Today, we are bringing other exciting results involving black holes and AI. We released a new paper:

"Black Hole Weather Forecasting with Deep Learning: A Pilot Study"

Work by Roberta Duarte (@import_robs), Rodrigo Nemmen (@nemmen) and João Paulo Navarro (from @NVIDIABrasil).

https://t.co/odzm9VTdwZ

Thread for today. /0

It is fashionable for people to create sympathy to the unseen / unknown organisms. The poor things that can't stand up and fight for their own existence.

It makes for a brilliant narrative. It melts your hearts. And you get to play saviour of the oppressed by outraging. /1

But, for most part, such things are also false.

Amazon are the lungs of the world. Never mind that most of the world's oxygen production happens in open oceans. But these are harmless ones. Of course, we all love to maintain forests.

However, some things are sheer scare mongering.

For instance - take this: coral reefs will be permanently gone if mean / median temperatures raise by 1°C ..

But, really - how? Then you get a lecture on how CO2 will affect calcification.

Dig a bit deeper from another angle+

+ and you find that the earth was much much warmer during the age of Dinosaurs. So much so, that we had cold blooded lizards growing to sizes of buildings. Surely, there must have been tons of CO2 then!

And the ocean temps were quite high too.

What is carbon capture? And how does it work?

While carbon capture is regularly discussed in the media, no one really ever explains what it is.

Below is a quick thread discussing the technology behind traditional carbon capture 👇

Carbon capture is broadly the "capture" of CO2 emissions from a power plant or other type of industrial facility.

Technology is connected to the "tailpipes" of these facilities and is used to remove CO2 from the plant exhaust.

Once the CO2 is removed from the plant exhaust, it is typically pressurized and sent under ground for permanent storage.

This step is called "sequestration" and is why experts often talks about "carbon capture and sequestration" or "CCS".

So how do you "capture" the CO2 molecules from exhaust?

Currently, one of the most economic forms of carbon capture is called "amine-based" capture.

An "amine" is a special liquid chemical which selectively grabs on to CO2 molecules.

To get the amine to grab on to the CO2, the amine is put into the top of a large column, while the exhaust is put into the bottom of the column.

The exhaust bubbles up through the column, and the amine drips down.

The liquid amine and gas exhaust mix in the column.

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.

1/

Get a cup of coffee.

In this thread, I'll help you understand the basics of Binomial Thinking.

The future is always uncertain. There are many different ways it can unfold -- some more likely than others. Binomial thinking helps us embrace this view.

2/

The S&P 500 index is at ~3768 today.

Suppose we want to predict where it will be 10 years from now.

Historically, we know that this index has returned ~10% per year.

If we simply extrapolate this, we get an estimate of ~9773 for the index 10 years from now:

3/

What we just did is called a "point estimate" -- a prediction about the future that's a single number (9773).

But of course, we know the future is uncertain. It's impossible to predict it so precisely.

So, there's a sense of *false precision* in point estimates like this.

4/

To emphasize the uncertainty inherent in such predictions, a better approach is to predict a *range* of values rather than a single number.

For example, we may say the index will return somewhere in the *range* of 8% to 12% (instead of a fixed 10%) per year.

5/

10 years from now, this implies an index value in the *range* [8135, 11703]: