Preface
to
the
Definitive
Edition
More
than
forty
years
have
passed
since
Richard
Feynman
taught
the
intro-
ductory
physics
course
that
gave
rise
to
these
three
volumes,
The
Feynman
Lectures
on
Physics.
In
those
forty
years
our
understanding
of
the
physical
world
has
changed
greatly,
but
The
Feynman
Lectures
have
endured.
They
are
as
powerful
today
as
when
first
published,
thanks
to
Feynman’s
unique
physics
insights
and
pedagogy.
The
Lectures
have
been
studied
worldwide
by
novices
and
mature
physi-
cists
alike;
they
have
been
translated
into
at
least
a
dozen
languages
with
more
than
1.5
millions
copies
printed
in
the
English
language
alone.
Perhaps
no
other
set
of
physics
books
has
had
such
wide
impact,
for
so
long.
This
new
Definitive
Edition
of
The
Feynman
Lectures
on
Physics
differs
from
previous
editions
in
two
ways:
all
known
errata
have
been
corrected,
and
it
is
being
published
in
concert
with
a
new
fourth
volume,
Feynman's
Tips
on
Physics:
A
Problem-Solving
Supplement
to
The
Feynman
Lectures
on
Physics.
This
Supplement
contains
additional
materials
from
Feynman’s
course:
three
lectures
by
Feynman
on
problem
solving
and
one
on
inertial
guidance,
plus
exercises
and
answers
prepared
by
Feynman’s
colleagues
Robert
B.
Leighton
and
Rochus
Vogt.
How
this
Edition
Came
to
Be
The
three
original
volumes
of
The
Feynman
Lectures
were
produced
very
quickly
by
Feynman
and
his
co-authors,
Robert
B.
Leighton
and
Matthew
Sands,
working
from
and
expanding
on
tape
recordings
and
blackboard
photos
of
Feynman’s
1961-63
course
lectures.'
Inevitably,
errors
crept
in.
Feynman
accu-
mulated
long
lists
of
claimed
errata
over
the
subsequent
years—errata
found
by
students
and
faculty
at
Caltech
and
by
readers
around
the
world.
In
the
1960’s
and
early
70’s,
Feynman
made
time
in
his
intense
life
to
check
most
of
the
claimed
errata
for
Volumes
I
and
II,
and
insert
corrections
into
subsequent
printings.
However,
Feynman’s
sense
of
duty
never
rose
high
enough
above
the
excitement
of
discovering
new
things
to
make
him
deal
with
the
errata
in
Volume
III.”
After
his
untimely
death
in
1988,
lists
of
unchecked
errata
were
deposited
in
the
Caltech
Archives,
and
there
they
lay
forgotten.
In
2002 Ralph
Leighton
(son
of
the
late
Robert
Leighton
and
compatriot
of
Feynman)
informed
me
of
the
old
errata
and
a
new
long
list
compiled
by
Ralph’s
friend
Michael
Gottlieb.
Leighton
proposed
that
Caltech
produce
this
new
Definitive
Edition
of
The
Feynman
Lectures
with
all
errata
corrected,
and
publish
it
alongside
the
Supplement
volume
that
he
and
Gottlieb
were
preparing.
Leighton
also
sought
my
help
in
making
sure
that
physics
errors
had
not
crept
into
Gottlieb’s
edited
tran-
scription
of
the
Supplement’s
four
lectures,
and
in
obtaining
Caltech’s
agreement
for
the
Supplement
to
be
published
officially
in
concert
with
this
Definitive
Edition
of
the
three
original
volumes.
'
For
descriptions
of
the
genesis
of
Feynman’s
lectures
and
these
volumes,
see
the
Special
Preface,
Feynman's
Preface,
and
the
Foreword—all
in
this
volume
and
its
companions—and
also
Matt
Sands’
Memoir
in
the
new
Supplement.
?
In
1975,
he
started
checking
errata
for
Volume
II
but
got
distracted
by
other
things
and
never
finished
the
task,
so
no
corrections
were
made.
y
hero
and
a
close
personal
friend.
When
I
saw
the
|
t
of
the
Supplement,
I
quickly
agreed
to
help.
Fortunaye
of
rrata
and
the
Supplement’s
physics;
Dy.
Mice!
ae]
Feynman
was
™,
errata
and
the
conten’
knew
the
ideal
person
to
vet
the
e!
