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 • • • • • • • • 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 • • • • 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.