Would you rather step on a piece of lego barefoot everyday for a week, or get a single paper cut between your toes?
would you rather know when you will die or how you will die?
would you rather sweat mayonnaise or sweat ketchup?
would you rather have legs as long as your fingers, or fingers as long as your legs?
would you rather drink orange juice, expecting it to be milk, or drink milk expecting it to be orange juice?
would you rather have all farts be silent but extremely deadly, or all farts be harmless but extremely loud?
would you rather make your internet browsing history for the last 12 months accessible to anyone for a year, or give up the internet for a year?
would you rather understand any language, or be able to play any instrument?
would you rather always be a little bit too hot, or a little bit too cold?
would you rather fight 100 duck-sized horses or one horse-sized duck?
would you rather take a 50% chance of winning €100 million, or a 99% chance of winning €1 million?
would you rather never being able to lie, or never be able to tell the truth?

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)