What do astronomer's mean when they say that Earth is not in a special spot?
A. All space is expanding so Hubble's law would apply around all galaxies.
B. The Big Bang explosion sent all material blasting away from the Earth.
C. Hubble measured the expansion law from the Moon, not from the Earth.
D. Hubble's law applies to some galaxies but not to others, so many planets besides Earth have their own Hubble's law.
E. The Sun is at the center of the universe, but the Earth is not.
Ans: A. All space is expanding so Hubble's law would apply around all galaxies.
You might also like to view...
Spiral galaxy rotation curves are generally fairly flat out to large distances. Suppose that spiral galaxies did not contain dark matter. How would their rotation curves be different?
A) The orbital speeds would fall off sharply with increasing distance from the galactic center. B) The orbital speeds would rise upward with increasing distance from the galactic center, rather than remaining approximately constant. C) The rotation curve would be a straight, upward sloping diagonal line, like the rotation curve of a merry-go-round. D) The rotation curve would look the same with or without the presence of dark matter.
A metal having a work function of 2.8 eV is illuminated with monochromatic light whose photon energy is 3.9 eV. What is the threshold frequency for photoelectron production? (h = 6.626 × 10-34 J • s, 1 eV = 1.60 × 10-19 J)
A) 6.8 × 1014 Hz B) 2.7 × 1014 Hz C) 7.6 × 1014 Hz D) 8.5 × 1014 Hz E) 9.4 × 1014 Hz
There is direct evidence for the discreteness of energy levels in atoms
What will be an ideal response?
What do we mean by inflation?
A) the rapid expansion of the universe, driven by white dwarf supernova, that we still observe today B) the expansion of universe starting with the instant after the Big Bang C) the sudden release of photons when particles and antiparticles annihilate each other D) a sudden expansion of the universe driven by the energy released when the strong and electroweak forces froze out from the GUT force E) the photons released when electrons and protons first combined, forming the Cosmic Microwave Background Radiation