1 control systems - short history -...
TRANSCRIPT
©D
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Ŝ.
JA
NU
SZ L
ICH
OT
A
CO
NT
RO
L S
YST
EM
S
Short
his
tory
of
contr
olsy
stem
s
Faculty of Mechanical and Power Engineering
CO
NT
EN
TS
•P
reh
isto
ry60
0 B
.C. –
12
58
A.D
.
•1
258
-1750
? T
he
Mid
dle
Ag
es...
•1
750
–19
00
Ma
them
ati
cal
fou
nd
ati
on
s
•1
900
–19
39
Co
ntr
ol
syst
ems
an
aly
sis
•1
939
–19
62
Worl
ds
war
•1
960
–20
07
Mo
der
n c
on
tro
l sy
stem
s
•F
utu
re
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
Fie
ld o
f re
searc
hes
Beg
inn
ing
of
elec
trom
ag
net
ism
sci
ence
•T
ha
les
of
Mil
etu
s(6
24
-54
6,
VI
B.C
.) i
sru
bb
ing
gra
ssa
nd
am
ber
. H
e o
bse
rves
att
ract
ion
as
resu
lt.
•T
ha
les’
fri
end
sa
reo
bse
rvin
gh
im.
•G
reek
s an
d A
rab
s m
easu
reti
me
•C
hin
ese
mea
sure
dir
ecti
on
s
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
Fie
ld o
f re
searc
hes
Gre
eks
an
d A
rab
s m
easu
re t
ime
•A
su
nd
ials
wer
eea
rlie
stti
me
mea
sure
form
•w
ate
r cl
ock
s w
ere
use
d o
n K
tesi
bio
s is
lan
d,
27
0 B
C,
Float
Tim
e scale
Diaphragm
Tim
e scale
Float
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
Fie
ld o
f re
searc
hes
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
•W
ate
rcl
ock
wa
s u
sed
on
Her
on
isla
nd
, 1
00
BC
•In
12
58
B.C
.M
on
go
lia
n c
ap
ture
Ba
gh
da
d a
nd
bei
ng
no
t
cap
ab
le t
o d
o a
ny
thin
g e
lse
they
are
sto
pp
ing
res
earc
h i
nto
wa
ter
clo
ck
•8
ext
clock
wil
l b
e m
ech
an
ica
l, X
IV c
entu
ry
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
•In
XII
cen
tury
Ch
ines
e u
sed
ch
ari
ots
wit
h s
tatu
e sh
ow
ing
So
uth
dir
ecti
on
•It
wa
s m
ech
an
ical
solu
tio
n -
gea
rs w
ere
use
d.
Co
ach
ma
n
dri
ved
acc
ord
ing
to s
tatu
e’s
ind
icati
on
.
•A
ccu
racy
wa
s n
ot
hig
h.
Ab
ou
t2
0 k
m.
•T
ha
t’s
wh
yC
hin
ese
did
no
t re
ach
Tib
et.
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
Op
en-l
oo
pco
ntr
ol
•A
rch
imed
es o
f S
yra
cuse
du
rin
gsi
ege
isca
usi
ng
pa
nic
in
Ro
ma
n a
rmy
, w
hic
h w
as
no
t a
ccu
sto
med
to
lea
rnin
g,
con
stru
ctin
g c
ata
pu
lts.
PR
EH
IST
OR
Y 6
00 B
.C.
–1258
1258-1
750 ?
The M
iddle
Ages.
..
•M
ech
an
ical
clock
ina
to
wer
•M
ill
wh
eels
wer
eco
nst
ruct
edto
Cer
va
nte
s a
nd
Do
n Q
uix
ote
del
igh
t
•O
pen
-lo
op
con
trol
–si
mp
lela
nch
ero
fm
elte
d s
ton
es–
fire
arm
s
1750–1
900
Math
em
ati
cal fo
undati
ons
•W
att
’sfl
yb
all
go
ver
no
r
•W
ate
r-le
vel
flo
at
reg
ula
tor
•R
esea
rch
on
ele
ctri
c fi
eld
s
•M
ath
ema
tica
l fo
un
da
tio
ns
•J
am
es’a
Watt
(1769)
con
troll
edsp
eed
of
a s
team
eng
ine
•„
ba
llet
da
nce
rru
le”
–ro
tary
mom
ent
con
serv
atr
ion
ru
le
•T
wo
ba
lls
wei
gh
tsm
ov
ea
rou
nd
sha
ft–
as
the
spee
din
crea
ses
wei
gh
ts
rise
an
d m
ov
e a
way
fro
m t
he
shaft
th
us
clo
sin
g t
he
valv
e.
