TIL: Today I Learned

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The origin of to decimate: a Roman punishment where a disgraced army was divided into groups of ten, one was picked by lottery and the other nine beat him to death.
 
That sounds demoralizing.
 
For totally not-mad science reasons, I've added up the mass of the Moons of Jupiter, Saturn, Uranus, and Neptune; the mass of the Asteroid Belt, and the mass of the Kuiper belt.

The results were...disappointing.

For starters, the Earth has a mass of around 6,000 10^21 kg.

The second runner up, the Kuiper Belt in its entirety, has 400 10^21 kg. Jovian Moons - 260 10^21 kg. Saturnine Moons - 140 10^21 kg. Uranian Moons - 9, 140 10^18 kg. The Asteroid Belt? A paltry 3 10^18 kg. Neptunian Moons - 2, 150 10^18 kg.

Which looks like:

6,000,000,000,000,000,000,000,000 ♁ - We're here.
---400,000,000,000,000,000,000,000 ♇ - Eris, Pluto, Charon, et al.
---260,000,000,000,000,000,000,000 ♃ - More evenly distributed between the main four.
---140,000,000,000,000,000,000,000 ♄ - Most of this is Titan. Like, 96 % of it.
-----70,000,000,000,000,000,000,000 ☾ - The moon, for comparison.
-------9,000,000,000,000,000,000,000 ♅
-------3,000,000,000,000,000,000,000 ⚳ - Ceres is about half of all of this
-------2,150,000,000,000,000,000,000 ♆ - Triton is most of this.

If somehow all of this mass was put together it would be a MEASLY

814,000,000,000,000,000,000 KG. Or around 1/6th, 1/7th of the Earth.

And apparently we started out with 30 Earth masses of junk out there, now it's gone. And no, the Theoretical Oort Cloud doesn't really count. Going around the galaxy eight or so times, so many stars doing drive by's, and our own internal gravity 'dance' threw most of it out. And yet the system still looks like a mess.

Ah well, it's easier to peel the crust off moons and then crack them bit by bit when they're smaller anyway.
 
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TIL about sand. Yes sand. That stuff that is basically really small rocks created by erosion of bigger rocks. Well it turns out that it is really important for construction as it is one of the main ingredients for making concrete. And since concrete is used to make roads and buildings, us humans use a lot of it. And we are running out of it.

But how could that be? Go to the beach and there is sand everywhere!

Well I'm glad I asked. Sand commonly found on ocean beaches tends to be smoother and more circular which makes it unsuitable for construction. What we need is the more irregularly shaped sand found in river beds and around small lakes. The irregular shape allows the grains of sand to lock more easily preventing it from flowing freely. So that cuts the amount of usable sand significantly. This lack of sand and the high demand for it has led to "sand mafias" to spring up. These sand mafias illegally take sand from ecologically sensitive areas which leads to beach degradation and upsets the local ecosystem as some wildlife depends on the sand. There has been some efforts to deter these sand mafias, mostly at local levels, but like your normal run of the mill mafias, they resort to intimidation and violence in order to continue their illegal sand mining operations.
 
Imaus said:
For totally not-mad science reasons, I've added up the mass of the Moons of Jupiter, Saturn, Uranus, and Neptune; the mass of the Asteroid Belt, and the mass of the Kuiper belt.

The results were...disappointing.

For starters, the Earth has a mass of around 6,000 10^21 kg.

The second runner up, the Kuiper Belt in its entirety, has 400 10^21 kg. Jovian Moons - 260 10^21 kg. Saturnine Moons - 140 10^21 kg. Uranian Moons - 9, 140 10^18 kg. The Asteroid Belt? A paltry 3 10^18 kg. Neptunian Moons - 2, 150 10^18 kg.

Which looks like:

6,000,000,000,000,000,000,000,000 ♁ - We're here.
---400,000,000,000,000,000,000,000 ♇ - Eris, Pluto, Charon, et al.
---260,000,000,000,000,000,000,000 ♃ - More evenly distributed between the main four.
---140,000,000,000,000,000,000,000 ♄ - Most of this is Titan. Like, 96 % of it.
-----70,000,000,000,000,000,000,000 ☾ - The moon, for comparison.
-------9,000,000,000,000,000,000,000 ♅
-------3,000,000,000,000,000,000,000 ⚳ - Ceres is about half of all of this
-------2,150,000,000,000,000,000,000 ♆ - Triton is most of this.

