# What is Paper: Definition and 1000 Discussions

Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, packaging, decorating, writing, cleaning, filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency and security paper and a number of industrial and construction processes.
The papermaking process developed in east Asia, probably China, at least as early as 105 CE, by the Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. The modern pulp and paper industry is global, with China leading its production and the United States following.

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1. ### Compare rotational inertia of 2 paper cups in 2 diff orientations

Figure 1: I assume this is a conceptual question regarding the usage of the above inertia equations but the axes are really confusing me. I would imagine that around I1 and I3, you could say that the total inertia is just the sum of all the ring-shaped "slices" of the paper cups (i.e. use the...
2. ### Graduate School Advice regarding Arvix

I'm a junior based in the U.S and my research project is ending in one or two months, so I am writing a report with my results. I am not sure if I will be a first author as there are two other students, but they have graduated so I have been working on it alone for a while now since the summer...
3. ### I Drag Coefficient of a 'flexible' object (e.g. a piece of paper)

Hi all and thanks for your time. I'm a little new to this site and was unsure what the prefix to this post should be, so I put it under 'intermediate'. Imagine having a piece of paper glued to the palm of your hand. You swing your hand down and the edges of the paper bend backwards because of...
4. ### I Help working on this example exam please

Hi My grandson who is dyslexic and who I need to help sometimes has the attached example paper for an exam which is iminent. The lecturer has gone is unavailable and he seeks to try fnd a source for te answers. Its a shot in the dark but I wonder if anyone can help please? Thanks Martyn
5. ### B Can anyone explain the zero bias dark current observations in this paper?

I’ve been trying to understand the conclusions in this paper for a long time… https://apps.dtic.mil/sti/tr/pdf/ADA429637.pdf It seems it was published in Optical Engineering, Vol 38, No. 8, August 1999. I thought if we have a photodetector with no light shining on it and no outside voltage...
6. ### Room temperature superconductor paper published

This paper is circulating around fintwit , has not been replicated, but does it pass a smell test? https://arxiv.org/abs/2307.12008 The First Room-Temperature Ambient-Pressure Superconductor Sukbae Lee, Ji-Hoon Kim, Young-Wan Kwon
7. ### A Has anyone read this new paper on extending the BGV?

I was wondering if anyone has read this new paper (link provided) one of the authors Will Kinney, seems very sure it forecloses on any cosmological model with no singularities. Can anyone speak about the limitations of the paper or if it does definitively prove a singular beginning in space...
8. ### B Units of S/N ratio in some papers

So this is a paper by Xavier Michalet and Shimon Weiss C. R. Physique 3 (2002) 619-644, showing that S/N ratio is given by equation (2). This is a fairly famous comprehensive paper on fluorescence microscopy, where other references regarding the same topic show the same equation more or less...
9. ### A Looking for a paper describing the Raman effect

Hi, I am looking for this paper in the study of Raman effect which has the following reference: Bir, G. L. & Pikus, G. E. 1961 Soviet Phys.-Solid State, 2, 2039. Can someone tell where I can find it? Thank you a lot for your help, TthePhysicist
10. ### How to achieve a paper effect in CSS for Joplin?

I want to achieve this effect in Joplin. I need some CSS for it in userstyle.css. I've few examples here: https://freefrontend.com/css-paper-effects/ So, I am wondering if anyone could write a userstyle.css for me. I've gave a try but it's not working. /* The below controls how a note...
11. ### A New paper claims there is evidence of suppression of structure growth

A paper by Nhat-Minh Nguyen, Dragan Huterer, Yuewei Wen titled "Evidence for suppression of structure growth in the concordance cosmological model" https://arxiv.org/abs/2302.01331 The abstract says: We present evidence for a suppressed growth rate of large-scale structure during the...
12. ### Great Youtube Video Review of the GPT-4 Paper

Gets into a lot of stuff tucked away in the 98 page report from OpenAI on GPT-4. - GPT-4 can process a lot more text in queries than GPT-3.5 - training data cutoff was at 2021 same as ChatGPT but it seems that the ChatGPT cut off was later in the year. - in contrast Bing with GPT-4 can search...

Looking for something else I just stumbled over this paper the declare as introducing a field they call "bayesian mechanics". I thought I would create a new thread for a change and just highlight this paper. It's the first time I've seen this from the authors so I don't have their full...
14. ### I Research paper and sources investigating Earth's moons

Hi. I am looking for scientific papers, articles and/or even simulations that investigate how many moons it would be possible for earth to have and maybe modern theories about what these moons can be and look like (i.e what characteristics they have) if they were to exist. I have googled and...
15. ### Study on ruled vs unruled paper?

