Imagine an advanced civilization living on a planet orbiting at a distance of 10 AU (1.5 billion kilometers) from a close binary star system that consists of a 15 MSun red giant star and a 10 MSun black hole.
The black hole is surrounded by an accretion disk. Sometime within the next million years or so, the civilization's planet is likely to be doomed because A) the red giant will probably supernova within the next million years.
B) jets of material shot out of the accretion disk will shoot down their planet.
C) the red giant star, which provides most of energy the civilization needs to exist, will soon be destroyed in the accretion disk.
D) tidal forces from the black hole will rip the planet apart.
Question 2
What is the difference in meaning between the terms weather and climate?
A) Weather refers to local conditions, and climate refers to global conditions.
B) Weather refers to short-term variations in conditions, and climate refers to long-term variations in conditions.
C) Weather refers to small storms, and climate refers to large storms.
D) Weather refers to wind and rain, and climate refers to processes like convection.
E) There is no difference between weather and climate.
These older adults are participating in an exercise class at their assisted-living facility
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Distance from Earth to Sun schematic
The DNA from one chromosome has a mass of ~20 billion Daltons
Planet Earth compared to all its water and air!
Physical distance versus recombination distance on human male and female chromosome 19