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Hey Bill Nye! Can We Desalinate Water for Human Consumption on a Massive Scale?

The ability to desalinate water on an industrial scale would change the world, says Bill Nye the Science Guy, bringing fresh water to populations all over the globe that currently going without.

Amy: Hey Bill. This is Amy from Minnesota. I was wondering if — when I was five years old I did this science experiment where we stuck a stick in salt water and it made a crystal. I was wondering if there was, in terms of desalinating water for human consumption, if there is a chemical compound that could work as a catalyst for some sort of reaction and if we could do this on a massive scale?

Bill Nye: Amy, that is a fabulous question. Desalinization of water could be the key to the future for so many of us humans. I'm fascinated with this question. So you use the word catalyst, this would be a chemical that would enable another chemical reaction, in general doesn't affect the catalyst so you could reuse the catalyst. Right now, as far as I know, there is no such thing. But two aspects of this that are really important right now. The first one is not real and I cannot help but hearken to a book by Kurt Vonnegut in which the characters creates something called Ice-nine where you get water molecules to rearrange themselves. And the chemist who does this is fascinated with the way cannonballs are stacked in statues or in memorials to people who fought wars with cannons.

That's fictional but it is kind of a cool idea. I won't tell you what happens at the end of the book; it's big fun. The real thing that's going on right now is people are able to take the salt out of salt water by forcing the water backwards through a very fine filter, which generally is called a membrane, and right now we call it osmosis. And osmosis is an old Greek word that means kind of happens on its own. And so the classic example is to take an egg, take the shell off with vinegar and then put the membrane contained egg in salt water and the water will go into the egg and the egg will swell if it's in salt water. If you put that same type of egg, naked egg, in distilled water the egg embryo is slightly salty so the water will work it's way out and that egg will shrink. Anyway, people have found ways to make synthetic membranes with things like Teflon and polyester and so on and you can pump, force the salt water backwards through the membrane and leave the salt behind. And this is done all the time. It's done in Australia at several industrial scale citywide installations, San Diego, Carlsbad California has one. And cruise chips and I guess the U.S. Navy exploit this technology all the time, but Amy, people are trying this new material, which has come to become graphene. And it's just like graphite, it's just like the thing that makes coal black or pencil lead gray except this material now is one molecular layer thick and it has these amazing properties. It's fantastically strong when stretched longitudinally or in the same direction, in the plane of the graphene. It's crazy strong. And so people believe that the slip length, as it's called, of the salt water is longer than the thickness of this one molecule or one atom thick graphene. So there's hardly any pressure needed to get the water to flow through the graphene leaving the salt behind and having fresh water come out on the other side. Now the key to any of these processes is you have to filter the water first to take out regular old particulates, regular old dust and sand, I exaggerate trash, you've got to take that out before you run it through your reverse osmosis membrane or this new being experimented with grapheme.

But you are living at a time where this breakthrough may be made on an industrial scale. And if we can do that Amy, it would change the world. We could have all the clean water we wanted for everybody all over the world and we would power the pumps with solar power, regular old photovoltaic solar cells, and when the sun is not shining you don't pump the water. So you pump the water when the sun is shining and and you fill up reservoirs all over the world. And so humankind could, if this stuff works out it could have access to clean water for the billions of us that need it. It's an exciting time Amy. Go get them. Become a chemical engineer or material scientist and solve this problem.

The ability to desalinate water on an industrial scale would change the world, says Bill Nye the Science Guy, bringing fresh water to populations all over the globe that currently going without. While nature creates membranes that desalinate water, creating the right balance of salt to fresh water, humans must rely on synthetic membranes. While our current prototypes work, they are energy inefficient. The particle graphene, however, might provide a streamlined way of brining fresh water to the world.

Does conscious AI deserve rights?

If machines develop consciousness, or if we manage to give it to them, the human-robot dynamic will forever be different.

Videos
  • Does AI—and, more specifically, conscious AI—deserve moral rights? In this thought exploration, evolutionary biologist Richard Dawkins, ethics and tech professor Joanna Bryson, philosopher and cognitive scientist Susan Schneider, physicist Max Tegmark, philosopher Peter Singer, and bioethicist Glenn Cohen all weigh in on the question of AI rights.
  • Given the grave tragedy of slavery throughout human history, philosophers and technologists must answer this question ahead of technological development to avoid humanity creating a slave class of conscious beings.
  • One potential safeguard against that? Regulation. Once we define the context in which AI requires rights, the simplest solution may be to not build that thing.

A new hydrogel might be strong enough for knee replacements

Duke University researchers might have solved a half-century old problem.

