What do you mean by dark matter?
dark matter, a component of the universe whose presence is discerned from its gravitational attraction rather than its luminosity. Dark matter makes up 30.1 percent of the matter-energy composition of the universe; the rest is dark energy (69.4 percent) and “ordinary” visible matter (0.5 percent).
Which best describes dark matter?
Dark matter is composed of particles that do not absorb, reflect, or emit light, so they cannot be detected by observing electromagnetic radiation. Dark matter is material that cannot be seen directly. We know that dark matter exists because of the effect it has on objects that we can observe directly.
What is dark matter quizlet?
Dark matter is the name given to the unseen mass whose gravity governs the observed motions of stars and gas clouds. Dark energy is the name given to whatever may be causing the expansion of the universe to accelerate.
What does dark in dark matter mean?
Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation (like light) and is, therefore, difficult to detect.
Where is the dark matter?
The answer is gravity. Astronomers indirectly detect dark matter through its gravitational influences on stars and galaxies. Wherever normal matter resides, dark matter can be found lurking unseen by its side.
Why do we call dark matter dark quizlet?
Why do we call dark matter "dark"? It emits no radiation that we have been able to detect. Although most astronomers assume dark matter really exists, there is at least one other possible explanation for the phenomena attributed to dark matter.
What is dark matter Answer Key?
Dark matter defines how the objects in the Universe were made, and it also determines the fate of the Universe, whether it's open, closed, or flat. Dark matter also governs the motions of individual stars and the motions of galaxies as a whole. It makes the galaxies and large structures form.
What is the dark matter made of?
Scientists only speculate what dark matter is made of. It could be composed of baryons but it could also be non-baryonic, that means consisting of different types of particles. Most scientists think that dark matter is composed of non-baryonic matter.
What is meant by dark energy quizlet?
What is dark energy? (AKA cosmological constant) Dark energy is the name given to the mysterious force that counteracts the effects of gravity on larger scales, and leads to the acceleration in the universe's expansion.
Which is a characteristic of dark matter quizlet?
Dark matter is matter that gives off little or no light. Dark energy is the name given to whatever it is that is causing the universe's expansion to accelerate.
What is dark matter astronomy quizlet?
dark matter. Matter that does not give off electromagnetic radiation. dark energy. A mysterious force that appears to be causing the expansion of the universe to accelerate.
Which of the following statements best summarizes current observations concerning dark matter?
Which of the following statements best summarizes current evidence concerning dark matter in individual galaxies and in clusters of galaxies? Dark matter is the dominant form of mass in both clusters and in individual galaxies.
Which of the following is evidence of dark matter?
Strong evidence for the existence of dark matter comes from observations of: clusters of galaxies. A photograph of a cluster of galaxies shows distorted images of galaxies that lie behind it at greater distances.