Nuclear powered commercial ships were tries, for example NS Savannah. They ended up getting barred from a lot of ports. The international shipping industry is extremely cost conscious, and that includes crew and maintenance. You need highly trained crew to safely run a nuclear reactor, which means high crew costs. Maintenance is also extremely important. If a Diesel engine breaks down it is a mild annoyance. If a nuclear reactor breaks down it is a serious problem.

Incidentally steam turbo-electric drive was used in ships in the past. Several US battleships and aircraft carriers of the 1920s era used it, for example. Geared turbine are generally cheaper and more reliable, though, but modern Diesel engines are even cheaper.

Stilton is near the area where it is traditionally made and on a major route, the old Great North Road (now the A1), so it was where people who made the cheese often sold it, and it acquired the name.

The comment wasn't wrong, though. If you break the front wheel you will go over the handlebars.

A similar, sibling company, the Hudson Bay Company, ruled much of Canada, though with nothing like the military side of things, and still exists today as a chain of department stores.

Yes, and for this reason submarines don't use active (pinging) sonars when they are trying to stay undetected. In fact any noise a submarine makes can be used to detect it, so submarine designers go to a lot of effort to make their submarines as quiet as possible, with things like machinery noise from the engines, and noise from the propellers, being particularly important. While detecting the noise of an otherwise hidden submarine can give you a good idea of the direction it is from you, using directional sound detectors, it it somewhat harder to determine the distance it is, unless you have several listening devices that are separated by a large enough distance to get a good triangulation.

If you haven't seen it, watch the Hunt for the Red October. It's a classic movie, and gives a good sense of how submarines try to find one another, and how they try to avoid being found. "One ping only" is a classic moment from that film.

Probably the most important thing to appreciate when thinking about colour and colour perception is that the way the human brain processes what the eyes see is very complex and has a huge influence on how we perceive colour that is distinct from what colours are, in terms of the light entering the eye.

In terms of light, an Individual photon has a frequency that relates to colour: lower frequency for red, higher for blue. Of course there isn’t just one photon, there are loads of them. If the mix of photons come in all frequencies in equal numbers, we call that “white”.

The human eye has three types of sensing cells that relate to colour, one type is most sensitive to lower frequencies, and sees red, one to middle frequencies, and sees green, and one for higher frequencies, and sees blue. They are not, however, narrowly sensitive, so their ranges overlap to some extent. If we get some red and some green, we perceive that as yellow. However, this can happen in two ways. One would be photons of a single frequency between red and yellow, that equally excite the red and green receptors, the other is a mix of red and green separately. The eye can not differentiate between these two cases.

The perception of colour is affected by how the brain handles what you see. The brain is inclined to presume the light around you is white. If the light around you is not white, the brain will adjust how it weights the intensity of the average light it is getting from each of the colour cells to make you think you see white, but the effect of this is the adjustment will alter how you perceive actual colours. If the ambient light is yellow (so less blue than true white), the brain will amplify the blue it gets to compensate, so you perceive the world as being more blue than it really is. This effect can persist for a time. There was a restaurant I used to go to that had pink lighting, and after spending a while there, when I went outside, for several minutes the whole world looked green.

if you have a light source of a certain colour, how you perceive it will depend not only on its colour but also how intense it is relative to all the other light. If it is very bright relative to the ambient light, it will trigger your brain’s white rebalancing, so it will seem more white to you.

Some of these brain perception effects in unusual light conditions can lead to strange illusion effects, a classic example being the photograph of the dress from a few years back that some people see as blue and black, and others as white and gold.

But big Al says dog's can't look up

Because density plays a role in Reynolds number, for smaller engines at high altitude (low air density), you can't always count on the flow being turbulent. Laminar flow and transition to turbulence are significant design issues for things like business jet size engine compressors.

Typically the fan tips are supersonic at the design condition. Tip Mach numbers of about 1.3 are typical.

I've worked for two different aero-engine companies, one based in Europe and one based in the US. There are significant differences in terminology between them. There is also the issue that the engines spin the other way.

Formerly frozen turkeys. They thaw them out before they fire the into the engines, as a large block of ice is rather more damaging to an engine than a bird. The bird ingestion test is part of the type approval for all aero-engines, not just P&W.

I think your comparison with the information revolution is a good one. Programmable digital electronic computers did exist and were used based on tube technology, and while they did lay the foundations and get the ball rolling with the information revolution, without the solid state transistor (and later the integrated circuit), the full impact of the "Information Age" could not be achieved. In that sense, the early factories of the likes of Arkwright were a clear start on the path to intense industrialisation, but to realise the full potential required both powerful and efficient steam engines, and the ability to make the machinery they drove.

I would take issue with your comment that everything from Watt to the 1940s in steam engine technology was incremental, though. While James Watt built engines that were recognisably the ancestors of engines still in use in the mid C20th, Watt himself was vehemently opposed to "strong steam", all of his engines were based on a boiler at atmospheric pressure, expanding down to condenser vacuum.

When Trevithick tried to develop higher pressure boilers, Watt used the patent protections he had to effectively shut down this development, and it was only when those patents expired that positive boiler pressure engines, a necessary prerequisite for things like railway locomotives or ship engines, that progress resumed.

The other major thermodynamic advance was the use of superheated rather than saturated steam, a development that came in the later 19th century, and also significantly changed the thermodynamics of the steam engine.

For high pressure superheated steam to be used effectively, compound engines were a necessary development, and in terms of the efficient operation of steam engines, the development of the steam turbine by Charles Parsons was also a huge leap forward. In modern thermal power stations, high pressure superheated steam expanded through multiple turbines are still in use today.

As with anything as complicated as "the industrial revolution", it took multiple steps in terms of science, engineering, finance and supporting social and agricultural systems to all come together to enable the change to take place, and a case can be made for any one of these things being the trigger. An argument could be made, for example, that the invention of the limited liability joint stock company was actually the key enabler, as industrialisation on a large scale was impossible within the limits of the capital an individual person could raise, and the risk that a company with unlimited liability would pose.

Not exactly. While slaves don’t need to be paid, they are not free to keep, and there is a limit to what one slave can do in a day. If you are working with high value products, there is also the problem that an unwilling workforce (slaves) has the potential to destroy a lot of value simply due to being uninterested in doing a good job.

If a factory machine can produce more in a day than 10 manual workers and require 1 operator, but if the operator neglects their job the machine gets badly broken, it is far more economically advantageous to have 1 happy, paid worker to run the machine than 5 slaves whose cost is the same as the paid worker doing the job by hand.

Thanks for this post, it is interesting to see the steps needed and taken to allow modern type metalworking. I would, however, take issue with this being the necessary step to denote the beginning of the industrial revolution. Steam engines, albeit in less efficient formats, had existed for quite some time before Watt’s improvements, and those improvements came when they did because a requirement emerged to make improving the steam engine a problem that needed a solution rather than an interesting curiosity.

At it’s core the industrial revolution is taking what had been artisanal skilled craft based trades and using machinery to deskill them, allowing for a huge increase in volume and reduction in cost of production. The two milestone events in this were the opening of the Etruria pottery in 1769 and the Cromford Mill cotton mill in 1772.

Both of these events preceded the machining developments you describe by a few years, and I would suggest that it was these and similar developments in the factory system that showed the need for and motivated the improvements in machining technology, rather than the machining technology being the key enabler that you imply.