Why all scientists write math/physics on blank paper, for example Einstein,in that time already exist lined/cell papers? Is there any benefits to use blank paper notebooks when study engineering? What notebooks do you use when study math/physics/engineering?
16. ### Marking an A Level Paper: Method vs Answer

I am marking this now...just need your insight...the second part has [2] marks. I am giving [1] mark for the correct method...i expect use of second derivative test or otherwise for Method Mark...then the correct answer ##(0,0)## would realize the Answer mark. The student has not shown any...
17. ### A Trying to reproduce the energy levels of a molecule from a paper

Hello! This is quite a specific question, so if anyone knows the details I would really appreciate your help (@Twigg ?). I am trying to reproduce figure 1 from this paper (it's for the PV experiment performed on BaF). While I am getting quite close to it, the levels don't fully match (I am...
18. ### B Why is Maldacena's paper published in two journals?

The famous Maldacena's paper, the first paper on what is today called AdS/CFT correspondence, is published in two journals. It's not two parts of one work, it's one complete paper published twice. I presume that there is some interesting story behind it, but I don't know it. Does anybody know...
19. ### I Tipler 1976: Clarifying Symbol Meaning

I'm reading Tipler's 1976 paper, "Causality Violation in Asymptotically Flat Spacetimes" and he keeps using a symbol which seems to resemble the symbol for Future Null Infinity in a strange font, but it's usage doesn't make sense with what I would expect if that's what the symbol meant. He...
20. ### I Physics of paper absorbing Water -- Doesn't this decrease Entropy?

Summary: doesn't this decrease entropy ? Cellulose is known for its hydrophilic quality, which can be explained from the polarity of its hydroxyl groups. We all know water can overcome the force of gravity through a piece of paper you put in the water. Correct me if I'm wrong but this is a...
21. ### Can I submit my paper to arXiv if it has been accepted by a journal?

Hi. My paper has just been accepted by PRD. Can I still submit this manuscript to arXiv? Will this action violate any copyright? Thanks.
22. ### A (paper) Stability properties of Kerr BH's

Have these articles been discussed here previously? I could not find it but my search skills suck. Kerr stability for small angular momentum https://arxiv.org/abs/2104.11857 (just 800 pages) Recently (31th May this year) Wave equations estimates and the nonlinear stability of slowly rotating...
23. ### B How does the Paper Spiral work?

Hot air rises due to the candle below. But how does that create a horizontal force, which is needed to produce the rotational torque?
24. ### B Why is this JWST paper a cause for 'Panic'?

Hello. Could somebody please explain to me why the discovery of the unexpected number of spiral galaxies in this image is a cause for panic? My naïve understanding is that this is at odds with the currently accepted model of galaxy formation in the early universe. Any help give at a Basic...
25. ### A LQG Legend Writes Paper Claiming GR Explains Dark Matter Phenomena

A new group of investigators are attempting something similar to Deur's work, which seeks to explain dark matter phenomena with general relativity corrections to Newtonian gravity is systems like galaxies. Deur's most similar publication to this one along these lines was: One thing that makes...
26. ### A Calculate the group velocity in EIT (famous paper: light speed 17m/s)

hello everyone! Recently,i'm reading a paper about slow light,that's really a famous work published in Nature.[Light speed reduction to 17 metrespersecond in an ultracold atomicgas]. But I'm trouble with some calculation about the velocity of slow light.here are below: i try to use the...
27. ### I Searching for "Why Is Minkowski Spacetime Non-Euclidean" by Cronkhite

I cannot find the paper that is referenced here https://www.nist.gov/publications/why-minkowski-spacetime-non-euclidean Why Is Minkowski Spacetime Non-Euclidean? Author(s) J M. Cronkhite I have looked here https://aapt.scitation.org/action/doSearch?SeriesKey=ajp&AllField=Cronkhite&ConceptID=...
28. ### I What does it take to solve the measurement problem? (new paper published)

Yesterday Jonte Hance and Sabine Hossenfelder published this preprint on the arXiv: https://arxiv.org/abs/2206.10445 What does it take to solve the measurement problem?
29. ### Other Becoming anxious since my paper was submitted to journals

I am increasingly anxious since my first paper was submitted to journals and it has been rejected three times directly by editors. Although my advisor thinks it is an interesting work and keeps submitting it to high-quality journals, I am not very confident in myself. I am always worried that...
30. ### Almost 9000 authors on this paper

8778 authors - curious how they coordinated that https://hal.archives-ouvertes.fr/hal-03583443
31. ### Other How to efficiently post questions related to paper material?

Hi guys.Lately I have been posting questions related to paper material and I am getting no replies (here, here and here). I am convinced it's not only due to the difficulty of the topic but the way I am posting it. Should I "go to the point"? Honestly, it's also acceptable that people only...
32. ### A Question about an equation from anapole measurement paper

Hello! I have a question about this paper. They claim that the hyperfine and spin-rotational terms can be treated perturbatively (they do perform a full diagonalization, too, but they claim that perturbation theory is good to get an estimate of the effect). I agree with that for most of the...
33. ### I with my quantum magnetism paper

(I have to write a 1500 word essay briefly explaining quantum magnetism. But i am having a hard time structuring my essay as I need to select what is crucial and what is not since 1500 words is not a lot. is there anyone with any input for me? Ideas, recommendations, sources anything is...
34. ### Intro Physics Readable paper version of Feynman's Physics textbooks

Hi, In my old age I've gone back to study physics at college. I own a really old (1976) edition of Feynman's physics textbooks, but the paper has yellowed to the point where I have trouble reading them, the contrast is low even though the print quality is ok. Is there a printing on good...

