Talk:Discovery of nuclear fission/GA1

GA Review

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Reviewer: Ponor (talk · contribs) 16:08, 6 August 2020 (UTC)

Review notes

Happy to review. Stay tuned for my comments. I believe we can have a new GA in the next few days.

Intro

Q: Why is it "by physicist Lise Meitner", and not "by physicists Lise Meitner and Otto Frisch"?

A: Read the article, and then you tell me who discovered fission. Bear in mind that Otto Hahn alone won the Nobel Prize for the discovery. The article explores what we mean by "discovery". Added Otto Robert Frisch. Hawkeye7 (discuss) 20:57, 6 August 2020 (UTC)

I think this is fine. Check the Deutsches Museum figure caption.

Q: This is a standalone article, so it would be nice to know from the beginning what other nuclear reactions and radioactive decay processes were known at the time and how this one was different.

A: Added to the first paragraph: "Scientists already knew about alpha decay and beta decay" and moved "the discovery that a nuclear chain reaction was possible led to the development of nuclear power and nuclear weapons" up to the top. Hawkeye7 (discuss) 20:57, 6 August 2020 (UTC)

Radioactivity

Q: Pls try to clarify: "had a screen coated with barium platinocyanide that would fluoresce when exposed to cathode rays" (from what I understand, this screen was outside of the vacuum tube, where electrons could not reach it) & 2 "he noticed that even though his cathode ray tube was not pointed at his screen, and it was covered in black cardboard, it still fluoresced" (he probably had a sample inside the tube and was shooting electrons onto it; I don't understand what they were observing with the outside screen because electrons cannot go through glass, was it there for some other reason?; "it still fluoresced" - "it" refers to black cardboard, screen (✓), or the tube?

A: The fluoresce is caused by X-ray photons emitted from the CRT, not electrons. They easily penetrate glass. Hawkeye7 (discuss) 03:28, 7 August 2020 (UTC)

What I meant is: 1 we have "screen would fluoresce when exposed to cathode rays", and cathode rays are electrons; I wonder what he used the external screen for (not knowing about X-rays).

2 "tube was not pointed at the screen"..."it still fluoresced"? the tube? I didn't want to touch this because I don't know the details. X-ray article is a bit more clear.

Tried to clarify. A cathode ray tube produces X-rays as well as electrons. One thing that bothering me is that fission produces X-rays too; the article refers to them as gamma rays, which is sort of correct. Hawkeye7 (discuss) 05:57, 7 August 2020 (UTC)

Transmutation

Q: Why is the nitrogen to oxygen transmutation written like this - isn't there an electron missing? Conventions vary, so it might be a good idea (for those who add As and Zs) to say the reaction is written for the nuclei only.

A: Possibly because Blackett didn't mention it. But because we're using the modern notation anyway, added the electron. Hawkeye7 (discuss) 20:57, 6 August 2020 (UTC)

Forgive me, I am going to revert this edit. I did some research, and it seems that writing the reaction for the whole atoms might be confusing. I'm adding that the formula is valid for the nuclei. No electron is emitted from the nucleus, and we don't really know when and how the electrons find their new nuclei.

Forgiven. Hawkeye7 (discuss) 03:28, 7 August 2020 (UTC)

Q: Explanation why this wasn't fission would be nice: "known as 'splitting the atom', but was not nuclear fission"

A: Added: as it was not the result of initiating an internal radioactive decay process. It may have also contributed to throwing Fermi, Meitner and Curie off the scent, as nuclear reactions were supposed to just chip fragments off nuclei. (Aside: The names of the scientists in the article are as they appear in their scientific papers.) Hawkeye7 (discuss) 03:28, 7 August 2020 (UTC)

Discovery

Q: "Bohr's liquid drop model had not yet been formulated, so there was no theoretical way to calculate whether it was physically possible for the uranium atoms to break into large pieces." The model was introduced in the previous section as Gamov's liquid drop model. When did Bohr formulate his model?

A: The previous section said: The current model of the nucleus was the liquid drop model first proposed by George Gamov in 1930. His simple and elegant model was refined and developed by Carl Friedrich von Weizsäcker and, after the discovery of the neutron, by Werner Heisenberg and Niels Bohr Hawkeye7 (discuss) 03:28, 7 August 2020 (UTC)

Still, it kind of appears out of the blue because we, at that point, don't know when Bohr developed his own model. How about "and Niels Bohr (in 193x)."

Added "in 1936". Hawkeye7 (discuss) 05:57, 7 August 2020 (UTC)

Q: Last two paragraphs of "Objections" (why this title?) don't seem too relevant, should they be rather be in their respective biographies? The story is interesting, for sure, but the article is already too long.

A: It tells the reader how this team came together, and why Meitner and Hahn were engaged in digging in to this mystery instead of running the KWI for Chemistry. Meitner's later departure is also foreshadowed. (The title refers to objections to Fermi's claim to have discovered Hawkeye7 (discuss) 03:28, 7 August 2020 (UTC)

It's a biographic digression that I found a bit too long. Interesting, but long. No reason to fail GAN, though.

Q: Last few sentences in "Eureka" - it's unclear if all these dates were in 1939. Frisch conducted exp. in February, but mailed papers (about what?) in January.

A: Added "1939". Hawkeye7 (discuss) 05:57, 7 August 2020 (UTC)

Eureka

Q: At first I thought this was the name of a project or a new element. Adding exclamation mark, Archimedes style, hope you're ok with that.

A: Sure. Hawkeye7 (discuss) 05:57, 7 August 2020 (UTC)

Assessment

GA review – see WP:WIAGA for criteria

1. Is it well written?

   A. The prose is clear and concise, and the spelling and grammar are correct:

   B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation:

2. Is it verifiable with no original research?

   A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline:

   B. All in-line citations are from reliable sources, including those for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged, and contentious material relating to living persons—science-based articles should follow the scientific citation guidelines:

   C. It contains no original research:

   D. It contains no copyright violations nor plagiarism:

3. Is it broad in its coverage?

   A. It addresses the main aspects of the topic:

   B. It stays focused on the topic without going into unnecessary detail (see summary style):

4. Is it neutral?

   It represents viewpoints fairly and without editorial bias, giving due weight to each:

5. Is it stable?

   It does not change significantly from day to day because of an ongoing edit war or content dispute:

6. Is it illustrated, if possible, by images?

   A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

   all CC or public domain

   B. Images are relevant to the topic, and have suitable captions:

7. Overall:

   Pass or Fail: