BC SCIENCE
Saved by @troclodyte

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.

More from Science

Sean Carroll
Sean Carroll
@seanmcarroll
Hugh Everett's birthday! Pioneer of the Many-Worlds Interpretation of quantum mechanics. Let us celebrate by thinking about ontological extravagance. I will do so by way of analogy, because I have found that everyone loves analogies and nobody ever willfully misconstrues them.


We look at the night sky and see photons arriving to us, emitted by distant stars. Let's contrast two different theories about how stars emit photons.

One theory says, we know how stars shine, and our equations predict that they emit photons roughly uniformly in all directions. Call this the "Many-Photons Interpretation" (MPI).

But! Others object. That is *so many photons*. Most of which we don't observe, and can't observe, since they're moving away at the speed of light. It's too ontologically extravagant to posit a huge number of unobservable things!

So they suggest a "Photon Collapse Interpretation." According to this theory, the photons emitted toward us actually exist. But photons that would be emitted in directions we will never observe simply collapse into utter non-existence.
SCIENCE
Benedikt Kuhnhaeuser
Benedikt Kuhnhaeuser
@BenKuhnhaeuser
The calamoid palms 🌴 have over 500 species spread across the world, but their higher-level relationships were a bit of a mystery. Until now.

Out today in #MolecularPhylogeneticsAndEvolution:

A robust phylogenomic framework for the calamoid palms https://t.co/JiCbSUlheH

1/10


First some background info, so that you know what we are talking about:

Calamoid palms look a bit like snakes 🐍 (don't they!?!), because their fruits are covered in overlapping scales. And with their often fierce spines, they are equally fearsome. 😱

2/10


They are classified into 17 genera, 10 subtribes and 3 tribes. They have an amazing variety of growth forms, from stemless to climbing to tree habit. 🌱🌴

3/10


But as I said, their relationships have been a bit of a mystery. Here's the varying relationships previous studies found over the last 20 years.

4/10


We tackled this mystery with a phylogenomic approach: we sampled almost a thousand genes (a hundred times more than previous studies!) of 75 species representing all calamoid tribes, subtribes and genera.

The resulting data matrix is pretty massive...

5/10
SCIENCE
Advertisement
Stephen Barlow
Stephen Barlow
@SteB777
1) Science denial is destroying our societies, our civilization. Various vested interests, usually right wing ideologues find various scientific facts and information contrary to their agenda, so through propaganda they are orchestrating the public into denying this science.

2) We are seeing this with regard to the COVID virus, where a range of denial is being promoted, ranging from absolute denial the virus exists, to different levels of denial, such as only some people are vulnerable to the virus, to facilitate business as usual.

3) For a long time, to promote business as usual, vested interests have been promoting the denial of the climate and ecological crisis through propaganda. The aim being to create a large enough body of public denial to prevent action which can change anything.

4) We have seen similar patterns over a long time, such as when tobacco companies promoted denial of the emerging scientific evidence of how harmful and addictive tobacco smoking was. This further denial uses exactly the same methods.

5) Understandably, the public can't be educated about everything and have to rely on experts to inform them of concerns about threats to public safety. Malicious vested interests take advantage of this by using pseudo-experts to misinform the public.
SCIENCE
Michael Adebayo \U0001f1f3\U0001f1ec\U0001f1eb\U0001f1f7
Michael Adebayo 🇳🇬🇫🇷...
@MichAdebayo
Wonder why your Ph.D./Master's application is being rejected?

Here are some insider reasons (from a committee member) that result in such "Love Letters" 👇

- A Short Thread

1) First, you should know that sometimes, an independent reviewer is required (especially in the US) to review applications even after PIs must have selected their candidates. So, even if any bias slips through the PI, the independent reviewer will pick it up.

2) Having said this, there are three major issues that application reviewers/committees often find with your application. These three components make your applications almost challenging to assess.

3) NUMBER ONE - Incomplete Applications

This occurs when you do not upload the requested documents needed to evaluate your file. Think of a candidate that did not send a GRE score when the institution clearly requires it for admission.

4) NUMBER TWO - Error laden Essays

This is particularly interesting because based on reports from this resource person, it is not particularly about how little your experience is but how you communicate it error-free or at least extensively minimized. This gives headache!
SCIENCE
Duncan J Campbell
Duncan J Campbell
@Maven1967
What is going on at SWANSEA UNIVERSITY in Wales?
1.
https://t.co/d5NKtNlxxa
Sounds as if its connected to Bill Gates "LUCIFERASE" Vaccine?

2.
https://t.co/k0w1mjaPg0

"HILLARY RODHAM CLINTON SCHOOL OF LAW"
- AT SWANSEA UNIVERSITY!!!


3.
https://t.co/jifuWq6cGq
Remember all those FIRES, over the Summer!!!

4.
https://t.co/H3lstFyYx8
WUHAN PARTNERSHIP

"Links between Swansea & Wuhan date back to 1855 when Swansea missionary Griffith John founded the Wuhan Union Hospital.
This relationship was strengthened when representatives of the two cities signed an agreement".


5.
https://t.co/5b1JqiEQzi
Swansea University Strengthens Links with China
SCIENCE

You May Also Like

Panic! in the Discord
Panic! in the Discord
@discord__panic
Neo-nazi group #PatriotFront held a photo op in #Chicago last weekend & is currently marching around #DC so it's as good time as any to compile a list of their identified members for folks to watch for

Who are these chuds?

Patriot Front broke away from white nationalist org Vanguard America following #unitetheright in #charlottesville after James Alex Fields was seen with a VA shield before driving his car into a crowd, murdering Heather Heyer & injuring dozens of others

Syed Robbie Javid a.k.a. Sayed Robbie Javid or Robbie Javid of Alexandria,


Antoine Bernard Renard (a.k.a. “Charlemagne MD” on Discord) from Rockville, MD.

https://t.co/ykEjdZFDi6


Brandon Troy Higgs, 25, from Reisterstown,
EXTREMISM
\u2728Anshika Sharma
✨Anshika Sharma
@Anshi_________
Low-risk, High-return stocks are what we look for relentlessly

But many of them we know but ignore
some of them don't grab financial headlines

Here are 10 low-risk, high return stocks (that we ignore):

What I mean by “high-return”?

These stocks have OUTPERFORMED the market:

💹Chart with upwards trend Since IPO
💹Chart with upwards trend Over the last 5 Years or since IPO

These are all long-term winners that will keep on winning

What do We Mean by “low-risk”?

A combination of:

❣️Great management
❣️Broad moat
❣️Financially strong
❣️High ROCE
❣️Low Disruption/Dilution/Volatility
❣️Consistent Organic Growth
❣️Assorted Customers/Suppliers
❣️Low debt

1-#CDSL

A depository is a big business and will grow continuously, Its a sustainable business
cause "Market hai toh CDSL bhi hai or rahega"


2- #Dixon

High Management Efficiency with a high ROE of 19.30%
Healthy long-term growth as Net Sales has grown by an annual rate of more than 30%
High Institutional Holdings
LOW RISK HIGH RETURN STOCKS , LOW RISK HIGH RETURN STOCKS FOR LONG TERM , LOW RISK STOCK IDEAS
Advertisement
Vibhu Vashisth
Vibhu Vashisth
@VIBHU_Tweet
TILAK:AN AGE OLD PRACTICE OF HINDUS

The beautiful Matribhumi of Bharat is the land of many religions &cultures but its Hinduism with which the world identifies this great Nation. Hinduism is the religion with science at its heart &its also a religion of many rituals &traditions.


Today we will talk about a very prominent and noticeable Mark on the foreheads of #Hindus called 'Tilak'. Tilaks are of different designs and colors. It symbolizes different meanings for different people such as religious expression, spiritual symbol, marital status etc.


Tilak is a very alluring design that is made in between the eyebrows. Vermilion, Chandan, Turmeric, Kumkum, Rice and Rice water, Vibhuti etc can all be used as Tilaks.
Why this particular spot is used for Tilak? Bcoz, it is mentioned as 'Ajna Chakra' in terms of yoga.


This chakra is the sixth & most important chakra of the human body. It's the junction where the highest number of neurons meet & is described as most important and sensitive spot in the human body.Different #Hindu traditions use different shapes and ingredients to make the Tilak.


SPIRITUAL SIGNIFICANCE

Various Hindu Scriptures mention the importance of Tilak in Sanatan Dharma. It is believed that energy, strength and divinity comes to those who apply Tilak. It is also regarded as a welcoming expression and to honour the guests when they arrive.
ALL
Sumit Grrg
Sumit Grrg
@sumitgrrg
These 10 threads will teach you more than reading 100 books

Five billionaires share their top lessons on startups, life and entrepreneurship (1/10)


10 competitive advantages that will trump talent (2/10)


Some harsh truths you probably don’t want to hear (3/10)


10 significant lies you’re told about the world (4/10)
ALL , MOTIVATION , BOOKS
Sahil
Sahil
@sahilypatel
Want to do an MBA for free ?

A thread 👇

1) Leadership: Foundations of Teamwork and Leadership

School: wharton

2) Marketing: Marketing Management

School: wharton

3) Microeconomics: Microeconomics for Managers

School:

4) Financial Theory

School:
ALL , MBA , MBA SERIES