Transcript NASC 1100 Lecture 1

Other Planetary Systems
Over 130 extrasolar planets have been discovered
since 1995 The Extrasolar Planet Encyclopedia
Stars are too far away from the Sun, and direct
imaging cannot detect planets near them
Current strategy involves watching for the small
gravitational tag the planet exerts on its star
The tag can be detected using the Doppler effect
Planet Transits
The Nature of Extrasolar Planets
The discovery of extrasolar planets gives us an
opportunity to test the solar system formation
theory
Most of the discovered planets are different from
those of our system
They are mostly Jupiter-size and located closer to
their stars
But: possible planet migration
discovered planets are exceptions
The Kepler Project will look for terrestrial planets around other stars
Life outside the Solar System
NASC 1100
Our Physical World
The Course Overview
Course structure
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Methodology of Science (lecture 1)
Overview of our place in the Universe (lecture 2)
Physics (August 27  October 1)
Chemistry (October 4  October 22)
Earth Science (October 27  November 12)
Astronomy (November 15  December 8)
The Course Summary (December 10)
Final Exam (December 16)
The Scientific Method
The Scientific Method is a general scheme for looking at
the Universe
The 4 major steps of the scientific method
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Formulating a problem
Observation and Experiment
Interpreting the Data
Testing the Interpretation by further Observation
and Experiment
Main Laws of Physics
Newton’s Laws
Kepler’s Laws
Conservation of Energy
Conservation of Momentum (+angular momentum)
Coulomb’s Law
Ohm’s Law
Laws of Ideal Gas
The Doppler Effect (types of waves)
Electromagnetic Waves (spectral regions)
Energy is directly proportional to frequency
Atomic Physics
Models of Atom (Rutherford, Bohr)
Chemical Elements (isotopes)
Concept of Binding Energy
Fusion and Fission
Elementary Particles
The Periodic Law
Inorganic Chemistry
Elements, Mixtures, and Compounds
Chemical Bonds (covalent, polar covalent, ionic)
Electronic Shells (open and closed)
States of Matter (solid, liquid, gas, plasma)
Crystalline and Amorphous substances
Electron “gas” in metals
Van der Waals forces
Solutions (saturated and unsaturated)
Liquids (polar and nonpolar)
Dissociation (acids, bases, salts, pH scale)
Chemical Energy (electron potential energy)
Organic Chemistry
Carbon bonds
Alkanes (organic compounds containing C and H)
Petroleum
Structural Formulas (H  C  C  H)
Saturated and Unsaturated hydrocarbons
Functional Groups (hydroxyl, carbonyl, carboxyl)
Monomers and Polymers
Carbohydrates, Lipids, Amino Acids
Earth Sciences
Atmosphere and Hydrosphere
Atmospheric composition (N, O, CO2, noble gases)
Clouds (saturated and unsaturated air)
Winds (Coriolis Force)
Weather Systems (cyclones and anticyclones)
Climate
Ocean Currents
Rocks (igneous, sedimentary, metamorphic)
Rock Cycle, Minerals
Earth’s structure
Astronomy
Solar System
Stars
Galaxies
The Universe
The Solar System
Creation from one molecular cloud
Central star (the Sun)
Two families of planets (terrestrial and Jovian)
Small objects - asteroids (rocky leftovers) and
comets (icy leftovers)
Stars
Objects that emit radiation in whose interiors at
some point fusion reactions H -> He takes place .
Masses: 0.08 - ~100 Msun.
Lifetimes: few million - few billion years
Low-mass, intermediate-mass, and high-mass stars.
The Hertzsprung - Russell diagram.
Galaxies and Universe
Huge stellar systems (up to 1 trillion stars)
Spiral, elliptical, and irregular galaxies
Hubble’s Law - universal expansion
Quasars - early galaxies with extremely luminous
nuclei (perhaps, due to supermassive black holes)
Dark matter  invisible mass that explains galactic
rotation laws and formation of galaxies
The Universe
The Big Bang theory  the theory of the universe’s
earliest moments.
It predicted the cosmic microwave background
(radiation from the moment when the Universe
became transparent for photons, T = 2.7 K)
and the proportion of the primordial He to H (~1/3).
Age of the Universe is approximately the inverse
Hubble constant (~14 billion years)
Sample Questions for the Final
Exam
Definition questions:
What is a scientific theory?
Types of mechanical waves
How does the force of gravity depends on the
distance between the objects?
What is chemical energy?
What are igneous rocks?
What is weight?
What Happens to Saturated Air if
… it cools?
Saturated air cannot take more moisture.
At higher temperatures air can get more moisture.
Thus, if saturated air cools, water has to condense
out.
Stellar Luminosity
Luminosity is the total amount of power the star
radiates into space.
It is measured in power units (Watts).
Brightness of a star in the sky depends on the
distance towards a star and its luminosity.
The apparent brightness is the amount of light
reaching us per unit area.
Apparent brightness obeys an inverse square law
with distance.