Archive for the 'Technology' Category

Nov 05 2019

Another Artificial Leaf

Published by under Technology

Scientists report a new process for using sunlight to convert atmospheric carbon dioxide into oxygen and fuel. Anything that does a version of this basic process has been called an “artificial leaf” because that is what photosynsthesis does, convert CO2 and water into oxygen and glucose. The balanced equation is this: 6CO2 + 6H2O ——> C6H12O6 + 6O2, and the process is driven by energy from sunlight.

Plants evolved to do this efficiently. So, if we want an efficient system to remove CO2 from the air and make useful molecules, we can use life that already does this: plants, algae, or photoplankton. This is the basic concept of biofuels. Of course, when you burn biofuels you release the CO2 back into the atmosphere, so this isn’t a way to remove CO2 permanently, but it is a potentially carbon neutral process, with the energy ultimately coming from the sun.

I say potentially carbon neutral, because it depends how you are growing the biomass. If you are using fossil fuel based fertilizer and the farming itself is energy intensive, then you may release more CO2 than you take out. This is a limiting factor for using biofuels as a strategy for decarbonizing the energy infrastructure. Also, farming is very land intensive, and we need that land to grow food. For these reasons I don’t see biofuels as a major solution to the carbon problem. At best it can be used to recycle biomass that would otherwise be wasted to replace fuels for applications (like jet fuel) that are not easily replaced with electric motors.

The “artificial leaf” approach is very similar to the biofuel approach, except we use technology instead of biology. The key is in developing catalysts that will efficiently produce the reactions we need, getting their primary energy from sunlight. The advantage over biofuels is that if we could develop a scalable, efficient, and cost effective process it may not depend at all on farmland or large amounts of water. In the end this is an energy storage solution for solar energy, and in that manner is similar to using photovoltaics and batteries. In the case of the artificial leaf, the leaf is the photovoltaic, and the end product is the “battery” or energy storage medium.

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Nov 01 2019

Musk Wants the Moon by 2022

Published by under Technology

From SpaceX we get the following statement:

“Aspirationally, we want to get Starship to orbit within a year. We definitely want to land it on the Moon before 2022. We want to […] stage cargo there to make sure that there are resources for the folks that ultimately land on the Moon by 2024, if things go well, so that’s the aspirational time frame.”

That is quite aspirational. People have mixed feelings about Elon Musk, who tends to dream big but not always deliver. But sometimes he does, and SpaceX has perhaps been his most successful endeavor. His goal is to make commercial spaceflight practical and reduce the cost of getting into space. His primary mechanism for that is the development of the reusable rocket, which SpaceX has perfected. By now you have probably seen video of SpaceX rockets landing vertically. To me that accomplishment wins Musk an eternal place in the pantheon of awesome people.

A the very least that has earned him the right to be taken seriously when he states his next big goal for space. SpaceX has developed the Falcon 9 followed by the Falcon Heavy, both of which have been flying successfully with many recoveries of the rocket boosters, as they were designed. They have also developed the Dragon capsule, which has successfully autonomously docked with the ISS, and is able to deliver and return cargo. The first crewed mission is scheduled to go up in 2020, and that will hopefully end our dependence on Russia for lifts to the space station.

Meanwhile NASA is developing its Orion spacecraft system, with the first crewed flight of its new capsule slated for 2022. NASA originally planned to return to the Moon by 2028, but the Trump administration arbitrarily asked them to move that up to 2024. NASA is dutifully complying, but many are skeptical they will be able to achieve that accelerated timeline.

On top of all this SpaceX is developing an entirely new spacecraft, called Starship. This is a completely independent system, so it will not use any of the major components from the Falcon, Falcon Heavy, or Dragon capsule. Starship is a two-stage system – there is the Starship spacecraft and the Super heavy rocket, collectively referred to as Starship. The Super heavy rocket will get the spacecraft into Earth orbit and then return and land to be reused. The Starship spacecraft will then be able to travel into higher Earth orbit, return to Earth for fast long-distance travel, or travel to the Moon, Mars, or other deep space destinations.

