Transcript Milestones of Science

Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE☻
c 2 000 000 BC
evidence of stone tools
c 1 000 000 BC
fascination with sun, moon, stars, seasons
c 500 000 BC
control of fire (heat, light, cooking, etc)
c 200 000 BC
evidence of religion and/or belief in an afterlife
c 100 000 BC
some knowledge of poisonous plants/berries
and basic skeletal similarities of animals
c 30 000 BC
beginning of written communication (pictures)
c 12 000 BC
domestication of animals
c 8 000 BC
agriculture, pottery, bricks
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 5 000 BC
irrigation, first systems of measurement
c 4 000 BC
end of stone age, beginning of metallurgy
(copper), sundial
c 3 500 BC
bronze age (tin/copper), hieroglyphic writing,
papyrus, early machines (wheel, lever, plough)
c 3 000 BC
advanced cultures, astrology (sun, moon and
several planets, with gods attached to their
movements), discovery of 
c 2 500 BC
astronomical year and seasons (Nile observed to
overflow when Sirius rises with the sun)
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 2 000 BC
early calendar (12 months of 30 days), days
of week named after sun/moon/planets, number
system based on “60”, glass
c 1 500 BC
several languages with alphabets
c 1 200 BC
iron age
c 600 BC
libraries, coins
c 500 BC
geometry, theorem of Pythagoras, discovery of
irrational numbers
c 400 BC
concept of the atom, advanced schools of
philosophy (Plato)
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 350 BC
Aristotle and Aristarchus, geocentric vs
heliocentric model
c 300 BC
advanced geometry (Euclid), similar triangles
a b c
 
d e f
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 250 BC
prediction of eclipses perfected, Eratosthenes
determines the radius of the Earth
  7, D  800 km
Circumference = 2R
2R 360

 50
D
7
R
50800 
 6400 km
2
Accepted radius  6380 km!
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 150 BC
Hipparchus’ table of chords, beginning of
trigonometry, catalog of stars and brightness
Chord for 2
equals
Chord for 360 - 2
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 150 AD
Ptolemy, law of sines, solving triangles, distance
from earth to moon calculated
sin  
1
2
opp
hyp
adj
cos  
hyp
opp
tan  
adj
opp AM

hyp OA
AB 12 chord


OA
radius
sin  
Important Note:
sin 180     sin 
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 150 AD
Ptolemy, law of sines, solving triangles, distance
from earth to moon calculated
PC
PC
 sin  ,
 sin 180     sin 
AC
BC
PC  AC sin  , PC  BC sin 
b sin   a sin 
a
b

sin  sin 
Law of Sines
a
b
c


sin  sin  sin 
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 150 AD
Ptolemy, law of sines, solving triangles, distance
from earth to moon calculated
From the diagram,
= 50 and  = 180 – 70 = 110
So,  = 20
By the sine law,
b
c

sin  sin 
b
c sin  400 sin 110

 1099m
sin 
sin 20
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 150 AD
Ptolemy, law of sines, solving triangles, distance
from earth to moon calculated
Thanks to Eratoshenes, Earth’s radius was known,
i.e. AB = 6400 km.
Also, on the diagram (not drawn to scale!),
arc DB = 1675 km and 180 –  = 15.26.
Angle  could then be found from
DB , so   3601675 

2 6400
360 2  AB 

Finally, using the sine law,
b
c

sin  sin 
and b 
c sin  6400 sin 164.74


sin 
sin 0.26
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 200 AD
early algebra (middle east), Greco-Roman empire
declines, beginning of “dark ages” (a lot of
science probably “lost”)
c 800 AD
algebra continues to develop (middle east, India,
far east), dark ages continue in Europe
c 1 100 AD
dark ages end, scholarship returns to Europe, first
universities begin, scholars were often clergy
c 1 500 AD
early Renaissance period (da Vinci, Copernicus,
Brahe)
c 1 600 AD
peak of the Renaissance (Kepler, Galileo,
Descartes)
Gsci 1010
HISTORICAL MILESTONES IN HUMAN
DEVELOPMENT AND SCIENCE
c 1 650 AD
classical physics and calculus formally develop
(Newton, Huygen, Leibnitz)
c 1 700 AD
higher mathematics flourishes (Lagrange, Bernoulli,
Laplace, etc)
c 1 800 AD
beginning of “industrial” and “scientific” ages (steam
engine, atomic theory  chemistry, thermodynamics,
electricity, optics, spectrum analysis, etc)
c 1 900 AD
“modern physics” (atomic & nuclear physics, quantum
mechanics, relativity theory, atom bomb)
c 1 950 AD
“space age” (satellites, moon landings, advances in
astronomy)