This is true for only red and green loght detecting proteins (opsins) - the blue opsin gene is on chromosome 7.

The red and green detecting proteins have an interesting history in humans.

Fish, amphibians, lizards and birds have 4 different opsins: for red, green, yellow and blue colours. And the blue opsin sees up into the ultra-violet. Most animals can see waaaay more colours in the world than we (or any mammal) can. So what happened that makes mammal vision so poor?

It’s thought that all mammals descend from one or a few species of nocturnal mammal that survived the catastrophe that wiped out the dinosaurs at the end of the Cretaceous. The colour detecting cells (the cones) need a lot of light compared to ones that see in black-and-white (the rods) and therefore nocturnal animals frequently lose cones in favour of the more sensitive rods for better night vision. The mammals that survived the Cretaceous extinction had also lost the green and yellow opsins while keeping red and blue - basically the two different ends of the light spectrum.

Consequently today most mammals still have only 2 opsins so your cat or dog is red-green colourblind.

Why do humans see green? Probably because our monkey forebears, who lived in trees and ate leaves, needed to distinguish red leaves and red fruit (visible to birds) from the green background.

But how did we bring back the green opsin? A whole section of the X chromosome (where the red opsin is coded) got duplicated in a dna copying mistake and then there were two genes for red opsins. As there are different alleles (versions), they could be selected for independently and so one red opsin drifted up the spectrum to be specific for green. So our green opsin is a completely different gene to the green opsin in fish, birds, etc. This kind of evolution happens a lot which is why, for example, there are many families of similar hormones like testosterone and estrogen. And steroids too.

It is the defecal standard though.

All junior devs should read OCs comment and really think about this.

The issue is whether is_number() is performing a semantic language matter or checking whether the text input can be converted by the program to a number type.

The former case - the semantic language test - is useful for chat based interactions, analysis of text (and ancient text - I love the cuneiform btw) and similar. In this mode, some applications don’t even have to be able to convert the text into eg binary (a ‘gazillion’ of something is quantifying it, but vaguely)

The latter case (validating input) is useful where the input is controlled and users are supposed to enter numbers using a limited part of a standard keyboard. Clay tablets and triangular sticks are strictly excluded from this interface.

Another example might be is_address(). Which of these are addresses? ‘10 Downing Street, London’, ‘193.168.1.1’, ‘Gettysberg’, ‘Sir/Madam’.

To me this highlights that code is a lot less reusable between different projects/apps than it at first appears.

Which is difficult to give without that arm

It is terribly sad - they must live in a world of hurt.

However so many of these people actively try to hurt LGBTQ+ and trans people by inciting hate and changing laws to harm the non-straight. In particular they have been preaching that being gay/trans equates to being a child molester. This is horrific and needs to stop. Exposing the hypocrisy is essential to reducing the harm they are inflicting to real people right now

Ackshually they do this, not with cars but, with WW2 era prop planes.

The Spitfire for example:

The Merlin consumed an enormous volume of air at full power (equivalent to the volume of a single-decker bus per minute), and with the exhaust gases exiting at 1,300 mph (2,100 km/h) it was realised that useful thrust could be gained simply by angling the gases backwards instead of venting sideways.

During tests, 70 pounds-force (310 N; 32 kgf) thrust at 300 mph (480 km/h), or roughly 70 hp (52 kW) was obtained, which increased the level maximum speed of the Spitfire by 10 mph (16 km/h) to 360 mph (580 km/h). The first versions of the ejector exhausts featured round outlets, while subsequent versions of the system used “fishtail” style outlets, which marginally increased thrust and reduced exhaust glare for night flying.

From Wikipedia

I had a Sinclair QL which pioneered the keyboard. It wasn’t great - it was far behind the Acorn BBCs and the Commodores) but it was quite usable.

There was significant vertical travel, and there was variation in the push the key gave back - increasing to a point of no return, then a quick downward movement to the thunk of the end of key travel.

I could type moderately fast on it.

Exactly!

While the continents might look like they fit together, and the rock types and ages and fossils match at key points all down the coasts from Canada/Scotland all the way down to South America and South Africa, how on earth (sorry) would you explain how the continents are thousands of miles apart?

One theory posited the earth spinning so fast centrifugal forces ripped ehat would become the moon out of the Pacific, sucking Eurasia and America into the void.

That’s a Randall Monroe WhatIf if ever I saw one. Think of the energy involved! All life on earth would be extinct.

So these theories were laughed out of scientific court. Until Vine and Matthew’s seminal paper on magnetic stripes being mirrored over the mid ocean ridge showed there had to be something forcing the plates apart.