Download Antiquity - PhysicsLAB!

Antiquity before 476 AD
1. Pythagoras of Samos (born 570 BC)
Pythagoras was a Greek philosopher and mathematician. He was the first influential Western practitioner of
vegetarianism. He established a community of followers in Croton who adhered to the way of life he prescribed.
His followers contributed countless theorems in the realms of science, astronomy, music theory and mathematics.
Pythagoras first studied the proportions of musical intervals and scales. The 3-4-5 right triangle was known to
antiquity.
2. Democritus (460 BC- 370 BC)
Democritus was an ancient Greek philosopher. He was also known as the “Laughing Philosopher," for his
tendency to mock fellow citizens for their follies. Democritus is said to not have any care for wealth and preferred
to put everything into his studies, investigations and explorations. He is said to have remarked that he would
rather discover a new cause of nature than be King of Persia. Democritus held that nothing could come from
nothing, that everything is already in the world and it is merely a matter of combination and re-combination of
eternal bits of immutable stuff called atoms that remain indivisible in and of themselves, but are capable by hooks
and barbs or balls and joints to combine to other atoms to make up the materials of life. He also proposed that the
solidness of any given material was dependent upon the shapes of these atomic bits.
Democritus spent a literal fortune on his studies that produced the fundamental rules governing the modern
atomic theory:
1) All matter is made of atoms which are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms.
3. Aristarchus_of_Samos (310-230 BC)
Aristarchus was a famous astronomer who is remembered as the first to determine the size and proximity of the
sun and the moon in relation to the earth. He also correctly described the lunar phase changes as the moon
reflecting sunlight. Moreover, he proposed that the sun was at the center of the solar system. Copernicus sited
Aristarchus as one of the first ancient astronomers to believe that the earth moves.
4. Euclid of Megara & Alexandria (322-275 BC) Greece/Egypt
Euclid may have been a student of Aristotle. His book The Elements outlined the construction of points, lines, and
planes, correctly proved the existence of only five “platonic solids” and initiated the study of projective geometry.
He was the first to prove that there are infinitely many prime numbers; he stated and proved the unique
factorization theorem; and he devised Euclid's algorithm for computing greatest common denominator (gcd).
His text endured for two millennia as a principal text on geometry. It commences with definitions and five
postulates.
x
x
x
x
x
A straight line may be drawn between any two points.
A piece of straight line may be extended indefinitely.
A circle may be drawn with any given radius and an arbitrary center.
All right angles are equal.
If a straight line crossing two straight lines makes the interior angles on the same side less than two right
angles, the two straight lines, if extended indefinitely, meet on that side on which are the angles less than
the two right angles.
5. Archimedes of Syracuse (287-212 BC)
Archimedes is universally acknowledged to be the greatest of the ancient mathematicians.
Archimedes made advances in number theory, algebra, and analysis, but is most renowned for his many
theorems of plane and solid geometry. He was the first to prove Heron's formula for the area of a triangle. One of
his most remarkable and famous geometric results was determining the area of a parabolic section. He was the
first to distinguish between uncountable and countable infinities (a distinction which wasn't resolved until Georg
Cantor, who lived 2300 years after the time of Archimedes), the relationship and formulae for the volume and
surface area of a sphere, and may even have been first to notice and prove the simple relationship between a
circle's circumference and its area. PI is often referred to today as Archimedes’ constant
He invented countless mechanisms and set forth numerous ideas that initiated many modern fields in physics.
Famous discoveries in physics include: his method of finding volume of irregular objects (water displacement), the
first law of hydrostatics, the center of mass for hemispheres and, cylinders, and cylindrical wedges. He boasts the
inventions of the hydraulic screw, the compound pulley, complex levers, and war machines (the most famous of
which is Archimedes’ Claw which uplifted and subsequently capsized ships when they came too close to the
battlements).
6. Eratosthenes of Cyrene (276 BC - 194 BC.)
Eratosthenes will always be remembered for his ingenuity in measuring the circumference of Earth and for the
creation of a calendar that takes leap years into account.
The sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers. It is still one of the most
efficient ways to find smaller primes (below 10 million).
7. Ptolemy – (90-168 AD)
Created a mathematical model which accurately predicted when and where the planets (wandering stars) would
rise or set. His system was a geocentric model, making the Earth the center of the Solar system with the Sun,
planets and stars revolving around it. As shown below, his system involved the planets traveling not only on their
primary orbitals around the Earth, but also around epicycles - smaller circular paths. The outer planets’ motion
through their epicycles explained what was called retrograde motion – that is, why they sometimes seemed to be
traveling backwards in their orbits.
It is doubtful that Ptolemy actually believed in the reality of his system. He may have thought of it only as a
method of calculating positions. Regardless, his model was considered the standard for nearly 1500 years until
Copernicus, Kepler and Galileo proved the heliocentric (Sun centered) model of the solar system.