The top third of Starship is for crew or cargo, with various possible configurations. The lower two-thirds are for fuel. The craft will be able to land intact on the Moon or Mars and then lift off again for return to Earth, and ultimate reuse. The Starship is what SpaceX plans to take to the Moon by 2022.

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Oct 22 2019

Prime Editing the Genome

Move over CRISPR – enter Prime Editing.

Maybe. What we can say is that the pace of technological advancement in genetic editing is advancing so quickly it’s hard to keep up. Now a new study, published in Nature, details a new method for editing called prime editing. The authors write:

Here we describe prime editing, a versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9 fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit.

So actually this is built off of CRISPR technology, using a Cas9 component, and then pairing it with a bit of RNA (pegRNA) that both targets the bit of the genome you want to edit and also has the new code you want to insert. Insertion is accomplished by the enzyme reverse transcriptase. How does this compare to existing methods for gene editing? The authors again:

“Prime editing offers efficiency and product purity advantages over homology-directed repair, complementary strengths and weaknesses compared to base editing, and much lower off-target editing than Cas9 nuclease at known Cas9 off-target sites. Prime editing substantially expands the scope and capabilities of genome editing, and in principle could correct about 89% of known pathogenic human genetic variants.”

It is more precise and has fewer errors, and is able to target 89% of known genetic diseases. It cannot fix errors where a gene is entirely missing, or where there are too many copies of a gene. They tested the method on two human genetic diseases in human cells, Tay Sachs and sickle cell anemia, with success.

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Oct 21 2019

Aluminum Air Batteries

Published by under Technology

An article about a new battery is making the rounds and I am getting a lot of questions about it – Ex-Navy officer turned inventor signs a multi-million deal to produce his electric car battery that will take drivers 1,500 miles without needing to charge. As stated, that sounds like a significant advance, about a 5 fold improvement over the current lithium-ion batteries powering a Tesla, for example.

That would certainly be a huge advantage and give the electric car industry a significant boost. Increased range would alleviate “range anxiety” and also mean the recharging could happen once a week rather than every night. It would also make electric vehicles easier to use on long trips. Further, increased range is the same as smaller batteries. Instead of a range of 1,500 miles, you cold have a battery with a 300 mile range that weighs one-fifth as much. (I am assuming that when they state the range they are comparing batteries of the same size.) That would make the vehicle more efficient and potentially cheaper.

But as always, the devil is in the details. What exactly are they talking about? There are lots of red flags in this article, starting with the fact that it is in the Daily Mail, which doesn’t exactly have a good reputation for high quality journalism. Also it makes it seem like this is the invention of one guy, rather than a lab, company, or even industry. That’s not realistic. There is also this:

Few will have heard of Jackson’s extraordinary invention. The reason, he says, is that since he and his company Metalectrique Ltd came up with a prototype a decade ago, he has faced determined opposition from the automobile industry establishment.

Sorry, but this conspiracy theory does not pass the smell test. New battery tech would not threaten the automotive industry, it would be a new option.

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Oct 14 2019

Recycling Nuclear Fuel

Published by under Technology

Evaluating the risks and benefits of nuclear fission is a bit of a moving target as the technology develops. Even with established nuclear power plant designs and management technology, I think the benefits outweigh the risks when you compare it to the alternatives and factor global warming into the mix. (I discussed this before and won’t go over all the points again here.)

However, we are not stuck with the current nuclear technology. We are on the brink of developing so-called Generation IV reactors that have a number of advantages. They are safer, smaller, more efficient, and generate significantly less waste (used nuclear fuel – UNF). Scientists, however, have now reported an advance that can potentially significantly reduce UNF, with or without Gen IV reactors.

Closing the Nuclear Fuel Cycle with a Simplified Minor Actinide Lanthanide Separation Process (ALSEP) and Additive Manufacturing.

This is a process for separating various components of the UNF, specifically removing the actinide lanthanide elements. The targets are long-lived isotopes of americium (Am) and curium (Cm) and also neptunium (Np). These are called minor actinides (MA) in the paper. Why is it important to separate out these elements from the UNF? There are two potential reasons.

