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.
Programming and in general tech work has been extremely highly compensated compared to most other industries the past few decades.
This means a lot of intelligent (and not so) folks who could do whatever they wanted chose tech to chase the money. Get a little lucky in life and maybe stock options and they get to do what they actually enjoy the latter half of their life.
Most of society can only dream of such capability. The ones who actually have the bravery to pull it off vs. grinding out their final days in a career they are not passionate about are incredibly inspirational to me at least!
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...
The best night's sleep I ever had was on the sand of a turn in a dry creek bed, after a very long day's hike. It must have had a big rock underneath that caught the day's warmth and kept me toasty all night. And the sand itself felt like floating on a cloud. It was a magical place. And one of the stupidest I ever slept in due to the risk of flash floods.
One of the best meals I ever ate was a store bought can of chiii cooked over a tiny camp burner after a long hiking through the Grand Canyon. Sometimes it's the simple things during the most exceptional situations that can cement such a strong memory... It did for me anyways.
Yes, but. I had some of the most memorably bad sleeps on the same trip. Like wrapped around a tree trunk on a slope in a blizzard. Not magical one bit.
One of the most romantic dalliances I ever did have was on the soft sand on the beaches of Italy, moonlight, red wine, the sand felt like velvet and silk rolled into one. I just think back on it and think to myself "let me brag about how great it was on the internet" 10/10 you missed out.
You should try sleeping on a fresh haystack. Most people will never experience this. But the haystack is made up of cut flowering meadow plants. So it's like sleeping in a bouquet of dried flowers. And the aromatic organic chemicals released all night can have a very calming effect.
It's kind of wild to think about, but people used to get it on in haystack barns all the time.
I tried that and it was made of cut grasses. You know how grasses have foxtails that cling to animals to help distribute the seeds over a wider area? I was that animal that night and I didn't like it one bit.
Reminds me of getting can of S.Pellegrino water with something in it. Looked at back of the can and wondered why is this in Japanese... So my guess is that it was first made in Italy, then shipped to Japan and then imported back to Finland...
One starts to question sanity of our consumption habits at times. I am no way environmentalist, but this sort of stuff just seems waste of energy inputs.
As long as you can ship stuff on a boat over the ocean, and don't care too much how long it takes, shipping it even multiple times across the planet is fine. Barely costs anything, both in terms of money and in terms of resources.
The (first and) last miles via truck can cost a lot more, but you can't guess those from whether there's Japanese writing on the label.
It is not surprising to me that products which have lots of differentiation are both imported and exported. It was surprising to me that something I thought of as a commodity goes in both directions.
While not sand, I remember reading about the state of Colorado importing specialty dirt from around the world while constructing I-70 through the Rockies. Various properties were required that couldn’t be found from local dirt.
Yeah but there is going to be a massive imbalance in the quantity of those two types of sand. I bet the sand required for aquariums is a rounding error on the amount of sand required for concrete.
Well not really Bermuda has population of 60000 only so the sand they import for construction might even be less than the sand US import from Bermuda for its aquariums
Especially as many aquarium owners, these days, use a topsoil-clay mixture instead. Planted tanks take far less maintenance, need less filtering, can fit more (and happier) fish, and the plants grow better in soil.
Yes, though the difference in value is probably not quite as stark as the difference in mass. (Ie aquarium sand is probably more expensive than concrete sand.)
> 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 knowledge even though it's incorrect. There are many well-researched blog articles like this out there, where the author has dug deep, done the hard research, and found mistakes at many levels, but because it's not in what academia or Wikipedia considers a "citable" source, the mistaken assertion continues to be propagated. Until someone manages to present it in an academically acceptable format, if that happens at all.
Solving the "what should be a citable source" problem is complicated, but in the interim, I hope we can at least find a way to transfer these well-researched findings and corrections from non-academic sources to citable forms regularly and easily.
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.
If you're bilingual, it's often useful to read a wikipedia topic in more than one language, as the editorial slant may be different in different languages.
The BBC Maths and Statistics programme 'More or Less' has coined a term for statistics like this - 'Zombie Statistics'. An initial, often misquoted fact, which is useful as a soundbite and gets repeated over and over and over again, despite multiple debunkings.
Grady is a hero in engineering reporting and documentaries. I've learned so much about how the world works in other engineering disciplines from Practical Engineering, and often in neglected fields that are losing talent faster than it can be replaced.
It gives me hope that teenagers are watching his videos and becoming inspired to go into infrastructure. More than anything, I appreciate his calm and reasoned perspectives that are so lacking in video content in this modern day and age.
100% - he calmly explains various approaches and their tradeoffs.
He’s not exactly a traditional journalist, but this is what I want the future of journalism to be like. People with subject matter expertise explaining their thing simply and clearly.
>It gives me hope that teenagers are watching his videos and becoming inspired to go into infrastructure.
Sadly, that was me ~10 years ago, but the lure of FAANG money was too strong and I went into EE/CS after 1 year as a civil engineering major. I wonder if one day we will really start feeling the affects of this talent reallocation, and civil engineering will become a higher paying profession.
> the crucibles used to create ingots of silicon which become microchips are made from an ultra-pure quartz sand -- and 70% of the world's supply comes from just one place in North Carolina [Spruce Pine]
> and 70% of the world's supply comes from just one place in North Carolina
A quick search seems to say there are more places available for getting that than North Carolina.
Is it possible that this specific mine just happens to be the cheapest available right now, but in case they for some reason disappear, there are alternatives everyone would switch to? Or is the situation that if that mine disappears, there is no other alternatives at all?
Could not even be the cheapest, Just the refinement process was developed for this particular sand. A different sand might have different impurities and need different processes to handle.
Almost all our modern tech has extremely long tails measured in decades.
It's basic economics to exploit one source for as long as possible before feasibility changes, but that's a hard argument to make for anyone, even the most experienced personnel because it's all so site specific.
If the particular impurities of this source can be chelated out with safer or cheaper chemicals, maybe in fewer steps, then the cost goes down.
Of course jurisdictions with poor worker conditions can just use the less safe chemicals and externalize the human toll instead of using more complex safety procedures.
Availability, production scale, and knowledge base.
I think things will probably pan out okay, maybe a rough month or two as roads (even if rough cut new logging roads), utilities, and prioritized community services get fixed up. Synthetic option is available, apparently, just a bit costly.
Yeah, this is being overblown. It may very well be that there will be a short term constriction as competitors ramp, but to argue that this is some kind of fundamental bottleneck in semiconductor production is ridiculous.
It's quartz: literally the single most common crystal on the surface of the planet. Now, sure, I'm sure this particular mine had great stuff, but it's not like it's hard to find.
No, surely what we have here is a single source provider precisely because the material is so cheap to mine (and therefore unprofitable to try to compete with from scratch).
I'm pretty sure the implied argument is that, while this source currently supplies 70% of the total, we aren't actually dependent on it - i.e. production could be scaled up elsewhere.
Sadly, given the insane amount of devastation in western NC, I'll get a chance to test my hypothesis. That is, despite Spruce Pine going offline, the overall impact to the global semiconductor industry will be relatively unnoticeable.
Could also go the other way. Some of you may be old enough to remember the 1993 fire in the Sumitomo epoxy resin factory. Following that, DRAM chips became drastically more expensive (prices increased from $30 to $80 per megabyte) for much longer than the supply disruptions lasted, and interestingly also much longer than other ICs which saw only moderate price increases.
The majority of the earth's crust is believed to be made of silicon dioxide. I don't know how much I would believe that we would have a scarcity. It may all come from one source simply because of history.
Really interesting video. This is the first time I have seen the (apparently entirely fabricated) idea that desert sand isn't suitable for construction challenged. I had definitely absorbed that idea into my consciousness without enough due diligence.
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?
One of the proposals for exploiting zero (or negative) electricity prices is storage of the heat at high temperature in refractory solids. This would be used by people who normally burn a fuel for the heat. Instead, they can preheat air and reduce the fuel needed (perhaps reduced to zero).
Firebrick works up to about 1000 C. A spinoff from MIT is using special nickel-doped chromium oxide (chromia) bricks, which can work up to 1800 C, about the temperature of a natural gas-air flame. These bricks are electrically conductive and can act as their own heating elements.
It's quite likely that the cost of idle capital is much higher than the cost of paying others to accept electricity. Depending on the price swings, a battery may be a much better investment.
A company such as Riot also can profit by buying power at negotiated rates ahead of time — retail power companies allow big companies to lock in prices that way — then selling it back into the state market when energy prices soar during extreme heat or cold. In Riot’s case, when electricity prices soared during the summer heat wave, Riot sold power back to TXU, a Dallas-based electricity provider, which sold it back to the grid.
