# A105 Stars in addition to Galaxies How will the class work First News Quiz Use the News Quiz link on Oncourse to find the article The Sun Today

## A105 Stars in addition to Galaxies How will the class work First News Quiz Use the News Quiz link on Oncourse to find the article The Sun Today

Hayes, Sherron, News Director has reference to this Academic Journal, PHwiki organized this Journal A105 Stars in addition to Galaxies Essential Facts Worksheet due today First News Quiz on Sept. 5 Read units 5, 6, 10 as long as next week Course Organization Syllabus/Oncourse Text Assigned Reading Lecture Notes Written Assignments Projects Quizzes Observing Office Hours Caty P.: Thursday, 11-noon SW 315 Tara Angle: Tues. 11-noon Weds. 2-3 PM SW 313 How will the class work News Quiz every Tuesday best 10 of 13 Homework every Thursday best 10 of 13 Project due Nov. 30 4 observing activities (required) Exams Sept. 28 in addition to Nov. 2 Final exam Dec. 12

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First News Quiz In Class QUIZ – Sept. 5 Astronomy Magazine article on Pluto: Use the News Quiz link on Oncourse to find the article A copy of the textbook is on 2-hour reserve in the Swain West Library (2nd floor of this bldg.) The Sun Today Solar Orbiting Heliospheric Observatory (SOHO) Orbits between the Sun in addition to Earth, about a million miles away  a constant view of the Sun Another view from Soho View of Mercury from the Solar Orbiting Heliospheric Observatory satellite Mercury Regulus

Review Scientific Notation Write in addition to work with very large or small numbers without so many digits. Only one digit should be in front of the decimal. The exponent positive when the number is greater than one, negative when the number is less than one. 43,000,000. = 4.3 x 107 0.000043 = 4.3 x 10-5 Use the worksheet with the first homework as long as practice Powers of 10 Basic Definitions Distances Solar Radius (700,000 km) Astronomical Unit (AU) Light year Mass Earth masses Solar masses Speed Speed of light (300,000 km per second)

What is an Astronomical Unit The average distance between the Earth in addition to Sun 150,000,000 km = 1.5 x 108 km 93,000,000 miles = 9.3 x 107 miles 8 LIGHT MINUTES Approximation Some numbers are know very accurately, but some are NOT Use an appropriate number of digits We will use approximate numbers What is a Light Year a light year is a distance! a light year is the distance that light can travel in one year light can travel about 10 trillion km (10,000,000,000,000 km) in one year The speed of light is 300,000 km/second Basic Definitions Collections Solar system Star System Galaxy Cluster or group of galaxies Supercluster Universe Observable universe Objects Star Planet moon, satellite, asteroid, comet Nebula

The star Betelgeuse is about 500 light years away from us in the constellation Orion. If this star exploded right now, how long would it be until we found out about it almost immediately 8 minutes 10 years 500 years 500 light years Size in addition to Scale know those essential facts! Beyond the Milky Way

Using those essential facts! Which of the following diagrams most closely depicts the relative sizes in addition to distance between Earth in addition to the Moon Modern science relies on observations in addition to experiments! Underst in addition to ing Science Purpose  to underst in addition to the universe well enough to figure out the basic relationships that govern it A process as long as underst in addition to ing in addition to predicting will it rain tomorrow what will be on the quiz what will happen if What about facts new discoveries better data new theories facts change!

The Science of Astronomy Learn what is known in addition to what is NOT known Develop a model to explain or describe what is known Use the model to predict what is not known TEST the predictions Refine the model But science rarely proceeds in this idealized way For example: Sometimes we start by just looking then coming up with possible explanations. Sometimes we follow our intuition rather than a particular line of evidence. Testing the Predictions Experiments in addition to Observations repeatable quantitative well defined fair Statistics evaluate the reliability of observations Examples What time is it Heads or tails

