Talk:Trinity (nuclear test)

Timing of the 'atmosphere ignition' report

In the Gadget section it says:

'It was feared by some that the Trinity test might "ignite" the earth's atmosphere, eliminating all life on the planet, although a classified report produced several years earlier had demonstrated that this was not possible.[17]'

The report in reference 17 seems to have been written in 1946 (http://www.fas.org/sgp/othergov/doe/lanl/docs1/00329010.pdf), a year after the test, so I think this should be re-worded to remove the reference.

— Preceding unsigned comment added by Ggaughan (talk • contribs) 07:02, 28 November 2011 (UTC)

Although this is not a reliable reference, I once attended a talk by Richard Hamming, the inventor of the Hamming code. In WWII, he was assigned to the Manhatten project, and one of his job was to do this particular calculation. When he showed it to his boss, the boss said thanks and laid the report on a pile of other papers. Hamming asked "Aren't you going to check my work?" and his boss said "I assure you that if you are wrong no-one will complain." So this particular calculation was done before the test, and I believe that given the impact of the problem, several groups were asked to do this calculation. LouScheffer (talk) 12:11, 28 November 2011 (UTC)

Here's a reference to doing the calculation before the test, though the report may be after Mathematics on a Distant Planet, by Hamming. LouScheffer (talk) 13:43, 28 November 2011 (UTC)

Interesting - another pioneering computer scientist working on Manhattan. It's good they did the calculations before the test. It does seem that reference 17 isn't that report from 'several years earlier' though. — Preceding unsigned comment added by Ggaughan (talk • contribs) 21:54, 28 November 2011 (UTC)

I've heard that the reason for the report in 1946 was to provide some proof of due diligence after the fact and to support the development of Teller's SuperBomb (thermonuke). My understanding from informal sources is that Bethe was assigned the problem by Oppenheimer (see http://www.sciencemusings.com/2005/10/what-didnt-happen.html) soon after arriving at Los Alamos, and that Hamming did a later calculation at the request of another physicist (as he relates in the reference). SkoreKeep (talk) 06:32, 7 December 2013 (UTC)

OK, I did this. LouScheffer (talk) 12:23, 29 November 2011 (UTC)

Tchaikovsky

I've heard a few mentions of a story that some sort of radio interference made a radio station playing Tchaikovsky's Serenade for Strings cut into the military channels during the Trinity test. Does anyone have references on whether or not this is simply urban legend, and if so, is it noteworthy enough for inclusion? It seems quite widespread, even if people usually recount it with the qualifier that it is probably just a good story. --87.55.111.25 (talk) 15:00, 18 June 2013 (UTC)

Hawkeye? EEng 21:31, 16 August 2023 (UTC)

Seems cool if its true. Where could a source for this be found? Who knows lots about the subject? Anyone? Bucky winter soldier (talk) 12:31, 6 October 2023 (UTC)

DYK

Congratulations to everyone in bringing this back to GA status. As a new(?) GA, is it eligible for WP:DYK?

Some suggested hooks (more formatting needed)

• ... that the first nuclear bomb to be detonated was hauled up with an electric winch into an oak platform and a shack made of corrugated iron?
• ... that the first nuclear bomb to be detonated had a truckload of mattresses placed underneath it in case the winch cable broke?
• ... that Richard Feynmann claimed to be the only person to see the first nuclear bomb explosion without protective goggles, using a truck windscreen instead?
• ... that before the explosion of the first atomic bomb, anger was caused by one physicist scaring other staff by speculating on the chance the Earth's entire atmosphere would ignite and burn?
• ... that for the explosion of the first ever atomic bomb, cameras were placed in bunkers only 800 yards (730 m) from ground zero, mounted on sleds so that a lead-lined Sherman tank could tow them out?
• ... that after they saw the first atomic bomb explosion, Bainbridge told Oppenheimer, "Now we are all sons of bitches"?
• ... that a U.S. transport aircraft pilot perceived the first ever atomic bomb as "the sun rising in the south", and when radioing for instructions was told "don't fly south"?
• ... that after the first ever atomic bomb explosion, Robert Oppenheimer said, "We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent"?
• ... that after the first ever atomic bomb explosion, Robert Oppenheimer said that he recalled a line from Hindu scripture, "Now I am become Death, the destroyer of worlds"?
• ... that after the first atomic bomb explosion, a coded message was sent from New Mexico to the Secretary of War who was at the Potsdam Conference, saying "Doctor has just returned most enthusiastic and confident that the little boy is as husky as his big brother"?
• ... that the press releases for different outcomes of the first ever nuclear bomb detonation had been written by William L. Laurence, and he knew that if the most negative were issued, it would likely be his own obituary?
• ... that newspapers on the east coast of the USA largely ignored unofficial reports of the first ever nuclear bomb detonation, including a blind woman 150 miles from the site who asked "what's that brilliant light"?

