Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 26: Problem 31

What does it mean to say that the universe is darkenergy-dominated? What happened when the universe changed from being matter-dominated to being darkenergy-dominated?

Short Answer

Expert verified
The universe being 'dark-energy-dominated' refers to the state where the majority of the cosmic energy density comes from dark energy, which causes the universe's expansion to accelerate. The transition from the universe being 'matter-dominated' to 'dark-energy-dominated' likely caused this expansion to transition from decelerating to accelerating, leading to galaxies moving away from each other at increasing rates.

Step by step solution

01

Understand Dark Energy Domination

Dark energy domination refers to the state of the universe where the majority of the cosmic energy density is made up by dark energy. Dark energy is a mysterious form of energy that affects the universe's expansion, causing it to accelerate. When we say that the universe is dark-energy dominated, it means that the majority of the energy in the universe comes from dark energy.
02

Contemplate the Matter-Dominated Era

Before the universe became dark-energy dominated, it was matter-dominated. During this epoch, the expansion of the universe was decelerating due to the gravitational effects of matter (both regular and dark). As both matter and dark energy densities decrease over time due to the universe's expansion, dark energy density remains almost constant. Consequently, there was a point in the universe's history when the densities equaled each other and the universe transitioned from being matter-dominated to dark-energy dominated.
03

Consider the Transition

The transition from being matter-dominated to dark-energy dominated occurred when the energy density of the universe from dark energy surpassed that of matter. This likely caused the expansion of the universe to transition from decelerating to accelerating, thus leading to the current epoch where galaxies are moving away from each other at an increasing rate, rather than a stable or decreasing rate. The precise effects, however, remain a subject of ongoing scientific investigation.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

What would be the critical density of matter in the universe \(\left(\rho_{c}\right)\) if the value of the Hubble constant were (a) \(50 \mathrm{~km} / \mathrm{s} / \mathrm{Mpc}\) ? (b) \(100 \mathrm{~km} / \mathrm{s} / \mathrm{Mpc}\) ?

As a group, create a four- to six-panel cartoon strip showing a discussion between two individuals describing why the sky is dark at night.

What is Olbers's paradox? How can it be resolved?

Suppose we were living in a radiation-dominated universe. Discuss how such a universe would be different from what we now observe.

Imagine an astronomer living in a galaxy a billion light-years away. Is the observable universe for that astronomer the same as for an astronomer on Earth? Why or why not?
See all solutions

Recommended explanations on Physics Textbooks

Oscillations

Read Explanation

Space Physics

Read Explanation

Thermodynamics

Read Explanation

Translational Dynamics

Read Explanation

Geometrical and Physical Optics

Read Explanation

Torque and Rotational Motion

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free