COSMIC PERSPECTIVE
9th Edition
ISBN: 9780135729458
Author: Bennett
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 20, Problem 53EAP
To determine
Age of the universe.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Using our example from the previous unit, let's try to determine the Hubble time for this example universe. You were given that a good representative galaxy receded at a speed of 4000 km/s and was found to be 20 Mpc away. With that in mind, what would the age of that universe be in years (aka what is that universe's Hubble time)? Go ahead and take the number of kilometers per Mpc to be approximately 3.1*10^19 km/Mpc. While this problem may look scary at first, this is really just bringing you full circle to one of the unit conversion problems you encountered at the beginning of this course.
mathematician Archimedes, responding to a claim that the number of grains of sand was infinite,
calculated that the number of grains of sand needed to fill the universe was on the order of 1063. Our
understanding of the size of the universe has changed since then, and we now know that the
observable universe alone is a sphere with a radius of 1026 m. Estimating the size of a grain of sand,
A) Approximately how many grains of sand would fill the observable universe?
B) How many times larger or smaller is this number than Archimedes' result?
Assume the observable Universe is charge neutral, and that it contains n nuclei (hydrogen plus helium nuclei, ignoring other elements). Take the helium mass fraction as 1/4. How many electrons are there in the observable Universe? Enter your answer in scientific notation with one decimal place.
Values: n = 1*10^80
Chapter 20 Solutions
COSMIC PERSPECTIVE
Ch. 20 - Prob. 1VSCCh. 20 - Prob. 2VSCCh. 20 - Prob. 3VSCCh. 20 - Prob. 4VSCCh. 20 - Use the following questions to check your...Ch. 20 - Prob. 6VSCCh. 20 - Why do we need to understand the evolution of the...Ch. 20 - Prob. 2EAPCh. 20 - Prob. 3EAPCh. 20 - Prob. 4EAP
Ch. 20 - Prob. 9EAPCh. 20 - Prob. 10EAPCh. 20 - Prob. 11EAPCh. 20 - Prob. 12EAPCh. 20 - Prob. 13EAPCh. 20 - What is the cosmological horizon, and what...Ch. 20 - Prob. 15EAPCh. 20 - Prob. 16EAPCh. 20 - Prob. 17EAPCh. 20 - Prob. 18EAPCh. 20 - Prob. 19EAPCh. 20 - Decide whether the statement makes sense (or is...Ch. 20 - Prob. 21EAPCh. 20 - Prob. 22EAPCh. 20 - Prob. 23EAPCh. 20 - Prob. 24EAPCh. 20 - Prob. 25EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 27EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 29EAPCh. 20 - Prob. 30EAPCh. 20 - Prob. 31EAPCh. 20 - Choose the best answer to each of the following....Ch. 20 - Choose the best answer to each of the following....Ch. 20 - Choose the best answer to each of the following....Ch. 20 - Prob. 35EAPCh. 20 - Prob. 38EAPCh. 20 - Prob. 41EAPCh. 20 - Prob. 42EAPCh. 20 - Prob. 43EAPCh. 20 - Prob. 45EAPCh. 20 - Prob. 46EAPCh. 20 - Prob. 47EAPCh. 20 - Prob. 48EAPCh. 20 - Prob. 51EAPCh. 20 - Prob. 52EAPCh. 20 - Prob. 53EAPCh. 20 - Prob. 54EAPCh. 20 - Extremely Distant Galaxies. The most distant...Ch. 20 - Stretching of the Universe. The most distant white...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- What does the term Hubble time mean in cosmology, and what is the current best calculation for the Hubble time?arrow_forwardAssume the observable Universe is charge neutral, and that it contains n nuclei (hydrogen plus helium nuclei, ignoring other elements). Take the helium mass fraction as 1/4. How many electrons are there in the observable Universe? Enter your answer in scientific notation with one decimal place. Value: n = 4*1080arrow_forwardIf a galaxy is 9.0 Mpc away from Earth and recedes at 488 km/s, what is H0 (in km/s/Mpc)? km/s/Mpc What is the Hubble time (in yr)? years How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating? How would acceleration change your answer? A.If the expansion of the Universe has been accelerating, the Universe could be substantially younger than the value entered above. BIf the expansion of the Universe has been accelerating, the Universe could be substantially older than the value entered above.arrow_forward
- How would I calculate the age of the universe in billions of years from the Hubble constant (73.48 +/- 1.66 km/s/Mpc)? I know I need to use basic unit conversion but I’m not sure which numbers to use.arrow_forwardAssume the observable Universe is charge neutral, and that it contains n nuclei (hydrogen plus helium nuclei, ignoring other elements). Take the helium mass fraction as 1/4. How many electrons are there in the observable Universe? Enter your answer in scientific notation with one decimal place.arrow_forwardWhat would be your estimate for the age of the universe if you measured Hubbleʹs constant to be 33 km/s/Mly? You can assume that the expansion rate has remained unchanged during the history of the universe.arrow_forward
- Hubble's First Attempt. Edwin Hubble's first attempt to measure the universe's expansion rate was flawed because the standard candles he was using were not properly calibrated. Look at (Figure 1) a.Estimate the value of Ho corresponding to the solid line in the figure. Express your answer kilometers per second per million light-years to two significant figures. b.What is the approximate age of the universe indicated by that erroneous value of Ho? Express your answer in years to one significant figure.arrow_forwardNow let’s determine when the universe “started its trip”. The distance is 800 Mpc, but first convert Mpcinto km because the rate, or velocity, is in km/sec.800 Mpc = _____________________kmUse equation (E) to determine how many seconds ago the universe started:_____________________secsarrow_forwardWhat was the maximum age of the universe predicted by Hubble's first estimate of the Hubble constant?arrow_forward
- If a galaxy is 8.9 Mpc away from Earth and recedes at 497 km/s, what is H. (in km/s/Mpc)? km/s/Mрс What is the Hubble time (in yr)? years How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating? years How would acceleration change your answer? If the expansion of the Universe has been accelerating, the Universe could be substantially younger than the value entered above. If the expansion of the Universe has been accelerating, the Universe could be substantially older than the value entered above.arrow_forwardCalculate the age of the universe for the following Hubble's constant, (b) 65 km/s/Mpcarrow_forwardThe Universe is approximately 13.8 Billion years old. What is the volume of the visible universe in m3?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage LearningAstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax