TIL: Today I Learned

[MaryKB]

obviously where this dude is from

Or where this fellow is from ..

 

[Phrossack]

There's a town in Missouri called Humansville. I liked to imagine it was named for its primary inhabitants, but apparently it was named for its founder, a certain John Human.

I now like to imagine he either came from a long line of Humans so named for their profession, or else he was an incredibly obvious alien spy and nobody had the heart to tell him they knew because he was nice.

 

[sophie]

obviously where this dude is from

Town's founder pictured below:

 

[yung.carl.jung]

(that's me on the ground)

 

[Lexicus]

*record scratch*
*freeze frame*
Yep, that's me.

 

[Takhisis]

TIL the same guy who played Chancellor Valorum in The Phantom Menace voiced the Prophet of Truth in Halo 3.

Terrence Stamp is an awesome actor.

 

[aimeeandbeatles]

TIL that it's the record labels that censor bad words out of the songs, not the radio stations. It was so inconsistent (the f-bomb is near universally bleeped, but it was 50/50 for fecal matter, and sometimes innocuous stuff like "ass") that I thought the guy in charge of doing that suffered from mood swings or something.

I also learned that Canada made all radio stations cut that one verse from the Dire Straits' "Money for Nothing." Even though it was satirical.

 

[Kyriakos]

Yil: paprika on gyros: very good...
Til: isothermal shirt is great for protection against the cold.

 

[Hrothbern]

TIL that the sister of the King of Thailand runs for PM against the ruling military junta

poor country

https://www.theguardian.com/world/2...-prime-minister-against-ruling-military-junta

 

[BenitoChavez]

TIL that dust from the Sahara desert fertilizes the Amazon. It blows my mind that soil from one of the most desolate places is essential to life in one of the fertile. And it blows my mind that enough of it is transferred across the oceans to be significant.

https://www.nasa.gov/content/goddar...s-how-much-saharan-dust-feeds-amazon-s-plants

This trans-continental journey of dust is important because of what is in the dust, Yu said. Specifically the dust picked up from the Bodélé Depression in Chad, an ancient lake bed where rock minerals composed of dead microorganisms are loaded with phosphorus. Phosphorus is an essential nutrient for plant proteins and growth, which the Amazon rain forest depends on in order to flourish.

Nutrients – the same ones found in commercial fertilizers – are in short supply in Amazonian soils. Instead they are locked up in the plants themselves. Fallen, decomposing leaves and organic matter provide the majority of nutrients, which are rapidly absorbed by plants and trees after entering the soil. But some nutrients, including phosphorus, are washed away by rainfall into streams and rivers, draining from the Amazon basin like a slowly leaking bathtub.

The phosphorus that reaches Amazon soils from Saharan dust, an estimated 22,000 tons per year, is about the same amount as that lost from rain and flooding, Yu said. The finding is part of a bigger research effort to understand the role of dust and aerosols in the environment and on local and global climate.

 

[hobbsyoyo]

Similarly, China is a major source of pollution for California.

 

[Takhisis]

Yil: paprika on gyros: very good...

Oooooh, I'll have to visit Xessaloníke then.

TIL that the sister of the King of Thailand runs for PM against the ruling military junta

poor country

https://www.theguardian.com/world/2...-prime-minister-against-ruling-military-junta

We have an East Asia thread with which we've been at war for some time (TI was reminded of).

TIL that dust from the Sahara desert fertilizes the Amazon. It blows my mind that soil from one of the most desolate places is essential to life in one of the fertile. And it blows my mind that enough of it is transferred across the oceans to be significant.

https://www.nasa.gov/content/goddar...s-how-much-saharan-dust-feeds-amazon-s-plants

This trans-continental journey of dust is important because of what is in the dust, Yu said. Specifically the dust picked up from the Bodélé Depression in Chad, an ancient lake bed where rock minerals composed of dead microorganisms are loaded with phosphorus. Phosphorus is an essential nutrient for plant proteins and growth, which the Amazon rain forest depends on in order to flourish.

Nutrients – the same ones found in commercial fertilizers – are in short supply in Amazonian soils. Instead they are locked up in the plants themselves. Fallen, decomposing leaves and organic matter provide the majority of nutrients, which are rapidly absorbed by plants and trees after entering the soil. But some nutrients, including phosphorus, are washed away by rainfall into streams and rivers, draining from the Amazon basin like a slowly leaking bathtub.

The phosphorus that reaches Amazon soils from Saharan dust, an estimated 22,000 tons per year, is about the same amount as that lost from rain and flooding, Yu said. The finding is part of a bigger research effort to understand the role of dust and aerosols in the environment and on local and global climate.

This reminds me of a documentary on how some coastal part of the Sahara blooms overnight at a time of the year when the moist winds blow in from the sea and a myriad lifeforms come out to feed and reproduce and then hide again every dawn. It was breathtaking.

 

[Kyriakos]

I found the paprika gyros in xessathens, though. It was a welcome change, cause in athens they just corrupt gyros by drowning it in that pitiful cucumber sauce :/

 

[aimeeandbeatles]

TIL I learned that sometimes people can see their white blood cells moving around in their eye when looking at a blue background (e.g. the sky). It's called blue field entopic phenomenon.

 

[Lohrenswald]

oh yea I've done that several times

wondered what that was about lol

 

[aimeeandbeatles]

Speaking of other weird visual things, I used to think that floaters (little clumps of protein in the vitreous) were bacteria crawling around the surface of my eye.

 

[Dachs]

floaters (little clumps of protein in the vitreous)

thank you for the clarification

 

[Takhisis]

If I hadn't had some of those myself I would only think of those danged purple aliens from Enemy Unknown when I read the word ‘floaters’ in a gaming forum.

 

[Valka D'Ur]

If I hadn't had some of those myself I would only think of those danged purple aliens from Enemy Unknown when I read the word ‘floaters’ in a gaming forum.

Carl Sagan used the term "floaters" in Cosmos when he was speculating about what sort of lifeforms could possibly exist in Jupiter's atmosphere.

 

[hobbsyoyo]

Today I learned you want the combustion chamber of a rocket engine to be as short as practical. During combustion, all of the stored chemical energy of the gas is released. Allowing the gas to expand in a straight pipe allows that heat energy to be converted into kinetic energy which lessens the overall amount of energy in the gas due to entropy (waste).

This will accelerate the gas, which is the point, but it is a wasteful way to do this chemical-to-kinetic energy conversion. If instead you restrict the diameter of the same length of pipe, the gas will be forced to accelerate without much entropy loss. The same amount of particles need to go through this restricted, smaller pipe so they have to move faster to squeeze through. This method of energy conversion incurs much less entropy losses which means more momentum is exchanged with the rocket when the gas is released through the pipe (nozzle) exit.

However, you cannot make the combustion chamber inifintely short to reduce entropy further still. The propellant is often injected as a liquid and must be atomized or evaporated into a gas before it can combust and this take space. Additionally, the gas molecules have to be mixed to the proper ratios and then combusted - a process which takes more space still.

Conversely, you can make the rest of the engine (the nozzle skirt) almost as short as you like. Most of the work is done at the nozzle throat which is immediately adjacent to the combustion chamber and is the 'waist' of the rocket engine. The skirt is the flared part after the throat and this part does extract more energy from the expanding gas but is a small fraction of the whole. Plus, while having a skirt that is too big is physically dangerous, having one that is too short is not hazardous and actually confers major weight and complexity savings.