Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 23: Problem 20

What is the difference between dark matter and dark nebulae?

Short Answer

Expert verified
Dark matter is a theoretical type of matter that is inferred through its gravitational effects and does not emit or interact with electromagnetic radiation. On the other hand, dark nebulae are dense interstellar clouds composed of gas and dust that block light from objects located behind them. Dark nebulae can be observed with radio and infrared telescopes.

Step by step solution

01

Define Dark Matter

Define dark matter as a type of matter hypothesized in astrophysics to account for a large part of the mass that seems to be missing from the universe. Dark matter is invisible to light and other forms of electromagnetic radiation, making it virtually impossible to detect with current instruments. However, dark matter's existence and properties are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe.
02

Define Dark Nebulae

Define Dark Nebulae as interstellar clouds so dense with gas and dust that it obscures the visible wavelengths of light from objects behind it, such as background stars or emission or reflection nebulae. They are composed primarily of hydrogen molecules and dust. Dark nebulae don't emit or reflect sufficient light to be detected with a normal telescope, but they can be observed with radio and infrared telescopes.
03

Highlight the Differences

Highlight the main differences between the two. Dark matter is a theoretical construct, whilst dark nebulae are observable and made of normal (baryonic) matter. Dark matter's existence is inferred from the gravitational effect it seems to have on visible matter. Whereas dark nebulae are visible because they block light from objects behind them.

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 must happen within a hydrogen atom for it to emit a photon of wavelength \(21 \mathrm{~cm}\) ?

Use the Starry Night Enthusiast \(\mathrm{TM}^{\mathrm{M}}\) program to observe the Milky Way. (a) Display the entire celestial sphere by selecting Favourites \(>\) Guides \(>\) Atlas. Select View \(>\) Stars \(>\) Milky Way to display this galaxy. Select Options \(>\) Stars \(>\) Milky Way, move the Brightness slide-bar to the far right to brighten the Milky Way and click OK. In the View menu, ensure that the Scrollbars are activated and use them to look at different parts of the Milky Way. Can you identify the direction toward the galactic nucleus? In this direction the Milky Way appears broadest. Open the Find pane, enter Sagittarius in the Query box and press Enter to center on this constellation to check your identification. (b) Use this full-sky view to determine the orientation of the plane of the Galaxy with respect to the celestial sphere. Move the vertical scrollbar to its central position to display the Celestial Equator as a horizontal line across the lower part of the view. Move the horizontal scrollbar until the Milky Way is centered upon the view. Estimate the angle between the Milky Way and the celestial equator on the screen. How well aligned is the plane of the Milky Way with the plane of the Earth's equator? (c) A third plane of interest is that of the ecliptic, which is shown as a green line. Use the scrollbars to adjust the view so that the ecliptic appears as a straight line rather than as a curve, thereby ensuring that you are viewing in a direction that lies in the ecliptic plane. Use the horizontal scrollbar to move the view to where you can see where the ecliptic crosses the Milky Way. Estimate the angle between the Milky Way and the ecliptic on the screen. How well aligned is the plane of the Milky Way to the ecliptic, the plane of the Earth's orbit around the Sun? (d) Click on Home in the toolbar to return to your home view, stop Time Flow and set the local time to midnight (12:00:00 A.M.). Select Options > Stars > Milky Way, move the Brightness slide-bar to the far right to brighten the Milky Way and click OK. Adjust the date to January 1, then February 1, and so on. In which month is the galactic nucleus highest in the sky at midnight, so that it is most easily seen from your location?

How do astronomers determine how fast the Sun moves in its orbit around the Galaxy? How does this speed tell us about the amount of mass inside the Sun's orbit? Does this speed tell us about the amount of mass outside the Sun's orbit?

Explain why globular clusters spend most of their time in the galactic halo, even though their eccentric orbits take them close to the galactic center.

What is the evidence that there is a supermassive black hole at the center of our Galaxy? How is it possible to determine the mass of this black hole?
See all solutions

Recommended explanations on Physics Textbooks

Medical Physics

Read Explanation

Mechanics and Materials

Read Explanation

Physical Quantities And Units

Read Explanation

Torque and Rotational Motion

Read Explanation

Atoms and Radioactivity

Read Explanation

Radiation

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