The Smell Of Space

August 5, 2020 by Jenny List 28 Comments

In space, so the Alien tagline goes, nobody can hear you scream. One of the most memorable pieces of movie promotion ever, it refers to the effect of the vacuum of space on the things human senses require an atmosphere to experience. It’s a lesson that Joss Whedon used to great effect with the Serenity‘s silent engine light-ups in Firefly, while Star Wars ignored it completely to give us improbable weapon noises in space battles.

Sound may not pass through the vacuum of space, but that’s not to say there are not things other than light for the senses. The Apollo astronauts reported that moon dust released a smell they described as akin to burnt gunpowder once it was exposed to the atmosphere inside their lander, and by now you may have heard that there is a Kickstarter that aims to recreate the smell as a fragrance. Will it replace the cloying wall of Axe or Lynx Africa body spray that pervades high-school boys’ changing rooms, or is it a mere novelty?

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Fresh Food Year Round? You Can Thank Frederick McKinley Jones

August 4, 2020 by Kristina Panos 27 Comments

When you’re a kid, one of the surest signs of summer is hearing the happy sound of the ice cream truck crawling through the neighborhood. You don’t worry about how that magical truck is keeping the ice cream cold, only that it rolls down your street, and that the stars align and your parents give you money for a giant ice cream-cookie sandwich with the edge rolled in tiny chocolate chips.

In the early days of mobile refrigeration, ice cream trucks and other food delivery vehicles relied first on ice, and then dry ice to keep perishables cold. Someone eventually invented an electric cooling system, but those had to be recharged periodically at power stations. There was also a short-lived mechanical system, but it was highly susceptible to road vibrations.

Until Frederick McKinley Jones came along, mobile refrigeration was fledgling, and sources of perishable food were extremely localized and limited. In the early 1940s, Frederick patented the first practical automated refrigeration system for trucks, and it revolutionized the shipping and storage of food and medicine.

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COVID Tracing Apps: What Europe Has Done Right, And Wrong

August 3, 2020 by Elliot Williams 63 Comments

Europe has been in COVID-containment mode for the last month, in contrast to the prior three months of serious lockdown. Kids went back to school, in shifts, and people went on vacation to countries with similarly low infection rates. Legoland and the zoo opened back up, capped at 1/3 capacity. Hardware stores and post offices are running “normally” once you’ve accommodated mandatory masks and 1.5 meter separations while standing in line as “normal”. To make up for the fact that half of the tables have to be left empty, most restaurants have sprawled out onto their terraces. It’s not really normal, but it’s also no longer horrible.

But even a country that’s doing very well like Germany, where I live, has a few hundred to a thousand new cases per day. If these are left to spread unchecked as before, the possibility of a second wave is very real, hence the mask-and-distance routine. The various European COVID-tracing apps were rolled out with this backdrop of a looming pandemic that’s tenuously under control. While nobody expects the apps to replace public distancing, they also stand to help if they can catch new and asymptomatic cases before they get passed on.

When Google and Apple introduced their frameworks for tracing apps, I took a technical look at them. My conclusion was that the infrastructure was sound, but that the implementation details would be where all of the dragons lay in wait. Not surprisingly, I was right!

Here’s an update on what’s happened in the first month of Europe’s experience with COVID-tracing apps. The good news is that the apps seem to be well written and based on the aforementioned solid foundation. Many, many people have installed at least one of the apps, and despite some quite serious growing pains, they seem to be mostly functioning as they should. The bad news is that, due to its privacy-preserving nature, nobody knows how many people have received warnings, or what effect, if any, the app is having on the infection rate. You certainly can’t see an “app effect” in the new daily cases rate. After a month of hard coding work and extreme public goodwill, it may be that cellphone apps just aren’t the panacea some had hoped.

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No-Melt Nuclear ‘Power Balls’ Might Win A Few Hearts And Minds

July 30, 2020 by Kristina Panos 137 Comments

A nuclear power plant is large and complex, and one of the biggest reasons is safety. Splitting radioactive atoms is inherently dangerous, but the energy unleashed by the chain reaction that ensues is the entire point. It’s a delicate balance to stay in the sweet spot, and it requires constant attention to the core temperature, or else the reactor could go into meltdown.

Today, nuclear fission is largely produced with fuel rods, which are skinny zirconium tubes packed with uranium pellets. The fission rate is kept in check with control rods, which are made of various elements like boron and cadmium that can absorb a lot of excess neutrons. Control rods calm the furious fission boil down to a sensible simmer, and can be recycled until they either wear out mechanically or become saturated with neutrons.

Nuclear power plants tend to have large footprints because of all the safety measures that are designed to prevent meltdowns. If there was a fuel that could withstand enough heat to make meltdowns physically impossible, then there would be no need for reactors to be buffered by millions of dollars in containment equipment. Stripped of these redundant, space-hogging safety measures, the nuclear process could be shrunk down quite a bit. Continue reading “No-Melt Nuclear ‘Power Balls’ Might Win A Few Hearts And Minds” →

Smashing The Atom: A Brief History Of Particle Accelerators

July 29, 2020 by Moritz v. Sivers 28 Comments

When it comes to building particle accelerators the credo has always been “bigger, badder, better”. While the Large Hadron Collider (LHC) with its 27 km circumference and €7.5 billion budget is still the largest and most expensive scientific instrument ever built, it’s physics program is slowly coming to an end. In 2027, it will receive the last major upgrade, dubbed the High-Luminosity LHC, which is expected to complete operations in 2038. This may seem like a long time ahead but the scientific community is already thinking about what comes next.
Recently, CERN released an update of the future European strategy for particle physics which includes the feasibility study for a 100 km large Future Circular Collider (FCC). Let’s take a short break and look back into the history of “atom smashers” and the scientific progress they brought along. Continue reading “Smashing The Atom: A Brief History Of Particle Accelerators” →

Ask Hackaday: Why Did GitHub Ship All Our Software Off To The Arctic?

July 29, 2020 by Ben James 95 Comments

If you’ve logged onto GitHub recently and you’re an active user, you might have noticed a new badge on your profile: “Arctic Code Vault Contributor”. Sounds pretty awesome right? But whose code got archived in this vault, how is it being stored, and what’s the point?

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Porsche’s Printed Pistons Are Powerful And Precise

July 28, 2020 by Kristina Panos 49 Comments

The 700-horsepower Porsche 911 GT2 RS is already pretty darn fast — over three times faster than the average regular-person car on the road today. For the sports car enthusiast, there’s likely no ceiling on the need for speed and performance. And so, Porsche was able to wrangle another thirty horsepower out of their limited-run supercar by printing a set of ultra-lightweight pistons.

Pistons being lasered into existence. Image via The Drive

These pistons are printed from high-purity aluminium alloy powder that was developed by German auto parts manufacturer Mahle. Porsche is having these produced by Mahle in partnership with industrial machine maker Trumpf using the laser metal fusion (LMF) process. It’s a lot like selective laser sintering (SLS), but with metal powder instead of plastic.

The machine dusts the print bed with a layer of powder, and then a laser melts the powder according to the CAD file, hardening it into shape. This process repeats one layer at a time, and supports are zapped together wherever necessary. When the print job is finished, the pistons are machined into their shiny final form and thoroughly tested, just like their cast metal cousins have been for decades. Continue reading “Porsche’s Printed Pistons Are Powerful And Precise” →