First, these are the highly toxic and very long-lived radioactive elements in UNF. If you separate them out, the rest of the nuclear waste can be stored much easier and the time it would take for the half-life to decrease the radioactivity down to the level of uranium ore would be reduced from hundreds of thousands of years to just hundreds of years. It’s also easier to store because it will not get as hot.

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Oct 11 2019

Preparing For an Inevitable CME

Published by under Technology

Let’s consider the following scenario – the Earth is at risk for a disruptive event. This event has, conservatively, about a 0.2% chance of happening on any given year. But that is the most conservative estimate, at the high end it could be more like 12% over the next decade. Either way the chance of this type of event happening in the 21st century is quite high, and no matter what it is inevitable.

The result will likely be taking out power grids, possibly world wide in a worst-case scenario. Reasonable recovery will take about a year, with full recovery taking about a decade. Just imagine what would happen if we lost our power grid for a year. No digital banking, no internet, no household power. The most conservative estimate of how much such an event would cost is $2 trillion dollars, but experts are increasingly leaning toward $20 trillion as being a closer estimate (and this figure will only go up in the future).

So here’s my question – what do you think we should spend now to avoid a high probability of civilization collapse over the next century costing tens of trillions of dollars and growing? I am not talking about global warming, or environmental degradation, the death of the bees, an asteroid strike, or massive crop failure. I am talking about a coronal mass ejection (CME) – a solar storm.

A CME is actually the greatest threat to civilization that we face, in terms of probability and effect. In fact I think we are underestimating the chaos that a worst-case scenario would cause. Imagine going without power for a year. I know, there are people around the world who live without power, and the residents of Peurto Rico recently experienced something similar. But if this happened on a global scale, there’s no one coming with aid. Global infrastructures on which we all depend would collapse. How many people would starve or freeze? How much wood would be burned to keep warm or cook until the power comes back on? There are so many downstream effects that we cannot anticipate.

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Oct 07 2019

Utilities vs Renewable Energy

Published by under Technology

We are beginning to experience some growing pain with widespread adoption of wind and solar energy. Solar in particular is causing utility companies some heartache because of its distributed design and intermittent energy production. None of the issues raised are fatal problems, but we do need to address them head on.

The basic problem is that we cannot simply look at each piece of energy production in isolation. It’s tempting to think that if you install solar roof panels, that is a pure environmental good because clean energy will be replacing more dirty energy. Initially this may have been largely the case, with very low penetration of distributed solar. However, as the amount of installed solar increases, tensions with utility companies and the complexity of integrating into the power grid are rising.

In 2018 solar was producing 1.6% of total electricity generation in the US (total renewable is 17.1%), but this is projected to rise considerably over the next decade. Solar and wind cause challenges for the grid because they are intermittent sources. For the individual installing solar will likely result in decreased electricity cost. However, if our concern is the overall efficiency and environmental impact, a more complicated evaluation is necessary.

A recent study by Duke Energy highlights this complexity. This is not an objective source – some utility companies are taking a hostile attitude toward distributed energy because of the problems it causes. Here is a quote from Dan Kish, distinguished senior fellow at the Institute for Energy Research, to give you an idea:

“Renewable energy sounds good, but it performs terribly. If you want electricity available when you need it, you don’t want intermittent, unreliable, renewable energy,” Kish said. “It’s like a cancer on an efficient grid, with its ups-and-downs forcing other sources to pick up the slack in the most inefficient ways, which, in some cases, are more polluting.”

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Oct 04 2019

Mission To Find Life On Mars

Published by under Astronomy,Technology

The next NASA rover to Mars, the Mars 2020 Rover (final name to be determined), launches next July. It will arrive at Mars in February 2021. This is the next iteration of rover design and has some interesting new features, include a drone that can fly around to survey more of the Martian surface.

But perhaps the feature that is getting the most attention is the drill. For the first time a Mars rover will have the ability to drill down into the rock and dirt. Why is this so important? If Mars ever contained life, then it is likely the remnants of that life can be found down in the rocks, rather than on the surface. This is the first rover specifically designed to look for signs of life.

