Transcript 1066 AD – Battle of Hastings

Telecommunications
• Economic prosperity in Europe
• Increased mining
• Development of barometer
– Meteorology & Electricity
• Electromagnetism
• Electromagnetic induction
• Telephone
1066 AD – Battle of Hastings
• Saxons vs. The Normands.
– Normands used stirrups on their
horses, which gave them a tactical
advantage in battle.
– The stirrup first used in 322 AD
China, is so simple yet had
enormous social and economic
affects in Europe.
Battle of Hastings
War Horse Improvements
• Higher saddle
cantle, and armored
riders.
• Bigger horses and
ultimately family
crests.
• Increased social
classes.
Knighthood became hereditary
1415 AD – The Battle of
Agincourt
• Perhaps the greatest English
victory of the “100 Year War.”
– English casualties: < 500
– French casualties: 7-12 thousand!
• Archers trained since childhood
only the best go to battle.
• A good archer could deliver 12-15
arrows a minute which could
penetrate armor within 200 yards.
• Archers easily took horses and
knights out of the equation.
6th Century – The New Plough
• Able to plow the dense rich soil of
Europe.
• New parts include the Coulter which
cuts the soil, the Moldboard turns soil
over and Landside prevents sideways
movement.
The Plow (600 AD)
The Plowshare was also on the ancient scratch plow
8th Century
• Introduction of horse
collar and
horseshoe and crop
rotation in Europe.
Crop Rotation
• The goals of crop rotation
are to help manage soil
fertility, disease and
insects.
• The four groups of plants
shown here require
different soil nutrients.
16th Century
• End of longbow in
warfare.
– Improved prosperity &
less longbow practice.
– Additionally cannons and
rifles made the longbow
obsolete.
China
• Philosophically driven to
better understand nature.
• Credited with development of
paper, printing, compass,
stern rudder, lateen sail, the
spinning wheel, the loom, gun
powder and others.
Technology and China
• Did not develop technologically
because to recreate nature would
disallow “Chi” which flows through
everything in nature. This was
contrary to their Taoistic philosophy.
• The government was firmly
bureaucratic and contained no profit
incentive.
1516 – The Slovakian Silver
Mine of Joachimsthal.
• Triggered by need for more cash money
during the boom period of the 16th Century.
• Published that water could only be vacuumed
up 30 feet, and no higher.
• Also consistent with well known problem of
not being able to vacuum water up > 30 ft. for
tall buildings.
The Barometer & Light
• 1643 –Evangelista Torricelli designed and
built a mercury barometer. Told us we “live
under an ocean of air.”
• 5 years later Hg barometer demonstrated on
Puy de Dome in France.
• 1675 - Picard observed a light emitted from a
shaken barometer which “sparked” interest in
electricity and light.
Barometer
• Since Hg is 13.5 x denser
than H2O only a one
meter tube is required.
These bulbs all
contain small
amounts of toxic
Hg
Watch this video and choose why
the candle rises into the flask
• A) The pressure inside the beaker is increasing.
• B) The pressure outside the beaker is increasing.
• C) The pressure inside the beaker is decreasing.
• D) I was sleeping and missed the video.
18th Century Electricity
• 1745 – Leyden Jar was invented to store a
static charge.
• 1786 – Luigi Galvani noticed that inserting a
brass wire into a frog spinal column and
touching the wire to the iron table caused the
frog legs to move.
Galvanic or Voltaic Cell
• 1800 – Alessandro
Volta proved
dissimilar metals
created an electric
current on contact
and created the
“pile” or battery.
Electricity (Cont.)
• 1820 –Oersted, using Volta’s
battery accidentally demonstrated
electricity flowing in a wire
produces a magnetic field.
• 1835 - Michael Faraday
discovered magnetic induction by
creating electricity from a
changing magnetic field.
What Oersted Saw
1875 – Alexander Graham
Bell’s Telephone.
• First telephone call
made in 1876.
• A vibrating metal
diaphragm affecting
an electromagnet’s
current.
• The modern
telephone
In the Readings
• Fossil fuel reserves may last 600 years.
• Cost, the environment and alternatives could
undermine their dominance.
• Alternatives include, hydro, gas, nuclear and
renewable sources, such as, wind and solar
energy.
• Wind energy is biggest growth area for 3rd
World countries.
Can Technology Spare the
Earth?
• Assuming the human population will continue
to expand, then will our resources be
sufficient to support us?
• Energy - current 5% efficiency will improve to
15% by 2100.
• Land - Current trends show that farming
efficiency is well ahead of demand.
• Materials - incomplete data
• Water - not an area of great future concern
Future Availability of
Natural Resources
• “The world already possesses the vast
majority of technical knowledge to serve
its resource needs. To ensure that
these goals are complements rather
than trade-offs, the world needs
concerted and collaborative innovation
in social, political and economic
systems”.
World Nuclear Industry
• Grid parity of solar energy is almost
here and may usurp future nuclear.
• Life expectancy of nuclear power plant
is 40 years. Average age is 28 years.
• 67 additional plants needed over what is
already scheduled to be built and online
by 2020.
Even Geniuses Make
Mistakes
• Scientists sometimes make mistakes
• Fred Hoyle held fast to his theory of a static universe
by patching his theory to explain away the “Big
Bang.”
• Einstein also believed in a static universe and
created a cosmological constant to explain it. The
“Big Bang” theory caused him to remove it. Later in
1998 his constant was brought back to explain the
acceleration of the universe’s expansion.
Things you should know
• What technology did the
Normands utilize to win the
battle of Hastings?
•
Saddle stirrups #2
•
Triggered Knighthood &
stratified social status. #4
• How the Welch longbow
changed war.
•
Demonstrated the vulnerability
of the knight in battle. #5
• Describe the difference and
similarity of the scratch plow
and European plow.
•
New plow added Coulter and
Moldboard. #6
• A Chinese discovery which
Europeans used as a
weapon.
•
Gunpowder #10-11
• Explain how the horse stirrup
affected social & economic
status of people.
Things you should know
• Four agricultural advances
during this period.
• Horse, horseshoe, horse collar &
crop rotation. #8-9
• Agricultural technology and • Prosperity and a better weapon.
#10
the cannon’s affect on
longbow usage.
• Explain why a vacuum pulls • 14.7 psi atmospheric pressure
pushes water up. #13-15
water up only 32’ at sea
level
• Connections page 75.
• Why does Hg(L) in a tube
illuminate, p75
• #21 Vibrating metal diaphragm
• How did Bell change voice
fluctuates current in electromagnet
into an electrical signal?