Did you know that all the nuclear bombs we exploded in the '40s-50s-60s have permanently contaminated all the steel the world has produced since then? All steel in the world is divided into two categories: pre-1945 non-contaminated steel, and post-1945 contaminated steel.

How?

Nuclear bombs (including the tests) create a lot of radioisotopes that are not found in nature. For example Cobalt-60 (a radioactive version of Cobalt-59). And since the 1945 Trinity test, these have all dispersed in the atmosphere.

What does this have to do with steel?
The process of manufacturing steel uses atmospheric air (or atmospheric oxygen). Some of the radioisotopes like Cobalt-60 get pulled in too, and as a result, any steel produced after 1945 has embedded in it some of these radioisotopes, sitting there emitting gamma rays.
Why do we care about traces of radioisotopes in steel? When making Geiger counters, or medical devices to check for radioactive contamination, or astronomical instruments, the emissions from the contaminated steel would interfere with the measurements.

So we need pre-1945 steel
Pre-1945 non-contaminated steel is called "low background steel". And when we need it, where do we get it from?

We go, find pre-World-War-II sunken shipwrecks, and then salvage the steel (and lead) from those to build our instruments which need heavy radiation shielding.
This is why the search for Dark Matter depends on sunken ships: https://t.co/DKufLQJLWx
I vaguely remember some TV serial where a forgery is detected because the steel used in the supposed-ancient-artifact was not low background steel. I don't know whether that's a real thing, or just fiction, but it's a great story. (We need more such stories in science teaching.)
Apparently, the use of radioactive isotopes to test for forgery is a real thing (thanks @achillesHeelV2): https://t.co/JTn0Kqujns
Just to be clear: the contamination of the atmosphere (and steel) with radioisotopes is not considered a health hazard (or even a significant environmental problem) because the amounts are really tiny.

https://t.co/nzmZGSKPe3
In fact, there are a lot of naturally occurring radioisotopes also. For example, Carbon 14 is regularly created naturally by cosmic rays. All of us are constantly breathing in all these radioisotopes. In fact, the entire concept of carbon-dating depends upon this.

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💥and so it begins..💥
It's time, my friends 🤩🤩

[Thread] #ProjectOdin


https://t.co/fO90N78fta


new quantum-based internet #ElonMusk #QVS #QFS

Political justification ⏬⏬
#ProjectOdin


#ProjectOdin #Starlink #ElonMusk #QuantumInternet
What are the classics of the "Science of Science" or "Meta Science"? If you were teaching a class on the subject, what would go in the syllabus?

Here's a (very disorganized and incomplete) handful of suggestions, which I may add to. Suggestions welcome, especially if you've dug into relevant literatures.

1. The already classic "Estimating the reproducibility of
psychological science" from the Open Science Collaboration of @BrianNosek et al.
https://t.co/yjGczLZ6Je

(Look at that abstract, wow!)


Many people had pointed out problems with standard statistical methods, going back decades (what are the best refs?). But this paper was a sledgehammer, making it impossible to ignore the question: what, if anything, were we actually learning from all those statistical studies?

2. Dean Keith Simonton's book "Creativity in Science: Chance, Logic, Genius, and Zeitgeist". If an essentially scientometric book could be described as a fun romp through science & creativity, this would be it

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Always. No, your company is not an exception.

A tactic I don’t appreciate at all because of how unfairly it penalizes low-leverage, junior employees, and those loyal enough not to question it, but that’s negotiation for you after all. Weaponized information asymmetry.

Listen to Aditya


And by the way, you should never be worried that an offer would be withdrawn if you politely negotiate.

I have seen this happen *extremely* rarely, mostly to women, and anyway is a giant red flag. It suggests you probably didn’t want to work there.

You wish there was no negotiating so it would all be more fair? I feel you, but it’s not happening.

Instead, negotiate hard, use your privilege, and then go and share numbers with your underrepresented and underpaid colleagues. […]