Would be nice... --Demiurge1000 (talk) 19:15, 25 September 2014 (UTC)

It is eligible. I already nominated it. I did think of a couple of your hooks (the Oppenheimer and Laurence ones) but nominated it with a different hook. It has now been reviewed, and with luck will soon appear. Hawkeye7 (talk) 20:26, 25 September 2014 (UTC)

Looking good, thank you! I agree the Fermi bet is one of the most interesting aspects. As there are more than 200 other language Wikipedias, I will try to make sure the article is translated into all of them, and thus none of my proposed hooks might need to be wasted. --Demiurge1000 (talk) 20:32, 25 September 2014 (UTC)

Also, would it be possible not to have two sections both entitled "Explosion"? --Demiurge1000 (talk) 20:35, 25 September 2014 (UTC)

How did they determine the yield?

At the very least we should relay the story of Fermi using bits of confetti paper to estimate the yield of the gadget, the story can be found on Enrico Fermi and in nuclear fireball, furthermore I'd like to see explained why the initial estimates of the yield stated by Oppenheimer were so wrong. — Preceding unsigned comment added by 92.251.175.116 (talk) 03:37, 24 October 2014 (UTC)

Will do! Hawkeye7 (talk) 08:58, 24 October 2014 (UTC)

Great, I was expecting a dedicated heading for yield determination though. Really we could get rid of that boring claptrap about the men using salt water soap, and fit in a section on yield determination with info on the piezoelectric gauges and Herbert L. Anderson's radiochemical analysis having the final say. I've since put in a table that shows Fermi's estimate as damned accurate! However the table is a bit anachronistic as readers might go - hang on a minute how'd they know 50% of the energy would go into the blast before the blast even happened? Well they didn't! With a dedicated yield determination heading we'd be able to communicate to readers how such a table began to come into existence in the first place from measurements at the Trinity site etc.

178.167.254.22 (talk) 01:09, 8 November 2014 (UTC)

Good job on the contemporary yield estimates section hawkeye7! All we have to do now is put a referenced sentence or two in on how the yield was revised, and finally came to be "20 kiloton". On a related note, I'm a bit disturbed by your removal of the fact that Gadget was a euphemism for a bomb. Can you explain why you continue to remove this?

178.167.254.22 (talk) 10:17, 9 November 2014 (UTC)

Gadget

AIUI, 'Gadget' had two meanings, depending on date and context.

Early on, 'Gadget' was the term for the design of a physics package, broadly the weaponising of a scientific principle. This was a specific and relatively narrow piece of work, because most of Manhattan's efforts were actually going into research in physics or metallurgy, or the problem of producing fissile materials. 'Gadget' work began with the concept of core compression (by linear assembly or implosion) and turning physics into a weapon.

Later on, 'The Gadget' became a term for the specific physics package to be used for Trinity. This was not a bomb: it had no casing, no fuzing and didn't necessarily have the mechanical robustness to be air-dropped. An even more obvious demonstration of the differences would be for the cryogenic thermonuclear devices, such as the Ivy Mike 'Sausage' / Mk 16 bomb. In Trinity's case, it ended up being mechanically very similar to Fat Man, although the X unit wasn't robust enough (you can make electronics to be easily modifiable during development, or packed solid to be robust, but it's hard to do both simultaneously) and AFAIK there had been proposals to test implosion with more crudely built mechanical prototypes at one time, overtaken by good progress on the mechanical design intended for Fat Man. Trinity was a test of physics and effects, not of engineering: there was already confidence that the engineering was good. The "thing built for Trinity" though was not a bomb, never a bomb and still needed something to call it - hence, 'The Gadget'. Andy Dingley (talk) 12:16, 9 November 2014 (UTC)

A bomb does not have to be an aerial bomb; consider the common road-side bomb. And while "Sausage" was a purely experimental device, the Trinity gadget was a Y-1561 Fat Man with only a few differences from the one used at Nagasaki. But if I understand you correctly, you are saying that in the subsequent historiography, the term "gadget" was misapplied to mean the Trinity gadget? Do we have sources for that? The ones I consulted were careful to avoid that. Hawkeye7 (talk) 20:06, 9 November 2014 (UTC)

No, I mean that the term 'Gadget' had two meanings, depending on date and context, at the time of the term's use.

