Suppose you are standing a few feet away from a bonfire on a cold fall evening. your face begins to feel hot. what is the mechanism that transfers heat from the fire to your face? (hint: is the air between you and the fire hotter or cooler than your face? )

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?