Archive for April, 2022

Apr 28 2022

Sustainable Jet Fuels

Published by under Technology

As we try to transition as much as possible away from fossil fuels, jet fuel remains a tricky problem to solve. Jets, like rockets, require a fuel with a high energy density (energy per volume) and specific energy (energy per mass). For rockets the specific energy is far more important – mass is everything, due to the rocket equation – and so perhaps the ideal fuel for rockets is hydrogen, because it is so light. For jets, however, energy density is also very important because there is only so much volume in the fuel tanks, and making them bigger can be counterproductive.

Jet fuel has another requirement. O-rings are used to seal metal-on-metal joints in the fuel tank and engine. In order for these O-rings to work optimally they have to swell during engine operation, a property known as seal-swell. Currently aromatics are added to jet fuel because they cause the seals to swell. In fact, this has been a huge hindrance to the use of replacement and more sustainable jet fuels, because they lack adequate seal-swell properties.

A new innovation, however, may have solved this problem. The researchers developed a lignin-based jet fuel additive (LJF) with several desirable properties. Here’s the highlight: “A new LJF is reported primarily composed of C6-C18 mono-, di-, and tri-cycloalkanes.” They tested a 10% blend of their new LJF with conventional jet fuel and it increased the fuels energy density and specific energy, both highly desirable effects. But perhaps more importantly, the LJF additive had great seal-swell properties. It could therefore replace the aromatics in the jet fuel.

This is important for the project of creating sustainable jet fuels because the aromatics have a significant negative impact on the environment. They produce a lot of soot when burned and contribute to contrails.  Contrails contribute to global warming, perhaps even more than the CO2 released by burning jet fuel. Reducing or eliminating soot from aromatics and the resulting contrails could significantly reduce the contribution to AGW from jet travel. As a blend the LJF, which is a biofuel, displaces fossil fuel, and by making the fuel more energy dense reducing overall fuel use.

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Apr 26 2022

A Dueling Narrative on Cultured Meat

Published by under Technology

Are we headed for a world in which most of the meat we consume was grown in a vat rather than in an animal? This is a fairly high-stakes question (pun intended). We have a growing population, we are already using most of the arable land available, and we are pushing the efficiency of agriculture. There is still some technological head room, mostly with GMO technology, to improve yields further. But we are already use more land than is optimal to feed ourselves, as well as a lot of water, and consuming a lot of energy, which has a carbon footprint. Anywhere we can achieve efficiency can have a huge impact, therefore.

The animal product industry is the focus of a lot of attention by environmentalists because of its inherent inefficiency. There are different ways to look at this. Cattle consume about 25 calories for each one they produce, pork is about 15, chicken 6, and fish is close to 1:1. But we can also look at calories produced per acre of land, in which case the comparison is not as clear.

One way to look at the issue is calories produced per acre of land. Here beef has the worst ratio, with 1.1 million calories produced per acre (I assume this is per year, although it is not explicitly stated in the linked reference). Potatoes are very efficient at 17.8 million calories per acre. But soybeans are also pretty inefficient at 2.1, while pork is more efficient than soybeans at 3.5. The ratio of efficiency between potatoes and soybeans is about the same as the ratio between wheat (6.4) and beef.

Some types of meat are more land-efficient than some plants, but yes, overall, plants are more efficient. The picture is also complicated because animals can produce high-quality nutrition and can use land not suitable for growing plant-based food. Simplistic comparison therefore breakdown when you look at a more complete picture. But I think it is scientifically non-controversial to say that the typical Western diet includes too much meat, and if we cut down it would improve the overall efficiency of our food production in terms of land, water, and carbon. This is a low-tech solution that is likely optimal for health and the environment.