But if the value of Bitcoin is low and the cost of electricity is high, crypto companies can make more money selling power than mining Bitcoin. In August 2023, Riot reported selling 300 Bitcoins for a net proceeds of $8.6 million. Meanwhile, the company said it earned $24.2 million in credits to its electric bill for selling power back to the grid.
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.
Yup, in one of eu countries i have it on my bill: it's ~0.10EUR/kWh electricity and additional ~0.15-0.20EUR/kWh for taxes + transmission + maintenance, IIRC
There’s also labor, wear on the machines and the lost opportunity of using your money to do something else. Building such crushing machines and only use them x% of the time (for, for now, fairly small values of x) may not be a good investment.
So, energy storage should be lucrative and incentivized for us to solve the Duck Curve, and Alligator Curve, and overcharging the grid forces the price to zero or unlucratively below problems.
For firms with depreciating datacenter assets that are underutilized, a Research Coin like Grid Coin or an @home distributed computation project can offset costs
Datacenters scrap old compute - that there's hardly electronics recycling for - rather than keep it online due to relative cost in FLOPS/kWhr and the cost of conditioned space.
Doesn't electronics recycling recover the silica?
Can we make CPUs out of graphene made out of recycled plastic?
Can we make superconductive carbon computers that waste less electricity as heat?
Hopefully, Proof of Work miners that aren't operating on grants have an incentive to maximize energy efficiency with graphene ASICs and FPGAs and now TPUs
The book mentioned, The World in a Grain: The Story of Sand and How It Transformed Civilization by Vince Beiser:
> The World in a Grain is the compelling true story of the hugely important and diminishing natural resource that grows more essential every day, and of the people who mine it, sell it, build with it--and sometimes, even kill for it. It's also a provocative examination of the serious human and environmental costs incurred by our dependence on sand, which has received little public attention. Not all sand is created equal: Some of the easiest sand to get to is the least useful. Award-winning journalist Vince Beiser delves deep into this world, taking readers on a journey across the globe, from the United States to remote corners of India, China, and Dubai to explain why sand is so crucial to modern life. Along the way, readers encounter world-changing innovators, island-building entrepreneurs, desert fighters, and murderous sand pirates. The result is an entertaining and eye-opening work, one that is both unexpected and involving, rippling with fascinating detail and filled with surprising characters.
>Sand, salt, iron, copper, oil, and lithium. These fundamental materials have created empires, razed civilizations, and fed our ingenuity and greed for thousands of years. Without them, our modern world would not exist, and the battle to control them will determine our future
Lithium seems like a weird one to add to that list. It definitely hasn’t been important for thousands of years. Potassium or Nitrates are a more likely addition.
Excellent point. I suspect it's more a nod to its recent importance --- bought the book for my ebook reader when it was on sale, but it hasn't gotten to the top of the to be read stack yet --- should probably accelerate that.
"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.
If you found this article interesting, definitely give "Material World: A Substantial Story of Our Past and Future" a read. One of the most eye-opening books I've read in the past few years.
I was in Vietnam on holiday a few years ago and dredging sand out of the Mekong was obviously big business. You could see ships full of it going down the river. Apparently it was supposed to be protected, but that didn't seem to be stopping anyone (there seems to be a lot of corruption in Vietnam). We were told it was causing houses to fall into the river, due to erosion.
Every time I watch a practical engineering video I like Grady more and more. Great presenter, interesting videos, great value for the time spent watching. Gets right to the point in the first sentence, and the rest of the video is still worth watching.
Add me to the long list of people who heard the bit about desert sand not being suitable for concrete and believed it. I'm happy to be corrected.
I almost feel like his videos are anti-clickbait. On my YouTube recommendations page, often his title and cover image are the least eye-grabbing, but the actual video is always satisfying.
That's the sign of a truly great "content creator". I've found myself watching a lot of different YT channels on topics I would NEVER have thought I had any interest in.
He's got a great book as well. I got it because my 4 yo is a Grady fan but I enjoy it and learn a lot as well. "Engineering in Plain Sight: An Illustrated Field Guide to the Constructed Environment"
Manufactured sand has those rough edges, and is often a waste byproduct of rock crushing anyway. But also, in practice, you want more weathered sand for ease of handling, since too-rough sand is less strong given the same level of workability!
I noticed that the two bars were breaking differently under the hydraulic press. One was crumbling and the other (manufactured) was exploding. There was no mention of this effect in the video. It couldn't be the due to force because in the 2nd half the manufactured bar broke at a lower force. Could this factor has consequences on how manufactured sand concrete behaves with natural phenomenon (hurricanes, earthquakes, fires, etc.)
Exploding means it was keeping its integrity for longer (i.e. not compressing), and then releasing it when it couldn't anywhere.
Crumbling means it was falling apart.
A paper book will explode in a press because it does not have any way to compress and release any of the force on it, until it releases all of it in one shot.
Putting stress on the concrete requires force, and causes the concrete to deflect. Force over displacement is work, and energy can't be lost to nothingness by just breaking the concrete. Thus, the concrete releases the stored up energy as kinetic energy of its fragments.
Stronger concrete requires more stress to cause it to fail, and as such it takes more force to break it. There is logically more energy because of the higher force, so more energy gets released.
I didn’t exactly understand the take away from this video. In the first test he does, the river sand concrete is three times stronger than the desert sand concrete, but in the second test, the desert sand concrete is 10% stronger than the river sand concrete. What exactly is going on?
If you normalise for the the same ratio of cement / water / gravel / sand then sharp-sand (crushed rocks) is stronger.
If you normalise for workability (i.e. the concrete flows and can be worked easily) you need to add additional water to sharp-sand, which means that the smooth-sand (e.g. river-rocks) end up stronger.
That’s what I mean, he doesn’t really test for absolute strength. Which one is stronger if the right amount of water for the corresponding concrete is added?
He explained it in the video. The amount of water was adjusted so the viscosity (well, workability) was identical between the samples in the second test. Less water in concrete has a huge positive influence on strength, and rough sand needs more water to be workable. Thus, for comparably workable samples, rounded sand concrete with less water was actually stronger.
Define "right" amount of water. There is no singular correct amount of water in a concrete mix. It is dependent on the properties you want, the materials you have available, how things are going that day, etc.
I'm sure if you have an easy form like a regular cylinder that you just have to fill from the top, then the sharp sand is stronger in an absolute sense.
It's when you have complex forms, logistics considerations on site, curing considerations like heat, using pretensioned steel rods, etc. Then you start to run into these workability tradeoffs and "strongest == best" is no longer true.
Yeah, I subscribe to Nebula -- and he's actually the reason I did. They have a decent size catalog although my interests are narrow enough that I only actually follow a couple of channels there. But that's certainly been worth the price.
So… this is really about costs? If costs increase for more environmentally destructive sand production, then other sand production gets relatively cheaper… and as he says, industry starts to use more appropriate materials that suddenly become relatively comparable in terms of costs to concrete?
I’m not an engineer or an economist, does this sound like a fair summary?
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.
Because the debt is in US dollars, the government will inflate away the debt. So the end game is dollar devaluation, followed by enforced budget discipline because lenders will no longer accept treasury bills.
The transcript is a pleasure to read. A familiar style to hear but not read. I can’t think of reading something written in the style of a YouTuber before but it is a animated read.
Note that "bury the lede" isn't really about "make the reader get to the end to find out the answer" but when a reporter/writer emphasizes the wrong part of a story in the intro then you'd say they buried the lede. Like, if the first graf is all about a politician attending a ribbon-cutting ceremony in Podunk, IL and then in the third graf you have "at the rally, he called for all left-handed people to be put in jail" then you've buried the lede.
If you have in the first graf "so-and-so proposed a radical, and illegal, prosecution of a minority group" it's not burying the lede to make the reader get to the third graf to find out it's against left-handed people. Annoying, perhaps, but not technically burying the lede. :)
>'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. Inverted pyramid.
That's the "inverted pyramid" organization that is (or was) taught in journalism. The way it was explained to me is: imagine the reader stops at the headline. Or after reading the first sentence. Or after the first paragraph, etc. In any case, they should have read the most important facts of the story up that point.
Your comment and my response exist in so many places on the internet, but I wanted to point out that most of the web-based recipes I use have a convenient "jump to recipe" button. I won't attempt to explain what SEO/copyright/whatever reasons there are for the excess prose at the beginning, though.
What bothers me more about these sites is how heavyweight they can feel even with ads stripped. I wonder if they all use a similar, bloated JS widget that my phone cannot run smoothly.
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)
The word "lede" was introduced in the 1970s as an alternative spelling for the word "lead" to resolve ambiguity between the leading paragraph of an article and the metal "lead" which was used in typesetting. It didn't even become popular until the 1980s.