Hon
i
in
physics
at
Caltech
ntly
completed
his
PhD
in
phy:
Caltech,
and
haq
Hartl
had
ve
fetime
achievement
award
for
excellence
in
teaching”
eye,
been
our
undergraduates.
Hartl
understands
Biven
ulous
physicists
I
have
known,
and
like
Fey,
icy
‘an
granted
the
only
to
a
Caltech
graduate
student
by
deeply,
he
is
among
the
most
metic’
he
is
an
outstanding
pedagogue.
.
woh
‘And
so
we
struck
a
deal:
Ralph
Leighton
and
Michael
Gottlieb
Prepareg
the
did
so
superbly
well),
with
authorization
from
Feynman’s
chi
Cerro
atichelle
who
own
the
Supplement's
four
lectures,
and
from
Rochas
and
Leighton
himself
for
the
Supplement’s
exercises
and
answers,
Leigh
®
Gottlieb,
and
the
Feynmans
gave
me
final
authority
over
the
Supplement’s
co!
tents.
Caltech
(i.e.,
Tom
Tombrello,
Chair
of
Physics,
Mathematics
and
Astronomy)
gave
me
authority
to
oversee
the
new
Definitive
Edition
of
the
Original
three
Vol.
umes
and
agreed
to
the
Supplement
being
published
in
concert
with
the
Definitiy,
Edition.
And
everyone
agreed
that
Michael
Hartl
would
act
in
my
behalf,
Velti
the
errata
for
the
Definitive
Edition,
and
editing
the
physics
content
and
phy
sie
style
of
the
Supplement.
I
would
spot
check
Hartl’s
work
and
APPTOVE
the
fina
version
of
all
four
volumes,
and
Addison-Wesley,
the
Publisher,
would
Dring
the
project
to
conclusion.
To
my
delight,
this
has
all
come
to
fruition
smoothly!
Feynman
woulq
be
pleased
and
proud
of
the
product,
I
do
believe.
The
Errata
The
errata
corrected
in
this
edition
come
from
three
sources:
about
80
per.
cent
are
from
Michael
Gottlieb;
most
of
the
rest
are
from
a
long
list
by
an
anony.
mous
reader,
submitted
to
Feynman
in
the
early
1970s
via
the
publisher;
and
the
remainder
are
from
scattered
short
lists
provided
to
Feynman
or
us
by
various
readers.
The
corrected
errata
are
mainly
of
three
types:
(i)
typographical
errors
in
the
prose;
(ii)
roughly
150
typographical
and
mathematical
errors
in
equations,
tables,
and
figures—sign
errors,
incorrect
numbers
(e.g.,
a
5
that
should
be
a
4),
and
miss.
ing
subscripts,
summation
signs,
parentheses
and
terms
in
equations;
(iii)
roughly
50
incorrect
cross
references
to
chapters,
tables,
and
figures.
These
kinds
of
errors,
though
not
terribly
serious
to
a
mature
physicist,
can
be
frustrating
and
confusing
to
students,
the
audience
Feynman
was
trying
to
reach.
It
is
remarkable
that
the
errata
included
only
two
inadvertent
errors
in
physics;
Volume
I,
page
45-4
now
says
“When
a
rubber
band
is
stretched
its
temperature
rises,”
not
“falls”
as
claimed
in
previous
editions;
and
Volume
II,
page
5-9
now
says
“,
..
no
static
distribution
of
charges
inside
a
closed
grounded
conductor
can
produce
any
[electric]
fields
outside”
(the
word
grounded
was
omitted
in
previous
editions).
This
second
error
was
pointed
out
to
Feynman
by
a
number
of
readers,
including
Beulah
Elizabeth
Cox,
a
student
at
The
College
of
William
and
Mary,
who
had
relied
on
Feynman’s
erroneous
passage
in
an
exam.
To
Ms.
Cox,
Feynman
wrote
in
1975,?
“Your
instructor
was
right
not
to
give
you
any
points,
for
your
answer
was
wrong,
as
he
demonstrated
using
Gauss’s
law.
You
should,
in
science,
believe
logic
and
arguments,
carefully
drawn,
and
not
authorities.
You
also
read
the
book
correctly
and
understood
it.
I
made
a
mistake,
so
the
book
is
wrong.
