1) The speed of light is approximately 299,792,458 meters per second.

2) The first computer mouse was invented by Douglas Engelbart in 1964 and consisted of a wooden shell and two metal wheels.

3) The word "umbrella" contains three vowels: U, E, and A.

4) The concept of separation of powers, as articulated by French philosopher Montesquieu, refers to the division of government responsibilities into distinct branches, such as the executive, legislative, and judicial, to prevent concentration of power.