They move from regions of high concentration to regions of low concentration by this natural flow down a concentration gradient.

从高浓度区域,向低浓度区域流动,顺浓度梯度流动

耶鲁公开课 - 生物医学工程探索课程节选

You don't want--you know that you'd like to take money away from yourself in the high-outcome years and give it to yourself in the low-income years.

你不想...你知道,你想在高收入的年份中,拿出一点钱,给你自己低收入的年份

耶鲁公开课 - 金融市场课程节选