Laws in addition to Theories ( in addition to models) A law is a set of hypotheses that explains WHAT is happening  usually mathematical Keplers laws of planetary motion A theory is a well-developed set of hypotheses that explains why many related natural phenomena happen Einsteins Theory of General Relativity Laws in addition to theories are both based on detailed in addition to repeatable observations in addition to measurements Laws in addition to theories both yield testable predictions What is a scientific theory The word theory has a different meaning in science than in everyday life. In science, a theory is NOT the same as a hypothesis, rather: A scientific theory must: Explain a wide variety of observations with a few simple principles, AND Must be supported by a large, compelling body of evidence. Must NOT have failed any crucial test of its validity. Is a Theory Right Cant ever prove a theory right Does the theory make correct predictions If it doesnt, then its wrong If its not tested or testable, its NOT a scientific theory Burden of proof is on the person making the claim Extraordinary claims require extraordinary proof (Sagan)

Underst in addition to ing Science Purpose  to underst in addition to the universe well enough to figure out the basic relationships that govern it A process as long as underst in addition to ing in addition to predicting will it rain tomorrow what will be on the quiz what will happen if What about facts new discoveries better data new theories facts change! An Ongoing Process The process of science has been so successful because results are widely shared in addition to evaluated experiments are reproduced in addition to checked value of ideas based on observation in addition to usefulness, not authority Criteria of Science Consistent Observable Natural Predictable Testable Tentative Consistent: The results of repeated observations or experiment are more or less the same. Observable: The event under study can be observed or natural evidence must be available. Natural: A natural caused must be used to explain why or how the event happens Predictable: The natural cause can be used to make specific predictions. Testable: Predictions must be testable through observations or experiments. Tentative: Science is subject to revision in addition to correction based on new observations

Debating Scientific Issues How do we tell who is correct Majority vs. minority opinions Majority isnt always right Debate is a poor technique as long as deciding EVIDENCE in addition to DATA How was the experiment done Was it repeated by others Is a new theory TESTABLE How can we distinguish science from non-science Defining science can be surprisingly difficult Science from the Latin scientia, meaning knowledge But not all knowledge comes from science Warning Signs of Bad Science How is it announced Is the source reliable How good is the evidence is it anecdotal does it appeal to authority does it fit what you already know does it violate widely-accepted laws or theories is contrary evidence ignored What kind of reasoning is used Can the claim be tested The Baloney Detection Collection Phil Plait’s Bad Astronomy: Home Page

PLANET-DISSOLVING DUST CLOUD IS HEADED TOWARD EARTH! September 12, 2005, by Yahoo! News By MIKE FOSTER CAMBRIDGE, Mass. – Scared-stiff astronomers have detected a mysterious mass they’ve dubbed a “chaos cloud” that dissolves everything in its path, including comets, asteroids, planets in addition to entire stars – in addition to it’s headed directly toward Earth! Discovered April 6 by NASA’s Ch in addition to ra X-ray Observatory, the swirling, 10 million-mile- wide cosmic dust cloud has been likened to an “acid nebula” in addition to is hurtling toward us at close to the speed of light – making its estimated time of arrival 9:15 a.m. EDT on June 1, 2014. The bad news is that the total annihilation of our solar system is imminent. To avoid widespread panic, NASA has declined to make the alarming discovery public. But Dr. Sherwinski’s contacts at the agency’s Ch in addition to ra X-ray Observatory leaked to him striking images of the newly discovered chaos cloud obliterating a large asteroid. If it continues unchecked, the chaos cloud will eventually reduce our galaxy to the state of absolute chaos that existed be as long as e the birth of the universe, the astrophysicist warned. Assignments as long as next week: Read units 5, 6, 10 News Quiz on Tues., Sept. 5 Moon worksheet due next Thursday

## Hayes, Sherron News Director

Hayes, Sherron is from United States and they belong to Evening News – WJBB-AM and they are from  Haleyville, United States got related to this Particular Journal. and Hayes, Sherron deal with the subjects like Local News; National News; Regional News

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This Particular Journal got reviewed and rated by University of the Gambia and short form of this particular Institution is GM and gave this Journal an Excellent Rating.