In fact, prior to the 1980s, it was indeed spelled "bury the lead". Here for example is an excerpt from a book about newswriting from the 1970s which uses "lead" as the spelling:
Meanwhile, the group "Led Zeppelin" also avoided the ambiguous spelling to prevent people from pronouncing their name "leed zeppelin". You can't win with lead.
> One account of how the new band's name was chosen held that Moon and Entwistle had suggested that a supergroup with Page and Beck would go down like a "lead balloon", an idiom for being very unsuccessful or unpopular.[21] The group dropped the 'a' in lead at the suggestion of [manager] Peter Grant, so that those unfamiliar with the term would not pronounce it "leed".[22] The word "balloon" was replaced by "zeppelin", a word which, according to music journalist Keith Shadwick, brought "the perfect combination of heavy and light, combustibility and grace" to Page's mind.[21]
It certainly doesn't help that in a rock context, "lead guitar" is very much pronounced with a long e! And one could be forgiven for thinking that a formation of flying things would necessarily have one member in the lead position. I'm glad they had the foresight to keep us from being led astray!
I would argue that there's no reason to continue misspelling "lead" as "lede" outside of a context where you are worried about conflating the "lead" paragraph with the "lead" piece of metal which was used as a spacer between words in a Linotype machine
It's not a misspelling, it's jargon. FWIW I prefer it and I think it's valuable to preserve in part because people who dig into it a bit learn about the history of the term and practice of putting publications (especially newspapers) together.
Right. Saying people outside the industry should feel free to use ‘lead’ instead of ‘lede’ is like saying people outside the tech business should feel free to talk about ‘kilobites’.
Funny thing is that crushing rocks could be solution to CO2. Olivine rock chemically fabsorbs CO2 when dumped in seawater. Crushing the rock increases the surface area.
Mining, crushing, and dumping rock are all something that we can do, and should be doable when electricity is cheap and green. It should be more efficient than pulling CO2 out of the air.
The sand is first screened to separate out larger objects, then washed to eliminate clay/silt/fine particles. Then it goes through a couple more steps to separate out quartz, magnetic minerals, etc before finally batches are tested for silicon dioxide content and impurities using xray fluoroscopy and other spectroscopy methods. The purer a batch is, the higher end the customer.
Most localities can’t produce sand good enough for semiconductors or optics because they contain impurities that are too hard to remove so most of it is used for concrete or glass.
there are lots of types of sand for specific purposes just like say different kinds of wood. unfortunately while we can essentially 'farm' certain kinds of wood that really isn't possible for sand.
The first time I heard about this, I wondered why we didn't just blast desert sand at itself to rough it up to give it better properties. Sure it takes some energy but the sand mafia probably isn't getting cheaper.
It turns we’re all in the pocket of big sand. Which I guess is better than having big sand in our pockets, as that would scratch up our phones. Then, we’d need new phones, or at least new phone screens… either way, big sand wins!
> I wondered why we didn't just blast desert sand at itself to rough it up to give it better properties.
The grain size of desert (or most maritime) sand is already far too small, and if you blast it to pieces it will get even smaller - too small to be used for concrete.
Isaac Asimov was an early writer on this, noting that if the earth's crust was converted into biomass the limiting element was phosphorous --- look at USDA photos of food crops grown w/ and w/o fertilizer including that element for a very sobering view.
Currently, we expend up to 10 calories of petro-chemical energy to get 1 calorie of food energy (depending on food) --- peak oil is still worrisome given how much of the input for fertilizers is from oil.
Sometime in the last century we crossed over from their being more weight in bony fish in the oceans than shipping tonnage to the latter predominating: https://what-if.xkcd.com/33/
My grandfather lived in a time when commercial hunting was outlawed --- I worry my children will live in a time when commercial fishing is no longer feasible.
>I worry my children will live in a time when commercial fishing is no longer feasible.
We are already well into it unfortunately. I've seen enough anecdotal evidence from old fishermen that we have already depleted and disrupted the sea biomass so much that it is already changed forever.
- Old sushi chefs talking about how there are numerous fish they can no longer get at any price that were common when they were young.
- Old fishing photos show smaller and smaller "prize" catches over time.
- Old fisherman talking about how they used to fish by slapping oars at the bay then simply hand/net catching the fish types they wanted near shore.
- Old whalers talking about how they could simply go out and pick what type of large catch they wanted and bring it back. Now they can go days or weeks without a single catch of anything.
There is nothing special about petrochemical energy when it comes to growing food. We could run the agricultural system on other energy sources. In the US, the total fraction of energy used for agriculture is about 1%. We use more energy cooking food than growing it.
Hydrocarbons contain massive quantities of easily liberated energy and large quantities of easily liberated hydrogen.
Which are then easily and economically converted to ammonia to power the largest single form of fertilizer used in the world - nitrogen fertilizer, in the form of ammonium nitrate and equivalents. [https://en.m.wikipedia.org/wiki/Haber_process]
10’s of millions of tons/year are produced right now.
That process alone is responsible for likely at least 50% of the human population increase since it was invented, literally billions of people.
It is much harder to get there with any other form of energy, albeit not impossible.
It's harder, but if one looks at the externalities from fossil fuel consumption, it's actually cheaper to use renewable energy now.
Hydrogen for ammonia production is very cheaply storable (underground, like natural gas is stored) and would provide a large dispatchable demand to ease integration of renewables into the economy, smoothing over long timescale intermittency.
In any case, because the energy used for agriculture is so relatively small, if the economy as a whole can get off fossil fuels, agriculture certainly can as well.
Interesting point about electric being only a small part of overall usage --- I guess direct heating and things such as smelting/refining metals makes up the bulk of energy usage?
Transportation. But be careful to distinguish "work" from "primary energy". The latter is raw energy content of fuels, maybe 80% of which is wasted when powering (say) a car. Moving to BEVs would reduce total energy use because as much as 5 units of primary energy gets replaced by 1 unit of electrical energy.
A similar effect (if not as dramatic) occurs when replacing a fuel-burning furnace with a heat pump. In the US, 2/3rds of industrial heat demand is below 300 C and could be addressed with industrial heat pumps of various kinds (especially if the process has a waste heat stream to recycle by feeding it into the heat pump.)
If we’re being honest, I think we should probably also include raw chemicals that would otherwise be used for things like direct heating. So for example, crude oil used for making asphalt, plastic, etc. or natural gas used for fertilizer.
Since replacing them would consume energy too.
That is a less obvious piece of math, but if we’re talking carbon neutral it would matter doesn’t it?
Another resource is sulfur. This is mostly obtained from desulfurization of fossil fuels, but without fossil fuel consumption that source dries up. Making it directly from sulfates could be done, but that requires more energy.
You're skating perilously close to "if something hasn't happened yet, it can't ever happen". This is not valid reasoning.
If the global economy can't get off fossil fuels, we're incredibly fucked, so I suggest there's nothing to be lost by assuming the problem is solvable.
And you’re skating awfully close to the ‘if something could be theoretically solved, that means it is already solved’. That is also not valid reasoning.
I’m pointing out that the scope and scale of the actual changes that need to happen is so large that it will require a lot of work to solve it, in practice. Without everyone (well, 90% probably) starving to death, anyway.
Should we be starting? Yes. But it will require actual concerted effort and significant tradeoffs. And a lot of time.
We’ve been working very hard to get to this point for a century now.
Now you're confusing "solvable" with "solved". Different concepts!
Of course a lot of work would be needed. The work, however, would be justified and very likely rewarded. There don't appear to be any showstoppers that would prevent it from succeeding.
The ultimate problem is one of collective action, internalizing costs that are now externalized. We've solved problems like this before, globally for example with the ban on CFCs. Here the costs and stakes are even higher.
Fossil fuel use will ultimately drive some countries near the equator to such levels of heating that life will become difficult or impossible. India and Pakistan have nuclear weapons, so they (particularly India, which has hydrogen bombs and a much larger economy) can threaten to kick over the global card table if the problem is not effectively addressed.
The issue is that many players are already defacto bankrupt (from a people starving to death/poverty perspective) even while externalizing the costs of fossil fuels.
Like India, Pakistan, many parts of China, Russia, etc.
So easy to say, hard to do. And it’s hard to say that threatening to nuke everyone is going to apply the right kind of leverage, if say India is already starting to drown. Wouldn’t it be better for everyone else then to take their nukes (or nuke them in advance) and let them drown?
Even if others haven’t gotten that far in their line of thinking, I’m guessing India sure has.
The CFC coalition was nothing compared to what will be required to deal with this situation - and notably, the CFC issue still isn’t really solved. Just mostly under control.
