Transcript Eight Primary Technological Developments

“Inventing the Future” & Basic
Electronics
• Storytelling alternatives
• Triggers of innovation
• Communications and rate of change
• Power = voltage x current
• AC vs DC
• Transformer
• Vacuum tubes
• Solid state electronics
Burk’s Eight Primary
Technological Developments
• Nuclear power
• Telecommunications
• Computer
• Assembly line
• Jet engine/Air Transport
• Plastics/Synthetic polymers
• Liquid fuel rockets
• Television
Storytelling Alternatives
• Heroic treatment of history
• Thematic treatment of history
• Periodic treatment of history
Heroic Treatment of History
• Assesses history based
on special persons
– However, no individual is
responsible for an
invention.
– Denies involvement of
humbler members of
society whose
contributions made the
inventor successful.
Thematic Treatment of
History
• Based on subjects such as computers,
telecommunication, etc.
• However, this neglects the interrelation
of different subjects.
• Naively implies a degree of
foreknowledge.
Periodic Treatment of
History
• Chronological approach to history
based on definite time periods
• Oversimplified
• Developments do not normally occur in
linear fashion.
Triggers of Innovation
• Deliberate attempts
• Unexpected discovery
• Unrelated developments
• War and Religion
• Accidents & unforeseen circumstances
• Weather
Deliberate attempts to
develop
• Soc. For the Encouragement of Nat’l
Ind.
• The electric light bulb
• Kinetoscope
• Von Linde’s refrigeration system
Unexpected discovery
through experimentation
• Looking for one thing and finding
something new.
• Perkin’s synthetic dye or Guericke’s
electricity
• Oersted’s unexpected electromagnet
• Moissan’s calcium carbide  fertilizer,
acetylene
Unrelated Developments
(“Connections”)
• New technology from old technology
• Pegged cylinder  Bouchon’s
perforated paper programming  the
computer
• Weaving tech.  cheap linen  paper
• Wilson’s cloud chamber  splitting the
atom
War and Religion
• Cannon  Defensive Architecture, map
making
• The need for timely praying  alarm
clock
Accidents & Unforeseen
Circumstances
• Decline of acetylene market  cheap
fertilizer
• Explosion of the Earl’s coal kiln  coal
gas
• Compass needle from China 
magnetism
• Failure to pump mines  barometer
Physical and Climate
Conditions
• “Little Ice Age”  chimney
• malaria  ice making machine
• Reclamation of Europe  modern
plough
Summarizing
• No inventor works alone
• Rate of technology change is proportional to
rate of information exchange (communication)
– Medieval Ind. Revolution
– 16th century specialization/democratization of
knowledge via printing press
– 19th century telecommunications
– 20th century digital telecommunications
Burke’s Alternatives to
Cope with Increasing Rate
of Change?
• Scrap all technology and go rural.
• Selective research only.
• Stop R&D and share out existing
technology
• Keep going the way have.
Stop, scrap advanced
technology – “Go Rural.”
• Many would not survive.
• This scenario is highly unlikely.
• USA’s technology developments are
most responsible for its wealth and
world leadership.
Selective research only
• Assess science and technology strictly
according to it societal worth.
• Curtail other “unworthy” research.
– Who decides where to focus efforts?
• Nevertheless, governments do provide
some tax incentives & subsidies to
selectively stimulate development.
Share out existing technology
to 3rd world countries.
• Produce more durable goods & less planned
obsolescence.
– How do you convince the haves that they have
had enough?
– Who’s going to pay for this transfer?
• This does go on where private industry seeks
advantage to sharing technology.
– Investments into China, India, E. Europe, etc.
Keep going the way we
always have.
• The most likely and probable
scenario.
“Science and technology
has immeasurably enriched
our material lives”.
James Burke
Alternating Current vs. Direct
• Alternating current (AC) is generated at
the power plant
– USA voltage fluctuates 60 cycles per
second (hertz) between + & - extremes as
a sine wave. Europe 50 hertz.
• Direct current (DC) comes from a
battery, fuel cell or solar cell and does
not fluctuate.
The Power Grid
Why AC & Not DC
• Large electrical generators happen to
generate AC.
• Transformers must have AC to work.
• Its easy to change AC to DC but difficult
and costly to change DC to AC.
Electricity
• Power = current x voltage
watts = amps x volts
• Using the analogy of a
garden hose:
– Voltage is like the water
pressure
– Current is like the amount
of water delivered.
•Resistance (ohms) = volts/amps
–Resistance is inversely proportional to the
hose or wire diameter.
Advantages of High Voltage
• Powerloss = resistance x current2
– Since voltage and current are inversely
proportional high voltage gets lower current
thus less power loss through the power
grid.
• AC has the advantage over DC in that
its voltage and current are easily
modified with little power loss.
