Advanced Life Should Have Already Peaked Billions of Years Ago

July 13, 2023

Did humanity miss the party? Are SETI, the Drake Equation, and the Fermi Paradox all just artifacts of our ignorance about Advanced Life in the Universe? And if…

Source: Advanced Life Should Have Already Peaked Billions of Years Ago

Reinventing cosmology: uOttawa research puts age of universe at 26.7 — not 13.7 — billion years

Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called “impossible early galaxy problem.”

Source: Reinventing cosmology: uOttawa research puts age of universe at 26.7 — not 13.7 — billion years

Here come the Moon landing missions (probably)

July 11, 2023

Good luck to all! Fingers crossed they will all be successful.


India's Chandrayaan-3 lunar spacecraft undergoes accoustic testing.

Enlarge / India’s Chandrayaan-3 lunar spacecraft undergoes accoustic testing.

As anyone who has been paying attention to space exploration knows, the Moon is red-hot. Up to half a dozen missions may launch to the lunar surface in the next six months, heralding a new era of Moon exploration.


Source: Here come the Moon landing missions (probably)

Google unveils its own ChatGPT-like AI chatbot

February 7, 2023

Google unveils its own ChatGPT-like AI chatbot

Google Bard search inquiry

This is not an ad, this is Bard in action. (Image credit: Google)

ChatGPT is the big thing in AI development these days, but it soon won’t be the only game in town. Google announced today that it’s launching an AI chatbot of its own very soon, an "experimental conversational AI service" called Bard.

"Bard seeks to combine the breadth of the world’s knowledge with the power, intelligence and creativity of our large language models," Google CEO Sundar Pichai said in the announcement. "It draws on information from the web to provide fresh, high-quality responses. Bard can be an outlet for creativity, and a launchpad for curiosity, helping you to explain new discoveries from NASA’s James Webb Space Telescope to a 9-year-old, or learn more about the best strikers in football right now, and then get drills to build your skills."

Bard will be powered by a "lightweight" version of Google’s Language Model for Dialogue Applications, also known as LaMDA. That will enable Bard to support more users, and thus generate more feedback, which will help ensure responses generated by Bard "meet a high bar for quality, safety and groundedness in real-world information."

As we’ve seen, that will be a real challenge for Bard developers, and not just because of end-of-the-world scenarios we’ve grown used to seeing in sci-fi flicks—although that’s obviously a concern. A more pressing short-term problem is the tendency for AI software to go off the rails in some pretty awful ways: Last week, for instance, 4chan users used an AI speech synthesis tool called Voice Lab to generate audio clips of celebrities making racist and homophobic statements, and just today a popular AI-powered Seinfeld bot was suspended from Twitch after unexpectedly making homophobic and transphobic jokes.

The underlying problem, generally speaking, is pretty simple: AI is trained by humans, and we’re not always the greatest teachers. But solving the problem is difficult because it’s not just the obvious cases of abuses that need to be addressed, such as when Twitter destroyed Microsoft’s Tay chatbot in less than a day. The same thing happened to Meta’s Blenderbot 3 chatbot just last year. Even advanced technology like ChatGPT is subject to the biases of its trainers, which can have unexpected and unwelcome consequences. 

Google Bard search results screen

(Image credit: Google)

Despite those difficulties, it’s not at all surprising that Google is jumping into the AI development game with both feet. Microsoft announced in January that it is making a "multiyear, multibillion dollar investment" into OpenAI, the company developing ChatGPT and DALL-E, and is also reportedly looking to incorporate ChatGPT tech into its Bing search engine in order to provide more human-like responses to queries. If successful, that could help Bing distinguish itself from Google search, and potentially give it a significant advantage if Google is unable to respond with something similar.

Bard is available to "trusted testers" now, and will be opened up to the public "in the coming weeks."

New battery seems to offer it all: lithium-metal/lithium-air electrodes

New battery seems to offer it all: lithium-metal/lithium-air electrodes

Image of battery charge icons in black and white and color, with various states of discharge.

Current lithium-based batteries are based on intercalation—lithium ions squeeze into spaces within electrode materials such as graphite. As a result, most of the battery’s volume and bulk is dedicated to things that don’t contribute to carrying charges between the electrodes, which sets a limit on the sorts of energy densities that these technologies can reach.

As a result, a lot of research has gone into finding ways of getting rid of one these electrode materials. People have tried pairing lithium-metal electrodes with various materials, while other efforts have tried using electrodes where lithium reacts with air to form lithium-oxygen compounds. While these worked by some measures, they tended to have problems that drastically shortened their useful lifetimes.

But a recent paper describes a battery that uses lithium metal at one electrode and lithium air for the second. By some measures, the battery has decent performance out to over 1,000 charge/discharge cycles.

Lots of problems

The problems with lithium metal are pretty well described: It’s very difficult to get the lithium to deposit evenly across the surface of the electrode. Over repeated charge/discharge cycles, things that start as subtle irregularities grow into spines called dendrites that the lithium doesn’t leave in order to carry charge; eventually, the spines grow until they short the system out. The solution is generally thought to be changes to the electrolytes that the lithium ions travel through when moving between electrodes. At least one company has said it has developed an electrolyte that allows lithium-metal batteries to operate as long as many current technologies.

The problems with lithium-air electrodes are very different and extensive. The support material for the electrode needs to be porous enough to allow air in to meet the lithium and remain that way over many cycles. The reactions it hosts have to avoid reactions with other materials in the atmosphere, like water vapor, which can permanently trap lithium at the electrode. And finally, the electrode has to manage a potentially complicated mix of lithium oxides and peroxides that can form during reactions with oxygen. In many cases, these problems have been so bad that test lithium-air batteries have died after a few dozen cycles.

It’s not clear that there’s a single solution for these problems. And, unlike the lithium-metal counter-electrode, it’s not clear that a different electrolyte would contribute significantly to a solution.

So it’s somewhat surprising that the electrolyte in this new work appeared to help manage the reactions with oxygen. And it also helped with keeping a lithium-metal electrode viable. But it wasn’t the only thing going on with the new battery design.

Conductors and catalysts

There are essentially two stories that are needed to understand why this battery seems to work. We’ll start with the lithium-air electrode, which has two components. The first is a porous matrix made of a water-repelling material. Embedded in that are nanoparticles of a catalyst that the research group has a long history with, tri-molybdenum phosphide (Mo3P). They started looking at this in 2019, thinking it might be a good option for splitting water to produce hydrogen since molybdenum is relatively inexpensive. A year later, they considered using it in lithium-air batteries, which also require rearranging bonds among oxygen atoms.

At that point, Mo3P showed exceptional endurance, remaining viable for over 1,200 charge/discharge cycles. But the energy efficiency wasn’t all that great. For that, apparently, they needed a better electrolyte.

The electrolyte they worked with is a solid at the temperatures that the batteries would be operating in. It may be difficult to imagine a solid material allowing ions to flow through it. But several solids have been developed with internal channels large enough for ions to pass through. The interior of these channels contains sites that ions can interact with, allowing the ions to make short hops from one stable location to another as they transit. Finally, the density of channels can ensure that newly arriving ions are spread relatively evenly across the surface of an electrode, avoiding issues like dendrite formation on lithium metal.

In this case, it has an added advantage: it keeps the lithium-air electrode exposed to the air. When the researchers tried the same electrode materials in a liquid electrolyte, the chemical reactions that occurred at the lithium-air electrode only went partway to completion.

The solid portion of the electrolyte is carbon-based but contains a lot of oxygen and silicon atoms linked to the carbon backbone. These polar atoms help provide the lithium ions a something they’re happy to interact with. The nanoparticles act like a waystation on the trip between the electrodes. They’re composed of Li10GeP2S12, a material with both lithium and atoms that like to interact with lithium. This ensures that the electrolyte is filled with lithium ions even when the battery isn’t in use, so charges can flow the second the battery becomes active.