The best solution we have so far is outlawing all fishing in certain areas of the ocean. Picked well, the fish are safe there to breed and recover population numbers, and you only harvest schools that leave the exclusion zone due to crowding.
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.
The whole idea of making your own sand is not sound. It will cost more, perhaps many times more. Seems clear when you think about it: hard to beat the cost of 'natural' sand because you just drive over and load it up. Add any more to that process, it's gonna go up in price. Including crushing rock etc - energy-intensive, then sieving. All add cost over and above, well, just hauling.
And vague comments about 'couldn't find the science behind river sand being less useful' (because it's rounded not jagged). That's no kind of science.
This guy is lauded but I"m not so sure he's someone to listen to. "I hit some rocks in my garage and made my own sand!" isn't any kind of interesting. At what cost? At what scale? It's all about money, baby. Anything that doesn't add up cost is just storytelling.
Did you watch the entire video? I ask because Grady discusses EXACTLY this point.
He explains that the whole 'more expensive' thing is really just noting the actual cost of sand versus ignoring the externalized costs of mining it. When you dig up a river bed there is a cost there that isn't necessarily reflected in the cost of the sand you mined from there, sometimes because that cost is passed on to someone else who has to remediate the site after you mined it (like taxpayers). He empirically points out that different sands need a different water/cement ratio and also points out that the papers on sand use in concrete understand that. The 'bug' seems to be that people just add 'x' water to the mix and if the sand changes they might get different results.
Sand is often a byproduct of other operations. So the cost is complex, to be sure.
I was annoyed that he dropped the idea that smooth sand is not necessarily worse, because he couldn't find the paper on that. Not much of an argument.
Then he proceeded to make sand, and came out with what, 50%? stronger cement. Because, of course, it was new sand.
All sand is made by cracking larger stones. The moment it is made, it is as rough as it will ever be. All subsequent natural processes are smoothing, rounding, knocking the rough off the sand. His garage experiment supported exactly that point: 'old' weather-and-water smoothed sand is an inferior product as far as the resulting cement strength is concerned. When compared to virgin sand.
And yes, cracking your own sand is always going to be more expensive than just driving to where good sand is already lying and loading it up. The mining argument is subject to economies of scale, larger diggers and dredges make the cost of mining per pound negligible.
Where the energy cost of cracking your own totally doesn't scale. Every pound you make requires exactly the same exhorbitant energy cost, no matter a pound or a million pounds.
Definitely the cost structure of sand is changing, in future it will only be more expensive. The days of 'big cement' are changing forever. We may never see these days again.
I heard his comments on smooth sand differently; As I heard it he was saying "People say smooth sand is worse but I can't find any research that would back that up, and even the paper cited in support of that argument doesn't say smooth sand is worse." He then goes on to reason why people might think that (the slump test) but the slump test is really about ratio of water to cement and not the texture of the sand. When he adjusted his water for smooth vs non-smooth sand to achieve equivalent slump tests, he found that the smooth sand concrete was stronger in his experiments.
My summer job as the 'mud man' for the masons building walls in Las Vegas certainly didn't go into this aspect of cement but my brother-in-law who is a civil engineer has a similar reverence / amazement that Grady does for concrete and seemed to agree with Grady's points. He pointed out the 'problem' was getting folks using concrete to change their mix recipes depending on the type of sand, that was, in his opinion, the big stumbling block. He felt any concrete that was mixed with the wrong ratios would under perform and the guys doing the mixing would never admit to screwing it up. They would always blame the ingredients.
Haven't read the article, but I watched the video. He goes on to say that it's not the full story, and he also does some tests where instead of optimizing for a particular water ratio in the mix, he optimizes for a specific texture when mixed, which is termed "workability". If you keep "workability" constant, you can put much less water in the mix, resulting in a stronger concrete when cured.
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.
Just marveling as an old school computer programming geek that I happen to be in a forum that also includes someone in the tugboat business.
We have the programmer to woodworker pipeline, programmer to runner pipeline... is there a programmer to tugboat operator pipeline I'm missing out on?
Programming and in general tech work has been extremely highly compensated compared to most other industries the past few decades.
This means a lot of intelligent (and not so) folks who could do whatever they wanted chose tech to chase the money. Get a little lucky in life and maybe stock options and they get to do what they actually enjoy the latter half of their life.
Most of society can only dream of such capability. The ones who actually have the bravery to pull it off vs. grinding out their final days in a career they are not passionate about are incredibly inspirational to me at least!
From what I remember from this particular code-base, there are also:
- Programmer to farmer
- Programmer to musician
- Programmer to writer
and of course
- Programmer to landlord.
There is also literally anything to programmer. I didn’t use to be a programmer, but now I’m a programmer consultant.
Duck farmer specifically.
Don’t forget programmer to pilot. Every time an aeronautical post appears they come out of the woodwork and chat about equipment.
Can we just agree there's X to Y for every X and Y?
There is, but the size of the "to" and the dissimilarity of Y to X is what makes the pathway interesting.
Tugboat pilot has always been my GOTO answer for "dream job".
I also became an old school computer programming geek (and still am) before ending up managing pirates.
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 best night's sleep I ever had was on the sand of a turn in a dry creek bed, after a very long day's hike. It must have had a big rock underneath that caught the day's warmth and kept me toasty all night. And the sand itself felt like floating on a cloud. It was a magical place. And one of the stupidest I ever slept in due to the risk of flash floods.
One of the best meals I ever ate was a store bought can of chiii cooked over a tiny camp burner after a long hiking through the Grand Canyon. Sometimes it's the simple things during the most exceptional situations that can cement such a strong memory... It did for me anyways.
Yes, but. I had some of the most memorably bad sleeps on the same trip. Like wrapped around a tree trunk on a slope in a blizzard. Not magical one bit.
Magic can also be scary, so... the other kind of magical?
One of the most romantic dalliances I ever did have was on the soft sand on the beaches of Italy, moonlight, red wine, the sand felt like velvet and silk rolled into one. I just think back on it and think to myself "let me brag about how great it was on the internet" 10/10 you missed out.
You should try sleeping on a fresh haystack. Most people will never experience this. But the haystack is made up of cut flowering meadow plants. So it's like sleeping in a bouquet of dried flowers. And the aromatic organic chemicals released all night can have a very calming effect. It's kind of wild to think about, but people used to get it on in haystack barns all the time.
I tried that and it was made of cut grasses. You know how grasses have foxtails that cling to animals to help distribute the seeds over a wider area? I was that animal that night and I didn't like it one bit.
I was reading your first sentence with apprehension as my first thought was flash floods!
Glad you made it out safe, with a story to boot.
The sand people have over 50 different words for sand.
A few examples would be nice!
Coarse, irritating, gets-everywhere…
I don't like sand either.
Trrru'uunqa! (Probably).
They identify as and prefer to be called Tusken Raiders, thank you very much.
> A country can be both an exporter and importer of sand.
That's pretty normal in general. Eg Germany both imports and exports a lot of cars.
My favorite example of this is trucks transporting Finnish bottled water to France and then bringing French bottled water back.
Reminds me of getting can of S.Pellegrino water with something in it. Looked at back of the can and wondered why is this in Japanese... So my guess is that it was first made in Italy, then shipped to Japan and then imported back to Finland...
One starts to question sanity of our consumption habits at times. I am no way environmentalist, but this sort of stuff just seems waste of energy inputs.
As long as you can ship stuff on a boat over the ocean, and don't care too much how long it takes, shipping it even multiple times across the planet is fine. Barely costs anything, both in terms of money and in terms of resources.
The (first and) last miles via truck can cost a lot more, but you can't guess those from whether there's Japanese writing on the label.
It's more that ocean shipping is extremely cheap. Meaning it uses very little labour and resources per mile.
It is not surprising to me that products which have lots of differentiation are both imported and exported. It was surprising to me that something I thought of as a commodity goes in both directions.
Trade is a technology that turns concrete sand into aquarium sand.
While not sand, I remember reading about the state of Colorado importing specialty dirt from around the world while constructing I-70 through the Rockies. Various properties were required that couldn’t be found from local dirt.
Yeah but there is going to be a massive imbalance in the quantity of those two types of sand. I bet the sand required for aquariums is a rounding error on the amount of sand required for concrete.
Well not really Bermuda has population of 60000 only so the sand they import for construction might even be less than the sand US import from Bermuda for its aquariums
Especially as many aquarium owners, these days, use a topsoil-clay mixture instead. Planted tanks take far less maintenance, need less filtering, can fit more (and happier) fish, and the plants grow better in soil.
