There is evidence in mammals that recovering from jetlag after westward travel is faster than after eastward travel. To understand why, mathematical models have been used, along with theories of entrainment rooted in experimental evidence. The most complete understanding relies on detailed mathematical modeling, so it is helpful to develop an intuition about why there is an east-west asymmetry. One such intuition is that humans have long periods and therefore recover better when they can delay. Although this is part of the reason, it does not explain why short-period mice also recover from westward travel faster. Our goal is to provide a simple intuition consistent with detailed mathematical theories, but which does not require mathematical expertise to follow. Here, we present the intuition that westward travel is easier to recover from because of a simple principle: delays are self-enhancing.

哺乳动物有证据表明，向西旅行后从时差中恢复的速度比向东旅行后更快。为了理解原因，使用了数学模型以及植根于实验证据的夹带理论。最完整的理解依赖于详细的数学建模，因此有助于形成关于为什么存在东西不对称的直觉。其中一种直觉是人类有很长的时间，因此当他们可以延迟时恢复得更好。虽然这是部分原因，但这并不能解释为什么短周期老鼠从西行中恢复得更快。我们的目标是提供与详细数学理论一致的简单直觉，但不需要数学专业知识来遵循。这里，