Briefly discuss dark matter
What will be an ideal response?
When astronomers measure the masses of galaxies, they often find that the measured masses are much larger than expected from the luminosities of the galaxies. Measured masses of galaxies amount to 10 to 100 times more mass than you can see. Dark matter is difficult to detect, and it is even harder to explain. Some astronomers have suggested that dark matter consists of low-luminosity white dwarfs and brown dwarfs scattered through the halos of galaxies. Searches for white dwarfs and brown dwarfs in the halo of our Galaxy have found a few but not enough to make up most of the dark matter. The dark matter can't be hidden in vast numbers of black holes and neutron stars, because astronomers don't see the X-rays these objects would emit. The evidence indicates there is 10 to 100 times more dark matter than visible matter in galaxies, and if there were that many black holes they would produce X-rays that would be easy to detect. Because observations imply that the dark matter can't be composed of familiar objects or material, astronomers are forced to conclude that the dark matter is made up of unexpected forms of matter.
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A) the same B) amplified C) shorter D) longer E) stationary
Where are bedrock channels more likely to be found?
The internal energy of n moles of an ideal gas depends on
a. one state variable T. b. two state variables T and V. c. two state variables T and P. d. three state variables T, P and V. e. four variables R, T, P and V.
When studying light, a nanometer is a unit
used for a) resonance. b) frequency. c) wavelength. d) loudness.