That stuff about metal is really counterintuitive, because normally when we talk about iron, gold, copper, nickel, zinc, magnesium, aluminium etc it’s usually about the element in its metallic form. However, when you study chemistry a bit more, you’ll come to realize metals can be dissolved in water and they can be a part of a completely different compound too.

Calcium, sodium and potassium are basically the exact opposite in this regard. Normally when people talk about these metals, they are referring to various compounds that obviously aren’t metallic at all. This leads to people thinking of these elements as non-metallic, but it is possible to purify them to such an extent that you are left with nothing but the metal.

In the case of Ca, Na and K, the resulting metal is highly reactive in our aggressive atmosphere, so that’s why we rarely see these elements in a metallic form. Our atmosphere contains water and oxygen, which makes it an incredibly hostile environment for metals like this. Imagine, we’re breathing this stuff that attacks so many elements mercilessly.

Yo OP. We're carbon based, which you accept. Diamond is stronger than almost all metal, and it's pure carbon. Why wouldn't we have metal in our veins? We atomically won that round before inflation was even over.

I'm just playin, carbon under high enough pressure is metal too.

Twice over, my favorite fact is that humanity has only existed during the time frames that the moon and the sun have been the same size in our sky, this allowing total eclipse - which is so obviously ridiculously rare I don't see the point in quantifying with maths.

I think it's bizarre to think we have free will. Everywhere around us, in all our tech, tools, toys we see the realities of determinism. Cause and effect. To think that our minds are somehow not governed by this in a universe that unequivocally is is beyond Babel levels of arrogance.

Beyond that, the idea that's gaining ground about shared consciousness I find really intriguing. Rather fascinating stuff.

Consciousness is the biggest mystery of the all, after all.

The USA has 157 million workers, shuffling 140,000 years of work a day. One in 4 has an idea. One in five of those is a good idea. Two thousand stakeholders can make it an innovative idea. So, they can pump 3.5 years of brute force innovation into the world every single day. That's well over a thousand years of advancement per year.

Critical mass populations that can keep up with their own development are a serious creative force to be reckoned with. And human evolution has been exceeded by innovation, dramatically.

Using engine brakes can cause your car to not use fuel in some cases.

I've read and heard this from different sources (even driving instructors) and I don't get how it's possible. Your engine is still running, doesn't it use at least as much as it does while it's idling?

Edit: thank you all for your answers. I knew how the engine brake effect worked, my confusion was about exactly why the engine didn't consume fuel in the process. I now understand so thanks all.

Cows are evolutionarily closer to whales than horses.

How?!

Women have orgasms

The fact that things are able to float, despite of gravity pulling all objects towards the big mass of Earth. You would think that the push of gravity should be more than enough to overcome the slight fluid displacement that allows balloons and boats to push away from the Earth's surface.

To be fair, the single iron atoms are surrounded by a lot of carbony goodness. There's a few metals that have minor biological uses in humans like that, and even sodium and potassium are metals in pure form.

It's hella weird to me how we suddenly developed democracy and industrialisation after thousands of years of kind of the same thing. I have yet to hear a convincing explanation; right now I'm playing with Lanchester's laws as a theory.

To piggy back on your "bizarre fact", the same type of iron can be found added to cereal.

I remember several times in school we'd do a science demonstration where we'd smash up Cheerio (or a knock off) brand ceral, mix the powder with water and slowly drag a magnet through the slurry. Every time the magnet would be pulled out of the mix, there'd be more and more tiny iron bits.

Concepts coming from quantium mechanics take you into a rabbit hole. 2022 Nobel winning experiment that proved universe is not locally real.