56K leased line = 56,000 bits per second
T1 = 1.544 million bitts per second
T3 = 45 million bits per second
From 1995-2005, the cost of bandwidth will drop faster than
the cost of computing. From 1995-2005, the cost of switching
will drop faster than the cost of bandwidth.
History: The cost of a T1 line coast to coast in 1985 was $40,000/month;
in 1995, it’s $2,000/month.
The 30-30 rule: Humans can take in information at only about
30 megahertz through our eyes or, even slower, at 30 kilohertz
through our ears.
Light travels about four inches in a nanosecond in today’s
wires, so that, in a 500-megaherty (two nanosecond) computer
design, we have less than eight inches of room for our signals
to travel in a synchronous processor design.
bob metcalfe
"bottleneck
providers" -- things are slow for the other guy so i'll wait for
him. deadline.
- dial-up telephone numbers
are an abomination. putting packets atop voice switches.
we need continuous access. telco circuit switching vs.
packet switching.
- ISDN - continuing reminder
of what to expect from the telephone monopoly.
- DSL -- copper. continuous.
his fave. telephone companies in the way. zero competition.
- wireless -- bypass (rah!)
best use probably in mobile
- satellite -- trouble
is to take total bandwidth, need to blacken the sky
with these things. use is rural.
- powerline -- use the
electric wires
- other -- "nothing
to say"
core competence of phone
companies = lobbying and legislation. net = the force. telepopy
death stars with lead isp-woks and java-the-hut.
PCs were developed as
standalone devices. low-volume, modular pieces. WP, spreadsheets.
nerds only.
- new
replacements will be as different as last changes (mainframe
to mini to PC to next).
- What
would I use the NC for if the computer goes down? Do
you ask this about your phone and TV? Hip folks ask
what we'll do when the net is up?
networking. why? to be road warriors?
no, to stay at home more. substituting communication for
transportation.
deca da 10
hecto h 102
kilo k 103
mega M
104
giga G 109
tera T 1012
deci- d 10-1
centi- c 10-2
milli- m 10-3
micro- mu 10-6
nano- n 10-9
pico- p 10-12
femto- f 10-15
atto- a 10-18
kilobyte 1024
megabyte 10242
(1.045 x 10 to the 6th)
millions
gigabyte 10243
(1.073 x 10 to the 9th)
billions
terabyte 10244
(1.10 x 10 to the 12th)
trillions
Table 2: Decimal
multiples and submultiples to be used with SI
(prefix) (symbol) (power)
(value)
exa E 10^18 1 000 000 000 000 000 000
peta P 10^15 1 000 000 000 000 000
tera T 10^12 1 000 000 000 000
giga G 10^9 1 000 000 000
mega M 10^6 1 000 000
kilo k 10^3 1000
hecto h 10^2 100
deca da 10^1 10
10^0 (1) 1
deci d 10^ 1 0.1
centi c 10^ 2 0.01
milli m 10^ 3 0.001
micro (mu) 10^ 6 0.000 001
nano n 10^ 9 0.000 000 001
pico p 10^ 12 0.000 000 000
001
femto f 10^ 15 0.000 000 000 000 001
atto a 10^ 18 0.000 000 000
000 000 001
Table 3: Conversion
of non SI units to SI units
(from)
(to) (multiply
by)
(to)
(from) (divide
by)
inch (in)
m 2.54
x 10^ 2
feet (ft)
m 0.3048
sq. inch (in^2)
m^2 6.4516
x 10^ 4
sq. foot (ft^2)
m^2 9.2903
x 10^ 2
cu. inch (in^3)
m^3 1.638
71 x 10^ 5
cu. foot (ft^3)
m^3 2.831
68 x 10^ 2
litre (l)
m^3 10^
3
gallon (gal)
m^3 4.546
09 x 10^ 3
mile/hour (mi hr^ 1) m s^ 1 0.477
04
kilometer/hour (km hr^ 1) m s^ 1 0.277
78
pound (lb)
kg 0.453
592
gram/cm^3 (g cm^ 3) kg m^ 3 10^3
pound/in^3
kg m^ 3 2.767
99 x 10^4
dyne
N 10^
5
kgf
N 9.806
65
poundal N 0.138 255
lbf
N 4.448
22
mmHg
Pa 133.322
atmosphere (atm)
Pa 1.013
25 x 10^5
horsepower (hp)
W 745.7
erg J 10^ 7
electronvolt (eV)
J 1.602
10 x 10^ 19
kilowatt hour (kW hr) J 3.6
x 10^6
calorie (cal)
J 4.1868
distance to moon = 240,000 miles
diameter of earth = 8000 miles
If the Queen Elizabteh II were 3/16" long, the earth
would be 666 feet in diameter (Washington monument = 555'
tall)
Cost of computer power 8000 times less than 30 years ago.
(If the price of a Cad had depreciated at the same
rate, would cost $2.50) ENIAC occupied 3000 cubic feet and weighed 30 tons. The number of components that can be
contained on a chip is doubling every eighteen months.
1Hz-5KHz Rotating generators,
musical instruments, voice microphones
Radio Services 3kHz-300GHz
106 3-30KHz VLF
30-300KHz LF Marine and aeronautical navigation equipment
300-30000KHz MF
(AM radio broadcast; LORAN maritime navigation;
long-distance aeronautical and maritime navigation
3MHz-30MHz HF shortwave
broadcast, amateur radio, CB
108 30MHz-300MHz VHF private
radio land mobile services such as police, fire and taxi
dispatch; TV channels 2-13; FM boradcasting; cordless phones;
baby monitors
300MHz-3000MHz (3GHz)
UHF UHF TV channels; cellular phones; common
carrier point-to-point microwave trasnmission used by long-distance
phone companies
109 3
GHz+
SHF Radar, microwave and satellite transmission
(includes cordless phones, cellular phones, digital radio,
instructional TV, tax dispatch, radio astronomy, altimeters,
radiolocation, personal phones, air route surveillance,
shipborne navigation radar)
1012 1-30 TeraHz
Infrared Lasers, guided missiles, rangefinders,
thermal sights, incandescent and fluorescent lights
1014 Visible
light
1015 Ultraviolet Lasers, guided missiles, rangefinders,
thermal sights, incandescent and fluorescent lights
1018 X
rays
1021 Gamma
rays Particle
beam energies, linear accelerators, betatrons, synchrotrons
The voyage begins 1 billion light years out, 1025
meters out. At 1
million light years, the spiral of our galaxy becomes recognizable.
At 1016 meters, the sun becomes visible;
that's one light year. At 1014, the orbits of the planets
can be seen. At
108, the features of the earth can be made out.
At 105, you can see the streets of Chicago. At 104, you can see individual blocks.
As the viewpoint keeps getting closer and closer, we enter
the skin. At 10
5 meters (10 microns), a giant white blood cell swims
by. At 10 7 meters (.1 micron, 1 thousand
angstoms), DNA appears.
At 10 13 meters (.1 picometer, 100 fermis),
the nucleus of the becomes clear.
At 1 fermi, we don't really know what it looks like
for real.
1932 world population = 2 billion
1989 world population = 5 billion
three-sigma qualty -- three bad parts in a thousand
six-sigma -- three bad parts per million
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