There is even the remote possibility of finding signs of recent, or even current life. The mission will be looking for life signatures, such as certain forms of carbon, or signs of sustained water presence in the past. Once the rover lands and is operational, it should only take a few months for answers to start beaming to life. We may know by the middle of 2021 if life ever existed on Mars.

Finding signs of life on Mars will have profound scientific implications. However, CNN, when reporting about this, chose to go with this headline: “When — or if — NASA finds life on Mars, the world may not be ready for the discovery, the agency chief says.” They quotes NASA chief scientist, Jim Green:

“It will be revolutionary,” Green told the Telegraph. “It will start a whole new line of thinking. I don’t think we’re prepared for the results. We’re not.”

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Sep 26 2019

Using AI for Diagnosis

A recent systematic review and meta-analysis of studies comparing humans to artificial intelligence (AI) in diagnosing radiographic images found:

Analysis of data from 14 studies comparing the performance of deep learning with humans in the same sample found that at best, deep learning algorithms can correctly detect disease in 87% of cases, compared to 86% achieved by health-care professionals.

This is the first time we have evidence that the performance of AI has ticked over that of humans. The authors also state, as is often the case, that we need more studies, we need real world validation, and we need more direct comparisons. But at the very least AI is in the ball park of human performance. If our experience with chess and Go are any guide, the AI algorithms will only get better from here. In fact, given the lag in research, publication, and then review time, it probably already is.

I think AI is poised to overtake humans in diagnosis more broadly, because this particular task is right in the sweet spot of deep learning algorithms. Also, it is very challenging for humans, who fall prey to a host of cognitive biases and heuristics that hamper optimal diagnosis. A lot of medical education is focused on correcting these biases, and replacing them with clinical decision-making that works better. But no clinician is perfect or without blind-spots. Even the most experience clinician also has to contend with an overwhelming amount of information.

There are a couple ways to approach diagnosis. The one in which human excel is the gestalt approach, which is essentially based on pattern recognition. With experience clinicians learn to recognize the overall pattern of a disease. This pattern may include signs or symptoms that are particularly predictive. Eventually the pieces just click into place automatically.

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Sep 20 2019

The Next Agricultural Revolution

Published by under Technology

The current world population is 7.7 Billion. World population will approach 10 billion by 2050. The primary limiting factor on human population is the availability of food. We are already currently using essentially all the available practical arable land. Expanding farmland further at this point would involve using less productive land, cutting down forests, or displacing populations. Converting ecosystems into farmland also has a huge impact on the environment and species diversity.

So how are we going to feed 10 billion people in 30 years? So far agricultural development has kept up with demand. It’s tempting to assume that such development will continue to keep up with our needs. This is the endless “peak whatever” debate – if we extrapolate any finite resource into the future, it always seems like it will run out. But historically scientific development and simple ingenuity has generally changed the game, pushing off any resource crash into the future. This has lead to two schools of thought – those who argue that history will continue to repeat itself and we will indefinitely push our resources as needed, and those who argue that no matter how clever we are, finite is finite and will eventually run out.

When we are talking about food, the result of a crash in resources means mass starvation. That is how nature solves the limited food problem; animals starve and reduce the population until a natural equilibrium is reached. And you cannot say that mass starvation has never happened. In the 1960s at least 36 million people in China starved to death due to mismanagement of their agricultural system. We may be setting ourselves up for repeats of this situation. If we push our agricultural system to its limits in order to feed a growing population, does that system become increasingly vulnerable? What if a blight wipes out a staple crop, or bad weather significantly reduces yield? We may have less and less reserve or buffer in the system to handle these kinds of events.

We can talk about population control, and that is a valid approach. I mostly favor population control through lifting people out of poverty and gender equality, which are the most significant causes of overpopulation. Regardless, there is no reasonable expectation that we will stop the human population from reaching 10 billion and it’s not clear where we will level off. We need a plan to feed this population. I reject the radical suggestion that we should keep food production where it is, or even reduce it, and let that be a natural check on population growth. This solution is mostly suggested by those will little chance of starving as a result, a burden that will mostly fall on the poor and oppressed.

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