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Apr 25 2022

Scalar Energy Scam

Published by under Pseudoscience

Because I host a popular podcast, I often get solicitations to offer people to be interviewed on the show. They are mostly scientists and science-communicators with a new book to promote. This is actually a helpful resource, although I end up booking very few. One of the reasons for the low hit rate is that the promoters are surprisingly undiscriminating, sometimes laughably so. Recently I received an e-mail regarding “scientist” Tom Paladino:

He’d appreciate the opportunity to come on your show, The Skeptics Guide to the Universe, to explain what Scalar Light is and how it can be used to help heal the human body naturally.”

After taking a look at his website I questioned whether Paladino knows what scalar light is, although it may be different than Scalar Light. Apparently scalar light was something researched by Nikola Tesla – in my opinion invoking his name is an extremely reliable marker for pseudoscience and chicanery, up there with Galileo.

Let’s start with the actual science – what is “scalar light” or more generally, a scalar energy field? In physics the word “scalar” just means a physical property that has a specific magnitude value at each point in space, and that value is independent of perspective or frame of reference.  Temperature is scalar because you can give a magnitude value at every point, but direction is irrelevant.  Scalar properties are distinguished from vector properties, which have both magnitude and direction. Earth’s gravitational field is a vector energy field, because each point in space has a specific magnitude and direction.

Is light a scalar or vector phenomenon? Well, the speed of light (c) is always the same regardless of the observer, so it is a scalar phenomenon (the speed of light only refers to its magnitude). The velocity of light refers to its magnitude and direction, so it is a vector quality. From the perspective of physics, then, “scalar light” refers to the speed of light. Or it’s redundant – it’s just light, which has a scalar property (speed).

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Apr 24 2022


Published by under General

Since many of my regular commenters are intent on talking about their Wordle scores in the comments, you can now use this thread rather than my Topic Suggestions. Please put the following phrase at the top of every comment to avoid spoilers (fresh comments appear on the homepage, so people can see them even if they are not reading this post).

“To all WORDLE fans
We are discussing today’s WORDLE puzzle.
If you do not want to see the answer,
then please avert your eyes.

For those who may not know, Wordle is a popular word puzzle created by Welsh software engineer Josh Wardle in 2013. After it became popular it was purchased by the New York Times, who now hosts the game. The game has become popular partly because people like publishing their solutions on social media. The game has also provoked a lot of questions. There is no evidence to suggest that playing Wordle makes you smarter, and we now have a lot of research that shows that puzzle games like this make you better at the specific game, but does not boost general intelligence. However, the game may make people feel smart. That’s because it is easy to underestimate how quickly word options can be eliminated, and therefore how quickly we can whittle down the options to the correct answer, so we feel really smart when we get it.

Math nerds have also used the game as an opportunity to teach about entropy and information theory. How much information do you get out of each guess? What is the optimal starter word? If you played a statistically perfect game, what would your score distribution be?

Which country has the best Wordle players? Well, if Twitter is a fair indication then it’s Sweden. What’s the best state? North Dakota.


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Apr 21 2022

The Skeptics’ Guide to the Future

Published by under Skepticism,Technology

I am happy to announce that pre-orders are open for my upcoming book, The Skeptics’ Guide to the Future, which will be released by Grand Central Publishing on September, 27th. You can preorder your book here.

This was a particularly fun book to write, with my two brothers, Bob and Jay (who also co-host the SGU podcast with me). This is our second book, with Evan and Cara also contributing to the first one (The Skeptics’ Guide to the Universe). In this new book we explore futurism itself – what have we learned from past attempts at predicting the future and how can we use those lessons to perhaps do a little better? We explore, for example, what I call “futurism fallacies”, common errors in trying to extrapolate our world into a vision of the future. One common fallacy is to extrapolate current trends indefinitely into the future, even though this is generally not the path that history has taken. Disruptive technologies, changing priorities, the interaction among various types of technology, and evolving culture all introduce zigs and zags into the course of history, and therefore the future.

