Linfeng Jin

“历史者，所以说明社会进化的过程者也。”
― 吕思勉

“Turbojets are like people: if anything is wrong, the temperature goes up.”
― Stanley Hooke

“At speeds up to about 300 mph air can be regarded as incompressible, like water. In other words, the pressure differences caused by the air velocities are small compared with the pressure of the atmosphere, and so the air behaves as if its density remained constant.

For example, at 200 mph the maximum pressure that air can exert is only 5 percent of the atmospheric pressure, which has a negligible effect on the air density and the flow. But at 400 mph the pressure increases to 21 per cent and at 600 mph to 51 per cent. These pressure increases have a significant effect upon the density of the air, and, hence, upon its flow pattern and the forces that the air exerts.”
― Stanley Hooke

“If Men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and the next place, oblige it to control itself.”
― James Madison