36. ### Other How can scientists effectively review papers outside of their expertise?

A week ago I accepted to review a paper for a top journal. I was contacted because I've published several papers on the same semi-obscure topic in the last two years. I accepted because the abstract was interesting and thought provoking. However, after having access to the full paper I...
37. M

### Help identifying a length for this paper edge

Hi PF! Two years ago my lab launched experiments aboard the ISS. The experiment was simple: place two water droplets on a substrate, set camera above the drops, and watch them coalesce. However, the exact size of the drops is unknown (approximately 1 cm radii, though this number is debated)...
38. ### A Derivation of Equation 26 in Bardeen's Four Laws of Black Hole Thermodynamics

Hi all, I am currently reading Bardeen's Paper on The Four Laws of Black Hole Thermodynamics: https://projecteuclid.org/journals/communications-in-mathematical-physics/volume-31/issue-2/The-four-laws-of-black-hole-mechanics/cmp/1103858973.pdf and am struggling with the derivation of equation 26...
39. ### Question about paper 10 January: Cross-reactive memory....SARS-CoV-2....

Hello everyone, I'm a physicist so I'm not an expert in immunology etc., but I'm interested in this topic. I read the abstract of this paper (Discussion was very scholarly for me) but still, I'm not sure if I understand it correctly. So I have some questions: 1) Is there exist some possibility...
40. ### What is the paper trying to say…

Summary:: What is this? https://arxiv.org/abs/1703.10470/
41. ### What are the ways I could get my hands on this paper?

There is a soviet paper I would really love to read: https://www.osti.gov/search/semantic:5509754. Unfortunately, I have found no pdf nor anything of the sort on the Internet. Google told me it was published by some Ukranian University (thankfully it still exists and has a website). There is 1...
42. ### MHB How to read research paper, textbook, long text content?

I can read less text content easily. my way of reading it is to make slides of all those texts and learn from the slides. But I have issue with reading huge huge texts as you know in this case it will require too much time when I do this. Is there way to simplify this reading style? eg-: of...
43. ### Why/how does filter paper block/trap coffee oils?

What mechanism or mechanisms cause filter paper to block coffee oils? As I understand it, these "oils" are mostly cafestol and kahweol, which are both functionalized polycyclic molecules with a molar mass around 315. Cloth filters do not prevent these oils from getting into the brewed coffee...
44. ### A Why is gauge invariance important in quantum mechanics?

I bought a paper written by Kuo-Ho Yang (gauge transformations and QM) in which i read this: since Lamb [1] asserted that in order to describe the interaction of a bound system with external time-varying fields to the lowest order and in the long wavelength approximation one should use an...
45. ### Find R.H. Dicke's Paper: "Gravitation without a Principle of Equivalence

Summary:: Searching for Paper by R H Dicke Good day all. Does anyone know where I might obtain a copy of the Paper R. H. Dicke. Gravitation without a principle of equivalence. Review of Modern Physics, 29(3):363–376, 1957 I am prepared to pay for it. Thanks Paul
46. ### A Casimir heat transfer (Ballistic heat transfer) paper

In general, in the paper Casimir assumes that between the boundaries of a crystal the heat transfer can be imagined as electromagnetic radiation between two hollow bodies connected by a tube (at least this what I understood from his approach), I'm reading about Casimir limit (Ballistic heat...
47. ### I Reading Paper on Earth Occultation Technique

The Burst and Transient Source Experiment Earth Occultation Technique https://www.semanticscholar.org/paper/The-Burst-and-Transient-Source-Experiment-Earth-Harmon-Fishman/b4e57f91de6fec73fa680bcd7d6efbdf0de10bee In **Appendix B**, the authors derive the equations for the occultation times...
48. ### I Problems with Paper on QM Foundations

I was on you-tube and saw a video from Oxford on QM foundations. I didn't agree with it, but that is not an issue - I disagree with a lot of interpretational stuff. The video mentioned a paper they thought essential reading...
49. ### A How to find the value of the baryon asymmetry in this paper

I'm trying to understand from this paper https://pdg.lbl.gov/2020/reviews/rpp2020-rev-bbang-nucleosynthesis.pdf What is the value of the baryon to photon ratio ##\eta=n_b/n_\gamma## as named in figure 24.1, but I can't get from the figure or the paper how ##\eta## is of order ##10^{-10}## Any...
50. ### A An interesting paper about measurement and locality in QFT

Bostelmann, H., Fewster, C. J., & Ruep, M. H. (2021). Impossible measurements require impossible apparatus. Physical Review D, 103(2), 025017.