If economics was physics, macro would be cosmology and relativity while microeconomics would be Newtonian mechanics.

如果经济学是物理，宏经济学是宇宙论和相对论，经济学是牛力学。

And then later, Euler and Lagrange reformulated Newtonian mechanics in a totally different way.

后来，欧拉和拉格朗以完全不同的方式重新表述了牛力学。

Now let's go back to Newtonian mechanics.

现在让我们回到牛力学。

Now, we talked about Newtonian mechanics, leading all through different Lagrangian, Hamiltonian mechanics.

现在，我们讨论了牛力学，贯穿了不同的拉格朗力学和哈密力学。

Newtonian mechanics allow you to coast without too much trouble from Earth to the Didymos system, but hitting the target requires active guidance.

牛力学让你可以轻松地从地球滑行到 Didymos 系统，但击中目标需要主动引。

The original aim of the hypothesis was to explain why the velocities  of stars in galaxies were observed to be larger than expected based on Newtonian mechanics.

该假设的最初目的是解释为什么根据牛力学预期，星系中恒星的速度被测到比预期的大。

To quote him, he said that, " In this Hopi view, time disappears and space is altered, so that it is no longer the homogenous and instantaneous timeless space of our supposed intuitions or of classical Newtonian mechanics."

引用他的话，他说，“在霍皮族人看来，时间消失了，空间也被改变了，所以并没有同质和瞬时的永恒空间，这一思想完全不同于我们的假定直觉和经典牛力学。

So I discussed briefly when I talked about the connection between Newtonian mechanics and the Euler-Lagrange reformulation of the Newtonian mechanics and interpretation of this Euler-Lagrange formalism in terms of the paths that the particle take.

因此，当我谈到牛力学与欧拉-拉格朗对牛力学的重新表述之间的联系，以及从粒子所采取路径的角度来解读这一欧拉-拉格朗形式体系时，我简要地讨论了这一点。