Transformer
• Increases or decreases alternating current
• Transmission of high voltage AC results in
lower power loss than low voltage.
• With a transformer AC voltage can be
increased/decreased with < 1% power loss
• Power = current x voltage
• Combination of Oersted and Faraday effect.
• # coil turns is proportional to magnetic field &
volts
AC Transformer
High Voltage 10,000 v
Street voltage 1100 v
Vin x Nout/Nin = Vout
Your house 110 v
AC Transformer
Vin x Nout/Nin = Vout
110v x 10/5 = 220v
Now flowing in the
opposite direction
220v x 5/10 = 110v
Westinghouse vs. Edison
• Tesla argued for AC
power grid.
• Edison argued for DC
power grid.
– Electrocuted animals with
AC to demonstrate its
dangers.
– Triggered the electric chair
• Tesla/Westinghouse won.
Vacuum Tube
• Aka Thermionic Valves
• Two electrodes (diode) control
flow of current.
– Hot cathode, emits electrons
– Anode, accepts electrons
• Three electrode tube is triode.
– Used as electrode switch or
amplifier in radios.
• Third electrode in triode is a grid
controlling electron flow to the
anode.
Diode
Triode
Anode
Rectifier
• Allows current flow in one direction only.
• Diode used to convert AC to DC.
• Diode used to filter out carrier signal in
radio transmissions.
Transistor
• Solid state switch. Replaced most
vacuum tubes in the 1960s.
• Boron or Arsenic doped Silicon or
Germanium junctions.
• Smaller, lighter, rugged, longer
life, more efficient and cheaper
than vacuum tubes.
• Ultimately replaced by the
Integrated Circuit (IC).
• Making an IC
Silicon
• Silicon comprises about
15% of our planet Earth.
• Normally found as
silicates.
• It is a metaloid element
exhibiting some metalic
and some nonmetallic
qualities.
• Si has 4 valence electrons
like Carbon and other
elements in its group.
Solid State Diodes
• Silicon can be doped
with other elements to
affect it conductivity.
• P and As have an extra
valence electron while
Boron has a vacant
valence orbital.
• Current will flow from N
side to the P side not
the reverse.
• N side is cathode and P
side is anode.
Boron
doped
side is
electron
deficient
Arsenic
doped
side is
electron
rich
In reverse biased no current flows
Moore’s Law
• Gordon Moore (Intel)
stated in 1965 that the
number of transistors
on a chip could double
every 24 months.
• Since then his
statement has become
the benchmark for the
industry.
Light Emitting Diodes (LEDs)
• These are solid state
lights.
• Electrons from the
higher energy N side
drop at the junction to
lower energy p side.
• Giving off the energy
as light particles
(photons).
Lasers
• "light amplification
by stimulated
emission of
radiation”
• Emits light with
spatial coherence
• Semiconductor
lasers
Nanotechnology
Carbon Nanotube Transistor
Fossil Fuels
• Petroleum, coal and gas. The U.S. is
very dependant these fuel sources.
• Coal comes from anaerobic
decomposition of plant material
• Petroleum (oil) comes from anaerobic
decomposition of marine life.
• Natural gas comes from both.
California’s Power Sources
Nuclear
22%
Geothermal
Wind
11%
3% Other Renewables
4%
Coal
18%
Natural Gas
33%
Large Hydroelectric
9%
Acid Rain
• Industrial production of carbon, sulfur
and nitrogen oxides beyond the levels
which nature can consume is pollution.
• Acid rain is caused by sulfur and
nitrogen oxides in the air. These kill
plants and fresh water marine animals.
What you should know
• Major technological
developments according to
Burke
• #2
• The six triggers of innovation
and examples of each.
• #7-13
• Explain why rate of
innovation is proportional to
rate of information
exchange.
• #14 information exchange is
directly proportional to
innovation.
• What are Burke’s ideas to
cope with the increasing rate
technology change.
• #15-19
What you should know
• How a transformer works
• 1000 volts and 2 amps
enters a transformer with 10
coils and exits with 20 coils.
What is the exit voltage and
amperage? How does the
wattage change?
• What does a diode do and
how does it work? Explain
the vacuum tube and
transistor.
• Explain what a triode is, how
it works and what it may be
used for in electronic
equipment.
• #26-28
• #26-28
• #30-35
• #30 & 32
What you should know
• What is the difference
between direct and
alternating current?
• #33 and lecture notes. AC is
double polarity (sine wave)
and DC is one polarity.
• Why AC, not DC is used to • AC voltage exits the generator
transmit electricity over high
and its voltage is easily and
voltage lines.
efficiently changed.
• What is Acid Rain?
• #40
• Which side of the LED may
be doped with phosphorus?
• The N side #36