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Comment by 00N8 | Hacker News Reader

Reminds me of my favorite story from the Manhattan project: The project needed massive amounts of wire for all the equipment, but copper was in short supply for the war effort. They ended up working out a deal with the Treasury Department to use silver instead, since it was an even better conductor & apparently more available at the time. Part of the deal involved making sure not to lose any silver & IIRC they managed to not only return all the borrowed silver, they even found some extra to return by tearing up the floors in all the mints, warehouses & workshops, to incinerate & reclaim the precious metal, just like in the article!

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Another fun Manhattan fact: They needed a code name for plutonium, so they called it "copper", but what was a poor scientist or engineer who needed to use actual copper to do? The official code name for copper was "Honest-to-God copper".

I am intrigued at how much thought went into "copper". Was the thinking that everyone's eyes would glaze over at such a common material? My initial reaction would be to use a different rare element. However, a rare element might draw more scrutiny to the casual observer. Then again, the potential for confusion is incredibly high. Interesting spycraft.

Supposedly the opsec at the Manhattan Project was so good, significant portions of the workforce had no idea on what they were laboring. Post war interviews thought the facility was all a sham, dedicated to nothing but medical testing.

My dad’s relative (uncle I think?) ran the team that fabricated the detonators for the bombs. They weren’t told what the purpose was when they built them. They found out what the purpose was when they were used.

Real genius

> My initial reaction would be to use a different rare element. However, a rare element might draw more scrutiny to the casual observer. Then again, the potential for confusion is incredibly high. Interesting spycraft

Worth noting (unless someone else already did) that the UK program that technically started before the Manhattan Project was called 'Tube Alloys'.

Copper had the advantage of already being directed 100% at the war effort.

And almost all of that for bulk uses like shell casings and electrical wiring - vast supply chains which no competent enemy agent would waste time looking into.

> vast supply chains which no competent enemy agent would waste time looking into.

Isn’t this exactly what should be looked into? Find weak point and hit them. Germanys ball bearing plants and oil refineries got targeted this way.

If the Axis had been dropping 1000+ tons of bombs on American industry every day, then maybe that would have been rational.

Similar if the Axis had large-scale resistance forces operating in America, able to sustain at-scale acts of industrial sabotage.

But the Axis already knew that America had a huge copper industry. With no way to affect that industry, at scale - long lists of American copper mines, refining facilities, factories, etc. were no more valuable to the Axis than collections of apple pie recipes.

You're thinking of the honest-to-god copper supply chain, not the "copper" supply chain.

The bearing plants didn't have much of a long term impact if I recall...

The oil campaign OTOH, worked out well.

I'd guess actually going after stuff like wire/brass casing production, while it could have an impact, the 'ROI' is likely lower than more important logistics meta-targets (i.e. oil and gas production and transport infra/equip) and those are far easier to 're-boot-strap', one can theoretically draw copper wire from their garage with a reasonable base starting piece and draw jig/rig.

Also, like bearings, it's easier to 'surplus'. Surplus Oil sitting in a field or penetrable location? Obvious easy pickings. Stockpiled wire? I mean you could but frankly even if you burned/melted all the wires someone can just collect it and re-make wire. It's not like oil where the resource gets completely destroyed in the process.

(Ammo depots, OTOH, would make sense.)

There wasn't much of a Nazi spy presence in the US much less effective saboteur operations. One of the few people convicted for espionage had their conviction overturned because the information they passed was publicly available. The US was never under much direct threat, there were a smattering of attacks and raids on the West Coast but those didn't amount to much. Extreme distance was a better shield than any secrecy or military might, it's part of why the post war years were so good and continued for decades afterwards, the US was completely untouched and the rest of the (then) modern world was bombed to absolute smithereens.

https://www.neh.gov/article/nazi-spies-america

That sounds like the start of a story that ends up with wires made out of plutonium.

Nothing like H2GCu. It’s even just pennies on the dollar.

They called Polonium cobalt.

Think about it, cobalt is too slow. Polonium is ideal - you need a much smaller amount, and in five years it's gone, ten years, it's undetectable. Except that it decays into a specific isotope of lead, which could raise some questions, but you call it a toxin, and hope that the evidence gets destroyed in the process...

And they wondered how the Soviets infiltrated the project so thoroughly.

There is a story to go with that story. The colonel responsible for the negotiations with the Treasury would later recall:

> He explained the procedure for transferring the silver and asked, "How much do you need?" I replied, "6000 tons."

> "How many troy ounces is that?" he asked. In fact, I did not know how to convert troy ounces to tons, and neither did he. A little impatient, I responded, "I don't know how many troy ounces we need, but I know I need 6000 tons - that is a definite quantity. What difference does it matter how we express the quantity?"

> He replied rather indignantly, "Young man, you may think of silver in tons, but the Treasury will always think of silver in troy ounces."