Is futurism, therefore, doomed to failure? This is actually a matter of scholarly debate, with critics and advocates. Overall I think predicting the future is similar to predicting the weather – while it is impossible to predict the details beyond a very short window, we can make broad predictions about the climate. Similarly we can say that technology will not only continue to advance but the pace of that advance is accelerating. We explore those individual technologies that are just emerging and most likely to have a profound impact on our future, such as genetic engineering, additive manufacturing, artificial intelligence, and metamaterials. There are also some established technologies that will continue to advance, expanding into new niches, such as robotics.

We also discuss technologies that are just in the conceptual stage, and give our opinion as to whether or not they are likely to ever come to fruition. We will likely have fusion power someday, but I doubt we will ever have a space elevator (at least not on Earth).

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Apr 19 2022

Using Sound To Kill Cancer

Sound can be a powerful form of energy, and is often underappreciated. Remember the weirding modules in Dune, that focused and amplified sound as a weapon? That is not an unrealistic technology. If you are near a powerful explosion, even without being exposed to heat or shrapnel, you can be killed by the pressure wave alone, which can cause significant internal damage.

Sound has also been used for years as a medical tool. You are probably most familiar with ultrasound technology, a non-invasive and safe way to image living tissue in real time. Many parents are familiar with this technology, as it is safe enough to image a growing fetus. But sound can also be used medically to destroy, and this application has many potential advantages.

One such technique is called High-Intensity Focused Ultrasound, or histotripsy. This is the latest approach to using sound to destroy unwanted tissue inside the body. There are older techniques that would use sound wave to heat up tissue and cause thermal damage. Histrotripsy uses a different method, and early research suggests this is a potentially significant step forward. The basics of the technology is the use of two highly focused beams of very short (<50 microseconds) bursts of high intensity sound. Where the beams cross, I am assuming through constructive interference, the intensity is great enough to cause cavitation within the tissue.

Cavitation is negative pressure that will cause a bubble of gases to expand inside the cells. These bubbles then collapse, resulting in significant mechanical stress on the cells that destroy them. Repeated applications of the histotripsy over the same area causes these areas of cavitation to coalesce into one large area filled with “liquified homogenate” – i.e. goo. This process can be targeted by simultaneous ultrasound imaging (the cavities appear bright on ultrasound), which makes the entire setup fairly portable and convenient.

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Apr 18 2022

Implantable RFID and NFC Chips

Published by under Technology

Would you get a readable chip implanted in your hand? In a 2021 European survey 51% of people said that they would. What are the risks and potential benefits of the technology as it currently stands?

There are currently two main technologies for implantable chips that can be read at close range through the skin. The more familiar technology is RFID – radio frequency identification. There is also Near Field Communication (NFC) which is a type of device that uses short range connections, less than 4cm. Both NFC and RFID use radio frequency wireless communication. They are activated by coupling with an external antenna that allows one-way or two-way data communication. The devices are therefore passive, they do not require their own power, which is a huge advantage for something implantable.

This is the same technology used in wireless card readers or similar non-implantable technology. The real difference is that these chips are designed to be implanted, so that are small (slightly larger than a grain of rice) and are encased in a bioplastic that is tissue compatible. The first such chip was implanted in a person in 1998. They have been used routinely for implantation in pets. They are FDA approved for implantation in humans, and the data shows that they are medically safe. They are also MRI safe, meaning that (despite rumors) they won’t explode, overheat, or move if a person with a chip implant goes through an MRI scan. However, some brands may not be MRI compatible, meaning that the data on them may be wiped or destroyed by the MRI scan. This is likely a solvable problem, however. Chip designs could be made MRI resistant. It’s also theoretically possible to put on a glove that would shield the chip to reduce or avoid damage.

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Apr 11 2022

The Day the Dinosaurs Died

Published by under General Science

This is one of the coolest science news stories of the last decade, and I’m a bit surprised it’s not getting more play. Paleontologists have discovered and been examining a fossil deposit from the exact day that the asteroid hit 66 million years ago, at the K-Pg boundary. The site is in Tanis (isn’t that where the Ark of the Covenant was found?) North Dakota (Oh, so no).  Actually it’s the Tanis site within the Hell’s Creek formation, which is a productive fossil bed. How can scientists be sure what they are looking at comes from the time of impact? That’s one of the interesting parts of the story.