If somehow all of this mass was put together it would be a MEASLY

814,000,000,000,000,000,000,000 KG. Or around 1/6th, 1/7th of the Earth.

And apparently we started out with 30 Earth masses of junk out there, now it's gone. And no, the Theoretical Oort Cloud doesn't really count. Going around the galaxy eight or so times, so many stars doing drive by's, and our own internal gravity 'dance' threw most of it out. And yet the system still looks like a mess.

Ah well, it's easier to peel the crust off moons and then crack them bit by bit when they're smaller anyway.
Click to expand...
For the purposes of speculative/science fiction, I wonder (a) how much of the Earth's raw material we've used, like in the entire history of human engineering, and (b) how much of the raw material in the Solar System will be available to us, once we've figured out how to get there and construct things out there. As I understand it, the great cost of putting things in orbit comes from getting it off the surface of this gravity well we live on. If you could construct things in space, and with the mass of material Out There, I think that an artificial space station the size of, say, Manhattan Island would be no big deal (the question of whether people can actually live in space long-term might turn out to be the greater limitation than what we could build).
 
If you have too much of this chocolate frosting I can gladly sacrifice myself. I'll PM you my address.

TIL (technically YIL) that I'm not alone regarding this subject of not wanting to have yet another oilfield opened and instead having real technologies with a real future developed.
 
EgonSpengler said:
For the purposes of speculative/science fiction, I wonder (a) how much of the Earth's raw material we've used, like in the entire history of human engineering, and (b) how much of the raw material in the Solar System will be available to us, once we've figured out how to get there and construct things out there. As I understand it, the great cost of putting things in orbit comes from getting it off the surface of this gravity well we live on. If you could construct things in space, and with the mass of material Out There, I think that an artificial space station the size of, say, Manhattan Island would be no big deal (the question of whether people can actually live in space long-term might turn out to be the greater limitation than what we could build).
Click to expand...
You're correct - the cost driver of space exploration and exploitation is the cost of launch. It is huge and it drives other costs in pernicious ways. When you are paying $500 million to launch something into space, you want to make absolutely certain that the thing you are launching is completely fool-proof and without error. So you wind up spending $2 billion designing and building a perfect satellite to launch on a $500 million rocket and then pay some tens of millions in insurance against launch failure. Launch prices are falling and this has enabled a lot of experimentation and innovation on the satellite side such that now even NASA is launching shoebox-sized satellites past freaking Mars that cost 'only' a million to build. When launch costs come down to the <$1000/kg range, space exploration and exploitation will kick into high gear. One of the key problems of the late 21st century is how to structure an economy when raw material costs for almost everything fall through the floor, thanks to cheap imports from outer space.

And space has other features, namely unlimited solar power and zero gravity, which will enable off-planet manufacturing to take off following raw mineral extraction, further upending the economy of the globe. Oh and imagine when all of the pollution that comes with extraction, refining and production get shifted off the planet? That's the future I'm hoping for anyways.
 
I suppose a space elevator is still just science fiction?
 
hobbsyoyo said:
Oh and imagine when all of the pollution that comes with extraction, refining and production get shifted off the planet? That's the future I'm hoping for anyways.
Click to expand...

Could they launch all the garbage into the sun?
 
aimeeandbeatles said:
Could they launch all the garbage into the sun?
Click to expand...
I was thinking that you could use a solar sail, because if it's garbage anyway, you don't need it to get there fast. But can a solar sail carry something towards the sun?
 
BenitoChavez said:
Sand commonly found on ocean beaches tends to be smoother and more circular which makes it unsuitable for construction.

These sand mafias illegally take sand from ecologically sensitive areas which leads to beach degradation
Click to expand...

:dubious: This seems to be saying that, because beach sand can't be used, they use beach sand. :confused:

There's no mention of desert sand, and I would guess that there's much more desert sand than beach sand,
 
EgonSpengler said:
I was thinking that you could use a solar sail, because if it's garbage anyway, you don't need it to get there fast. But can a solar sail carry something towards the sun?
Click to expand...
Well, there are techniques for sailing in a zig-zag against regular wind.
 
The sun would complain.
 
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