In the early context, the need was to talk about 'gadgeteering' as a branch of engineering. Later there was a need to refer to the device being built for Trinity, in particular in the ways that it was distinct from Fat Man. Both of these needed a neologism – they had to call it something. Andy Dingley (talk) 00:01, 11 November 2014 (UTC)

Continuing

While the article should certainly explain what the term "gadget" means, how and why it was used, etc., I can't see any justification for using it in running text instead of some other term such as "bomb". Mr. Hawkeye7, what say you, sir? EEng 07:19, 11 August 2023 (UTC)

The personnel at Los Alamos were instructed to always say "gadget" instead of "bomb" in case they were overheard. The two words are completely interchangeable, but since the readers were not at Los Alamos, we want to avoid giving any impression that "gadget" meant a particular bomb, or a particular type of bomb. So "bomb" is preferred. Hawkeye7 (discuss) 08:04, 11 August 2023 (UTC)

I think that means we're in agreement, so I've acted accordingly. EEng 09:18, 11 August 2023 (UTC)

Trinity energy fractionation

this [1] is not in the source. Are we looking at the same document? Hawkeye7 (discuss) 00:25, 16 May 2018 (UTC)

Pg 4 of the reference lists the energy fractionation from the fission of uranium. A sterile listing of numbers that you would need to be familiar with the physics to understand the relevance of, a sterile listing isn't very helpful or connective to the table we're editing in this encyclopedic Trinity article. A table that the Manhattan Project scientists would actually have had to know a rough estimate on how it would look, even before the test. For that reason I put some basic scientific explanation onto these numbers, as a note to those who can at least follow percentages.

• The various energies emitted per fission event.

• 167 MeV is emitted by means of the repulsive electrostatic energy between the now formed 2 daughter nuclei, as they're both positively charged, this takes the form of the kinetic energy of the fission products, this kinetic energy/heat results in both later blast and thermal effects.

• 5 MeV is released in prompt or initial gamma radiation, 5 MeV in prompt neutron radiation (99.36% of total),

• 7 MeV in delayed neutron energy (0.64%) and
• 13 MeV in beta decay and gamma decay(residual radiation).
• Total energy emitted 197 MeV

—Data from the Trinity test, and others, resulted in— the following total energy distribution being observed for kiloton range detonations near sea level

Blast	50%
Thermal energy	35%
Initial ionizing radiation	5%
Residual fallout radiation	10%

So in basic terms of percentages then(how it pretains to the FAS table at right). ~83% of the energy is emitted as blast, light and heat. ~5% of the energy is emitted by the two initial/prompt nuclear radiations and with a little time-overlap wrt the delayed neutrons. ~7-13% is residual radiation. As can be seen, this fundamental physics, manifests in the observed weapons effects and specifically the FAS table we have in the article.

Another reference Hawkeye7 that corroborates this presentation, this manifestation of the fundamental physics into the effects of fission weapons in the atmosphere is : NUCLEAR EVENTS AND THEIR CONSEQUENCES by the Borden institute..."approximately 82% of the fission energy is released as kinetic energy of the two large fission fragments. These fragments, being massive and highly charged particles, interact readily with matter. They transfer their energy quickly to the surrounding weapon materials, which rapidly become heated" Boundarylayer (talk) 03:24, 16 May 2018 (UTC)

References

Proposed as start-date for Anthropocene epoch

My edits linking the Anthropocene-epoch proposal have been challenged, as needing references. There are plenty in that article, but duplication here seems like clutter. (Well, it does to me.) Yet the point seems an important one to bring to the reader’s attention. My idea is to leave it to the interested reader, who wants references, to seek them in the linked article. What do people think?

Probably the best single reference there is this *together with the references it provides*.