What appears to have happened is that a large asteroid, about 12 km wide, struck the Yucatan peninsula in the Gulf of Mexico. The crater (Chicxulub crater) from the impact can still be seen. The impact threw a lot of material up into the atmosphere. It also caused a massive tidal wave that spread out, sending material along the Gulf shore, across Mexico, and up along the coasts. But part of this wave also snaked north along a riverbed that led inland to where modern day Tanis is, 3,000 km away. There the water came to rest in a large basin. The wave had swept up sea and land creatures, depositing them in a jumble in the basin. That is one of the lines of evidence that this fossil deposit is a direct result of the impact, the mix of land and sea creatures so far inland, and the fact that the deposit appears to be the result of a sudden chaotic event. It would take something massive to do that, like a meteor impact in the gulf.

An interesting technical detail is that the wave was likely only partly a tidal wave phenomenon from the “splash” of impact. Published evidence indicates that the deposit also likely coincided with a seismic wave – a harmonic wave in the body of water resulting from the impact. So it was more like a megatsunami.

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Apr 08 2022

Axiom 1 To Launch Today

Published by under Astronomy

That’s the plan anyway, weather permitting. While the launch itself is nothing new, the mission is a milestone for the space industry. The launch involves a SpaceX Falcon 9 rocket with the Dragon Crew Endeavor spacecraft – this will be the third launch for this spacecraft, highlighting the reusability of these capsules. Right now the launch is planned for 11:17 AM EDT, and you can watch coverage live at the Axiom website.

Notice that you can watch on Axiom, a private space company. While NASA will also be broadcasting the launch, they will not be providing their own clean feed. That’s because this is not primarily a NASA mission. In fact, for the first time, NASA will not be providing mission control, which instead will be run out of Axiom’s Houston command center. Further (and this is a first) the crew will be comprised of four private citizens.

“The astronauts onboard are all private citizens, with the mission commander, Michael López-Alegría, a previous NASA astronaut. The other three members, Larry Connor, Eytan Stibbe, and Mark Pathy are described by the company as “entrepreneurs” and “investors.””

These are not billionaires just going on a joyride, although they are all wealthy private citizens, each of whom paid $55 million dollars toward the mission. As stated, one is a prior NASA astronaut, also one a commercial pilot, and one a former military pilot. Any of them could quality as NASA astronauts. The AX-1 mission, as they are calling it, is a 10-day mission, with 8 days spent onboard the ISS conducting scientific experiments. NASA is providing some funding and logistical support, but this is primarily a commercial mission.

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Apr 07 2022

Cheap Water Purification

Published by under Technology

Have you ever done the thought experiment where you imagine yourself back in time, in a technologically primitive society? What would life really be like, and what could you do to improve it? We are fairly dependent on our modern technology, and that does not give us the knowledge or skill to understand pre-industrial technology. Would you know how to design and build a flush toilet, for example?

But I have also come to realize that this thought experiment reflects my bias coming from an industrialized nation. You don’t have to go back in time to confront the challenges of lacking electricity, basic sanitation, or clean water. You just have to visit poor and developing parts of the world today. It’s not exactly the same situation, because the technology exists somewhere in the world, but that is not much help to the 1,800 children who die every day from diarrhea from contaminated water. This is another way that our developed-nation bias might manifest – I tend to get interested and excited about advances in technology at the cutting edge, squeezing another 10% out of the energy density of Li-ion batteries, for example. But the technologies that might help the most people are those that can bring basic affordable services to poor countries.

More attention is being paid to this problem. Low-income countries (LICs) lack the resources and institutional infrastructure to invest in the kinds of research most likely to benefit them, while high-income countries (HICs) are much better at leveraging research to improve their economies and standard of living. We tend to think of the X-Prize as progressing the most advanced technology, but even they are turning their attention to basic problems, such as literacy.

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