Yes, though the difference in value is probably not quite as stark as the difference in mass. (Ie aquarium sand is probably more expensive than concrete sand.)
> 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 knowledge even though it's incorrect. There are many well-researched blog articles like this out there, where the author has dug deep, done the hard research, and found mistakes at many levels, but because it's not in what academia or Wikipedia considers a "citable" source, the mistaken assertion continues to be propagated. Until someone manages to present it in an academically acceptable format, if that happens at all.
Solving the "what should be a citable source" problem is complicated, but in the interim, I hope we can at least find a way to transfer these well-researched findings and corrections from non-academic sources to citable forms regularly and easily.
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.
If you're bilingual, it's often useful to read a wikipedia topic in more than one language, as the editorial slant may be different in different languages.
Can at least confirm for German/English.
Could you give some examples?
The BBC Maths and Statistics programme 'More or Less' has coined a term for statistics like this - 'Zombie Statistics'. An initial, often misquoted fact, which is useful as a soundbite and gets repeated over and over and over again, despite multiple debunkings.
Grady is a hero in engineering reporting and documentaries. I've learned so much about how the world works in other engineering disciplines from Practical Engineering, and often in neglected fields that are losing talent faster than it can be replaced.
It gives me hope that teenagers are watching his videos and becoming inspired to go into infrastructure. More than anything, I appreciate his calm and reasoned perspectives that are so lacking in video content in this modern day and age.
100% - he calmly explains various approaches and their tradeoffs.
He’s not exactly a traditional journalist, but this is what I want the future of journalism to be like. People with subject matter expertise explaining their thing simply and clearly.
>It gives me hope that teenagers are watching his videos and becoming inspired to go into infrastructure.
Sadly, that was me ~10 years ago, but the lure of FAANG money was too strong and I went into EE/CS after 1 year as a civil engineering major. I wonder if one day we will really start feeling the affects of this talent reallocation, and civil engineering will become a higher paying profession.
Ironically, we just hit an entirely different "sand catastrophe" - https://mastodon.social/@mimsical/113232531800424706
> the crucibles used to create ingots of silicon which become microchips are made from an ultra-pure quartz sand -- and 70% of the world's supply comes from just one place in North Carolina [Spruce Pine]
Essential node in global semiconductor supply chain hit by Hurricane Helene | 196 points | 50 comments | https://news.ycombinator.com/item?id=41701862
> and 70% of the world's supply comes from just one place in North Carolina
A quick search seems to say there are more places available for getting that than North Carolina.
Is it possible that this specific mine just happens to be the cheapest available right now, but in case they for some reason disappear, there are alternatives everyone would switch to? Or is the situation that if that mine disappears, there is no other alternatives at all?
Could not even be the cheapest, Just the refinement process was developed for this particular sand. A different sand might have different impurities and need different processes to handle.
Almost all our modern tech has extremely long tails measured in decades.
It's basic economics to exploit one source for as long as possible before feasibility changes, but that's a hard argument to make for anyone, even the most experienced personnel because it's all so site specific.
If the particular impurities of this source can be chelated out with safer or cheaper chemicals, maybe in fewer steps, then the cost goes down.
Of course jurisdictions with poor worker conditions can just use the less safe chemicals and externalize the human toll instead of using more complex safety procedures.
Availability, production scale, and knowledge base.
I think things will probably pan out okay, maybe a rough month or two as roads (even if rough cut new logging roads), utilities, and prioritized community services get fixed up. Synthetic option is available, apparently, just a bit costly.
Yeah, this is being overblown. It may very well be that there will be a short term constriction as competitors ramp, but to argue that this is some kind of fundamental bottleneck in semiconductor production is ridiculous.
It's quartz: literally the single most common crystal on the surface of the planet. Now, sure, I'm sure this particular mine had great stuff, but it's not like it's hard to find.
No, surely what we have here is a single source provider precisely because the material is so cheap to mine (and therefore unprofitable to try to compete with from scratch).
You're right, but I wouldn't be surprised if this becomes a bottleneck at least for a few months, generating a lot of headaches for some companies.
>> and 70% of the world's supply comes from just one place in North Carolina
> A quick search seems to say there are more places available for getting that than North Carolina.
I mean, I deduced it straight from “70%”.
I'm pretty sure the implied argument is that, while this source currently supplies 70% of the total, we aren't actually dependent on it - i.e. production could be scaled up elsewhere.
Oh, cool. One of the most common glass batches (raw materials melted to make glass) used by artists is "Spruce Pine Batch".
Wonder if it’s the same stuff or if glass people get a different bin.
The quartz is crushed and sorted for purity so yes it'd be a different bin than the stuff going to make fused quartz for semiconductors.
Spruce Pine doesn't use sand, they mine large quartz crystals out of pegmatites.
I wrote this comment on an article that was on HN about 6 months ago: https://news.ycombinator.com/item?id=39818778
Sadly, given the insane amount of devastation in western NC, I'll get a chance to test my hypothesis. That is, despite Spruce Pine going offline, the overall impact to the global semiconductor industry will be relatively unnoticeable.
Could also go the other way. Some of you may be old enough to remember the 1993 fire in the Sumitomo epoxy resin factory. Following that, DRAM chips became drastically more expensive (prices increased from $30 to $80 per megabyte) for much longer than the supply disruptions lasted, and interestingly also much longer than other ICs which saw only moderate price increases.
I'm not sure that's technically irony but rather an interesting coincidence.
A coincidence is not ironic
The majority of the earth's crust is believed to be made of silicon dioxide. I don't know how much I would believe that we would have a scarcity. It may all come from one source simply because of history.
Really interesting video. This is the first time I have seen the (apparently entirely fabricated) idea that desert sand isn't suitable for construction challenged. I had definitely absorbed that idea into my consciousness without enough due diligence.
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.
One of the proposals for exploiting zero (or negative) electricity prices is storage of the heat at high temperature in refractory solids. This would be used by people who normally burn a fuel for the heat. Instead, they can preheat air and reduce the fuel needed (perhaps reduced to zero).
Firebrick works up to about 1000 C. A spinoff from MIT is using special nickel-doped chromium oxide (chromia) bricks, which can work up to 1800 C, about the temperature of a natural gas-air flame. These bricks are electrically conductive and can act as their own heating elements.
https://www.fastcompany.com/91129126/these-bricks-conduct-el...
https://electrifiedthermal.com/
https://dspace.mit.edu/handle/1721.1/130800
It's quite likely that the cost of idle capital is much higher than the cost of paying others to accept electricity. Depending on the price swings, a battery may be a much better investment.
better make it a sand battery: https://www.euronews.com/green/2024/03/10/sand-batteries-cou...
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
Related: Bitcoin miner RIOT made $32 mln by reducing or being willing to reduce if needed — its energy use consumption.
https://www.texastribune.org/2024/01/03/texas-bitcoin-profit...
A company such as Riot also can profit by buying power at negotiated rates ahead of time — retail power companies allow big companies to lock in prices that way — then selling it back into the state market when energy prices soar during extreme heat or cold. In Riot’s case, when electricity prices soared during the summer heat wave, Riot sold power back to TXU, a Dallas-based electricity provider, which sold it back to the grid.
But if the value of Bitcoin is low and the cost of electricity is high, crypto companies can make more money selling power than mining Bitcoin. In August 2023, Riot reported selling 300 Bitcoins for a net proceeds of $8.6 million. Meanwhile, the company said it earned $24.2 million in credits to its electric bill for selling power back to the grid.
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.
I assume there are taxes and transmission fees on top of the spot electricity price
Yup, in one of eu countries i have it on my bill: it's ~0.10EUR/kWh electricity and additional ~0.15-0.20EUR/kWh for taxes + transmission + maintenance, IIRC
Free power doesn’t mean free production.
There’s also labor, wear on the machines and the lost opportunity of using your money to do something else. Building such crushing machines and only use them x% of the time (for, for now, fairly small values of x) may not be a good investment.
So, energy storage should be lucrative and incentivized for us to solve the Duck Curve, and Alligator Curve, and overcharging the grid forces the price to zero or unlucratively below problems.
For firms with depreciating datacenter assets that are underutilized, a Research Coin like Grid Coin or an @home distributed computation project can offset costs
Datacenters scrap old compute - that there's hardly electronics recycling for - rather than keep it online due to relative cost in FLOPS/kWhr and the cost of conditioned space.
Doesn't electronics recycling recover the silica?
Can we make CPUs out of graphene made out of recycled plastic?
Can we make superconductive carbon computers that waste less electricity as heat?
Hopefully, Proof of Work miners that aren't operating on grants have an incentive to maximize energy efficiency with graphene ASICs and FPGAs and now TPUs
Time to setup some gravitational batteries to exploit that opportunity.
The book mentioned, The World in a Grain: The Story of Sand and How It Transformed Civilization by Vince Beiser:
> The World in a Grain is the compelling true story of the hugely important and diminishing natural resource that grows more essential every day, and of the people who mine it, sell it, build with it--and sometimes, even kill for it. It's also a provocative examination of the serious human and environmental costs incurred by our dependence on sand, which has received little public attention. Not all sand is created equal: Some of the easiest sand to get to is the least useful. Award-winning journalist Vince Beiser delves deep into this world, taking readers on a journey across the globe, from the United States to remote corners of India, China, and Dubai to explain why sand is so crucial to modern life. Along the way, readers encounter world-changing innovators, island-building entrepreneurs, desert fighters, and murderous sand pirates. The result is an entertaining and eye-opening work, one that is both unexpected and involving, rippling with fascinating detail and filled with surprising characters.
* https://www.goodreads.com/book/show/36950075-the-world-in-a-...
Another book on this is:
_Material World: The Six Raw Materials That Shape Modern Civilization_ by Ed Conway
https://www.goodreads.com/book/show/112974899-material-world
>Sand, salt, iron, copper, oil, and lithium. These fundamental materials have created empires, razed civilizations, and fed our ingenuity and greed for thousands of years. Without them, our modern world would not exist, and the battle to control them will determine our future
Lithium seems like a weird one to add to that list. It definitely hasn’t been important for thousands of years. Potassium or Nitrates are a more likely addition.
Excellent point. I suspect it's more a nod to its recent importance --- bought the book for my ebook reader when it was on sale, but it hasn't gotten to the top of the to be read stack yet --- should probably accelerate that.
"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.
What about eg air, wood? Used by mass or volume or?
It seems likely to me that both concrete and plastic are used in greater mass and greater volume than wood.
Yes sorry I didn't cite my source - it is per weight: https://www.sciencedirect.com/science/article/abs/pii/S13506...
Per tonne, twice as much concrete is used per year than all other building materials (including wood, plastic, metal) combined.
And concrete dates back to (at least) Roman times
Roman concrete was a drop in the water compared to the modern era concrete.
If you found this article interesting, definitely give "Material World: A Substantial Story of Our Past and Future" a read. One of the most eye-opening books I've read in the past few years.
Agreed, I read it earlier in the year and found it enlightening.
I was in Vietnam on holiday a few years ago and dredging sand out of the Mekong was obviously big business. You could see ships full of it going down the river. Apparently it was supposed to be protected, but that didn't seem to be stopping anyone (there seems to be a lot of corruption in Vietnam). We were told it was causing houses to fall into the river, due to erosion.
Every time I watch a practical engineering video I like Grady more and more. Great presenter, interesting videos, great value for the time spent watching. Gets right to the point in the first sentence, and the rest of the video is still worth watching.
Add me to the long list of people who heard the bit about desert sand not being suitable for concrete and believed it. I'm happy to be corrected.
I almost feel like his videos are anti-clickbait. On my YouTube recommendations page, often his title and cover image are the least eye-grabbing, but the actual video is always satisfying.
His water infrastructure videos always get me because the thumbnail shows off the very cool model that he built just for it :)
I don't even care about sand but he's so great I couldn't stop watching it
That's the sign of a truly great "content creator". I've found myself watching a lot of different YT channels on topics I would NEVER have thought I had any interest in.
He's got a great book as well. I got it because my 4 yo is a Grady fan but I enjoy it and learn a lot as well. "Engineering in Plain Sight: An Illustrated Field Guide to the Constructed Environment"
> Add me to the long list of people who heard the bit about desert sand not being suitable for concrete and believed it. I'm happy to be corrected.
Cristobol and Hank's whole business strategy down the drain! (From Barry)
I loved how he tackled this from multiple angles.
Manufactured sand has those rough edges, and is often a waste byproduct of rock crushing anyway. But also, in practice, you want more weathered sand for ease of handling, since too-rough sand is less strong given the same level of workability!
I love his book too. I ended up buying a copy for my sister who kept asking me how I knew all their weird details about things like sewer systems :-)
> Gets right to the point in the first sentence,
Huge respect or the "tldr: no" right at the start.
I noticed that the two bars were breaking differently under the hydraulic press. One was crumbling and the other (manufactured) was exploding. There was no mention of this effect in the video. It couldn't be the due to force because in the 2nd half the manufactured bar broke at a lower force. Could this factor has consequences on how manufactured sand concrete behaves with natural phenomenon (hurricanes, earthquakes, fires, etc.)
Exploding means it was keeping its integrity for longer (i.e. not compressing), and then releasing it when it couldn't anywhere.
Crumbling means it was falling apart.
A paper book will explode in a press because it does not have any way to compress and release any of the force on it, until it releases all of it in one shot.
Putting stress on the concrete requires force, and causes the concrete to deflect. Force over displacement is work, and energy can't be lost to nothingness by just breaking the concrete. Thus, the concrete releases the stored up energy as kinetic energy of its fragments.
Stronger concrete requires more stress to cause it to fail, and as such it takes more force to break it. There is logically more energy because of the higher force, so more energy gets released.
This issue has been discussed here in the past.
One example:
https://news.ycombinator.com/item?id=21869624
I didn’t exactly understand the take away from this video. In the first test he does, the river sand concrete is three times stronger than the desert sand concrete, but in the second test, the desert sand concrete is 10% stronger than the river sand concrete. What exactly is going on?
It's normalising for different things.
If you normalise for the the same ratio of cement / water / gravel / sand then sharp-sand (crushed rocks) is stronger.
If you normalise for workability (i.e. the concrete flows and can be worked easily) you need to add additional water to sharp-sand, which means that the smooth-sand (e.g. river-rocks) end up stronger.
That’s what I mean, he doesn’t really test for absolute strength. Which one is stronger if the right amount of water for the corresponding concrete is added?
He explained it in the video. The amount of water was adjusted so the viscosity (well, workability) was identical between the samples in the second test. Less water in concrete has a huge positive influence on strength, and rough sand needs more water to be workable. Thus, for comparably workable samples, rounded sand concrete with less water was actually stronger.
But given the right amount of water, which one has the higher absolute strength?
Define "right" amount of water. There is no singular correct amount of water in a concrete mix. It is dependent on the properties you want, the materials you have available, how things are going that day, etc.
Just enough water for the given concrete to maximize for absolute strength.
I'm sure if you have an easy form like a regular cylinder that you just have to fill from the top, then the sharp sand is stronger in an absolute sense.
It's when you have complex forms, logistics considerations on site, curing considerations like heat, using pretensioned steel rods, etc. Then you start to run into these workability tradeoffs and "strongest == best" is no longer true.
Learned so much about sand in 20 minutes! He mentions nebula.tv at the end. Does anyone have feedback on the content over there?
Nebula is fantastic
Yeah, I subscribe to Nebula -- and he's actually the reason I did. They have a decent size catalog although my interests are narrow enough that I only actually follow a couple of channels there. But that's certainly been worth the price.
Thank you.
Reminds me of the Onion:
https://theonion.com/geologists-we-may-be-slowly-running-out...
So… this is really about costs? If costs increase for more environmentally destructive sand production, then other sand production gets relatively cheaper… and as he says, industry starts to use more appropriate materials that suddenly become relatively comparable in terms of costs to concrete?
I’m not an engineer or an economist, does this sound like a fair summary?
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.
Public debt is more like a brake that gets worse and worse really slowly over time.
And then it suddenly explodes - more and more of the budget goes to interest payments instead of procurement.
At one point the government has to borrow to make payments on the debt, and then you’ve got a very bad spiral.
Because the debt is in US dollars, the government will inflate away the debt. So the end game is dollar devaluation, followed by enforced budget discipline because lenders will no longer accept treasury bills.
The transcript is a pleasure to read. A familiar style to hear but not read. I can’t think of reading something written in the style of a YouTuber before but it is a animated read.
Bonus points for articles that start with a tldr and don't try to bury the lead
Note that "bury the lede" isn't really about "make the reader get to the end to find out the answer" but when a reporter/writer emphasizes the wrong part of a story in the intro then you'd say they buried the lede. Like, if the first graf is all about a politician attending a ribbon-cutting ceremony in Podunk, IL and then in the third graf you have "at the rally, he called for all left-handed people to be put in jail" then you've buried the lede.
If you have in the first graf "so-and-so proposed a radical, and illegal, prosecution of a minority group" it's not burying the lede to make the reader get to the third graf to find out it's against left-handed people. Annoying, perhaps, but not technically burying the lede. :)
Burying the lede is in the same spirit as “the real wtf was…”
is graf short for paragraph? i haven't seen that before
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. Inverted pyramid.
That's the "inverted pyramid" organization that is (or was) taught in journalism. The way it was explained to me is: imagine the reader stops at the headline. Or after reading the first sentence. Or after the first paragraph, etc. In any case, they should have read the most important facts of the story up that point.
Holy cow, don't look for recipes on the web. If you're luck any ingredients and instructions are only 2/3 through. More often 23 pages through.
Your comment and my response exist in so many places on the internet, but I wanted to point out that most of the web-based recipes I use have a convenient "jump to recipe" button. I won't attempt to explain what SEO/copyright/whatever reasons there are for the excess prose at the beginning, though.
What bothers me more about these sites is how heavyweight they can feel even with ads stripped. I wonder if they all use a similar, bloated JS widget that my phone cannot run smoothly.
https://based.cooking/
I’ve been using this app “just the recipe” to avoid this problem. It’s not perfect, but saves me 90% of the time. I think I found it on hn originally.
I have no connection to the app, aside from being a happy user
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)
FYI it's "bury the lede," a lede being the introductory section of a news story.
The word "lede" was introduced in the 1970s as an alternative spelling for the word "lead" to resolve ambiguity between the leading paragraph of an article and the metal "lead" which was used in typesetting. It didn't even become popular until the 1980s.
In fact, prior to the 1980s, it was indeed spelled "bury the lead". Here for example is an excerpt from a book about newswriting from the 1970s which uses "lead" as the spelling:
https://books.google.ca/books?id=3IxbAAAAMAAJ&q=%22bury+the+...
Meanwhile, the group "Led Zeppelin" also avoided the ambiguous spelling to prevent people from pronouncing their name "leed zeppelin". You can't win with lead.
Huh, didn't know that! Via https://en.wikipedia.org/wiki/Led_Zeppelin#Formation:_1966%E... :
> One account of how the new band's name was chosen held that Moon and Entwistle had suggested that a supergroup with Page and Beck would go down like a "lead balloon", an idiom for being very unsuccessful or unpopular.[21] The group dropped the 'a' in lead at the suggestion of [manager] Peter Grant, so that those unfamiliar with the term would not pronounce it "leed".[22] The word "balloon" was replaced by "zeppelin", a word which, according to music journalist Keith Shadwick, brought "the perfect combination of heavy and light, combustibility and grace" to Page's mind.[21]
It certainly doesn't help that in a rock context, "lead guitar" is very much pronounced with a long e! And one could be forgiven for thinking that a formation of flying things would necessarily have one member in the lead position. I'm glad they had the foresight to keep us from being led astray!
> And one could be forgiven for thinking that a formation of flying things would necessarily have one member in the lead position.
Indeed. In which case you would have the lead zeppelin, and the led zeppelins.
Now that's what I call burying the lead!
I would argue that there's no reason to continue misspelling "lead" as "lede" outside of a context where you are worried about conflating the "lead" paragraph with the "lead" piece of metal which was used as a spacer between words in a Linotype machine
It's not a misspelling, it's jargon. FWIW I prefer it and I think it's valuable to preserve in part because people who dig into it a bit learn about the history of the term and practice of putting publications (especially newspapers) together.
You can prefer one spelling over another, absolutely, but it's a bit too strong to say someone using the actual word "lead" is incorrect.
Oh, I wouldn't correct someone for saying "lead" -- or "intro" or any other variant that makes sense. Leed is right out, though.
Right. Saying people outside the industry should feel free to use ‘lead’ instead of ‘lede’ is like saying people outside the tech business should feel free to talk about ‘kilobites’.
If the choice is betwixt overloading a morpheme and having two distinct I shall take the latter.
>I would argue that there's no reason to continue misspelling "lead" as "lede"
Does it still count as misspelling when "lede" is in the dictionary (Merriam Websters & Cambridge & Oxford)?
Pretty sure it's just a word at that point, right?
That's a pretentious, anachronistic affectation - the phrase predates the use of "lede".
I just got back from the beach and my car is full of it if anyone needs some.
FTA
> And we have engineered machines that can transform big rocks into small ones.
OK, so you solve a problem of decreasing resources by using additional energy, so more CO2 emissions...
Funny thing is that crushing rocks could be solution to CO2. Olivine rock chemically fabsorbs CO2 when dumped in seawater. Crushing the rock increases the surface area.
Mining, crushing, and dumping rock are all something that we can do, and should be doable when electricity is cheap and green. It should be more efficient than pulling CO2 out of the air.
So I'm confused. How are we to differentiate sand for semiconductor from sand for fiber optics? Or say sand for windows?
The sand is first screened to separate out larger objects, then washed to eliminate clay/silt/fine particles. Then it goes through a couple more steps to separate out quartz, magnetic minerals, etc before finally batches are tested for silicon dioxide content and impurities using xray fluoroscopy and other spectroscopy methods. The purer a batch is, the higher end the customer.
Most localities can’t produce sand good enough for semiconductors or optics because they contain impurities that are too hard to remove so most of it is used for concrete or glass.
Frackers bought the Kermit Sand Dunes in Texas 7 or 8 years ago cause the sand there was ideal for fracking.
Didn't know artisanal sand is a thing.
great new yorker piece on this
https://www.newyorker.com/magazine/2017/05/29/the-world-is-r...
there are lots of types of sand for specific purposes just like say different kinds of wood. unfortunately while we can essentially 'farm' certain kinds of wood that really isn't possible for sand.
> unfortunately while we can essentially 'farm' certain kinds of wood that really isn't possible for sand.
The linked article demonstrates this to be false.
I recently bought his book. It's as great as you'd expect it to be.
The first time I heard about this, I wondered why we didn't just blast desert sand at itself to rough it up to give it better properties. Sure it takes some energy but the sand mafia probably isn't getting cheaper.
It turns we’re all in the pocket of big sand. Which I guess is better than having big sand in our pockets, as that would scratch up our phones. Then, we’d need new phones, or at least new phone screens… either way, big sand wins!
dale gribble was the forerunner
you're forgetting how much damage it'd do in the charging port!
That would probably cause the sand to become smoother.
> I wondered why we didn't just blast desert sand at itself to rough it up to give it better properties.
The grain size of desert (or most maritime) sand is already far too small, and if you blast it to pieces it will get even smaller - too small to be used for concrete.
tl;dw/dr - no, but not all sand are made equal, nor costs the same to procure.
Don't we have to move to GaN anyway?
If you think sand usage is primarily silicon power electronics you're missing a lot.
Betteridge's law never fails! (At least in this case the author immediately answers the question.)
no
the world is running out of sand if some crooked politician and his cronies can profit off of it. notice the pattern.
We're running out of most everything, in a very The Limits to Growth/World3 kinda of way.
Isaac Asimov was an early writer on this, noting that if the earth's crust was converted into biomass the limiting element was phosphorous --- look at USDA photos of food crops grown w/ and w/o fertilizer including that element for a very sobering view.
Currently, we expend up to 10 calories of petro-chemical energy to get 1 calorie of food energy (depending on food) --- peak oil is still worrisome given how much of the input for fertilizers is from oil.
Sometime in the last century we crossed over from their being more weight in bony fish in the oceans than shipping tonnage to the latter predominating: https://what-if.xkcd.com/33/
My grandfather lived in a time when commercial hunting was outlawed --- I worry my children will live in a time when commercial fishing is no longer feasible.
>I worry my children will live in a time when commercial fishing is no longer feasible.
We are already well into it unfortunately. I've seen enough anecdotal evidence from old fishermen that we have already depleted and disrupted the sea biomass so much that it is already changed forever.
- Old sushi chefs talking about how there are numerous fish they can no longer get at any price that were common when they were young.
- Old fishing photos show smaller and smaller "prize" catches over time.
- Old fisherman talking about how they used to fish by slapping oars at the bay then simply hand/net catching the fish types they wanted near shore.
- Old whalers talking about how they could simply go out and pick what type of large catch they wanted and bring it back. Now they can go days or weeks without a single catch of anything.
> I worry my children will live in a time when commercial fishing is no longer feasible.
I worry that my parents lived in a time when commercial fishing was no longer feasible, but no one noticed and kept siphoning all the seafood anyway.
Indeed.
https://en.wikipedia.org/wiki/Collapse_of_the_Atlantic_north...
There is nothing special about petrochemical energy when it comes to growing food. We could run the agricultural system on other energy sources. In the US, the total fraction of energy used for agriculture is about 1%. We use more energy cooking food than growing it.
Hydrocarbons contain massive quantities of easily liberated energy and large quantities of easily liberated hydrogen.
Which are then easily and economically converted to ammonia to power the largest single form of fertilizer used in the world - nitrogen fertilizer, in the form of ammonium nitrate and equivalents. [https://en.m.wikipedia.org/wiki/Haber_process]
10’s of millions of tons/year are produced right now.
That process alone is responsible for likely at least 50% of the human population increase since it was invented, literally billions of people.
It is much harder to get there with any other form of energy, albeit not impossible.
It's harder, but if one looks at the externalities from fossil fuel consumption, it's actually cheaper to use renewable energy now.
Hydrogen for ammonia production is very cheaply storable (underground, like natural gas is stored) and would provide a large dispatchable demand to ease integration of renewables into the economy, smoothing over long timescale intermittency.
In any case, because the energy used for agriculture is so relatively small, if the economy as a whole can get off fossil fuels, agriculture certainly can as well.
Since neither the general economy nor agriculture has gotten anywhere near getting off fossil fuels yet, that is assuming a lot isn’t it?
Even if electrical grid needs are 100% renewable, that is just a couple percent of most economies energy usage.
For some places that is happening:
https://www.smithsonianmag.com/sponsored/more-than-98-percen...
2020 had the UK reaching 43%:
https://www.nationalgrid.com/stories/energy-explained/how-mu...
Interesting point about electric being only a small part of overall usage --- I guess direct heating and things such as smelting/refining metals makes up the bulk of energy usage?
Transportation. But be careful to distinguish "work" from "primary energy". The latter is raw energy content of fuels, maybe 80% of which is wasted when powering (say) a car. Moving to BEVs would reduce total energy use because as much as 5 units of primary energy gets replaced by 1 unit of electrical energy.
A similar effect (if not as dramatic) occurs when replacing a fuel-burning furnace with a heat pump. In the US, 2/3rds of industrial heat demand is below 300 C and could be addressed with industrial heat pumps of various kinds (especially if the process has a waste heat stream to recycle by feeding it into the heat pump.)
If we’re being honest, I think we should probably also include raw chemicals that would otherwise be used for things like direct heating. So for example, crude oil used for making asphalt, plastic, etc. or natural gas used for fertilizer.
Since replacing them would consume energy too.
That is a less obvious piece of math, but if we’re talking carbon neutral it would matter doesn’t it?
Another resource is sulfur. This is mostly obtained from desulfurization of fossil fuels, but without fossil fuel consumption that source dries up. Making it directly from sulfates could be done, but that requires more energy.
You're skating perilously close to "if something hasn't happened yet, it can't ever happen". This is not valid reasoning.
If the global economy can't get off fossil fuels, we're incredibly fucked, so I suggest there's nothing to be lost by assuming the problem is solvable.
And you’re skating awfully close to the ‘if something could be theoretically solved, that means it is already solved’. That is also not valid reasoning.
I’m pointing out that the scope and scale of the actual changes that need to happen is so large that it will require a lot of work to solve it, in practice. Without everyone (well, 90% probably) starving to death, anyway.
Should we be starting? Yes. But it will require actual concerted effort and significant tradeoffs. And a lot of time.
We’ve been working very hard to get to this point for a century now.
Now you're confusing "solvable" with "solved". Different concepts!
Of course a lot of work would be needed. The work, however, would be justified and very likely rewarded. There don't appear to be any showstoppers that would prevent it from succeeding.
The ultimate problem is one of collective action, internalizing costs that are now externalized. We've solved problems like this before, globally for example with the ban on CFCs. Here the costs and stakes are even higher.
Fossil fuel use will ultimately drive some countries near the equator to such levels of heating that life will become difficult or impossible. India and Pakistan have nuclear weapons, so they (particularly India, which has hydrogen bombs and a much larger economy) can threaten to kick over the global card table if the problem is not effectively addressed.
The issue is that many players are already defacto bankrupt (from a people starving to death/poverty perspective) even while externalizing the costs of fossil fuels.
Like India, Pakistan, many parts of China, Russia, etc.
So easy to say, hard to do. And it’s hard to say that threatening to nuke everyone is going to apply the right kind of leverage, if say India is already starting to drown. Wouldn’t it be better for everyone else then to take their nukes (or nuke them in advance) and let them drown?
Even if others haven’t gotten that far in their line of thinking, I’m guessing India sure has.
The CFC coalition was nothing compared to what will be required to deal with this situation - and notably, the CFC issue still isn’t really solved. Just mostly under control.
We’ll see how this plays out.
The best solution we have so far is outlawing all fishing in certain areas of the ocean. Picked well, the fish are safe there to breed and recover population numbers, and you only harvest schools that leave the exclusion zone due to crowding.
> If we use the US Department of Agriculture’s soil textural triangle, sand is any granular material that is at least 85% sand…
Cool, I just added a single grain of sand to a tonne of snow, now I have a tonne of sand. How convenient.
If you add a single grain of sand to a tonne of snow, it’s not 85% sand.
Seems somebody slept through Intro to Logic.
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.
How does that one grain become 85% of a tonne?
I wonder if the desert kind of sand that isn’t suitable for construction can be used for those thermal mass sand batteries.
Seems like an obvious solution for storage to me but haven’t heard anything on that front
You didn’t watch the video.
The whole idea of making your own sand is not sound. It will cost more, perhaps many times more. Seems clear when you think about it: hard to beat the cost of 'natural' sand because you just drive over and load it up. Add any more to that process, it's gonna go up in price. Including crushing rock etc - energy-intensive, then sieving. All add cost over and above, well, just hauling.
And vague comments about 'couldn't find the science behind river sand being less useful' (because it's rounded not jagged). That's no kind of science.
This guy is lauded but I"m not so sure he's someone to listen to. "I hit some rocks in my garage and made my own sand!" isn't any kind of interesting. At what cost? At what scale? It's all about money, baby. Anything that doesn't add up cost is just storytelling.
Did you watch the entire video? I ask because Grady discusses EXACTLY this point.
He explains that the whole 'more expensive' thing is really just noting the actual cost of sand versus ignoring the externalized costs of mining it. When you dig up a river bed there is a cost there that isn't necessarily reflected in the cost of the sand you mined from there, sometimes because that cost is passed on to someone else who has to remediate the site after you mined it (like taxpayers). He empirically points out that different sands need a different water/cement ratio and also points out that the papers on sand use in concrete understand that. The 'bug' seems to be that people just add 'x' water to the mix and if the sand changes they might get different results.
Sand is often a byproduct of other operations. So the cost is complex, to be sure.
I was annoyed that he dropped the idea that smooth sand is not necessarily worse, because he couldn't find the paper on that. Not much of an argument.
Then he proceeded to make sand, and came out with what, 50%? stronger cement. Because, of course, it was new sand.
All sand is made by cracking larger stones. The moment it is made, it is as rough as it will ever be. All subsequent natural processes are smoothing, rounding, knocking the rough off the sand. His garage experiment supported exactly that point: 'old' weather-and-water smoothed sand is an inferior product as far as the resulting cement strength is concerned. When compared to virgin sand.
And yes, cracking your own sand is always going to be more expensive than just driving to where good sand is already lying and loading it up. The mining argument is subject to economies of scale, larger diggers and dredges make the cost of mining per pound negligible.
Where the energy cost of cracking your own totally doesn't scale. Every pound you make requires exactly the same exhorbitant energy cost, no matter a pound or a million pounds.
Definitely the cost structure of sand is changing, in future it will only be more expensive. The days of 'big cement' are changing forever. We may never see these days again.
I look forward to wind powered stamping mills.
I heard his comments on smooth sand differently; As I heard it he was saying "People say smooth sand is worse but I can't find any research that would back that up, and even the paper cited in support of that argument doesn't say smooth sand is worse." He then goes on to reason why people might think that (the slump test) but the slump test is really about ratio of water to cement and not the texture of the sand. When he adjusted his water for smooth vs non-smooth sand to achieve equivalent slump tests, he found that the smooth sand concrete was stronger in his experiments.
My summer job as the 'mud man' for the masons building walls in Las Vegas certainly didn't go into this aspect of cement but my brother-in-law who is a civil engineer has a similar reverence / amazement that Grady does for concrete and seemed to agree with Grady's points. He pointed out the 'problem' was getting folks using concrete to change their mix recipes depending on the type of sand, that was, in his opinion, the big stumbling block. He felt any concrete that was mixed with the wrong ratios would under perform and the guys doing the mixing would never admit to screwing it up. They would always blame the ingredients.
Haven't read the article, but I watched the video. He goes on to say that it's not the full story, and he also does some tests where instead of optimizing for a particular water ratio in the mix, he optimizes for a specific texture when mixed, which is termed "workability". If you keep "workability" constant, you can put much less water in the mix, resulting in a stronger concrete when cured.