For those wondering like me:

6000 metric tons of silver is approximately 192,904,200 troy ounces, and 6000 US tons of silver is approximately 175,000,000 troy ounces.

There is a US ton? My God...

To be perfectly fair, it was a little strange for the metric system to have a "ton" unit in the first place. Much like a foot or a cup, it's one of those units the metric system is trying to replace, but rather than use megagrams or something else perfectly sensible within the system they already created, they added to the confusion by defining yet another "ton" close enough to the historical units of the same name.

Older people in certain parts of France still use pound ("livre") to mean 500g. Pint ("pinte") for 500ml is more common.

it's because "megagram" and "milligram" are a hassle. With the added bonus of mm/MM being used to abbreviate millions, I'm personally very grateful for tonnes.

The SI unit of measure is the Kilogram, not the gram. Therefore they ought to be using the kilokilogram KKg, not the Mg.

Just because the definition is based on 1000 of the base unit doesn't mean the prefixes start being weird.

Not sure what you mean, kg is the base unit. /s

>The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), mole (mol, amount of substance), and candela (cd, luminous intensity).

https://en.wikipedia.org/wiki/International_System_of_Units

What does it actually mean for the base unit to be the kilogram, as opposed to the gram, now that they're defined in terms of fundamental constants?

It means if you are using SI units "The kilogram is defined by setting the Planck constant h to 6.62607015×10−34 J⋅s (J = kg⋅m2⋅s−2), given the definitions of the metre and the second."

and gram is some random word you made up, with no definition under SI.

https://en.wikipedia.org/wiki/International_System_of_Units

The gram is indeed defined by SI to be 1/1000th of a kilogram, it's not a random word I made up.

There is no logical difference between the definition you gave, and an alternative definition that says "the gram is defined by setting the Planck constant h to 6.62607015×10−31 J⋅s (J = g⋅m2⋅s−2), given the definitions of the metre and the second", and then defining 1 kg = 1000 g. Which is why I'm asking what this distinction actually means, if anything.

It meant something that feels more real when the kilogram was defined as the mass of a physical reference kilogram object in a vault in Paris, but that changed a few years ago.

the SI unit for kilogram is kg and not Kg

Huh. It looks goofy but it would sidestep the overloaded mm problem.

> gram

Don't you mean a millikilogram (mkg)?

There's the metric tonne 1000kg, the US short ton 2000lbs and the US long ton 2240lbs(1016kg) also known as imperial ton. I started calling the metric tonne a megagram because I got tired of trying to figure out if it was short, long or metric I was dealing with

The bane of all engineers having to do unit conversions and asking clarifying questions around what type of ton/tonne.

When is the long ton ever used, or is it just historical? I've only ever heard of the 2000lb variety my entire life.

This is from a web site that's been around since the Web 1.0 era: https://www.ibiblio.org/units/dictT.html#ton

oh there is a short ton, a long ton, a metric ton. the normal ton in the US is "short ton" which is 2,000 lbs.

https://en.wikipedia.org/wiki/Ton

we also often encounter a "f*ck ton" or even a "metric f*ck ton". these are usually informal units related to the number of things (especially annoying things) rather than strictly weight.

Yes, many of us Americans wish we would adopt the metric system.

You did. All your (USA) units use metric then are converted to US measurements. The US inch is officially 25.4mm exactly.

https://www.nist.gov/pml/owm/si-units-length

Yup. And more things are SI units every day.

I use them most of time now. We are getting there slowly.

Wrapped in ham to fool the masses.

Lol, sure.

I just made sure I did my homework so I can operate with anyone.

And it was huge. I have few worries.

And an imperial ton, which is different again.

$30.59 per ounce (current)

If anyone else was curious like me, 6000 US tons is 175 million troy ounces.

And worth $5.4 billion dollars at today's prices.

Do you have a source on that?

I'm finding "The Manhattan Project: the Important Role Silver Played In the Building of the Atomic Bomb" <https://discover.hubpages.com/education/The-Manhattan-Projec...> (2015).

Here's a more official source: https://www.osti.gov/opennet/manhattan-project-history/Event...

Groves' deputy, Nichols, who was responsible for the loan, also told the story in more detail in 1987 memoir, "The Road to Trinity."

Directly related to recapture of gold -- and related to the Manhattan Project by Farm Hall [0] too -- is the tale of German objector Max von Laue's Nobel Prize medal, which was dissolved during WWII and recast out of solution afterward [1]

[0] https://en.m.wikipedia.org/wiki/Max_von_Laue#Post-war

[1] https://en.m.wikipedia.org/wiki/Max_von_Laue#Hidden_Nobel_pr...

Thanks!

I think I first heard about it in a Scott Manley video - maybe this one, https://m.youtube.com/watch?v=JNT28WKAxgs - & read more on Wikipedia & possibly elsewhere

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