the origin of the universe
DESCRIPTION
The Origin of the Universe. Massimiliano Galeazzi. MALS 601. Miami, 20 November 2002. Summary. The Scientific method The view of the Universe before 1900: The Greeks The Heliocentric system The view of the Universe after 1900: Einstein Theory of relativity Beyond the solar system - PowerPoint PPT PresentationTRANSCRIPT
The Origin of the Universe
Massimiliano Galeazzi
Miami, 20 November 2002MALS 601
Summary
• The Scientific method• The view of the Universe before 1900:
•The Greeks•The Heliocentric system
• The view of the Universe after 1900:•Einstein Theory of relativity•Beyond the solar system•Hubble law
• The Big Bang theory
The Scientific Method
Observations
Theory
Predictions
Experimental verification
Philosophy
Observations
Observations
Theory
Predictions
Experimental verification
• Sun
Observations
Observations
Theory
Predictions
Experimental verification
• Sun• Moon
Observations
Observations
Theory
Predictions
Experimental verification
• Sun• Moon• Stars
Observations
Observations
Theory
Predictions
Experimental verification
• Sun• Moon• Stars
Theory
Observations
Theory
Predictions
Experimental verification
Theory 1 Theory 2
Philosophy
Geocentric theory
Observations
Theory
Predictions
Experimental verification
• Movement is not so simple
Philosophy
• The movement is not perfectly periodic
• There are monthly, annual, and longer term changes
Geocentric theory
Observations
Theory
Predictions
Experimental verification
• Movement is no so simple• Planets Mars
Philosophy
Geocentric theory
Observations
Theory
Predictions
Experimental verification
• Movement is no so simple• Planets• Distance to the objects
Philosophy
Geocentric theory
Observations
Theory
Predictions
Experimental verification
Philosophy
Ptolemy, The Almagest,A.D. c.100-c.178
Geocentric theory
Observations
Theory
Predictions
Experimental verification
Philosophy
Geocentric theory
Observations
Theory
Predictions
Experimental verification
Philosophy
EARTH
SUN
Mercury
Venus
Geocentric theory
Observations
Theory
Predictions
Experimental verification
Philosophy
EARTH
SUN
Mercury
Venus
Simplicity
“Simpler” theories
Observations
Theory
Predictions
Experimental verification
Heliocentric system: the planets (including Earth) rotate around the Sun, and the Earth is also spinning around its axisPythagoreans, Aristarchus of Samos, Plato (?), Copernicus
“Hybrid” geocentric system: the Earth is not moving, the planets rotate around the Sun that rotates around the EarthHeraclides of Pontus, Tycho Brahe
Heliocentric theory
Observations
Theory
Predictions
Experimental verification
Nicolaus Copernicus, On the Revolutions of the
Heavenly Spheres, 1473-1543
Johannes Kepler,Epitome of Copernican
Astronomy,The Harmonies of the World,
1571-1630Galileo Galilei,
Sidereus Nuncius, 1564-1642
Heliocentric theory
Observations
Theory
Predictions
Experimental verification
The phase of Venus
Observations
Theory
Predictions
Experimental verification
The phase of Venus
Observations
Theory
Predictions
Experimental verification
Galileo Galilei, c1610
Parallax
Observations
Theory
Predictions
Experimental verification
Parallaxwinter
Observations
Theory
Predictions
Experimental verification
Parallaxsummer
Observations
Theory
Predictions
Experimental verification
Parallaxsummer
Observations
Theory
Predictions
Experimental verification
1832Alpha Centauri (nearest star), Henderson
Vega, Friedrich von Struve 61 Cygni, Friedrich Bessel
Beyond the solar system
1) High concentration of stars along the milky way The stars are distributed more in a disk than in as sphere
Beyond the solar system
2) The star distribution in the milky way is asymmetric, with respect to the Earth, but is rather symmetric with respect to a
point in the constellation of Sagittarius (Shapley, 1915) The Sun is not at the center of the Galaxy
Beyond the solar system
3) There are other galaxies in the Universe in addition to ours (Hubble)
Beyond the solar system
4) There are billions of galaxies in the Universe
Solar System Galaxy Universe COSMOLOGY
Doppler effect
Doppler effect
Doppler Effect in Galaxies
Earth
MovementFast
toward usSlow
toward us
Not moving
Slowaway from us
Fastaway from us
Hubble law (redshift)
Speed = H · distance (H = Hubble constant)
Edwin Hubble1929
Observations
Theory
Predictions
Experimental verification
ALL DISTANT GALAXIES ARE RECEDING FROM US
Consequences of Hubble Law
If all the galaxies move away from us, does it mean that we are at the center of the Universe?
What happens if we rewind the tape of the Universe?
How old is the Universe?
Expansion of the Universe
If all the galaxies move away from us, does it mean that we are at the center of the Universe?
Raisin Cake
Balloon
Expansion of the Universe
What happens if we rewind the tape of the Universe?
REWIND
Age of the Universe
speed = H · distance
AGE OF THE UNIVERSE IS APRROXIMATELY THE INVERSE OF THE HUBBLE CONSTANT:
T ~ 1/H
T ~ 2 1010 years = 20,000,000,000 years
Evolution of the Universe
What happened at the beginning?
What will happen in the future?
• COLD BIG BANG
• HOT BIG BANG
Observations
Theory
Predictions
Experimental verification
The Big Bang Theory
Observations
Theory
Predictions
Experimental verification
The Big Bang Theory
Observations
Theory
Predictions
Experimental verification
The Big Bang Theory
Can we try to “see” the explosion?
YES!!!
Speed of light: 300,000 Km/s ~ 675,000,000 Miles/h
distance = 20,000,000,000 light years~100,000,000,000,000,000,000,000 Miles
Observations
Theory
Predictions
Experimental verification
The cosmic microwave background
Observations
Theory
Predictions
Experimental verification
Arno Penzias and Robert Wilson, 1965(Nobel Prize in 1978)
What will happed in the future?
What happened before the Big Bang?
?
Philosophy