Full Width 
Shortcuts 
Sign Up 
Log In 
Articles 
Reading List More from Bartosz Ciechanowski
In the vastness of empty space surrounding Earth, the Moon is our closest celestial neighbor. Its face, periodically filled with light and devoured by darkness, has an ever-changing, but dependable presence in our skies. In this article, we’ll learn about the Moon and its path around our planet, but to experience that journey first-hand, we have to enter the cosmos itself. This article has many interactive demonstrations which are best seen on the website.
The dream of soaring in the sky like a bird has captivated the human mind for ages. Although many failed, some eventually succeeded in achieving that goal. These days we take air transportation for granted, but the physics of flight can still be puzzling. In this article we’ll investigate what makes airplanes fly by looking at the forces generated by the flow of air around the aircraft’s wings. More specifically, we’ll focus on the cross section of those wings to reveal the shape of an airfoil – you can see it presented in yellow below: This article has many interactive demonstrations which are best seen on the website.
There is something delightful about riding a bicycle. Once mastered, the simple action of pedaling to move forward and turning the handlebars to steer makes bike riding an effortless activity. In the demonstration below, you can guide the rider with the slider, and you can also drag the view around to change the camera angle: Compared to internal combustion engines or mechanical watches, bicycles are fairly simple machines – most of their parts operate in plain sight. This article has many interactive demonstrations which are best seen on the website.
In the world of modern portable devices, it may be hard to believe that merely a few decades ago the most convenient way to keep track of time was a mechanical watch. Unlike their quartz and smart siblings, mechanical watches can run without using any batteries or other electronic components. Over the course of this article I’ll explain the workings of the mechanism seen in the demonstration below. You can drag the device around to change your viewing angle, and you can use the slider to peek at what’s going on inside: This article has many interactive demonstrations which are best seen on the website.
More in science
The first gonorrhea vaccination program, contact lenses that see infrared light, the protein behind sweet tastes, a baby cured with gene therapy, and more
An attack on a fundamental proof technique reveals a glaring security issue for blockchains and other digital encryption schemes. The post Computer Scientists Figure Out How To Prove Lies first appeared on Quanta Magazine
Koalas, which spend most of their lives high up in eucalyptus trees, usually die while on the ground, often mauled by dogs or hit by cars. More striking, a new study reveals that the amount of time they spend on the ground is only around 10 minutes a day. Read more on E360 →
Here are a number of items from the past week or so that I think readers of this blog might find interesting: Essentially all the news pertaining to the US federal funding of science continues to be awful. This article from Science summarizes the situation well, as does this from The Guardian and this editorial in the Washington Post. I do like the idea of a science fair of cancelled grants as a way to try to get alleged bipartisan appropriator notice of just how bad the consequences would be of the proposed cuts. On a more uplifting note, mathematicians have empirically demonstrated a conjecture originally made by John Conway, that it is possible to make a tetrahedral pyramid that, under gravity, has only one stable orientation. Quanta has a nice piece on this with a cool animated gif, and here is the actual preprint about it. It's all about mass distributions and moments of inertia about edges. As others have pointed out including the authors, this could be quite useful for situations like recent lunar lander attempts that seem to have a difficult time not topping over. A paper last week in Nature uses photons and a microcavity to try to test how long it takes photons to tunnel through a classically forbidden region. In this setup, it is mathematically legit to model the photons as if they have an effective mass, and one can model the barrier they need to traverse in terms of an effective potential energy. Classically, if the kinetic energy of the particle of interest is less than the potential energy of the barrier, the particle is forbidden inside the barrier. I've posted about the issue of tunneling time repeatedly over the years (see here for a 2020 post containing links), because I think it's a fascinating problem both conceptually and as a puzzle for experimentalists (how does one truly do a fair test of this?). The take-away from this paper is, the more classically forbidden the motion, the faster the deduced tunneling time. This has been seen in other experiments testing this idea. A key element of novelty in the new paper is the claim that the present experiment seems (according to the authors) to not be reasonably modeled by Bohmian mechanics. I'd need to read this in more depth to better understand it, as I had thought that Bohmian mechanics applied to problems like this is generally indistinguishable in predictions from conventional quantum mechanics, basically by design. In other non-condensed matter news, there is an interstellar comet transiting the solar system right now. This is very cool - it's only the third such object detected by humans, but to be fair we've only really been looking for a few years. This suggests that moderately sized hunks of material are likely passing through from interstellar space all the time, and the Vera C. Rubin Observatory will detect a boatload of them. My inner science fiction fan is hoping that the object changes its orbit at perihelion by mysterious means. This week is crunch time for a final push on US congressional appropriators to try to influence science agency budgets in FY26. I urge you to reach out if this matters to you. Likewise, I think it's more than reasonable to ask congress why the NSF is getting kicked out of its headquarters with no plan for an alternative agency location, so that the HUD secretary can have a palatial second home in that building.
As growing populations denude its slopes and heavy rain intensifies, Mount Elgon has become increasingly vulnerable to landslides. In response, Ugandan farmers are planting native trees and changing the crops they plant in efforts to build resilience against future disasters. Read more on E360 →
