How would you determine the ground state of a quantum system with no exact solution?

在没有精确解的情况下你如何确定量子系统的基态？

I would guess a wave-function and then vary its parameters until I found the lowest energy solution.

我会任意猜测一个基态波函数，通过参数找出能量最低的量子态。

But as some of the excited electrons fall back to their ground states, they emit energy as light.

不过当一部分的激发电子回到它们的基态的时候，它们会释出能量，即光。

Sometimes electrons in those atoms get into an excited state, and when they come back down again they give off light.

有时原子当中的电子被激发，而当它们回到基态时，便发出了光。

This, in turn, makes them open to physicists' probings, because there are no confusing changes happening inside the atoms themselves.

物理学可以检测反氢原子，为处于基态的反氢原子不会在原子内部发生难以解释的变化。

That is plenty of time for them to relax into their ground state, the most energetically stable condition they can be in.

这一时间足以让反氢原子弛豫，回到基态，即它们可能达到的能量最稳定状态。

Now when all those electrons drop down to the ground state, that atom is going to release some gamma radiation.

现在，当所有这些电子下降到基态时，该原子将释一些伽马辐射。

As the muon drops down to this different ground state, an x-ray is emitted—alerting Krauth's team that the transition has occurred.

当 μ 子下降到这种不同的基态时，会发出 X 射线——提醒 Krauth 的团队过渡已经发生。

Bombard an ordinary hydrogen atom with microwaves of the right frequency and you will lift it out of its ground state by flipping the spin of its electron.

以特定频率的微波轰击普通氢原子可以反转中电子的自旋，使跃迁离开基态。

So the muon starts in a semi-stable place—the food-messy desk—moves up to an unstable state—the clean desk—and then cascades down to a different stable ground state—the paper-messy desk.

，介子从一个半稳定的地方开始——食物凌乱的桌子——上升到一个不稳定的状态——干净的桌子——然后向下级联到另一个稳定的基态- 乱七八糟的桌子。

For example, if you heat table salt you'll always see the same two lines in the exact same part of the spectrum as certain electrons in sodium absorb energy and then return to their ground state, giving off light.

例如，如果你加热食盐，你总是会在光谱的完全相同的部分看到同样的两条线，为钠中的某些电子吸收能量，然后返回基态，发出光。