Fall 2000 ASTR 1120-001 Quiz 4
Choose the single best answer and enter it on your scantron form.
Be sure to fill in your
name and
student number.
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A fundamental postulate of special relativity is:
(a) there exists an absolute time, the same for all observers;
(b) objects in a gravitational field fall at the same rate;
(c) light is both a particle and a wave;
(d) light diminishes as the inverse square of distance;
(e) the speed of light is the same for all observers.
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Which of the following is not
a consequence of Einstein's theory of special relativity:
(a) the uncertainty principle;
(b) E = m c2;
(c) the speed of light is an absolute speed limit;
(d) time dilation;
(e) Lorentz contraction?
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A friend in a racecar passes you at almost the speed of light.
Relative to you, the light from the racecar's headlamps:
(a) moves hardly at all;
(b) moves at almost the speed of light;
(c) moves at the speed of light;
(d) moves almost twice the speed of light;
(e) moves almost four times the speed of light.
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You are not normally aware of special relativistic effects because:
(a) you cannot see light;
(b) you are not near a black hole;
(c) you move at much less than the speed of light;
(d) of quantum mechanical effects;
(e) special relativity involves advanced mathematics.
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If you traveled through the Galaxy at near the speed of light,
the Galaxy would appear:
(a) normal, but moving by fast;
(b) relativistically beamed ahead of you;
(c) relativistically beamed behind you;
(d) concentrated in a thin ring perpendicular to the direction you are moving;
(e) invisible.
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The superluminal (faster-than-light) motion observed in some cosmic jets
indicates that:
(a) special relativity is wrong;
(b) the jet is moving faster than the speed of light;
(c) the jet is moving towards us at almost the speed of light;
(d) the jet is moving away from us at almost the speed of light;
(e) the jet is falling into a black hole.
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You watch a friend fall through the horizon of a 30 solar mass black hole.
Which of the following is
false?
The friend appears:
(a) extremely redshifted at the horizon;
(b) to freeze to a halt at the horizon;
(c) to fall all the way to the central singularity;
(d) stretched by tidal forces;
(e) dead.
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At the instant you pass through the horizon of a
108 solar mass black hole, you observe that:
(a) time has come to a halt (your watch has stopped);
(b) all the future of the Universe passes before your eyes;
(c) the Universe appears concentrated into an ever-diminishing patch of sky, which closes off entirely at the instant you pass inside, leaving you in blackness;
(d) you are roasted by the Hawking radiation;
(e) nothing special happened at the horizon.
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The x-ray binary Cyg X-1 contains
an optically-observed massive blue main sequence primary
in orbit with a compact companion.
Astronomers believe that the compact companion is a black hole because:
(a) it is ripping the primary to pieces;
(b) its mass exceeds the maximum mass of a neutron star;
(c) the Hubble Space Telescope reveals a black object at the center of the accretion disk;
(d) the primary appears highly distorted;
(e) the x-rays are so energetic.
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Which of the following statements about wormholes is
false:
(a) wormholes connecting different Universes exist as mathematical solutions of general relativity;
(b) the collapse of a star to a black hole produces a wormhole;
(c) if a wormhole formed, it would be unstable and would fly apart rapidly;
(d) a traveler could not pass through a wormhole;
(e) to stabilize a wormhole would require negative mass at its throat.