1750–1
900
Math
em
ati
cal fo
undati
ons
Wa
ter-
lev
elfl
oa
tre
gu
lato
r
Tw
om
ain
ap
pli
cati
on
s–
wa
ter
dis
trib
uti
on
syst
ems
an
dst
eam
eng
ines
•T
ho
ma
s C
ra
pp
er u
sed
them
to t
oil
ets
•A
fter
17
91
Wa
tt u
sed
them
to s
team
eng
ines
1750–1
900
Math
em
ati
cal fo
undati
ons
Ele
ctri
cfi
eld
rese
arc
h.
Sin
ceT
ha
les
tim
esth
ere
wer
ep
rog
ress
•1
80
9,
Sir
Hu
mp
hre
y D
av
y d
emo
nst
rate
d a
rc l
am
p
•1
83
1,
Mic
ha
el F
ara
da
y s
ho
wed
mo
vem
ent
inel
ectr
ical
an
d
ma
gn
etic
fie
lds
•1
83
4,
curr
ent
gen
era
tors
wer
ep
rod
uce
do
ut
of
wir
e
•1
87
0-t
ies,
dev
elo
pm
ent
of
eng
ines
an
d g
ener
ato
rs
1750–1
900
Math
em
ati
cal fo
undati
ons
Math
ema
tica
l fo
un
dati
on
s
•P
ierr
e S
imo
n L
ap
lace
cre
ate
d m
ath
emati
cal
tool
kn
ow
n l
ate
r as
Lap
lace
tra
nsf
orm
x(t
) ->
X(s
)
•A
dva
nta
ge
of
tra
nsf
orm
wa
s p
oss
ibil
ity
to s
olv
ed
iffe
ren
tia
leq
uati
on
as
alg
ebra
iceq
ua
tion
•O
ne
sho
uld
tra
nsf
orm
eq
uati
on
on
Ga
uss
pla
ne
F(s
), a
nd
rece
ive
solu
tio
n
inti
me-
do
ma
inb
y m
ean
sof
rev
erse
La
pla
ce t
ran
sfo
rm
•It
wa
s g
ener
ali
zati
on
of
Jea
na
Ba
bti
ste
Fo
uri
er t
ran
sform
. In
stea
d
va
riab
les=
jω ωωωw
as
s=α ααα
+j ω ωωω
.
•C
au
chy
pu
bli
shes
theo
rem
com
mon
lyk
now
na
s principleofargument
of
fun
ctio
nF
(s)
at
po
int
s tr
avel
on
Gau
ss p
lan
e.
1750–1
900
Math
em
ati
cal fo
undati
ons
•D
r. G
uil
loti
n i
nv
ente
s gu
illo
tin
e
•C
yb
ern
etic
ma
rket
go
ver
no
r–
Ja
cob
ing
ov
ern
men
t–
bu
ys
inm
ass
es t
ha
teq
uip
men
t, f
ind
ing
itver
yu
sefu
ll
Process for research
Process
property
measurement
Processset-point
+
-
Ideas Error
Error≠ ≠≠≠0 ⇒ ⇒⇒⇒
guillotine
Cyberneticgoverner
1750–1
900
Math
em
ati
cal fo
undati
ons
1750–1
900
Math
em
ati
cal fo
undati
ons
Th
e M
aid
en,
an
old
er S
cott
ish
des
ign
.
Th
is e
xa
mp
le i
s a
n e
xh
ibit
at
the
Mu
seu
m o
f S
cotl
an
d,
Ed
inb
urg
h
•J
am
esM
ax
wel
l, m
ath
emati
cal
mod
elli
ng
•E
dw
ard
Ro
uth
–st
ab
ilit
y c
rite
rio
n
•A
.M.