I
prob-
ably
was
thinking
of
a
grounded
conducting
sphere,
or
else
of
the
fact
that
mov-
ing
the
charges
around
in
different
places
inside
does
not
affect
things
on
the
3
Pages
288-289
of
Perfectly
Reasonable
Deviations
from
the
Beaten
Track,
The
Letters
of
Richard
P.
Feynman,
ed.
Michelle
Feynman
(Basic
Books,
New
York,
2005).
outside.
I
am
not
sure
how
I
did
it,
but
I
goofed.
And
you
goofed,
too,
for
believ-
ing
me.”
Feynman
was
uncomfortably
aware
of
this
error,
and
of
others.
In
correspon-
dence
with
the
publisher
in
1975,
he
refers
to
“errors
of
physics
in
Volumes
II
and
III
that
are
more
than
just
typographical.”
I
do
not
know
the
other
errors.
Finding
them
is
a
challenge
for
future
readers!
To
this
end,
Michael
Gottlieb
is
creating
a
web
site,
www.feynmanlectures.info,
on
which
all
errata
corrected
in
this
Edition
will
be
listed,
along
with
any
new
errata
found
by
future
readers.
The
Supplement
Feynman's
Tips
on
Physics:
A
Problem
Solving
Supplement
to
the
Feynman
Lectures
on
Physics
is
a
fascinating
fourth
volume.
Its
highlight
is
four
lectures
mentioned
by
Feynman
in
his
Preface
to
the
original
volumes:
“Although
I
did put
in
three
lectures
in
the
first
year
on
how
to
solve
problems,
they
are
not
included
here,”
he
wrote.
“Also
there
was
a
lecture
on
inertial
guidance
which
certainly
belongs
after
the
lecture
on
rotating
systems,
but
which
was,
unfortunately,
omitted.”
Michael
Gottlieb
has
prepared
the
Supplement’s
written
version
of
these
four
lectures
working
with
Ralph
Leighton
from
tape
recordings
of
Feynman’s
presen-
tations
and
from
photographs
of
his
blackboards,
in
much
the
same
way
that
Ralph’s
father
and
Matthew
Sands prepared
the
original
three
volumes
40
years
ago,
but
without
the
pressure
of
time.
The
only
thing
missing
was
Feynman,
to
vet
the
written
manuscript.
Matthew
Sands
played
Feynman’s
role,
giving
Gottlieb
feedback
and
advice,
and
then
Hartl
and
I
provided
the
final
vetting.
Fortunately,
Gottlieb
did
such
an
excellent
job
of
capturing
Feynman’s
four
lectures
onto
the
written
page
that
our
task
was
easy.
These
four
“new”
lectures
are
a
delight
to
read,
especially
passages
where
Feynman
advises
the
students
about
how
to
deal
with
being
in
the
bottom
half
of
the
class.
The
“new”
lectures
are
accompanied,
in
the
Supplement,
by
an
equally
delight-
ful
Memoir
by
Matthew
Sands—reminiscences,
43
years
later,
about
the
genesis
and
creation
of
The
Feynman
Lectures
on
Physics,
and
by
a
selected
set
of
instructive
problems
and
answers
prepared
in
the
mid
1960’s
by
Robert
Leighton
and
Rochus
Vogt
for
use
with The
Feynman
Lectures.
Several
of
my
physicist
colleagues,
who
worked
through
these
problems
as
Caltech
students,
tell
me
how
well
crafted
and
useful
they
are.
The
Structure
of
this
Edition
This
Definitive
Edition
begins
with
front
matter,
paginated
in
Roman
numer-
als,
that
was created
in
“modern
times”,
long
after
the
First
Edition:
this
Preface,
a
brief
Biography
of
Feynman,
and
a
Special
Preface
written
in
1989
by
Gerry
Neugebauer
(who
participated
in
preparation
of
the
original
three
volumes)
and
David
Goodstein
(creator
of
The
Mechanical
Universe
course
and
films).
The
sub-
sequent
material,
paginated
with
Arabic
numerals
1,
2,
3,...,
is
identical
to
the
original
First
Edition,
except
for the
correction
of
errata.
Memories
of
Feynman’s
Lectures
These
three
volumes
are
a
self-contained
pedagogical
treatise.
They
are
also
a
historical
record
of
Feynman’s
1961-63
lectures,
a
course
required
for
all
Caltech
freshmen
and
sophomores
regardless
of
their
majors.
