
Concept explainers
Choose the best answer to each of the following. Explain your reasoning.
What is the current temperature of the universe?(a) absolute zero (b) a few degrees K (c) a few thousand degrees K

The current temperature of the universe.
Answer to Problem 1QQ
b. Few degrees K
Explanation of Solution
Introduction:
Some microwave photons are observed since the end of the era of nuclei travelling through the space. The cosmic microwave background consists of these microwave photons. The photon starts travelling when the neutral atom formed by joining the electrons with the nuclei. So, very few free electrons are available as constrains in the path of the photon. As a result, the maximum photons travelled in the space were unobstructed.
Option (b) is: Few degrees K
The Big Bang theory predicts that the cosmic microwave background would show a perfect thermal spectrum generated due to the heat of the universe. The universe was cooled to the temperature of about 3000 K when the cosmic wave background broke free. Originally, the spectrum shows peak at 1000 nm. The peak is observed at 1000 nm because the universe is expanded by a factor of 1000. Now the wavelength of the photon is extended 1000 times the original wavelength. So, the peak wavelength is expected to be about a millimeter which lies in the microwave portion of the spectrum and corresponds to a temperature of about 2.7 K.
So, option (b) is correct and (a) and (c) are incorrect.
Conclusion:
The temperature of the universe is few degrees above the absolute zero.
Want to see more full solutions like this?
Chapter 13 Solutions
Cosmic Perspective Fundamentals
Additional Science Textbook Solutions
Microbiology: An Introduction
Campbell Essential Biology with Physiology (5th Edition)
Human Anatomy & Physiology (2nd Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Campbell Biology (11th Edition)
Organic Chemistry (8th Edition)
- Please see the attached image and answer the set of questions with proof.arrow_forwardHow, Please type the whole transcript correctly using comma and periods as needed. I have uploaded the picture of a video on YouTube. Thanks,arrow_forwardA spectra is a graph that has amplitude on the Y-axis and frequency on the X-axis. A harmonic spectra simply draws a vertical line at each frequency that a harmonic would be produced. The height of the line indicates the amplitude at which that harmonic would be produced. If the Fo of a sound is 125 Hz, please sketch a spectra (amplitude on the Y axis, frequency on the X axis) of the harmonic series up to the 4th harmonic. Include actual values on Y and X axis.arrow_forward
- Sketch a sign wave depicting 3 seconds of wave activity for a 5 Hz tone.arrow_forwardSketch a sine wave depicting 3 seconds of wave activity for a 5 Hz tone.arrow_forwardThe drawing shows two long, straight wires that are suspended from the ceiling. The mass per unit length of each wire is 0.050 kg/m. Each of the four strings suspending the wires has a length of 1.2 m. When the wires carry identical currents in opposite directions, the angle between the strings holding the two wires is 20°. (a) Draw the free-body diagram showing the forces that act on the right wire with respect to the x axis. Account for each of the strings separately. (b) What is the current in each wire? 1.2 m 20° I -20° 1.2 marrow_forward
- 2). How much energy is stored in the 50-μF capacitor when Va - V₁ = 22V? 25 µF b 25 µF 50 µFarrow_forward9). A series RC circuit has a time constant of 1.0 s. The battery has a voltage of 50 V and the maximum current just after closing the switch is 500 mA. The capacitor is initially uncharged. What is the charge on the capacitor 2.0 s after the switch is closed? R 50 V a. 0.43 C b. 0 66 C c. 0.86 C d. 0.99 C Carrow_forward1). Determine the equivalent capacitance of the combination shown when C = 12 pF. +11/20 2C C Carrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningAstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage LearningFoundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning





