MIT invents $4 solar desalination device
freethink.com
freethink.com
Let’s maybe run it for a couple more weeks before we talk about it again?
“If it does prove durable, it could be a relatively cheap way to get freshwater to people in need of it.”
The engineers are unsure of how long it will last and if it’s actually cost effective, yet there’s many HN comments here that seem to suggest they know better. Where are you getting your information that the rest of us are not privy to?
I'd also think that the GDP doesn't factor in international aid, so 25$ per year for the poorest could be still better than the current alternative (no idea on what that is, though).
Can't salt accomulation be flushed away?
I think for example reverse osmosis machine also have to constantly flush filtration debris away from the main membrane to maintain efficiency.
In indistrial usage, a lot of the salt is removed before hitting RO filter.
That said, it exists right now and is well tested.
Your point still stands, but the $4 wouldn’t be paid by end users: it would likely be covered by these organisations, which would then be able to provide aid for a much larger population.
I meant, how sustainable is it to keep depending on foreign aid? Obviously dirty surface water that does not suffice for the whole population is not sustainable. But in the long run, creating new dependencies on aid can't be the solution. Any long-term plan that involves foreign aid is a bad plan.
Not having the knowledge or equipment for drilling water wells is a problem. Getting the knowledge and the equipment there is another. The result is not a dependency—rather, the alleviation of a dependency.
Money is ultimately numbers on a piece of paper. It's inherent worth is equal to that of monopoly money. It takes a lot of effort to keep that from happening.
I like how in this worldview giving money to the capital class of society is fine and dandy, but giving money to labour class is disasterous. Seems suspiciously convenient.
Giving money to the working class means that such luxuries as lettuce double in price.
The rich have been dealing with ridiculous cost of living inflation since 2000. No one particularly cares because fuck em. But if you think that the middle class can survive the same inflation you're in for a rude shock.
20% interest rates are the best thing that can happen to the economy now.
Only if the supply of lettuce doesn't keep up with the increase in the supply of money.
https://www.vox.com/future-perfect/2019/4/16/18251646/modern...
But it's heresy to blame the market for being shortsighted, and to suggest any kind of long-term planning is needed.
https://www.businessinsider.com/food-destroyed-farms-amid-co...
This was 2 years and a few months ago, at least the article is.
> wouldn't pay them and store this food
In the article the plant pictured being plowed over is an eggplant, which has a storage life of about a week if stored properly. How exactly can we store this food for a rainy day when it spoils so quickly? Grains can be stored for long durations, but fresh fruit and vegetables cannot be stored to save for much longer than a few weeks.
Then you’re also ignoring the costs. If they won’t be able to sell some crop, why keep dumping time and materials into it? You’re just exacerbating your losses.
Thats exactly the point of my critique that for the individual farmer it doesn't make sence to invest so much effort, but as a society wouldn't it be nice of we didn't waste what we had, we'd have something to fall back on.
Farmers grow food, they don’t process it outside what a combine does. This further increases costs as now you need mass grinders, canners, and pickling machines.
> Thats exactly the point of my critique that for the individual farmer it doesn't make sence to invest so much effort, but as a society wouldn't it be nice of we didn't waste what we had, we'd have something to fall back on.
Yes I get your point, but I’m a realist. Things expire, things can’t store as long. It’s not feasible to have a farmer be the entire, or even a majority of, the food supply chain. You’ve clearly never grown anything at scale.
I hate the constant conflation of rich and wealthy. People who earn a lot of money vs people who own a lot of money. A lot of criticism about inequality, by politicians and economists alike, is about rising wealth inequality, but they only advocate and undertake policies to hurt the higher income class. Why is there no wealth tax, but the govt is funded primarily by income and payroll tax. Why is the federal reserve always worried about falling asset prices. And again here, rising house prices benefited the wealthy, and hurt the high income class, but you didn't differentiate between them either.
Does income tax become negative when I loose money?
Wealth is not income until you realize the gains.
If your car goes up in value you can't sell 1/100th of it to cover the your tax obligations.
Maybe we can tax only productive assets. And you don't need to sell a small proportion, just let the government own that tiny bit
"I didn't think they were gonna tax me" says the guy who <checks HN demographics> is in the top 10% of income by almost any measure and who's FAANG monopoly bucks are exactly why the plumber gets priced out of the Boulder/Austin/Seattle housing market.
I'm perfectly happy for a government food program to give people food. Much less so for giving people money during an incredibly inflationary period. You still end up with people not having food, but also not having gas, rent or health money either.
A- Can I pay my landlord with a box of apples?
B - How does your second point about 'people end up without food if you give them money' work?
Either government or people buy the same food, either there is enough food or isn't.
C - If the government has made it illegal for me to work, why should I eat the loss but banks and landlords shoups never loose money? We are told they are earning their interest and rent because they are taking the risk, but when the time comes, the risk is always passed on to someone else.
That you can't even imagine a government owned integrated vertical food system not run for profit is extremely sad, but completely expected given that you speak English.
However in this case I was making a point about the stuation we were already in when covid hit.
Pretty bold of you to derive his world view from such a short statement of opinion. Just because he didn't like the 'rona stimmy payments doesn't mean he's fine with with pumping asset prices by buying assets.
I and many other people dislike both those things but for me personally they're a drop in the bucket compared to my hatred for the kind of unsound logic that underpins the strawman you built.
They didn't. The inflation we see is from money printed and given mostly to corporations.
Seems like the plan mostly worked to me.
Do you really think giving people more money would make developing countries develop faster? It would just create incentive for companies to keep things as they are, so they can extract that money in exchange for things like bottled water. Those companies would seek to corrupt local governments to do so. That leads to widespread aid redirection and skimming.
However, this does not mean that giving money to people is going to make those people want to develop themselves and their surroundings, unless they are already in the process of doing so.
And what stops the local government from trying to take a big cut?
It's not a perfect solution because it needs a certain level of stability and existing things to boost but it's a fairly robust way of helping people become less reliant on outside aid in the long run.
https://www.theatlantic.com/international/archive/2015/09/we...
Here is a more readable reference "Does it Work?": https://www.givewell.org/charities/give-directly#Does_it_wor...
Poverty is hard.
Boiling water for a few minutes is a common way to get rid of biological contamination.
No, it’s not. I’ve been drinking it exclusively for the last ~20 years and have no health issues.
So you're substituting in the lost minerals from other sources. I don't see how that detracts from my (rather weak) argument
Why do you seem to feel so strongly about distilled water?
If you have to compensate from other sources than I don't understand how something is necessarily harmless, without the qualifier that it should only be used in the context of a proper diet (which many/most don't have, particularly the types that might be susceptible to quack wellness claims)
Besides, one anecdote does not a disproven theory make
But it should be obvious that your mineralisation is not on a knife-edge. The tiny amount of minerals lost by drinking distilled water is massively made up in the other stuff you eat and drink.
No, this is not proven. To prove this, we must demonstrate that a person who only drinks distilled water would get sick sooner than the same person who only drinks tap water - in exactly the same conditions.
Clearly this experiment would be very hard to perform. But if someone did perform it, I'd love to hear about it.
This just seems like such a bizarre and indefensible hill to die on.
http://ecoewp.com/images/nutrientschap12.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4223198/
And FFS people, lighten up. The preferred way to correct someone wrong on the internet is gently.
Many of us have had the “citation needed” demand thrown in our face in very rude ways during the COVID vaccine debacle. It’s gonna take some years for it to settle down and be forgotten again.
It isn't and doesn't. Please stop pushing this annoying myth.
Please provide quality references, or even some argument, to support your statement, beyond 'you said so'. 'You said so' is always a useless information-less way to communicate that I would push back on, but this is a health relevant issue, and you are spreading misinformation that is dangerous. Provide some quality references if you're right, but you're not.
>if you're right, but you're not
where is your evidence?
This is a particularly annoying myth. When the water passes through the gut it picks up plenty of mineralisation, as well as other gunge.
On ships, vacuum vapor distillation is quite common for drinking water production. This is because the equipment is used to generate boiler feed water, which must be high quality distillate. Acquiring additional water-making equipment is redundant.
Nutritional content can be limited and lacking diversity. Many minerals in the body are of very low concentration, they are nevertheless, necessary. Osmosis will delpete the body of these over time. The health effects of this would require a longterm study for chronic symptoms to appear. I have never seen any study of this nature. I have seen mariners after several months at sea with no other water source and, yes anecdotally, they look like hell. I will not drink distilled water for any length of time, but a few weeks would never amount to anything.
So in your day to day life, sure, you have a healthy, diverse, first-world diet and have no ill-effect from drinking distilled water. You can 'live' drinking only Coke. Appalling, certainly, but doable. In terms of cost and energy expense, distilled water is likely higher than Coke to produce, though that is an aside.
You don't want water picking up minerals from your body .. you want it DEPOSITING minerals into your body. That's the way we evolved obtaining minerals from water from streams where the water runs over rocks to mineralise.
Aside from the ones that will boil together with water are those that will boil off before the water (methanol is the other common example that comes in practice). If you have any that boil off before water you have to know at what point it's safe to start condensing the vapour and storing it.
My dude, it's the first words in the article.
However, I do not know any easy way to exclude all translated from english-speaking sites articles and news to read only local ones.
(Not since I know these languages, but since I would like to be able to read some of those news.)
It feels like any topic on here is skewed by a factor of three towards the west, and a factor of ten towards the US. You could get the impression that 80% of the world population are doing nothing of relevance.
And .. yeh .. the Chinese research is essentially our secret sauce.
This is a much more general and tragic insight in fact, the vast majority of human experience is not available to you due to, among many other reasons, language barriers. Consider all the songs, novels, films, music, books and stories that you will never even hear about, because they are written or performed in a language other than the ones you know. If you know a second language, consider all the times you have thought "Oh gee, this is so much easier to express than in my mother tongue" about a neat idiom or grammatical construct, and think of the literal hundreds or thousands of languages that you don't even know the names of, and how full they must be of valuable new concepts and delianations and ways of thought and utterance.
Also I looked at what happens to top programming competitions winners: they are usually from China, go to the top university there, then quite often are happy to immigrate to US for a MSC/PhD.
My post was about top journals like Nature, Science etc...
What this whole process doesn't involve is anyone saying "Hang on, is this actually an important or interesting story". Does this invention move forward the cutting edge of desalination? Probably not. But it does boost MIT's reputation. Which is what this article is for.
MIT isn't more innovative than other institutions necessarily, but they are spending much more effort advertising their innovations.
That said, some of that is too sharp. There is some degree of "is this actually an important or interesting story." That's what the journalists/editors do. That's what the upvote button here is for. It also happens pretty extensively in HN's comments. The article itself expresses skepticism about the invention. I agree that it's not done very thoroughly, but skepticism definitely does exist in the process.
In any case, it's all pretty primitive. If this invention is worth discussing, it should be discussed. This article demonstrates how lame discussing with yourself is.
Where are the researchers, peers, people in the know. The subject matter here is a bad fit for factual reporting. We need subjective opinion. "Is this thing interesting?"
The three involved researchers from MIT are grad student Lenan Zhang, postdoc Xiangyu Li, and professor Evelyn Wang and "four others" which are not mentioned by name in the beginning of the article.
At the bottom of the article, it's mentioned that Zhenyuan Xu from Shanghai Jiao Tong University in China is one of those "four others".
Everyone wants to work with and associate with institutions like MIT, so MIT gets to pick the biggest fools.
(This isn't unique to MIT; that's true of many of the elites)
NSF and other agencies do have a call to this kind of outreach, and the program officer told me they often would pick a grant from a more deserving school over a big-name, even if the big-name received better reviews.
So it's sort of luck-of-the-draw. If you get someone like me, MIT will hurt your chances. If you get the douchebag lady, it will help.
(For the record, I support this, it protects the grad students, who are not showing up at MIT for the PI’s research in most cases and most junior PIs need to be taken down a peg or two)
The rich get richer....
How else would stories like this reach the hoi-polloi, if not for media covering their press releases?
>They also suck the oxygen out of the space for other science coverage
Media is not scarce. I've never even heard of Free Think.
Website space is infinite but space on the front page is not, and space on newsfeeds is not.
The man in this video [0] claims to be able to collect 10 liters of water in a day. His simple facility is less than 2 square meters but easily scalable.
I see you too are a MRE connoisseur
https://www.nature.com/articles/s41467-022-28457-8#Fig1
It does look like an optimal growth chamber for salt-tolerant and heat-tolerant microalgae, (i.e. biofouling is likely) but maybe wrapping the whole thing in aluminum foil will block enough light to keep growth levels relatively low.
All I’m seeing here is a petri dish sized experiment wrapped in a press release.
https://news.ycombinator.com/item?id=30342778 (10 comments)
https://news.ycombinator.com/item?id=30503013 (24 comments)
> it can be made from just $4 worth of materials.
> it would cost just $4 to build
These are not the same thing. Also I lack context of the cost of other desalination techniques and life spans of each.
https://news.mit.edu/2022/solar-desalination-system-inexpens...
— Related research paper:
http://doi.org/10.1038/s41467-022-28457-8
— PDF of research paper:
I would very much appreciate it if Hacker News could conveniently replace these newsbite-extracted-from-university-press-release-about-a-paper links with the paper itself as the main focus and then the university press release as supplementary material.
As it is, this is a game of Chinese whispers, and it’s a subtle infohazard. To begin with the university press release tends to subtly misunderstand the paper and misrepresent it and its context. For instance there is a tendency for the PR team to claim that the results are unprecedented and hitherto unknown, simply because the PR team isn’t a field expert and doesn’t know that they don’t know what is known. (Let alone the impact of PR incentives.) Then the aggregator-newsbite-feed site misunderstands and misrepresents further.
