It's the greatest story never told: It's the story of how a frugal county in the North of England invented the modern world.

Put on a flat cap and call up the whippet, because this is a thread about my home county, and the inventions that came out of Yorkshire!
Steel!

Benjamin Huntsman invented high homogeneity crucible steel in Sheffield in the 1740s, firing with coke to fully melt the steel and homogenise the carbon content.

This became used… everywhere, and supercharged the ongoing industrial revolution.

A liquid rocket boost stage needs to pump fuel and cryogenic oxidiser to the combustion chamber at a rate that beggars belief: The 33 engines on the boost stage of SpaceX's monstrous ‘Superheavy’ booster each chew through about 700 kg of propellant every second. Put all those engines together and the flow rate of liquid fuel & oxygen would be sufficient to empty an Olympic swimming pool in under 2 minutes, if you could find an Olympic swimming pool for cryogenic propellant.

Can you think of any conventional lightweight pump that can do this? Me neither. You need something special…

The turbopump comprises a typically-axial turbine powered by hot, pressurised gas flow that powers centrifugal compressor pumps that pump the colossal quantities of propellant required and pressurize it to, potentially, hundreds of standard atmospheres.

It's a handy, lightweight way to provide pumping power, but it does require that you have a source of hot, high-pressure gas to work with.

Now, where would you find that in a rocket engine?

Indeed. In order to burn fuel, we must pump it. In order to pump it, we may have to burn some of it.

Um…
The Gas Generator Cycle.

A small quantity of the pressurised fuel & oxidiser flows are tapped, brought to a small combustor, vaporised, ignited then expanded through a turbine that powers the fuel and oxygen compressor cycles.

Inevitably the gas generator can't run with a completely nominal fuel:oxy mix, as it would get so hot that it would melt the turbine blades, so typically a gas generator will trade off some efficiency and run fuel rich to power the turbopumps.

-Why not oxy rich? Because fuel has a higher specific heat at constant pressure (Cp) and so you need less mass flow through the gas generator if it's fuel rich than oxy rich, meaning more useful propellant goes to the main combustor & nozzle that moves the rocket.

So the upside of a gas generator cycle is relative simplicity and robustness, which is why it's used on the most reliable rocket motors around, the SpaceX Merlin. The downside is that you trade away efficiency by throwing away some of your propellant, meaning that the tyranny of the Tsiolkowsky rocket equation will kick you where the sun don't shine.

Last month Rolls-Royce won the UK's small modular reactor competition to develop and build SMRs in the UK. It could be a new dawn for nuclear power.

But who else was in the competition, what was special about each design, and which is your favourite?

An SMR thread… What's an SMR?

A small modular reactor is a way of beating the brutally high capital costs of building nuclear power: By simplifying assembly (modularity) and minimising subsystem size so almost all of it is factory built you harvest industrial learner effects and low costs.

In April on a mountain in Chile the Vera Rubin observatory gathered first light, and this telescope will be world-changing! -Not because it can see the furthest… but because it can see the fastest!

The Vera Rubin telescope thread! The value of speed, and unique technology… Who was Vera Rubin?

She first hypothesized the existence of dark matter, by observing that the rotation speed of the edge of the galaxy did not drop off with radius from the centre as much as it should. The search for dark matter, and other things, will drive this telescope…

Rotating detonation engines: Riding the shockwave!

A technology that could revolutionise aviation, powering engines with endlessly rotating supersonic shockwaves. It could bring us hypersonic flight, super high efficiency and more.

The detonation engine thread… Almost all jet engines use deflagration based combustion, not detonation, but while fuel efficiency has been improving for decades, we're well into the phase of decreasing returns and need some game-changing technologies.

One is the rotating detonation engine (RDE).

As a new graduate I once had to sit down and draft an engine test program for a subsystem of a new model of Rolls-Royce aero engine. It was illuminating.

So here's a thread on some of the weirder things that this can involve: The jet engine testing thread! Fan Blade Off!

Easily the most impressive test: A jet engine needs to be able to contain a loose fan blade. In the FBO test, either a full engine or a fan & casing rig in low vacuum is run to full speed, then a blade is pyrotechnically released.

How can humans realistically travel to another star, and why will it be an all-female crew that does it?

In this thread: Sailing on light, nuclear pulses, using the sun as a telescope and how to travel to another solar system. The interstellar thread! Slow starts…

The furthest man-made object from Earth, Voyager 1, is one of the fastest. Launched in 1977, it performed gravitational slingshots off Jupiter and Saturn and is heading to interstellar space at 17 kilometres per second.

How long until it reaches another star…?

How do we make nuclear new builds cheaper?

It's the defining question of the energy market. Nuclear power is clean, consistent, controllable and low-carbon, but in the West it's become bloody expensive.

Are there construction techniques available to Make Atomics Great Again? The problem.

Hinkley Point C, the world's most expensive nuclear plant, could hit a cost of £46 billion for 3.2 gigawatts of capacity, which is monstrous. Clearly nuclear needs to be cheaper, and in many places it already is. What are our options?

Last year, Airbus automatically refuelled a flock of drones in mid-air, controlled by a neural network from a mother ship.

So far, so Terminator 2.

