in this world, we will
make a different set of

156
00:07:01,610 --> 00:07:02,360
assumptions.

157
00:07:02,360 --> 00:07:05,480
And you will see that what we
will do is rather than look at

158
00:07:05,480 --> 00:07:09,160
a continuous set of values,
analog values, we will simply

159
00:07:09,160 --> 00:07:12,840
look at dividing up all values
into two distinct

160
00:07:12,840 --> 00:07:14,600
quantities, 1 and 0.

161
00:07:14,600 --> 00:07:17,620
And by doing so, we will build
up what we call the digital

162
00:07:17,620 --> 00:07:18,400
abstraction.

163
00:07:18,400 --> 00:07:20,800
And the first set of components
we will build in

164
00:07:20,797 --> 00:07:23,917
the digital abstraction are
what are called gates.

165
00:07:23,920 --> 00:07:27,200
Following that, we will build
even more complex logic,

166
00:07:27,200 --> 00:07:28,400
combinational logic.

167
00:07:28,400 --> 00:07:32,570
And then, using combinational
logic, we will apply some time

168
00:07:32,570 --> 00:07:35,400
[? keeping ?] signals, like
clocks and so on, and build

169
00:07:35,400 --> 00:07:39,820
what we call clock digital
systems. And abstractly, these

170
00:07:39,820 --> 00:07:42,830
clock digital systems will be
used to build even more

171
00:07:42,830 --> 00:07:45,710
complicated and useful
systems, such as

172
00:07:45,710 --> 00:07:46,790
microprocessors.

173
00:07:46,790 --> 00:07:50,340
So, for example, there the
abstraction we make is called

174
00:07:50,340 --> 00:07:54,300
the instruction set abstraction,
or ISA, I-S-A.

175
00:07:54,300 --> 00:07:57,210
And the instructions of
abstraction will allow us to

176
00:07:57,210 --> 00:07:59,750
build an even more complicated
class of systems that are

177
00:07:59,750 --> 00:08:01,740
characterized by their
instruction sets.

178
00:08:01,740 --> 00:08:04,290
So we can have the MIPS
instruction set, we can have

179
00:08:04,290 --> 00:08:06,800
the Pentium instruction set,
and so on and so forth.

180
00:08:06,800 --> 00:08:10,110
Following that, we will build
another level of abstraction.

181
00:08:10,110 --> 00:08:15,030
Try to build systems using
instructions in the ISA of a

182
00:08:15,030 --> 00:08:17,700
microprocessor is just way
too complicated still.

183
00:08:17,700 --> 00:08:19,250
So we build higher
level languages.

184
00:08:19,250 --> 00:08:22,070
And I'm sure many of you are
familiar with languages such

185
00:08:22,070 --> 00:08:26,010
as Java, Python, CC++,
and so on.

186
00:08:26,010 --> 00:08:28,660
Following that, we build
software systems or hardware

187
00:08:28,660 --> 00:08:32,400
systems, such as operating
systems, and web browsers, and

188
00:08:32,400 --> 00:08:33,530
things of that sort.

189
00:08:33,526 --> 00:08:34,796
And then, we combine.

190
00:08:34,799 --> 00:08:37,439
We have the big combination
where we take the subsystems

191
00:08:37,440 --> 00:08:40,920
we put together both from the
analog dimension, such as

192
00:08:40,919 --> 00:08:43,969
power supplies and so on, and
pieces of computer hardware,

193
00:08:43,970 --> 00:08:45,230
such as oscillators.

194
00:08:45,230 --> 00:08:48,680
And then from the digital side,
we take both software

195
00:08:48,680 --> 00:08:51,400
systems and hardware systems
like microprocessors and

196
00:08:51,400 --> 00:08:52,110
combine them.

197
00:08:52,110 --> 00:08:56,170
And after we combine them, we
end up with very interesting

198
00:08:56,170 --> 00:09:00,780
systems like games and so on on
your handheld devices, or

199
00:09:00,780 --> 00:09:02,410
the space shuttle,
for instance.

200
00:09:02,410 --> 00:09:04,230
Now, what does 6.002 cover?

201
00:09:04,230 --> 00:09:08,290
So 6.002 will help you make the
transition from physics

202
00:09:08,290 --> 00:09:12,430
and take it all the way into
analog and digital subsystems.

203
00:09:12,430 --> 00:09:16,940
So 6.002x will take you from
physics laws, make the jump to

204
00:09:16,940 --> 00:09:20,970
engineering, where we will
abstract these physics laws

205
00:09:20,970 --> 00:09:24,480
and properties into lumped
devices, build the lumped

206
00:09:24,480 --> 00:09:27,670
circuit abstraction, and then
take the one path on the

207
00:09:27,670 --> 00:09:31,270
analog direction and build
analog subsystems. And then,

208
00:09:31,270 --> 00:09:35,420
we will also go down a fair bit
down a digital path and

209
00:09:35,420 --> 00:09:38,400
take you all the way to
primitive clock digital

210
00:09:38,400 --> 00:09:39,020
components.

211
00:09:39,020 --> 00:09:43,210
And the reason we cover this
amount of ground in 6.002x is

212
00:09:43,210 --> 00:09:46,040
really, really to emphasize the
point that the foundations

213
00:09:46,040 --> 00:09:50,790
of both the analog and the
digital world are the same.

214
00:09:50,790 --> 00:09:53,410
The foundations are the same
lumped circuit elements.

215
00:09:53,410 --> 00:09:56,820
And whose foundations are your
basic laws of physics, such as

216
00:09:56,820 --> 00:09:57,710
Maxwell's equation.

217
00:09:57,710 --> 00:09:59,970
And of course, the foundations
of those laws is

218
00:09:59,970 --> 00:10:01,100
nature as you see it.

219
00:10:01,100 --> 00:10:02,510
So there you have it.

220
00:10:02,505 --> 00:10:05,315
This should give you a sense
of the grand scheme

221
00:10:05,310 --> 00:10:07,530
of things in 6.002x.

222
00:10:07,530 --> 00:10:10,630
And for that matter, in pretty
much an entire EECS

223
00:10:10,630 --> 00:10:11,180
curriculum.

224
00:10:11,180 --> 00:10:14,440
So just to show you why this
large map here pretty much

225
00:10:14,440 --> 00:10:18,700
covers the typical EECS
curriculum, notice that a

226
00:10:18,700 --> 00:10:23,260
course at MIT such as 6.061
will cover power supplies.

227
00:10:23,260 --> 00:10:28,280
A course such as 6.004 or 6.846
will cover computer

228
00:10:28,280 --> 00:10:30,760
architecture and parallel
computing.

229
00:10:30,760 --> 00:10:34,000
A course such as 6.002 will
cover introduction to

230
00:10:34,000 --> 00:10:34,780
programming.

231
00:10:34,780 --> 00:10:38,130
A course such as 6.033 will
cover basic software systems.

232
00:10:38,130 --> 00:10:40,490
And there will be many, many,
many other more advanced

233
00:10:40,490 --> 00:10:44,280
courses that will cover the
further advanced components.

234
00:10:44,280 --> 00:10:48,480
Nowt o get a sense of many of
these follow-on courses, you

235
00:10:48,480 --> 00:10:52,820
can get a sneak peak of
the material at OCW,

236
00:10:52,820 --> 00:10:57,980
OpenCourseWare, or over the next
few semesters, we shall

237
00:10:57,980 --> 00:11:02,120
make many of these courses
available on MITX as well.