In my opinion, defaulting to only one would be bad idea; better to just review them and if needed on case by case basis email the mods to make a change it needed.
I do think having a fields for “official source” or “notable coverage” might be a good idea, since it’s common to have a better non-official source or review an independent notable coverage — and dumping that into the comments in my opinion takes away from the core value of the comments.
https://www.google.com/search?q=advertising+vs+public+relati...
No, that doesn't follow at all. Both things are advertising != both things are absolutely identical. Do you not speak english natively?
Clearly you’re not interested in reasonable exchanges, since if you were should clearly understand after reviewing sources I provided that advertising is paid placement — and public relations is not; using that logic would lead to belief all news and all propaganda are identical — and they clearly are not.
When the denser, saltier water moves down, why doesn't salt accrue in the intermediate layer?
Also, what happens to the "regular" salt water on the bottom? Does it get evicted? Or does the middle layer gradually float up?
https://news.ycombinator.com/item?id=32329545
The description in the Freethink article is incomplete.
Edit: I don't know if this would be the most useful way to provide water at scale. Dumping small water contraptions on a poor country may not be as sustainable or as efficient as investing in long term water systems.
Let's also not forget about the need to sterilize the water further, thru boiling, or reverse osmosis, or whatever else, in order to eliminate bacteria, viruses, etc.
Funny editorialising you did there.
Today we have energy crisis in Europe and who would expect 5 or 10 years ago that situation will go that bad, that rationing of energy will be considered? There are already some predictions that water scarcity problem will get worse, so it's very good that there are already prototypes that might provide cheap conversion of salt water to clean water. Future seems to be about minimizing costs and decentralization, so we can better sustain all people and save environment.
That's putting it mildly. I recommend the book "When the Rivers Run Dry" if you feel like you don't have enough reasons to despair.
If it had, we'd have used less of them and used more alternatives like insulation. Just like farmers would use less water if they had some incentive to use less than every bit they could get their hands on.
The saltwater piping (and especially pumps if needed) does not build or maintain itself, and this filter is unnecessary for river, well or rain water. It may be useful for salt lakes, but these are likely to go first.
If you really need it for some reason, solar or other distillation is good enough on small scale.
That really depends on where you are, infrastructure, and economies of scale. The statement is ridiculous by itself.
If I pumped a cubic meter of drinking water here and mailed it to you, it would cost much more than $1. If I instead built pump and piping from scratch to provide you with a single cubic meter at your location, it would also cost way more. Especially if I could source neither parts nor know-how locally and instead had to ship them around half the globe.
Appeal to authority is not an argument
Yup. For example in Finland it costs between 1-3€/m3 depending on where you are in the country.
Then again it's "the land of a thousand lakes" and while most of the water isn't drinkable (at least according to "health standards", anymore, due to human activity) you can still drink from the lakes/streams in Lapland. And there are aquifers everywhere.
We've somewhat created this problem ourselves. Back in the day you wouldn't even consider settling anywhere without a reliable water source. Nowadays if the environment can't support you we'll just come up with some high-tech solution and have more babies and in the process we become dependent on state infrastructure. People like Elon Musk want higher tech and more people, and while I'd like to agree with him I don't see that as realistic, given human nature and the current landscape around the world.
Ok, that was a bit of a derail.
I really like innovation like this though. As long as someone can supply the materials for the device, it really improves quality of living in many places.
Even within the US aquifers that millions of Americans rely on for freshwater are being depleted at an accelerating rate.
There comes are point where these are empty and the ground collapses.
Prices of water are very regional and can become very costly.
Your logic is not sound.
A perfect anologue is the resent post regarding famine. Famine is a political failure. Yes, certainly, technology could prevent famine. If everyone on earth had a synthesizer to generate food then it wouldn't be an issue! So it must be a lack of technology keeping people hungry. Or, hear me out, what if the politicians stopped starving people to death through failures in governance ?
Almost exclusively in the modern world, famine is caused by politicians. So the answer lies in removing the cause of the problem. Developing technology to counteract the cause of famine, a cause that should solve the problems of food distribution....? It makes very little sense.
Merely convincing the populous that food could be in short supply has caused people to hoard food, thereby making a short supply. This caused people to starve to death while the hoarders looked on the starvation as evidence of the need to hoard food.
Technology cannot correct stupidity
meanwhile melting permafrost releases methane, destroys buildings, and creates swamps. It does not create viable, drinkable rivers