But this is just the latest step in the development of a world-changing technology. Let's tell that story… The first aerial refuelling trials were performed in 1923 by the US Army Air Service. Performed with hoses and hand held tanks pouring fuel & engine oil, it was nonetheless effective: A flight from the Canadian border to Tijuana, Mexico was performed in a DH-4 biplane.

You can't depend on the wind, and you can't sunbathe in the shade, but the sea never stops moving… can we power our civilization with the ocean wave?

The wave power thread! If not wind, why not waves?

It's a fair question. Wave power is much more predictable than the wind, it's available 90% of the time and has a higher power concentration per square metre of any renewable energy source.

But it's almost unheard of. Why is it so difficult?

By our rule of matter shall we change the world!

Industrial chemistry & materials science: What has been and what is coming up…

A quick thread-of-threads for your Saturday! Firstly…
Jet engine efficiency is linked to the temperature of combustion, and to survive the physical extremes of burning kerosene, the high pressure turbine blades must survive in a furnace beyond imagining, while pulling 20,000 g.

To do this, we must trick metallurgy…

This is the last in my series of Generation IV nuclear reactor threads, and for the finale we’ll look at the one everyone leaves out: The weirdo, the maverick…

The Gas-cooled Fast Reactor!

Why is this one ignored? We’ve covered fast reactors several times and the premise is simple, though hard to explain quickly: A fast neutron spectrum allows fuel breeding from plentiful Uranium 238, plus burn-up of heavy isotopes.

Fast reactors are typically cooled by molten sodium.

What about gas?

The Yerkes Observatory in Wisconsin holds the world's biggest refracting telescope. Weighing almost 6 tons, with a 40” main lens, it's so well balanced that it can be moved by hand.

Finished in 1897, no bigger one was ever made. What did we do instead?

The telescope thread… A refracting telescope uses convex lenses to focus light. Shown are the objective lens & eyepiece, with their respective focal distances: The ratio between these focal lens gives the magnification.

This also shows why the image in a simple refraction telescope is upside-down!

This is the NASA Ames low speed wind tunnel, the biggest in the world. It can fit full sized planes and takes up to 104MW of power to run!

But why use a wind tunnel, and what problems do you run into when trying to make it smaller? Let's go deep.

The wind tunnel thread… Why use one? For one thing, wind tunnels let you measure and visualize the flow field, using smoke, particle image velocimetry or a host of other techniques.

You can also directly measure the forces on your model with a force measuring ‘sting’ as shown.

An advanced Nuclear Power rabbit hole! This is not your father's atom bashing.

For your reading pleasure I've now covered five of the six Generation IV nuclear reactors: Clean, safe, hot running high tech beasts, the first have started arriving.

Let's go through them… Bringer of Alchemy: The molten salt fast reactor, thorium transmutation and the ‘infinite energy machine’.

In its liquid fuel form, it's definitely the most complex reactor type! But solid fuel, salt cooled reactors could appear soon.

Let's dive into the most Metal reactor of all! A high temperature nuclear reactor with a heart of liquid sodium.

Why cool a core with water when you can use molten metal?

The Sodium cooled fast reactor (SFR)! A GenIV reactor deep-dive… SFRs are expensive and complex, but they have interesting abilities, unlocking:

*Fuel breeding.
*Waste burning.
*Long periods between refuels.
*High temperature thermal cycles.
*Industrial process heat.
*Energy storage.

The death of steel.

Big ships are sturdy, but they're not immortal. Over time their maintenance costs soar until, after 30 years or more, they become more valuable as recycled metal and are sold to a scrapyard.

What happens next will surprise you… At the murky end of our supply chains lies this: The Chittagong breaking yards in Bangladesh, one of many places where old ships go to die.

But how is shipbreaking done,  what are the consequences, and is there a better way?

A thread.

What's Britain good at?

Is it an island of fog breathing has-beens, or a nascent industrial juggernaut? What, in fact, does Britain do well?

Here's a thread of a few surprising things…
Motorsport!

Almost all of the world's Formula 1 teams are based in this tiny region in Oxfordshire & Northamptonshire, which also supports 3,500 companies and 40,000 people in motorsport.

This is known as 'Motorsport Valley’ (not actually a valley).

Graphene!

The world's thinnest & strongest material, a one-molecule thick film of it could build a hammock that could hold up a cat, invisibly.

It was isolated 20 years ago, but what has happened with this super-material since then? And how do you mass produce it?

Read on... Graphene, a hexagonal one atom thick graphite crystal film, was theorised for decades but never characterised.

In 2004, Andre Geim & Konstantin Novoselov isolated & characterised a layer of Graphene in the University of Manchester using scotch tape (!)

And it's incredible.

Are you ready for BIG SCIENCE?

Not every scientific study involves drugged rodents or non-binary fish. Here's a selection of really massive, or just impressive, scientific projects for your viewing enjoyment.

Let's start… Fusion!

The National Ignition Facility was originally built to simulate nuclear bomb detonation, but has since fronted inertial fusion power research. In 2023 it first achieved controlled fusion ignition, producing more power from deuterium/ Tritium fusion than was applied.

The question you always wanted answered: How does a combine harvester work?

In this thread we take a dive into these awesome machines! The combine is among the greatest feats of automation in history, with one of the biggest effects on society. It freed entire towns & villages from the backbreaking toil of harvest and, with other innovations, took America from 90% of it's population in agriculture to 2% today.