Before the first atomic bomb was detonated, there were some fears that a fission bomb could “ignite the atmosphere.” Yes, if you’ve just watched Oppenheimer, read about the Manhattan Project, or looked into atomic weapons at all, you’ll be familiar with the concept. Physicists determined the risk was “near zero,” proceeded ahead with the Trinity test, and the world lived to see another day.
You might be wondering what this all means. How could the very air around us be set aflame, and how did physicists figure out it wasn’t a problem? Let’s explore the common misunderstandings around this concept, and the physical reactions at play.
A prerequisite for photovoltaic (PV) and concentrated solar power (CSP) technologies to work efficiently is as direct an exposure to the electromagnetic radiation from the sun as possible. Since dust and similar particulates are excellent at blocking the parts of the EM spectrum that determine their efficiency, keeping the panels and mirrors free from the build-up of dust, lichen, bird droppings and other perks of planetary life is a daily task for solar farm operators. Generally cleaning the panels and mirrors involves having trucks drive around with a large water tank to pressure wash the dirt off, but the use of so much water is problematic in many regions.
Keeping PV panels clean is also a consideration on other planets than Earth. So far multiple Mars rovers and landers have found their demise at the hands of Martian dust after a layer covered their PV panels, and Moon dust (lunar regolith) is little better. Despite repeated suggestions by the peanut gallery to install wipers, blowers or similar dust removal techniques, keeping particulates from sticking to a surface is not as easy an engineering challenge as it may seem, even before considering details such as the scaling issues between a singular robot on Mars versus millions of panels and mirrors on Earth.
There has been research into the use of the electrostatic effect to repel dust, but is there a method that can keep both solar-powered robots on Mars and solar farms on Earth clean and sparkling, rather than soiled and dark?
Harry Daghlian and Louis Slotin were two of many people who worked on the Manhattan Project. They might not be household names, but we believe they are the poster children for safety procedures. And not in a good way.
Slotin assembled the core of the “Gadget” — the plutonium test device at the Trinity test in 1945. He was no stranger to working in a lab with nuclear materials. It stands to reason that if you are making something as dangerous as a nuclear bomb, it is probably hazardous work. But you probably get used to it, like some of us get used to working around high voltage or deadly chemicals.
Making nuclear material is hard and even more so back then. But the Project had made a third plutonium core — one was detonated at Trinity, the other over Nagasaki, and the final core was meant to go into a proposed second bomb that was not produced.
The cores were two hemispheres of plutonium and gallium. The gallium allowed the material to be hot-pressed into spherical shapes. Unlike the first two cores, however, the third one — one that would later earn the nickname “the demon core” — had a ring around the flat surfaces to contain nuclear flux during implosion. The spheres are not terribly dangerous unless they become supercritical, which would lead to a prompt critical event. Then, they would release large amounts of neutrons. The bombs, for example, would force the two halves together violently. You could also add more nuclear material or reflect neutrons back into the material.
Historians may note that World War II was the last great “movie war.” In those days, you could do many things that are impossible today, yet make for great movie drama. You can’t sneak a fleet of ships across the oceans anymore. Nor could you dig tunnels right under your captor’s nose. Another defining factor is that it doesn’t seem we seek out superweapons anymore.
A Churchill Bullshorn plough for clearning minefields — one of Hobart’s “Funnies”
Sure, we develop better planes, tanks, submarines, and guns. But we aren’t working on anything — that we know of — as revolutionary as a rocket, an atomic bomb, or even radar was back in the 1940s. The Germans worked on Wunderwaffe, including guided missiles, jets, suborbital rocket bombers, and a solar-powered space mirror to burn terrestrial targets. Everyone was working on a nuclear bomb, of course. The British had Hobart’s Funnies as well as less successful entries like the Panjandrum — a ten-foot rocket-driven wheel of explosives.
Death Ray
Perhaps the holy grail of all the super weapons — both realized and dreamed of was the “death ray.” Of course, Tesla claimed to have one that didn’t use rays, but particles, but no one ever successfully built one and there was debate if it would work. Tesla didn’t like the term death ray, partly because it wasn’t a ray at all, but also because it required a huge power plant and, therefore, wasn’t mobile. He envisioned it as a peacekeeping defensive weapon, rendering attacks so futile that no one would dare attempt them.
Among the daily churn of ‘Web 3.0’, blockchains and cryptocurrency messaging, there is generally very little that feels genuinely interesting or unique enough to pay attention to. The same was true for OpenAI CEO Sam Altman’s Ethereum blockchain-based Worldcoin when it was launched in 2021 while promising many of the same things as Bitcoin and others have for years. However, with the recent introduction of the World ID protocol by Tools for Humanity (TfH) – the company founded for Worldcoin by Mr. Altman – suddenly the interest of the general public was piqued.
Defined by TfH as a ‘privacy-first decentralized identity protocol’ World ID is supposed to be the end-all, be-all of authentication protocols. Part of it is an ominous-looking orb contraption that performs iris scans to enroll new participants. Not only do participants get ‘free’ Worldcoins if they sign up for a World ID enrollment this way, TfH also promises that this authentication protocol can uniquely identify any person without requiring them to submit any personal data, only requiring a scan of your irises.
Essentially, this would make World ID a unique ID for every person alive today and in the future, providing much more security while preventing identity theft. This naturally raises many questions about the feasibility of using iris recognition, as well as the potential for abuse and the impact of ocular surgery and diseases. Basically, can you reduce proof of personhood to an individual’s eyes, and should you?
I’ve talked about a low-effort way to document your projects by taking plenty of pictures, and about ways that your PCBs could be documenting themselves. Today, let’s talk about a quick and easy way that you could help other hackers as you go through your own hacking adventures — leaving breadcrumbs.
In short, breadcrumbs are little pieces of crucial information that you had to spend time to figure out. They are solutions to problems that another hacker just like you could stumble upon in the future, something that you perhaps wish you didn’t have to figure out on your own, and certainly something that others won’t need to spend time figuring out.
Breadcrumbs are about saving time, for you and others. It helps if you think of your solved problems in terms of time spent. If you figure out a small problem and then publish your solution, you might be saving half an hour, a full hour, or a good few hours of time another hacker that’s could even be less experienced in debugging than you. In fact, your breadcrumb might even make a difference between someone completing a project and abandoning it!
However, there’s also the trade-off of taking time to document something. If you can’t publish your solution in a few minutes’ time, it might become much harder to persuade your brain to publish the next time you have something notable. Here’s a guideline: if you’ve just figured out a cool terminal command that helps you solve a certain kind of problem, you should have a quick way to publish that command within a minute. The good news is, the internet has a hundred different places you could easily share your findings, depending on the kind of problem you’ve solved! Continue reading “Share Your Projects: Leave Breadcrumbs”→
The last time that a human set foot on the Moon, it was December 1972 — when the crew of the Apollo 17 mission spent a few days on the surface before returning to Earth. Since then only unmanned probes have either touched down on the lunar surface or entered orbit to take snapshots and perform measurements.
But after years of false starts, there are finally new plans on the table which would see humans return to the Moon. Not just to visit, but with the goal of establishing a permanent presence on the lunar surface. What exactly has changed that the world went from space fever in the 1960s to tepid interest in anything beyond LEO for the past fifty years, to the renewed interest today?
Part of the reason at least appears to be an increasing interest in mineable resources on the Moon, along with the potential of manufacturing in a low gravity environment, and as a jumping-off point for missions to planets beyond Earth, such as Mars and Venus. Even with 1960s technology, the Moon is after all only a few days away from launch to landing, and we know that the lunar surface is rich in silicon dioxide, aluminium oxide as well as other metals and significant amounts of helium-3, enabling in-situ resource utilization.
Current and upcoming Moon missions focus on exploring the lunar south pole in particular, with frozen water presumed to exist in deep craters at both poles. All of which raises the question of we may truly see lunar-based colonies and factories pop up on the Moon this time, or are we merely seeing a repeat of last century?