La
pu
nov
–g
ener
al
stab
ilit
y c
rite
rion
•O
.Hea
vis
ide
–st
ep r
esp
on
se
1750–1
900
Math
em
ati
cal fo
undati
ons
Jam
esM
ax
wel
l in
18
68
pro
po
sed
math
emati
cal
mod
el d
escr
ibin
gW
att
’s
gov
ern
or
•H
e u
sed
lin
ear
ap
pro
xim
ati
on
s of
gov
ern
or
equ
ati
on
s
•H
est
ate
d, th
at
gov
ern
or
cha
ract
eris
tic
equ
ati
on
roo
tsm
ust
hav
e
neg
ati
ve
real
pa
rts
to s
tab
iliz
eco
ntr
ol
loop
•H
e w
ok
ed o
ut
sta
bil
ity
crit
erio
nfo
r tr
an
fer
fun
ctio
ns
of
2n
d a
nd
3rd
ord
er
1750–1
900
Math
em
ati
cal fo
undati
ons
Ed
wa
rd R
ou
th –
sta
bil
ity
crit
erio
n, 1
877
•H
e g
et A
dam
s’ p
rize
•H
eo
bse
rves
con
trol
loop
in
sta
bil
ity
in
ca
se,
ifo
ne
of
chara
cter
isti
c
equ
ati
on
coef
fici
ents
is
neg
ati
ve
or
zero
.
•W
riti
ng
do
wn
coef
fici
ents
inta
ble
(ma
trix
) co
ntr
ol
loo
p s
tab
ilit
yli
mit
can
be
com
pu
ted
1750–1
900
Math
em
ati
cal fo
undati
ons
A.M
. L
ap
un
ov
–g
ener
al
stab
ilit
ycr
iter
ion
, 1
893
•C
rite
rio
nis
ba
sed
on
no
nli
nea
rm
oti
on
dif
fere
nti
al
equ
ati
on
•S
oit
incl
ud
esli
nea
rp
roce
sses
•H
isw
ork
ises
sen
tial
inst
ate
-sp
ace
an
ali
sys
of
con
tro
llo
op
s
1750–1
900
Math
em
ati
cal fo
undati
ons
Oli
ver
Hea
vis
ide
(18
50-1
925)
–st
ep r
esp
on
se
•S
tep
res
pon
sea
llo
ws
to d
isti
ng
uis
hty
pes
of
dif
fere
nt
pro
cess
es
•It
is
geo
met
rica
l m
eth
od
wh
ich
des
crib
esall
po
ssib
leli
nea
rp
roce
sses
time
1
0
1750–1
900
Math
em
ati
cal fo
undati
ons
•1
910
,E
lmer
A.
Sp
erry
–d
evel
op
s th
e
gyro
sco
pe
an
dau
top
ilo
t
1750–1
900
Math
em
ati
cal fo
undati
ons
1900–1
939 C
ontr
olsy
stem
sanaly
sis
•H
.W.
Bod
e–
freq
uen
cya
na
lysi
sof
clo
sed
-
loo
pco
ntr
ol
•H
arr
y 8
yq
uis
t–
sta
bil
ity c
rite
rio
n
•8
. M
inors
ky
–P
ID c
on
troll
er
Am
pli
fier
wit
hp
osi
tiv
efe
edb
ack
(Arm
stro
ng
, 19
15
),
Hig
h a
mp
lifi
cati
on
, b
ut
sen
siti
ve
on
dis
turb
an
ces
Am
pli
fier
wit
h n
egati
ve
feed
ba
ck
H.S
. B
lack
(19
27
)
Gain
islo
wer
bu
t in
sen
siti
ve
on
dis
turb
an
ces
Ha
rold
W.
Bod
e(1
927)
–fr
equ
ency
an
aly
sis
of
clo
sed
-loo
p c
on
tro
l
•H
ein
ven
tes
feed
ba
cka
mp
lifi
erin
ord
er t
o e
lim
inate
dis
turb
an
ces,
bu
t
ha
s p
rob
lem
wit
h s
ho
win
g o
f p
ha
se s
hif
t
1900–1
939 C
ontr
olsy
stem
sanaly
sis
The Feedback Amplifier
The Feedback Amplifier
Telephone Calls Over Long Distances
Telephone Calls Over Long Distances
The Problem: How to Increase Signal Strength?
The Problem: How to Increase Signal Strength?
The Solution: The Feedback Amplifier
The Solution: The Feedback Amplifier
Patented by Black 1928
Patented by Black 1928
Patent Granted 1937
Patent Granted 1937
Strong Development of Theory and Design M
ethods
Strong Development of Theory and Design M
ethods
1900–1
939 C
ontr
olsy
stem
sanaly
sis
•P
hase
shif
tw
as
sho
wn
ver
sus
freq
uen
cy (
Bo
de
plo
t) o
n s
epa
rate
fig
ure
•B
od
ep
lots
–g
ain
an
dp
ha
se s
hif
tv
ersu
sfr
equ
ency
•It
can
be
use
dto
ga
in a
nd
ph
ase
ma
rgin
est
ima
tio
n.
