|
- What is the meaning of the expression Q. E. D. ? Is it similar to . . .
It's an abbreviation of quod erat demonstrandum, which is the Latin translation of a Greek phrase meaning "which had to be proven" To the ancient Greeks, a proof wasn't complete unless the last sentence in your proof was basically the statement of the theorem Putting QED after that sentence was their way of saying, "and that's what I was trying to prove, so there, I've proved it" We aren't
- What are the advantages of ending a proof with “QED”?
I know “QED” indicates the end of a proof We also use or similar How did we start doing it? It’s a very old practice passed down from Greek mathematicians like Euclid over twenty centuries ago But what are the advantages of doing so? I’d like an answer that addresses several contexts, ranging from books to papers to even posts here I can make guesses and persuade myself one way or
- 量子电动力学（QED）有多精确？ - 知乎
量子电动力学（QED，Quantum Electrodynamics） 是描述电磁相互作用的理论，可以说是目前为止最为精确的理论了。 在量子力学提出之后（主要标志为1926年薛定谔提出薛定谔方程），狄拉克紧接着于1927年提出了狄拉克方程用于描述电子与光子的相互作用。
- 以「Q. E. D」收尾证明语段，是什么梗？ - 知乎
(also written QED and QED) is an initialism of the Latin phrase quod erat demonstrandum, meaning "what was to be demonstrated", or, less formally, "thus it has been demonstrated"
- 量子电动力学（QED）存在缺陷吗？ - 知乎
量子电动力学（QED）存在缺陷吗？ QED被认为是物理学中最成功的理论，其理论预测与实验数据高度符合。 既然如此，为什么一些电磁现象至今也没有好的理论解释？ 比如石墨烯的超导问题。 是这些电磁… 显示全部 关注者 3
- Is $\\square$ an alias for QED? - Mathematics Stack Exchange
In math, proofs are often accompanied by 'QED' (quod erat demonstrandum) at the end, indicating their conclusion Some authors use a square symbol ($\\square$) instead of QED, with the same meaning
- 如何完全用量子电动力学描述一个匀强电场中做加速运动的电子? - 知乎
这导致电子在吸收光子被加速的同时也会出现发射光子被减速的过程，那么这个时候，我们将预期电子既不会加速e 也不会被减速，能量转移量为零，即 \Delta E_ {QED}=0 。 天啊，这怎么回事儿？ ！ 经典电子加速可以，量子波包加速也可以，但是QED加速就不可以了
- 请问静电力做功w＝qed其中q是场源电荷吗？ - 知乎
理解： 1、公式W=qEd，中的“qE”是电荷在电场中所受的 电场力，即F=qE，公式是W=Fd的导出式。 2、该静电力做功公式W=qEd，只适用于匀强电场电场，其中d为沿 电场线 方向的位移。 如下图： 3、公式W=qEd中的“Ed”是电场中两点间的 电势差，即U=Ed，所以与W=qU是
|
|
|