Readers
may
wonder,
as
have
I,
how
Feynman’s
lectures
impacted
the
students.
Feynman,
in
his
Preface
to
these
volumes,
offers
a
somewhat
negative
view.
“I
don’t
think
I
did
very
well
by the
students,”
he
writes.
Goodstein
and
Neugebauer,
xi
i i
while
Sands,
in
hj
in
their
1989
Special
Preface,
express
a
mined
vositive
vow
Out
oes
men,
i
ses
a
far
.
Tios
in
the
new
Supplement,
expres:
random
set
of
17
students
(out
one
in
juasi-
spring
2005
I
emailed
or
talked
to
aq
had
great
difficulty
with
the
clas.
Pou
who
150)
from
that
1961-63
class—some
WEN)
chemist'y,
en
class,
ay,
some
who
mastered
it
with
eases
majors
in
biology,
try,
engineering,
i
i
Reo}
cs
and
astronomy,
as
well
as
in
physics.
7
;
OOO
nrervening
years
might
have
glazed
Oe
ae
itis
euphori
but
about
80
percent
recall
Feynman’s
lectures
as
h
ao
inns
college
Yean
“Tt
was
like
going
to
church.”
The
lectures
were
i"
ant
‘ona
experience
“the
experience
of
a
lifetime,
probably
the
mos
Poand
ing
I
got
from
Caltech.”
“I
was
a
biology
major
but
Feynman
s
arian
ee
out
as
a
high
Poin
in
my
undergraduate
experience
.
-
-
though
I
mee
mi
uldn’t
do
the
home,
work
at
the
time
and
I
hardly
turned
any
of
it
in.
was
among
the
least
Promis,
ing
of
students
in
this
course,
and
I
never
missed
‘
lecture
.
I
remember
can
still
feel
Feynman’s
joy
of
discovery:
-
-
-
His
ectures
ad
an.
impact
that
was
probably
lost
in
the
printed
Lectures.
‘esd
By
contrast,
several
of
the
students
have
negative
sees
lue
largely
to
the
issues:
(i)
“You
couldn’t
learn
to
work
the
homework
problems
by
attending
the
lee
tures.
Feynman
was
too
slick—he
knew
tricks
and
what
approximations
Could
be
made,
and
had
intuition
based
on
experience
and
genius
that
a
beginning
studen,
does
not
possess.”
Feynman
and
colleagues,
aware
of
this
flaw
in
the
Course
addressed
it
in
part
with
materials
now
incorporated
into
the
Supplement:
the
Leighton-Vogt
problems
and
answers,
and
Feynman
s
problem-solving
lectures
owing
what
was
likely
to
be
discussed
in
the
next
lec.
(ii)
“The
insecurity
of
not
kn
:
:
ture,
the
lack
of
a
text
book
or
reference
with
any
connection
to
the
lecture
mate.
rial,
and
consequent
inability
for
us
to
read
ahead,
were
very
frustrating,
|.
dl
found
the
lectures
exciting
and
understandable
in
the
hall,
but
they
were
Sanskn,
outside
[when
I
tried
to
reconstruct
the
details].”
This
problem,
of
course,
Was
solved
by
these
three
volumes,
the
written
version
of
The
Feynman
Lectures
on
Physics.
They
became
the
textbook
from
which
Caltech
students
studied
for
many
years
thereafter,
and
they
live
on
today
as
one
of
Feynman’s
greatest
legacies,
C
tint
and
oe
€Motionaj
Acknowledgments
This
Definitive
Edition
of
The
Feynman
Lectures
on
Physics
would
not
have
been
possible
without
the
original
impetus
from
Ralph
Leighton
and
Michael
Gottlieb
and
the
outstanding
hands-on
work
with
the
errata
by
Michael
Hartl,
|
thank
Gottlieb
and
anonymous
readers
for
the
lists
of
errata
on
which
the
correc.
tions
were
based,
and
I
thank
Tom
Tombrello,
Rochus
Vogt,
Gerry
Neugebauer,
James
Hartle,
Carl
and
Michelle
Feynman,
and
Adam
Black
for
their
support,
sage
advice,
and
contributions
to
this
endeavor.
Kip
S.
Thorne
The
Feynman
Professor
of
Theoretical
Physics
California
Institute
of
Technology
May
2005
ali
