Activity for Mithrandir24601
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #289448 | Question closed | — | 8 months ago |
| Edit | Post #288406 | Initial revision | — | 11 months ago |
| Answer | — |
A: How are gravitational waves derived? The typical 'most simple' derivation of the gravitational wave equation (GWE) starts by a perturbation of the 'background metric' $\bar{g}$ to get $g{\mu\nu} = \bar{g}{\mu\nu} + h{\mu\nu}$, where $h$ is the perturbation that will be described by a wave equation. 'Far away' from the source of this ... (more) |
— | 11 months ago |
| Edit | Post #285554 | Initial revision | — | over 2 years ago |
| Answer | — |
A: What's the meaning of "outdated" in physics? That sounds like something I'd say, so I'll explain this from my point of view, in particular regarding 'relativistic mass'. An 'outdated' theory or piece of terminology isn't typically mathematically 'wrong'. Rather, a given law or piece of terminology being outdated would typically mean that the... (more) |
— | over 2 years ago |
| Comment | Post #283293 |
I think this is fine now, as far as book suggestions/recommendations go. Strictly speaking, it should be in a different category, but as it's not a category we have (yet), I'll leave it here until we do (more) |
— | over 2 years ago |
| Edit | Post #283293 | Question reopened | — | over 2 years ago |
| Edit | Post #283293 |
Post edited: |
— | over 2 years ago |
| Comment | Post #283293 |
I've thought about this for a while and I've came to the conclusion that it should be closed, at least temporarily. The meta post has some support, but also points out that we need detailed info on each post. The 2 things with this question is that it really needs the books category instead of Q&A an... (more) |
— | over 2 years ago |
| Edit | Post #283293 | Question closed | — | over 2 years ago |
| Comment | Post #283573 |
In general, you need some kind of reference to distinguish up from down, but lacking that, we normally say 'down' is the direction gravity pulls us. It's an arbitrary choice though, sure. If you swap up and down here, you'll just find a couple of minus sign differences, but as the direction has chang... (more) |
— | over 2 years ago |
| Edit | Post #283573 | Initial revision | — | over 2 years ago |
| Answer | — |
A: Find jerk of time varying force I'm assuming that what's happening is that, for $t<t0$, there's no gravitational field, then it's mysteriously instantaneously turned on at $t=t0$. We can perform a Taylor expansion of $x$ around $t=t0$ to give \begin{equation}x = x0 + \dot{x}\left(t-t0\right) + \frac{1}{2}\ddot{x}\left(t-t0\right... (more) |
— | over 2 years ago |
| Edit | Post #283251 |
Post edited: fixed Latex formatting |
— | over 2 years ago |
| Edit | Post #283009 |
Post edited: fixed Latex formatting |
— | over 2 years ago |
| Edit | Post #281631 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Is "homework-and-exercises" off-topic in Codidact? Homework and exercises questions are generally allowed (currently anyway) under the Problems category, although there is the requirement that you need to 'show your working/attempted solution'. I don't see any issues with your two questions here (although if you want to improve them further, includin... (more) |
— | almost 3 years ago |
| Edit | Post #281612 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Interaction terms in Srednicki's proof of spin-statistics theorem We don't need to, it just makes life easier (at least some of the time) As $\mathbf{k}$ is a 3D vector and $x$ a 4D vector, the answer doesn't appear quite as simple as 'Fourier Transforming makes them equivalent ways of doing the same thing, just in different spaces', but that essentially is the ... (more) |
— | almost 3 years ago |
| Edit | Post #281283 |
Post edited: Added link to Srednicki's page of textbook |
— | almost 3 years ago |
| Comment | Post #281581 |
This is a great example of a question best suited to the 'Problems' category, so I've decided to move it here. If people disagree with this decision, I can move it back (more) |
— | almost 3 years ago |
| Edit | Post #281581 |
Post edited: fixed Latex formatting |
— | almost 3 years ago |
| Edit | Post #280987 | Question closed | — | about 3 years ago |
| Edit | Post #280853 | Question closed | — | about 3 years ago |
| Comment | Post #280502 |
And... problems category created, wording adjustable. Meta post about specifics of textbook/paper review to follow (more) |
— | about 3 years ago |
| Edit | Post #280719 |
Post edited: |
— | about 3 years ago |
| Edit | Post #280736 | Initial revision | — | about 3 years ago |
| Answer | — |
A: What should our policy be toward rudeness? From my perspective, I can only agree that rudeness isn't exactly ideal. In general, if someone's being needlessly rude or aggressive etc., editing/suggesting an edit that improves the post is a good option. I'm keen to encourage good, helpful edits anyway. If, for whatever reason, you feel th... (more) |
— | about 3 years ago |
| Comment | Post #280502 |
People seem pretty happy with this, so I'll go ahead and add a problems category. I was thinking a paper review category would be articles. As for textbook review, this could similarly be articles, or even Wiki posts. Perhaps the textbook chapter should be talked about in another meta question... (more) |
— | over 3 years ago |
| Comment | Post #280486 |
I'm afraid I don't understand how this is a physics question - it looks like e.g. a DIY or home improvement question to me. Would you be able to expand on why this is about physics? (more) |
— | over 3 years ago |
| Edit | Post #280486 | Question closed | — | over 3 years ago |
| Comment | Post #280466 |
One category for each field of physics would be an extremely large number of categories. In the future, I could see this being useful but at the minute, tags are likely better for differentiating different topics (more) |
— | over 3 years ago |
| Edit | Post #280466 | Initial revision | — | over 3 years ago |
| Question | — |
New Category ideas Electrical Engineering has a Papers category, for writing short articles of original work, which I for one think is a great idea. Similar to such a category would be a 'paper review' category, where people could review and explain published papers and preprints. What are people's thoughts on s... (more) |
— | over 3 years ago |