1. GALILEO GALILEI (1564-1642) ITALIAN KNOWN AS THE FATHER OF: PHYSICIST
MATHEMATICIAN
ASTRONOMER
PHILOSOPHER
KNOWN AS THE FATHER OF:
MODERN OBSERVATIONAL ASTRONOMY
SCIENCE
MODERN PHYSICS
MODERN SCIENCE

2. GALILEO
"Galileo, perhaps more than any other single person, was responsible for the birth of modern science.“ STEPHEN HAWKING

3. GALILEO EARLY LIFE BORN IN PISA
FATHER WAS A MUSICIAN (HE BECAME INVOLVED WITH A NEW FORM OF MUSIC, OPERA)
HE WAS EDUCATED IN THE CHURCH
HE STARTED WORK ON A MEDICAL DEGREE BUT DID NOT FINISH AND, INSTEAD, TURNED TO MATHEMATICS
WHEN HE WAS 25 HE WAS APPOINTED CHAIR OF MATHEMATICS AT THE UNIVERSITY OF PISA.
HE BECAME INTERESTED IN ASTRONOMY AND, AS MOST ASTRONOMERS OF HIS DAY, HE ALSO STUDIED ASTROLOGY.

4. GALILEO HIS SCIENCE AND MATH
DYNAMICS OF MOVING SYSTEMS – BODIES FALLING UNDER THE INFLUENCE OF GRAVITY ACCELERATE AT THE SAME RATE REGARDLESS OF THEIR MASS
HARMONIC RELATION IN MUSIC – THE PITCH OF A STRETCHED STRING VARIES AS THE SQUARE ROOT OF THE TENSION
HE UNDERSTOOD MATHEMATICS BOTH AS GEOMETRY AND AS ALGEBRA– I.E. HE RECOGNIZED THAT A PARABOLA WAS NOT ONLY A CONIC SECTION BUT THAT IT HAD A MATHEMATICAL EXPRESSION: Y = X2.
HE DID NOT ACCEPT KEPLER’S ELLIPTICAL ORBITS ARGUING THAT THE CIRCLE WAS THE PERFECT SHAPE.

5. GAILIEO HIS STUDY OF THE TIDES
IN 1615 HE WAS CHALLENGED BY CARDINAL BELLARMINE TO PROVE THAT THE EARTH ACTUALLY MOVED.
HE PROPOSED THAT THE ACTION OF THE TIDES PROVED IT, CITING THE VARIATION OF THE HEIGHT OF THE TIDES IN OCEAN BASINS AND IN DIFFERENT PARTS OF THE ADRIATIC.
HIS OPPONENTS ARGUED THAT HIS THEORY IS INCORRECT AS THERE ARE TWO TIDES PER DAY, NOT ONE.
HE MAINTAINED THAT ONLY THE SUN CAUSED THE TIDES, NOT THE MOON. I’LL DISCUSS TIDES LATER.

6. GALILEO’S TECHNOLOGY IN 1604 HE MADE A MILITARY COMPASS
HE MADE AN AIR-EXPANSION THERMOMETER
HE MADE A REFRACTING TELESCOPE AND USED IT TO OBSERVE THE STARS
HE INVENTED THE COMPOUND MICROSCOPE
HE PROPOSED USING THE MOONS OF JUPITER AS AN INFALLIBLE CLOCK IN ORDER TO ACCURATELY DETERMINE ONE’S LONGITUDE.

7. EARLY LENSES AND TELESCOPES
CRUDE VERSIONS OF LENSES AROSE AS EARLY AS 1350
SPECTACLES BECAME STATUS SYMBOLS OF LEARNING
IN 1608 HANS LIPPERSHEY AND JACOB METIUS APPLIED FOR A PATENT ON A CONCAVE/CONVEX LENS THREE POWER TELESCOPE – THE PATENT WAS NOT AWARDED AS THE PATENTING COMMITTEE THOUGHT THE IDEA TOO SIMPLE TO COPY.

