Phys3030 Exam 1 Study Guide

Stars moving toward us
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Which of the following is a reason from a scientific perspective that the heliocentric model of the universe took so long to become the accepted model of the solar system?Scientists didn't have the technological tools available to observe parallax.Which of the following is a reason from a social/historical perspective that the heliocentric model of the universe took so long to become the accepted model of the solar system?Keeping Earth at the center of the Universe was largely important to many religious and other belief systems.The numbers of wavelengths that pass a single point in a second.FrequencyThe distance between two consecutive peaks (or troughs) in a wave.WavelengthThe standard way to write large numbersScientific NotationThe average distance between the earth and the sun.Astronomical Unit(AU)The distance that light travels in one year.Light-year (ly)Where do we get the majority of our information about the rest of the universe?LightPlease match the unit with the correct power of 10. Megaparsecs Kiloparsecs Nanoparsecs10^6 10^3 10^-9Which of the following wavelengths of light has the highest energy? 388 nm 294 nm 107 nm 135 nm107 nmWhich of the following frequencies of light has the highest energy? 472hz 222hz 175hz 398hz472hzA math concept in which one number gets smaller as another one gets larger.Inverse RelationshipThe amount of light from a star that actually reaches Earth (and that we measure).FluxThe total amount of light that a star actually gives off (and that we calculate).LuminosityAn object in the universe that has a known luminosity - which allows us to calculate distances.Standard CandleA certain type of star who's flux grows and shrinks in a predictable way according to its luminositCepheid Variable StarA type of stellar explosion that can be used as a standard candleType 1a SupernovaThe apparent shift of a star's position in comparison to the more distance stars in the background.ParallaxAssume I know of two properties that are inversely related. Call them the BLUE property and the RED property. What would happen to the red property if the blue one were to get largerIt would get smaller.If I look at the changing brightness of 2 different Cepheid Variable Stars, which statement will be true?The star that changes more slowly will have a higher luminosity.When we measure the distance to an astronomical object using parallax we look at the apparent motion of one star in reference to background stars. In reality the background stars, the star we are trying to measure the distance to and the earth are all moving. The movement of which of the following has the most impact when calculating distance using parallax? (Hint: The motion of which objects was considered negligible when deriving the parallax equation?)The earthStar A and Star B have the same intrinsic luminosity. If an astronomer measures a greater flux (more photons per second) from Star A than from Star B, which is closer?Star AIn order to calculate the distance to a certain cepheid variable star you would need to measure the1. ______["Luminosity", "Period", "Flux"] (the amount of light seen per unit area) and observe the star long enough to measure the 2.________ ["Period", "Luminosity", "Flux"] of the oscillation. You could then use the relationship first found by Henrietta Leavitt to calculate the intrinsic 3.________ ["Luminosity", "Period", "Flux"] of the star.Flux Period LuminosityTwo stars, A and B, are known to have the same intrinsic luminosity. If the flux from Star A is measured to be 9 times the flux of Star B, which of the following statements is true about their relative distances from the Earth.Star A is 1/3 the distance of Star BTrue or False. You measure the flux from a star. All that is known about this star is the flux measurement. You can still use this data to calculate the distance to the starFalseA single wavelength in the electromagnetic spectrum.Emission LineThe general term for the wavelength of a wave becoming stretched.RedshiftThe general term for the wavelength of a wave becoming compressed.BlueshiftThe specific term for the effect of light due to the expansion of the universe.Cosmological RedshiftHubble's constant is about 73 km/s/Mpc. That means that somewhere (far enough away from the Earth) stars are moving away from us faster than the speed of light.TrueWhy does an expanding universe imply that there was a Big Bang?Since it's expanding today, we can work backwards to a starting point - the Big Bang.The currently accepted value for Hubble's constant is 73 km/s/Mpc. Following the calculation in your reading, if Hubble's constant was instead measured to be 104 km/s/Mpc would the estimate of the age of the universe be larger, smaller or the same.smallerWhich photon has more energy?A blueshifted photon.intrinsic luminosityThe intrinsic luminosity of a star is its actual brightness and magnitude, not simply its apparent brightness that we can witness from earth.inverse relationshipa relationship in which one variable decreases when another variable increases