End Of An Era: Popular Science Shutters Magazine

November 30, 2023 by Tom Nardi 69 Comments

Just three years after the iconic magazine abandoned its print version and went all-digital, Popular Science is now halting its subscription service entirely. The brand itself will live on — their site will still run tech stories and news articles, and they have two podcasts that will keep getting new episodes — but no more quarterly releases. While you can’t complain too much about a 151 year run, it’s still sad to see what was once such an influential publication slowly become just another cog in the content mill.

Started as a monthly magazine all the way back in 1872, Popular Science offered a hopeful vision of what was over the horizon. It didn’t present a fanciful version of what the next 100 years would look like, but rather, tried to read the tea leaves of cutting edge technology to offer a glimpse of what the next decade or so might hold. Flip through a few issues from the 1950s and 60s, and you won’t see pulpy stories about humanity conquering the stars or building a time machine. Instead the editors got readers ready for a day when they’d drive cars with warbird-derived turbochargers, and enjoy more powerful tools once transistor technology allowed for widespread use of small brushless motors. It wasn’t just armchair engineering either, issues would often include articles written by the engineers and researchers that were on the front lines. Continue reading “End Of An Era: Popular Science Shutters Magazine” →

Iowa Demolishes Its First 3D Printed House

November 29, 2023 by Kristina Panos 130 Comments

It sounds like a headline from the future: the weekend before Thanksgiving, a bulldozer came for the first example of a printed home that was supposed to help the housing crisis in the city of Muscatine. Fortunately, it hadn’t been completed and sold yet.

Printing of this first house began in May 2023, and nine more were to be completed by the end of the year. Unfortunately, when tested for compressive strength, the cement mixture this first home was printed out of failed to meet the 5,000 PSI minimum required for the project. Rather than compromise on safety, the parties involved decided to knock it down and start over.

The goal now is to find out why the mixture, which met the strength requirements in laboratory testing, didn’t behave the same on-site. Currently, the plan is to start building the originally-planned second house in the spring, and begin construction on this first site after that.

The project is a collaborative effort between the Community Federation of Greater Muscatine (CFGM), Muscatine Community College, and Alquist 3D. Want to know more about the state of 3D printing when it comes to housing? Check out our handy guide.

Editors Note: The initial post initially indicated that the failed cement mixture contained hemp, but that has since found to be incorrect and the post has been edited accordingly.

Continue reading “Iowa Demolishes Its First 3D Printed House” →

Bowling With Strings Attached: The People Are Split

November 28, 2023 by Kristina Panos 52 Comments

There’s a bowling revolution in play, and not all bowlers are willing participants. In fact, a few are on strike, and it’s all because bowling alleys across America are getting rid of traditional pinsetting machines in favor of a string-based system.

In hindsight, it seems obvious to this American: attach strings to the tops of bowling pins so they can be yanked upward into holes that settle down the action so that the pins can be reset. In fact, European bowling “houses” have used string pinsetters for decades, instead of lumbering machinery that needs regular maintenance and costs several thousand dollars a month to maintain.

Continue reading “Bowling With Strings Attached: The People Are Split” →

Voice-Over-LTE: The Reason Why Your Phone May Soon Stop Working

November 27, 2023 by Maya Posch 45 Comments

Although wireless standards like 3G, 4G, and 5G are mostly associated with mobile internet, they also include a phone (voice) component. Up till 4G this was done using traditional circuit-switched telephony service, but with this fourth generation the entire standard instead moved to a packet-switched version akin to Voice-over-IP, called VoLTE (voice-over-LTE). Even so, a particular phone can choose to use a 4G modem, yet still use 3G-style phone connections. Until the 3G network is shutdown, that is. This is the crux of [Hugh Jeffreys]’s latest video.

In order to make a VoLTE phone call, your phone, your provider, the receiving phone and the intermediate network providers must all support the protocol. Even some newer phones like the Samsung Galaxy J3 (2016) do not support this. For other phones you have to turn the feature on yourself, if it is available. As [Hugh] points out in the video, there’s no easy way to know whether an Android phone supports it, which is likely to lead to chaos as more and more 3G networks in Australia and elsewhere are turned off, especially in regions where people use phones for longer than a few years.

The cessation of such basic functionality is why in most countries 2G networks remain active, as they are being used by emergency services and others for whom service interruptions can literally cost lives, as well as countless feature phones and Internet of Things devices. For some phones without VoLTE, falling back to 2G might therefore still be an option if they support this. With the spotty support, lack of transparency and random shutdowns, things may however get rather frustrating for some the coming years.

Continue reading “Voice-Over-LTE: The Reason Why Your Phone May Soon Stop Working” →

The Slow March Of Sodium-Ion Batteries To Compete With Lithium-Ion

November 26, 2023 by Maya Posch 56 Comments

The process of creating new battery chemistries that work better than existing types is a slow and arduous one. Not only does it know more failures than successes, it’s rare that a once successful type gets completely phased out, which is why today we’re using lead-acid, NiMH, alkaline, lithium, zinc-air, lithium-ion and a host of other battery types alongside each other. For one of the up-and-coming types in the form of sodium (Na)-based batteries the same struggles are true as it attempts to hit the right balance between anode, cathode and electrolyte properties. A pragmatic solution here involves Prussian Blue for the cathode and hard carbon for the anode, as is the case with Swedish Northvolt’s newly announced sodium-ion battery (SIB) which is sampling next year.

Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al. 2022) — Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al., 2022)

The story of SIBs goes back well over a decade, with a recent review article by Poonam Yadav and colleagues in Oxford Open Materials Science providing a good overview of the many types of anodes, cathodes and electrolytes which have been attempted and the results. One of the issues that prevents an SIB from directly using the carbon-based anodes employed with today’s lithium-ion batteries (LIB) is its much larger ionic radius that prevents intercalation without altering the carbon material to accept Na+ ions.

This is essentially where the hard carbon (HC) anode used by a number of SIB-producing companies comes into play, which has a far looser structure that does accept these ions and thus can be used with SIBs. The remaining challenges lie then with the electrolyte – which is where an organic form is the most successful – and the material for the sodium-containing cathode.

Although oxide forms and even sodium vanadium fluorophosphate (NVPF) are also being used, Prussian Blue analogs (PBAs) are attractive for being very low-cost and effective as cathode material once processed. An efficient way to process PB into fully sodiated and reduced Prussian White was demonstrated a few years ago, followed by successive studies backing up this assessment.

Although SIBs are seeing limited commercial use at this point, signs are that if it can be commercialized for the consumer market, it would have similar capacity as current LIBs, albeit with the potential to be cheaper, more durable and easier to recycle.

This Week In Security: SSH, FTP, And Reptar

November 17, 2023 by Jonathan Bennett 3 Comments

It’s time to strap on our propeller beanies, because we’re going to talk crypto. The short version is that some SSH handshakes can expose enough information for a third party to obtain the host’s private signing key. That key is the one that confirms you are connecting to the SSH server you think you are, and if the key validation fails, you get a big warning:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!

The math that makes this warning work is public-private key cryptography. The problem we’re talking about today only shows up in RSA authentication. Specifically those that use the Chinese Remainder Theorem (CRT) to quickly calculate the modulos needed to generate the cryptographic signature. If something goes wrong during that calculation, you end up with a signature that is mathematically related to the secret key in a different way than intended. The important point is that knowing this extra value *significantly* weakens the security of the secret key.

This attack has been known for quite some time, but the research has been aimed at causing the calculation fault through power vaults or even memory attacks like Rowhammer. There has also been progress on using a lattice attack against captured handshakes, to make the attack practical with less known information. The real novel element of this week’s approach (pdf) is that it has been tested against SSH.

The paper’s authors performed weekly scans of the entire IPv4 public network space, capturing the handshake from any listening SSH server, and also had 5 years of historic data to draw from. And the results are mixed. There is a Cisco SSH server string that is extremely common in the dataset, and only once did one of these machines send a miscalculated handshake. Possibly a random ram bit flip to blame. And on the other hand, the string “SSH-2.0-Zyxel SSH server” had so many bad signatures, it suggests a device that *always* sends a miscalculated signature. Continue reading “This Week In Security: SSH, FTP, And Reptar” →

Underwater Kites Buoying The Prospect Of More Tidal Power Generation

November 15, 2023 by Maya Posch 7 Comments

Swedish start-up Minesto has been for years trying to float the idea of having underwater turbines that generate power for use on-shore. These would be anchored to the seafloor by a long tether and move around in figure-of-eight patterns like a kite, which would increase the flow over the turbine’s blades. After a few years of trials, its 1.2 MW Dragon 12 kite will now be installed off the coast of the Faroe Islands.

Previously, Minesto had installed its much smaller DG500 (0.5 MW) kite turbine at Holyhead Deep, in Wales, where a single unit has been tested at a depth of between 65 and 91 meters. So far, only this unit has seen continuous operation. As noted in the linked Tethys report, this one unit was not connected to the grid, and research on its environmental impact is still ongoing as of September 2022. The main concerns are how it might affect cetaceans (whales, dolphins, etc.), including potential collisions with these as well as diving birds who might end up diving in the midst of a swarm of kites moving about at fairly high speeds.

One of the proposed Minesto Dragon 12 kite array installation sites at the Faroe Islands. (Credit: Minesto)

Although by itself putting a turbine into the much stronger and energetic ocean currents – not to mention near-continuous – makes sense, the marine environment is a tough one to survive. The DG500 prototype has seen a few years of use, but this would be the first large-scale deployment of such a system and thus the first significant long-term durability test. The goal at the Faroe Islands is to install 120 MW of capacity, across four kite groups, joining the smaller Dragon 4 (0.4 MW) unit that was grid-connected in May of last year.

Depending on the results, including the economics, this technology could prove to be either much better and cheaper than off-shore wind turbines, or turn out to be saddled with fundamental flaws that has plagued previous attempts to make use of the strong currents and tides that make the world’s oceans and seas into one of Nature’s most impressive sights.