8. GALILEO’S TELESCOPES
PLANO-CONVEX OBJECTIVE AND PLANO-CONCAVE EYEPIECE (OCULAR) – THE GLASS WAS GREENISH IN COLOR AND HAD BUBBLES IN IT – THE SHAPES OF THE LENSES WERE PRETTY GOOD NEAR THE CENTER BUT NOT AT THE EDGES.
IN JUNE 1609 HE BUILT HIS FIRST ONE – 3 POWER
TWO MONTHS LATER HE BUILT ONE WITH 8 POWER
TWO MONTHS LATER HE OBSERVED THE MOON AND JUPITER WITH AN ~ 20 POWER TELESCOPE. OBJECTIVE FOCAL LENGTH ~30-40 INCHES: OCULAR FOCAL LENGTH ~2 INCHES.
EVEN THOUGH HE WAS OFFERED A BIG INCREASE IN SALARY AT THE UNIVERSITY OF PADUA THE GRAND DUKE OF TUSCANY(COSIMO II DE’ MEDICI) TOPPED THE OFFER
GALILEO WAS GIVEN A LIFETIME APPOINTMENT TO THE DUKE’S STAFF IN 1610
NO ONE COULD VERIFY HIS FINDINGS AS YOU NEEDED A TELESCOPE TO DO SO.

9. CURRENT DAY OPERA GLASSES
GALILEAN TELESCOPE
VIRTUAL ERECT IMAGE
CURRENT DAY OPERA GLASSES
GALILEO OBTAINED HIS PRIMARY FUNDING FROM THE MILITARY
THEREFORE HIS TELESCOPE (BINOCULARS) HAD TO GIVE ERECT IMAGES

10. GALILEO’S TELESCOPIC DISCOVERIES
1. THE MILKY WAY IS “STARLIKE”, I.E., WHEN YOU MAGNIFY THE MILKY WAY IT BECOMES MILLIONS OF DISCRETE OBJECTS, NOT A CLOUD
2. THE PLANETS HAVE VISIBLE DISKS BUT THE STARS DON’T
WHEN YOU MAGNIFY A PLANET IT GETS LARGER AS YOU INCREASE THE MAGNIFICATION WHEREAS STARS REMAIN POINTS REGARDLESS OF HOW MUCH YOU MAGNIFY THEM
THIS WAS GRATIFYING TO COPERNICANS AS IT PUT THE STARS AT GREAT DISTANCES, THUS EXPLAINING TYCHO’S INABILITY TO SEE STELLAR PARALLAX

11. GALILEO’S TELESCOPIC DISCOVERIES
3. JUPITER HAS FOUR MOONS (ACTUALLY THE NUMBER THAT WE KNOW OF TODAY IS 49 WITH 14 MORE UNDER CONSIDERATION.)
THE DISCOVERY OF THESE MOONS ENCOURAGED GALILEO TO SUPPORT COPERNICUS’ HELIOCENTRIC THEORY
OBVIOUSLY THE EARTH WAS NOT THE ONLY CENTER OF REVOLUTION IN THE SOLAR SYSTEM
THE EARTH WAS NOT THE ONLY PLANET WITH A MOON
THE GALILEAN MOONS ARE NAMED
IO (CLOSEST) (ABOUT THE SIZE OF THE EARTH’S MOON)
EUROPA
GANYMEDE (LARGEST MOON IN THE SOLAR SYSTEM)
CALLISTO (FARTHEST)
BAD NEWS FOR TYCHONISTS

12. GALILEO’S TELESCOPIC DISCOVERIES
4. FEATURES ON THE MOON – HE NAMED MANY OF THEM
SEAS (MARIA)
MOUNTAINS
CRATERS
RILLES (VALLEYS)

13. GALILEO’S “STARRY MESSENGER”
AFTER HE HAD MADE THESE DISCOVERIES HE PUBLISHED A SMALL BOOK CALLED THE “STARRY MESSENGER” TO REPORT HIS OBSERVATIONS. HE DEVOTED ABOUT HALF OF IT TO REPORTING JUPITER’S MOONS.

14. GALILEO’S TELESCOPIC DISCOVERIES
5. SUNSPOTS – IN 1610
TO THE RIGHT SEE AN EARLY GALILEO DRAWING SHOWING SUNSPOTS
OTHERS HAD OBSERVED THEM EARLIER, SOME AS EARLY AS THE 4TH CENTURY BC.
IN 1611 DAVID AND JOHANN FABRICIUS OBSERVED SUNSPOTS AND REPORTED THAT THEY WERE ON THE SUN’S SURFACE AND THAT THE SUN ROTATED
IN 1612 GALILEO PUBLISHED “LETTER ON SUNSPOTS” WHICH ALSO REPORTED THAT THE SUN WAS ROTATING BUT WENT A STEP FARTHER IN SAYING THAT THE AXIS OF THE SUN IS INCLINED ABOUT 7 ½ DEGREES TO THE ECLIPTIC POLE.