Photo by Alexander Hassenstein/Getty Images
Technology & Innovation
  • Duke University researchers created a hydrogel that appears to be as strong and flexible as human cartilage.
  • The blend of three polymers provides enough flexibility and durability to mimic the knee.
  • The next step is to test this hydrogel in sheep; human use can take at least three years.
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Hints of the 4th dimension have been detected by physicists

What would it be like to experience the 4th dimension?

Two different experiments show hints of a 4th spatial dimension. Credit: Zilberberg Group / ETH Zürich
Technology & Innovation

Physicists have understood at least theoretically, that there may be higher dimensions, besides our normal three. The first clue came in 1905 when Einstein developed his theory of special relativity. Of course, by dimensions we’re talking about length, width, and height. Generally speaking, when we talk about a fourth dimension, it’s considered space-time. But here, physicists mean a spatial dimension beyond the normal three, not a parallel universe, as such dimensions are mistaken for in popular sci-fi shows.

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Predicting PTSD symptoms becomes possible with a new test

An algorithm may allow doctors to assess PTSD candidates for early intervention after traumatic ER visits.

Image source: camillo jimenez/Unsplash
Technology & Innovation
  • 10-15% of people visiting emergency rooms eventually develop symptoms of long-lasting PTSD.
  • Early treatment is available but there's been no way to tell who needs it.
  • Using clinical data already being collected, machine learning can identify who's at risk.

The psychological scars a traumatic experience can leave behind may have a more profound effect on a person than the original traumatic experience. Long after an acute emergency is resolved, victims of post-traumatic stress disorder (PTSD) continue to suffer its consequences.

In the U.S. some 30 million patients are annually treated in emergency departments (EDs) for a range of traumatic injuries. Add to that urgent admissions to the ED with the onset of COVID-19 symptoms. Health experts predict that some 10 percent to 15 percent of these people will develop long-lasting PTSD within a year of the initial incident. While there are interventions that can help individuals avoid PTSD, there's been no reliable way to identify those most likely to need it.

That may now have changed. A multi-disciplinary team of researchers has developed a method for predicting who is most likely to develop PTSD after a traumatic emergency-room experience. Their study is published in the journal Nature Medicine.

70 data points and machine learning

nurse wrapping patient's arm

Image source: Creators Collective/Unsplash

Study lead author Katharina Schultebraucks of Columbia University's Department Vagelos College of Physicians and Surgeons says:

"For many trauma patients, the ED visit is often their sole contact with the health care system. The time immediately after a traumatic injury is a critical window for identifying people at risk for PTSD and arranging appropriate follow-up treatment. The earlier we can treat those at risk, the better the likely outcomes."

The new PTSD test uses machine learning and 70 clinical data points plus a clinical stress-level assessment to develop a PTSD score for an individual that identifies their risk of acquiring the condition.

Among the 70 data points are stress hormone levels, inflammatory signals, high blood pressure, and an anxiety-level assessment. Says Schultebraucks, "We selected measures that are routinely collected in the ED and logged in the electronic medical record, plus answers to a few short questions about the psychological stress response. The idea was to create a tool that would be universally available and would add little burden to ED personnel."

Researchers used data from adult trauma survivors in Atlanta, Georgia (377 individuals) and New York City (221 individuals) to test their system.

Of this cohort, 90 percent of those predicted to be at high risk developed long-lasting PTSD symptoms within a year of the initial traumatic event — just 5 percent of people who never developed PTSD symptoms had been erroneously identified as being at risk.

On the other side of the coin, 29 percent of individuals were 'false negatives," tagged by the algorithm as not being at risk of PTSD, but then developing symptoms.

Going forward

person leaning their head on another's shoulder

Image source: Külli Kittus/Unsplash

Schultebraucks looks forward to more testing as the researchers continue to refine their algorithm and to instill confidence in the approach among ED clinicians: "Because previous models for predicting PTSD risk have not been validated in independent samples like our model, they haven't been adopted in clinical practice." She expects that, "Testing and validation of our model in larger samples will be necessary for the algorithm to be ready-to-use in the general population."

"Currently only 7% of level-1 trauma centers routinely screen for PTSD," notes Schultebraucks. "We hope that the algorithm will provide ED clinicians with a rapid, automatic readout that they could use for discharge planning and the prevention of PTSD." She envisions the algorithm being implemented in the future as a feature of electronic medical records.

The researchers also plan to test their algorithm at predicting PTSD in people whose traumatic experiences come in the form of health events such as heart attacks and strokes, as opposed to visits to the emergency department.

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