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Is the world really running out of sand?

practical.engineering

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Re: Is the world really running out of sand?

#111

Post by blitzar »

lb1lf wrote: post #103
mcculley wrote: post #79

One thing that surprised me when I started running a tugboat business: A country can be both an exporter and importer of sand. Sand of one type goes from the U.S. to The Bahamas to be used in concrete. Sand of another type goes from The Bahamas to the U.S. to be used in aquariums. Specialty sands go to make regulation volleyball courts.

Indeed! Then there is all kinds of specialty sands - say, when replacing the sand in our local athletics union long jump pits, I learned that one should use sand from river beds (as opposed to sand crushed at a plant) as the river sand is much less likely to cause abrasions, seeing as all the sharp edges have been worn away as the sand has been shifted back and forth by the river current... Sand is not just sand.

The sand people have over 50 different words for sand.

Re: Is the world really running out of sand?

#112

Post by timando »

sakras wrote: post #85
pinkmuffinere wrote: post #47

Earlier quoted context omitted.

I don’t understand how you got that conclusion — 1 grain of sand is not 85% of the [ton of snow + 1 grain sand]

I think OP wanted to construct “sand by induction”, but I also think you need more than one grain. If you have 9 grains of sand and add one snowflake, you now have something that’s 90% sand and is therefore 10 grains of sand. Take your 10 grains of sand and add another snowflake to create 11 grains of sand. Continue with each snowflake one by one, and you’ve inductively created a sand pile.

You don't need to construct sand by induction. Just notice that snow has the right particle size to be considered sand.

Re: Is the world really running out of sand?

#113

Post by tourmalinetaco »

sundarurfriend wrote: post #108

> I tried to track down the original source of this idea ... Beiser cites an article from the UN, which itself cites a 2006 paper about using two types of desert sand from China in concrete. But that paper doesn’t mention the roundness of the particles at all. This seems to be a fairly common pattern where a citable source (Beiser's book and the UN article) makes a mistake, that then propagates everywhere as common k…

The problem is that what defines a “citable source” for Wikipedia is loose at best and malicious at worst. There are many examples where “improper” sources are accepted, especially in social matters, because they benefit a certain viewpoint. STEM is, for the most part, decent, but anything covering the life of people needs to be considered carefully due to the lack of several types of important sources and the biases present on many people’s pages.

Re: Is the world really running out of sand?

#114

Post by niklasbuschmann »

cdchn wrote: post #104
larsrc wrote: post #81

We fools here in Germany sometimes _pay_ to get rid of excess electricity when it's very sunny and windy. How about having some rock crushing machines that instead use that cheap electricity to make more sand? Thanks for the puns, too.

I hate to say this, but why aren't the Bitcoin miners jumping all over that?

I assume there are taxes and transmission fees on top of the spot electricity price

Re: Is the world really running out of sand?

#115

Post by topspin »

lofaszvanitt wrote: post #94

Just like the US debt is about to collapse on pepl and kill the economy, but ... ... it never happens.

The US has had a long way to fall. In a wealthy economy can suffer a great deal of public finance abuse: there are many wells that need to be dried up. The progression of the US toward that goal includes, most recently: progressively shifting to ever shorter term notes to finance deficits and large scale monetizing of deficits, such as during the Great Recession and COVID.

We'll get there. You'll know it's over when you get "bailed in" and the treasury starting minting trillion dollar coins.

Re: Is the world really running out of sand?

#116

Post by colechristensen »

roca wrote: post #17
colechristensen wrote: post #11

Earlier quoted context omitted.

The Washington Post headline: >'The Eagle Has Landed' – Two Men Walk on the Moon That is the entire story, in the headline as it should be. I want to know more! The first sentence should add the most relevant added information. It shouldn't be "As a child Neil Armstrong always dreamed about..." burying the next most important detail 2/3 through the article. The importance/relevance/interest should start high, end low…

I have a theory that a lot of journalists really wanted to be novelists. When they get a chance to write a long-form article they can't resist the urge to flex their stylistic muscles; "look at me, I'm a Serious Writer".

I was talking to a journalist who worked for a major venue and the metric she cared about was number of seconds a user stayed on an article. She didn't say "this is the most important..." she just talked about it for 20 minutes and the different results from different demographics and link sources so it was quite obvious.

So that's what journalists are measured by these days apparently, how long a piece can keep the attention of a user.

Ironically she worked for what I would consider one of the best players in terms of not writing attention grabbing BS. (I won't mention which here)

Re: Is the world really running out of sand?

#117

Post by throwup238 »

cdchn wrote: post #104
larsrc wrote: post #81

We fools here in Germany sometimes _pay_ to get rid of excess electricity when it's very sunny and windy. How about having some rock crushing machines that instead use that cheap electricity to make more sand? Thanks for the puns, too.

I hate to say this, but why aren't the Bitcoin miners jumping all over that?

Metal foundries in Europe generally have dibs with large, long term power purchasing contracts. IIRC there's even some legislation that favours them since they're a national security resource.

Re: Is the world really running out of sand?

#118

Post by applied_heat »

cdchn wrote: post #104
larsrc wrote: post #81

We fools here in Germany sometimes _pay_ to get rid of excess electricity when it's very sunny and windy. How about having some rock crushing machines that instead use that cheap electricity to make more sand? Thanks for the puns, too.

I hate to say this, but why aren't the Bitcoin miners jumping all over that?

Because the mining equipment is expensive and the duration of free electricity intervals are outweighed by expensive electricity intervals

Re: Is the world really running out of sand?

#120

Post by alex-moon »

"Concrete blows most other materials out of the water."

In fact, according to Wikipedia, concrete is the "second-most-used substance in the world after water" - I was on the Concrete Wikipedia article while I read this as I realised it was a thing I have never thought about despite its ubiquity. Amazing how that can happen.

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