15. GALILEO’S TELESCOPIC DISCOVERIES
6. “RINGS OF SATURN”
ACTUALLY HE SAW THE DRAWINGS ON THE RIGHT WHICH SHOWED THAT SATURN WAS NOT ROUND
IN 1659 CHRISTIAAN HUYGENS, A DUCTCH ASTRONOMER, WAS THE FIRST TO CONCLUDE THAT SATURN’S APPENDAGES REALLY WERE RINGS. THEY WERE INCLINED TO THE ECLIPTIC PLANE. IF WE LOOK AT THEM EDGE-ON THEY ARE TOO THIN TO BE SEEN.
THEY ARE ACTUALLY ICY ROCKS ORBITING SATURN

16. SATURNS RINGS VOYAGER PHOTO OF SATURN’S RINGS
SATURN’S RINGS OVER A 26 YEAR PERIOD
MAXIMUM TILT = ~27 DEGREES
VOYAGER PHOTO OF SATURN’S RINGS

17. GALILEO’S TELESCOPIC DISCOVERIES 7. PHASES OF VENUS
GALILEO’S DRAWING SHOWING VENUS’ PHASES ACCORDING TO PTOLEMAIC THEORY AND COPERNICAN THEORY.
ON THE LEFT, PTOLEMY’S THEORY (GEOCENTRIC) SHOWS THAT VENUS WILL ALWAYS BE IN A CRESCENT PHASE
ON THE RIGHT, COPERNICUS’ THEORY (HELIOCENTRIC) SHOWS THAT VENUS WILL GO THROUGH A COMPLETE SET OF PHASES. NOTE THAT THE SIZE OF VENUS CHANGES BY A FACTOR OF SIX FROM NEW PHASE TO FULL PHASE, FULL VENUS BEING SMALLER.

18. GALILEO AND THE CHURCH
HIS IDEAS IN HIS FIRST TWO BOOKS, THE STARRY MESSENGER AND LETTERS ON SUSPOTS, HAD BEEN MUTED AND HAD NOT RAISED MUCH ATTENTION.
HE HAD CALLED THE MOONS OF JUPITER “MEDICEAN STARS”.
HE WAS AN AVID COPERNICANIST
HIS ENEMIES ANGLED TO USE THESE VIEWS AGAINST HIM
ULTIMATELY CARDINAL ROBERT BELLARMINE FORBADE HIM TO HOLD HELIOCENTRIC IDEAS UNTIL THEY WERE FIRMLY ESTABLISHED. HE ARGUED THAT, IN THE LIGHT OF THE “RECANTING” FORWARD TO DE REVOLUTIONIBUS, THAT EVEN THE AUTHOR DIDN’T BELIEVE IT.
IN 1616 CARDINAL BELLARMINE THEN PUT DE REVOLUTIONIBUS ON THE BANNED READING LIST.

19. DIALOGUE ON THE TWO GREAT WORLD SYSTEMS
IN 1623 GALILEO’S FRIEND MAFFEO BARBERINI BECAME POPE (URBAN VIII)
THE TITLE IMPLIED THAT THE DISCUSSION IN THE BOOK WAS BETWEEN PTOLEMAIC COSMOLOGY AND COPERNICAN COSMOLOGY.
HOWEVER, PTOLEMAIC COSMOLOGY WAS DEAD. MOST NON-COPERNICANS WERE TYCHONISTS
IN THE BOOK THREE MEN, SALVIATI (GALILEO), SAGREDO (A THOUGHTFUL PERSON) AND SIMPLICIO (A HARD-HEADED ARISTOTILEAN), DISCUSS TIDES, MOTIONS OF ACCELERATED OBJECTS AND GALILEO’S OBSERVATIONS.
UNFORTUNATELY GALILEO PUT THE POPE’S WORDS IN THE MOUTH OF SIMPLICIO.

20. GALILEO’S LAST DAYS
GALILEO WAS FORCED TO RECANT HIS COPERNICAN BELIEFS (LORE HAS IT THAT, AT HIS TRIAL BEFORE THE INQUISITION, HE MUTTERED UNDER HIS BREATH THAT THE SUN IS STILL AT THE CENTER OF THE SOLAR SYSTEM.)
GALILEO WAS SENTENCED TO HOUSE ARREST
BY NOW HE WAS IN HIS 70’S AND WAS ALMOST BLIND
MUCH OF GALILEO’S WORK ON ACCELERATION WAS REFERRED TO BY NEWTON
GALILEO DIED ONE YEAR BEFORE NEWTON WAS BORN