Briefly summarize current knowledge about the term flife in the equation
Number of Civilizations = NHP × flife × fcivilization × fnow.
What will be an ideal response?
flife is the fraction of habitable planets with life. We know that at least one planet within its star's habitability zone has developed life, namely the Earth, but beyond that, we have no real evidence on which to base an estimate of the value of flife.
You might also like to view...
Hurricanes are powered by
a. Hadley circulation. b. the Coriolis effect. c. the heat of vaporization of water. d. electrical conductivity of water. e. the greenhouse effect.
The temperature of Jupiter's core is higher than the surface temperature of the Sun.
Answer the following statement true (T) or false (F)
You find yourself in a place that looks (except for your own presence) perfectly symmetrical. There is no way to distinguish one place from another, and all forces are one
With this perfect symmetry, there is no obvious way to define the flow of time. Where are you? A) You are in the center of a young star. B) You are in the early universe before the Planck time. C) You are floating somewhere in the universe near its end, 10100 years from now. D) You are inside the nucleus of an atom. E) You are in the universe shortly after inflation.
A concave mirror has a radius of curvature of 1.0 m. An object is placed 2.0 m in front of the mirror. Determine the location of the image (in cm)
a. 130 b. 83 c. 67 d. 150 e. 200