Co
ntr
oll
er
pa
ram
eter
s ca
n b
e d
esig
ned
too
.
•B
lack
pro
pose
dh
iso
wn
ver
sion
of
Bo
de
plo
ts, of
cou
rse.
1900–1
939 C
ontr
olsy
stem
sanaly
sis
Fre
qu
en
cy
(ra
d/s
ec
)
Phase (deg); Magnitude (dB)B
od
e D
iag
ram
s
-20
-15
-10-50
Fro
m:
U(1
)
10
-11
00
10
1-1
00
-80
-60
-40
-200
To: Y(1)
Bo
de
plo
tsfo
r tr
an
smit
ati
on
G(s
)=1
/(s+
1)
1900–1
939 C
ontr
olsy
stem
sanaly
sis
Har
ry N
yq
uis
t–
stab
ilit
y c
rite
rio
n
•H
ep
ub
lish
stab
ilit
ycr
iter
ion
in1
93
2 b
asin
go
n C
auch
y t
heo
rem
•T
his
crit
erio
nal
low
sto
co
ncl
ude
abou
tcl
ose
lo
op c
on
tro
l
syst
em s
tabil
ity
inves
tigat
inopen
-loop
co
ntr
ol
syst
em
•S
imp
lest
ver
sio
no
fcr
iter
ion
N:
If �
yqu
ist
curv
ed
oes
no
t
incl
ude
po
int
(-1,
j0),
th
en c
lose
d-l
oop
co
ntr
ol
syst
em i
s st
able
1900–1
939 C
ontr
olsy
stem
sanaly
sis
Ny
qu
ist
curv
e fo
r fu
nct
ion
G(s
) =
1/(
s+1
)
Re
al
Ax
is
Imaginary Axis
Ny
qu
ist
Dia
gra
ms
-1-0
.8-0
.6-0
.4-0
.20
0.2
0.4
0.6
0.8
1-0
.8
-0.6
-0.4
-0.20
0.2
0.4
0.6
Fro
m:
U(1
)
To: Y(1)
1900–1
939 C
ontr
olsy
stem
sanaly
sis
19
21
–K
arel
Cap
ek w
rite
sp
lay
abo
ut
rob
ots
Rab
ota
= w
ork
(russ
ian
)
1900–1
939 C
ontr
olsy
stem
sanaly
sis
N.
Min
ors
ky
–P
ID c
on
tro
ller
, 1
92
2
•C
on
troll
erm
ult
ipie
ser
ror
by
gai
n(P
par
t), in
teg
rals
(I p
art)
an
d
dif
fere
nti
ates
(D p
art)
it.
•S
on
ame
‘PID
’ co
mes
in
to b
ein
g
•H
ep
rop
ose
dfi
rst
app
lica
tio
nto
ship
stee
rin
g
•N
ow
aday
s9
5%
co
ntr
ol
loop
sin
clu
des
PID
co
ntr
oll
er
N.
Min
ors
ky
, D
irec
tio
na
l st
ab
ilit
y of
au
tom
ati
call
y st
eere
d b
od
ies,
J.A
m.S
oc.
Nav
al.
En
g.,
34
, s.
28
4
1900–1
939 C
ontr
olsy
stem
sanaly
sis
1939–1
962 W
orl
ds
war
•v
on
Bra
un
, V
-1 r
ock
et
•1
94
2,
Zie
gle
r an
d N
ich
ols
, fi
rst
PID
tu
nin
g m
eth
od
•1
94
8,
Ev
ans,
ro
ot
locu
sm
eth
od
•B
ellm
an’s
dy
nam
ic p
rogra
mm
ing
equ
atio
n,
Po
ntr
iag
in’s
max
imu
m r
ule
•1
95
7,
Sp
utn
ik
•1
96
0,
Kal
man
fil
ter
vo
n B
rau
n (
19
42
), V
-1 r
ock
et (
Ver
gel
tun
gsw
affe
)
•In
co
ntr
ol-
loop
wer
e u
sed
lam
ps
(tra
nsi
stor
pre
dec
esso
r)
•O
ne
of
Hit
ler’
s cr
uci
alw
arp
rog
ram
ms
end
s b
ecau
se o
f
pro
ble
ms
wit
h c
ontr
ol
loop
s. ☺ ☺☺☺
.R
ock
ets
did
n’t
hit
the
targ
ets
in
Lo
nd
on
. T
hey
hit
ted
chic
ken
co
op
s in
vil
lag
es n
ear
Lo
nd
on
.
