The Drake equation now tells us that the number of technological civilizations in our Galaxy at this time is:
A) only our own.
B) five to ten at most.
C) perhaps 3,000.
D) millions.
E) not known; insufficient data to compute.
E
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The Large and Small Magellanic Clouds are satellites galaxies of the Milky Way
a. True b. False Indicate whether the statement is true or false
Suppose a planet is discovered by the Doppler technique and is then discovered to have transits. In that case, we can determine all the following about the planet except
A) its precise mass. B) its density. C) its physical size (radius). D) its rotation period. E) its orbital period.
The dimmest part of sunlight is
A) red. B) yellow. C) yellow-green. D) green. E) violet.
When a fixed amount of ideal gas goes through an isothermal expansion
A) its internal (thermal) energy does not change. B) the gas does no work. C) no heat enters or leaves the gas. D) its temperature must decrease. E) its pressure must increase.