- SquisherDa (talk) 13:15, 6 August 2019 (UTC)

References

• Anything need doing about this, before archiving? EEng 21:29, 16 August 2023 (UTC)

Detonation subsection

What is "MWT"? The link doesn't explain. Grassynoel (talk) 21:13, 14 March 2023 (UTC)

Mountain War Time (MWT). The 48 states of the US in 1945 were divided into four time zones: Eastern, Central, Mountain and Pacific. In 1942, year-round daylight savings was in force as a wartime measure to save energy. Hawkeye7 (discuss) 22:47, 14 March 2023 (UTC)

Fallout map ( 2023)

I see that in 2012, this page had a nuclear fallout map removed- Also given the recent renewed interest in the site due to Oppenheimer (film) with up to 100K hits per day, I think this absolutely needs to be on the page. Even if the last NCI map is controversial, as mentioned in https://www.nationalgeographic.com/history/article/lawmakers-move-urgently-to-recognize-survivors-of-the-first-atomic-bomb-test. Any suggestions? Wuerzele (talk) 18:01, 2 August 2023 (UTC)

Do you have a map that is free of WP:NFCC issues that we can freely use on this page? --Jayron32 18:09, 2 August 2023 (UTC)

This article never got above 100,000 page views per day, although J. Robert Oppenheimer got over a million. See the discussion earlier on this talk page for the reasons for the removal of the graphic. Hawkeye7 (discuss) 10:52, 4 August 2023 (UTC)

I think the map is a good idea Bucky winter soldier (talk) 12:29, 6 October 2023 (UTC)

Bomb design

@EEng: What is so had to envisage about a ring with a triangular cross-section? ] Hawkeye7 (discuss) 19:43, 16 August 2023 (UTC)

Fine. Where does it go? Are the rims of the hemispheres chamfered to accommodate it? How does it prevent jets (or whatever it says)? And as already noted, zillions of changes were made to later devices -- why is this particular one being called out? EEng 20:00, 16 August 2023 (UTC)

The two hemispheres were chamfered. Apparently the metallurgists found it easier to cast two perfect hemispheres than a perfect sphere. It prevents jetting because the ring stops the two hemispheres from sliding out of alignment. This all arose from a lot of discussion about how many parts the core was in. The design of the core forms an important part of the article, although there is more detail in the Fat Man article. The most important things that the reader needs to know is that the core was solid and not hollow (which would have been my first guess as to how to build one, and indeed is the way it is done today); that it consisted of two hemispheres of plutonium-gallium alloy; and that there was an insert for the polonium-beryllium urchin initiator (which gave trouble). Hawkeye7 (discuss) 20:57, 16 August 2023 (UTC)

OK, but to be clear, there was no such ring in the Trinity device. I suggest we remove precisely the following:

later cores were plated with nickel instead.[64] The Trinity core consisted of just these two hemispheres. Later cores also included a ring with a triangular cross-section to prevent jets forming in the gap between them.[65]

but moving cite [64] backwards to cover what remains. The Fat Man article is the place to trace details of device evolution. What thinkest thou? EEng 21:25, 16 August 2023 (UTC)

Earth callig. EEng

Yes, esteemed callig. I have moved the text to the Fat Man article. Hawkeye7 (discuss) 20:18, 15 September 2023 (UTC)

Esteemed caligflower . EEng 23:18, 15 September 2023 (UTC)

Caligraphy . EEng 23:20, 15 September 2023 (UTC)

Why the photos of cauliflower and calligraphy? That isn't really the topic of the article. Am I just missing something? 🤷 Bucky winter soldier (talk) 12:33, 6 October 2023 (UTC)

Read back more carefully. EEng 13:34, 6 October 2023 (UTC)

Oh ok, sorry to bother you.🙏 Bucky winter soldier (talk) 13:50, 6 October 2023 (UTC)

No bother at all. It was just a little wordplay based on my typo "Earth callig", which Hawkeye picked up on by addressing me as "esteemed collig" (colleague -- get it?). Then things went downhill from there. EEng 16:19, 6 October 2023 (UTC)

Link to J. Robert Oppenheimer

@Alexonion@Hawkeye7 I support addition of the link to the J. Robert Oppenheimer article in the list of the Trinity test observers. There are so many links to the J. Robert Oppenheimer in the entire Trinity article, that one more will not make a difference. Szelma W (talk) 12:04, 15 September 2023 (UTC)

There is only one in the body and one in the lead. Hawkeye7 (discuss) 20:07, 15 September 2023 (UTC)

The link should be added. Alexonion (talk) 13:48, 16 January 2024 (UTC)

Photo

Some of the pictures seem to be overlapping to the point where you have to click on them in order to view them well. Bucky winter soldier (talk) 12:29, 6 October 2023 (UTC)