•1
0 d
ays
bef
ore
War
saw
Up
risi
ng
AK
(H
om
eA
rmy
) d
eliv
ers
com
ple
te V
-1 t
o G
reat
Bri
tain
,
•A
fter
19
45
vo
n B
rau
n(P
hD
), b
ecau
se o
f la
cko
fem
plo
ym
ent
in
Ger
man
y a
nd
lack
of
po
rkch
op
sin
can
teen
leav
esG
erm
any
for
Gre
atB
rita
into
do
co
nse
cuti
ve
rese
arch
(he
did
n’t
kno
wab
out
Mar
shal
l’s
pla
n
for
euro
pe)
1939–1
962 W
orl
ds
war
19
42
, Z
iegle
r an
d N
ich
ols
, P
ID t
un
nin
g
•F
irst
scie
nti
fic
met
ho
d
•E
ver
yco
ntr
ol
engin
eer
kn
ow
sth
ism
eth
od
•T
her
ear
eab
ou
t3
00
dif
fere
nt
PI/
PID
co
ntr
oll
er t
un
ing m
eth
od
s
1939–1
962 W
orl
ds
war
1939–1
962 W
orl
ds
war
19
48
,E
van
s, r
oo
tlo
cus
met
ho
d
•C
han
gin
glo
cus
of
char
acte
rist
icp
oly
no
mia
l ro
ots
step
res
po
nse
of
clo
sed
-loop
syst
em c
han
ges
.
•O
ne
can
com
pu
teg
ain
atst
abil
ity
lim
it f
oll
ow
ing
roo
tslo
cus
1939–1
962 W
orl
ds
war
19
50
–S
ho
rtst
ory
„I R
ob
ot”
wit
het
hic
alco
de
1.d
on
’thar
m
2.e
xec
ute
hum
an’s
ord
ers,
if
they
don
’t
bre
ak r
ule
1
3.e
xis
tti
llit
do
esn
’tbre
akru
le1
or
2
1939–1
962 W
orl
ds
war
Sta
nis
ław
Lem
19
74
–th
e C
yber
iad
–m
ech
anic
al u
niv
erse
rule
d b
y r
ob
ots
19
57
–T
he
Sta
r d
iari
es-
Ijo
n T
ich
y d
ico
ver
sdif
fere
nt
cyber
net
icsy
stem
s(s
oci
alsy
stem
s)
ob
serv
ing
atth
esa
me
tim
eh
iso
wn
.
1962-2
007 M
odern
contr
olsy
stem
s
19
54
, G
eorg
e D
evo
l, b
uil
ds
firs
tm
od
ern
in
du
stri
alro
bot
1939–1
962 W
orl
ds
war
Bel
lman
’s d
yn
amic
pro
gra
mm
ing
(19
57
), P
on
tria
gin
’s m
axim
um
pri
nci
ple
(19
62
)
•E
qu
ival
ent
rule
sb
ased
on
Ham
ilto
n-J
acobi
equat
ion
(HJB
) al
low
ing
to d
eter
min
e op
tim
al p
ath
e.g
. fo
r ro
cket
•T
han
k t
ho
se r
ule
s, p
osi
tio
n s
atel
lite
an
d K
alm
an f
ilte
r, e
ver
last
ing
pro
ble
m o
f ex
act
nei
ghb
ou
r h
itti
ng
was
so
lved
. P
reci
sio
n i
s eq
ual
few
met
ers
on
glo
be
Un
inte
nti
onal
lyco
ntr
ibute
dto
this
: E
ule
r(1
70
7–
17
83
),
Lag
ran
ge
(17
36
–1
81
3),
Ham
ilto
n(1
80
5–
18
65
), J
acobi
(1804
–1
85
1).
1939–1
962 W
orl
ds
war
19
57
, S
pu
tnik
, S
ov
iet
Un
ion
ach
iev
emen
t
•F
irst
arti
fici
alea
rth
sate
llit
e
•U
nti
l n
ow
ther
e w
ere
laun
ched
mo
re r
ock
ets
in u
niv
ers.
Ple
ase,
be
care
ful
nex
t ti
me
du
rin
g t
rip
in
oute
r sp
ace.
Scr
ap i
s
dan
ger
ou
s
1939–1
962 W
orl
ds
war
19
60
, R
ud
olf
Kal
man
’s w
ork
s
•K
alm
an f
ilte
r–
op
tim
alst
ate
esti
mat
or
un
der
dis
turb
ance
sw
ith
no
rmal
dis
trib
uti
on
•L
inea
r-q
uad
rati
cco
ntr
oll
er
•L
apu
no
v f
un
ctio
n i
n t
ime-
do
mai
n
Pro
fit
: m
atri
xn
ota
tio
n a
llo
ws
to d
eter
min
e d
yn
amic
ch
ang
es i
n
syst
em, p
oss
ibil
ity
of
fin
din
g e
xac
t op
tim
al s
olu
tio
n i
n t
ime-
do
mai
n
1939–1
962 W
orl
ds
war
Oct
ob
er1
962
, C
ub
a, R
uss
ian
str
yto
in
stal
lro
cket
sat
Cas
tro
(Fid
el,
This
bea
rded
fel
low
ing
reen
trac
ksu
it).
Sat
elli
tes
and
Bel
lman
’seq
uat
ion
mak
es U
SA
an
d U
SS
R r
eali
zed
that
nucl
ear
gam
e ch
eckm
ates
bo
th s
ides
Iten
ds
gam
e.
Itu
nder
sto
od
bes
tp
rep
ared
to b
e p
rim
em
inis
ter
inU
SS
Rdir
ecto
r
of
ko
lkh
ose
Nik
ita
Kh
rush
chev
(o
uts
tan
din
gex
per
tin
stam
pin
g
his
feet
on
tab
lein
Un
ated
Nat
ion
s) a
nd
J.F
.Ken
ned
y.
1939–1
962 W
orl
ds
war
1962-2
007 M
odern
contr
olsy
stem
s
•P
roce
sso
ris
bu
ild
, W
. H
off
, 1
96
9
•P
LC
(p
rog
ram
mab
le l
ogic
co
ntr
oll
er)
•A
rtif
icia
ln
eura
l n
etw
ork
s, f
uzz
ylo
gic
, g
enet
ical
gori
thm
s, n
on
-
lin
ear
stat
e-sp
ace
contr
oll
ers,
mo
del
bas
edco
ntr
ol
•N
ano
tech
nolo
gy
, in
tern
et
•..
. B
y w
ire
19
69
-A
po
llo
mis
sio
n
19
97
-M
ars
Pat
hfi
nd
er, m
ov
emen
tal
go
rith
mb
ased
on
fu
zzy
logic
and
cre
ated
wit
h a
ssis
tan
ce p
rof.
J.S
ąsia
dek
1962-2
007 M
odern
contr
olsy
stem
s
1962-2
007 M
odern
contr
olsy
stem
s
1962-2
007 M
odern
contr
olsy
stem
s
Applicati
ons
Energy generation
Energy generation
Energy transmission
Energy transmission
Process control
Process control
Discrete m
anufacturing
Discrete m
anufacturing
Communication
Communication
Transportation
Transportation
Buildings
Buildings
Entertainment
Entertainment
Instrumentation
Instrumentation
Mechatronics
Mechatronics
Materials
Materials
Physics
Physics
Biology
Biology
Economics
Economics
Futu
re
•T
ime-
and
sp
ace-
scal
eco
ntr
ol
bro
adin
g:
fro
mn
ano
tech
nolo
gy
to s
pac
etim
e fo
ldin
gan
dti
me
tun
nel
s. P
leas
e, b
e ca
refu
l g
oin
g
for
a w
alk
-b
lack
hole
s!
•E
qu
ival
entl
y–
incr
ease
inac
cesi
ble
ener
gy
•E
xam
ple
of
con
seq
uen
ce–
wea
ther
con
trol
and
wea
ther
war
s
(an
yo
ne
has
idea
ho
wto
co
ntr
ol
wea
ther
?)
•D
eliv
erin
g e
ner
gy
fro
msu
n
•C
on
seq
uen
ce–
as p
rev
iou
s
•A
no
ther
idea
s?
Sam
ple
id
ea o
f co
ntr
oll
ing
wea
ther
Mir
ror
refl
ects
su
n r
adia
tio
n.
Tem
per
atu
re o
n E
arth
dec
reas
esq
=σ
T4
Futu
re
1 k
W/m
2
1 k
W/m
20
kW
/m2
Thank you
for your attention