Full Width [alt+shift+f] Shortcuts [alt+shift+k]
Sign Up [alt+shift+s] Log In [alt+shift+l]
30
This cube manages to balance itself on a corner, and can simultaneously rotate around its axis in a controlled manner. It does so using clever controls and a set of three reaction wheels. The original idea for this device comes from researchers at ETH Zürich, who demonstrate their “Cubli” in this video. Its design has… Continue reading Balancing cube
a year ago

Improve your reading experience

Logged in users get linked directly to articles resulting in a better reading experience. Please login for free, it takes less than 1 minute.

More from Willem Pennings

Fixing my heating system

The heating system in my apartment building consists of a group of heat pumps that deliver warm water to the underfloor heating system of about a dozen apartments, including mine. During the warm summer months, the system supplies cool water instead. The heat pumps figure out whether to supply warm or cool water, and a… Continue reading Fixing my heating system

11 months ago 51 votes
ClockSquared improvements

My ClockSquared project has a long history – it goes all the way back to 2015, when it was simply called the “Birthday word clock”. I haven’t spent much time on the project in recent years, but I’ve upgraded the internals a while ago and finally felt like writing a post about it. Two things… Continue reading ClockSquared improvements

over a year ago 22 votes
ClockSquared Mini, a word clock wristwatch

About a year ago, I had some time to spare over the summer and decided to challenge myself with a project that I call “Clocksquared Mini”. It is Clocksquared, but in a tiny wristwatch package. This gives rise to a major challenge, as everything has to be shrunk down approximately ten times from a 300x300x50… Continue reading ClockSquared Mini, a word clock wristwatch

over a year ago 15 votes
Home Assistant-compatible air quality sensor

I recently moved and our new home is equipped with a ventilation system that distributes fresh (outside) air through the house and recoups heat from the air that is exhausted. There is a problem with this system, though. Sometimes, for example when a neighbour lights their wood stove, the system pulls in smoke, even though… Continue reading Home Assistant-compatible air quality sensor

over a year ago 20 votes

More in science

A Month In Northern Peru, Part 18: Wattled Curassows at Muyuna Lodge (February 26, 2024)

February 26, 2024 As dawn broke, Laura, Moises and I slowly cruised along a quiet watercourse. The dawn chorus was active and included species like Ferruginous Pygmy-Owl, Zimmer's Woodcreeper and Black-tailed Antbird, but I stayed focused on the treeline, hoping that a curassow-shaped bird would appear.  The dawn chorus quieted as the sun rose above the horizon. Early morning is the best time to find the curassow, and we were running out of time.  Domain of the Wattled Curassow - Muyuna Lodge, Loreto, Peru And there it was! It was the bright red bill that first caught my attention and 0.05 seconds later, my brain registered that I was staring at a female Wattled Curassow. Wattled Curassow - Muyuna Lodge, Loreto, Peru But it was better than I had imagined - the female was accompanied by a tiny chick! For a few magical minutes we watched the duo in their element.  Wattled Curassow chick - Muyuna Lodge, Loreto, Peru Wattled Curassow chick - Muyuna Lodge, Loreto, Peru Wattled Curassows are closely associated with these rivers in the western Amazon basin and that has led to their downfall. The rivers are the highways, and curassows have a lot of meat. But in a few areas like here, hunting of the curassows does not occur and encounters with this secretive species are possible. The curassows like feeding on the fruits of mahogany trees that line the watercourses, and that is likely what this female was on the hunt for.  Wattled Currasow - Muyuna Lodge, Loreto, Peru We were on cloud nine after such an epic start to the day! I was pleased that I even managed some mostly in-focus photos with my broken lens.  For the next few hours we cruised around by boat, checking out different waterways in search of some of our target birds. We were successful with Black-tailed Antbird and Short-tailed Parrot.  Black-tailed Antbird - Muyuna Lodge, Loreto, Peru Short-tailed Parrot - Muyuna Lodge, Loreto, Peru It was a very birdy morning and we cleared the hundred species mark before returning to the lodge for breakfast.  Bluish-fronted Jacamar - Muyuna Lodge, Loreto, Peru Black-tailed Tityra - Muyuna Lodge, Loreto, Peru Proboscis Bat (Rhynchonycteris nasa) - Muyuna Lodge, Loreto, Peru After breakfast, we searched by boat for some of the few remaining target birds I had in mind such as Purple-throated Cotinga, Gray-eyed Greenlet and Wing-barred Seedeater, but were unsuccessful.  Unidentified katydid - Muyuna Lodge, Loreto, Peru We were also on the lookout for Dusky-billed Parrotlets, a potential lifer for Laura and a new photographed bird for me. Moises claimed sightings on a few occasions, but each time my photos revealed that they were the more expected Riparian Parrotlets.  Band-tailed Antbird - Muyuna Lodge, Loreto, Peru At one point during the afternoon we entered an area of higher ground where there was a small walking trail. After spending most of the day in a boat it felt great to feel the earth beneath our boots, even though this meant that we were accompanied by a swarm of mosquitoes. Amazonian Trogon - Muyuna Lodge, Loreto, Peru Methona confusa - Muyuna Lodge, Loreto, Peru We found several groups of Eastern Pygmy Marmosets, one of the smallest species of monkey! Eastern Pygmy Marmoset (Cebuella niveiventris) - Muyuna Lodge, Loreto, Peru Eastern Pygmy Marmoset (Cebuella niveiventris) - Muyuna Lodge, Loreto, Peru Our guide, Moises had a stake-out for Nancy Ma's Night-Monkey (Aotus nancymai) that was visible from the main watercourse.  Nancy Ma's Night-Monkey (Aotus nancymai) - Muyuna Lodge, Loreto, Peru During the mid-afternoon, Moises took us down a channel choked with vegetation to look for some herps. We kept a close eye on the vegetation until Laura spotted the first snake, as she is known to do! Giant Parrot Snake (Leptophis ahaetulla nigromarginatus) - Muyuna Lodge, Loreto, Peru While we have seen this widespread species before, this was a new subspecies for us. The extensive black markings between the scales are quite distinctive.  Giant Parrot Snake (Leptophis ahaetulla nigromarginatus) - Muyuna Lodge, Loreto, Peru Even better than the parrot snake was this next species: a Northern Caiman Lizard (Dracaena guianensis)! I have wanted to see this huge species of lizard for many years but had never gotten lucky. As the name suggests, particularly large individuals somewhat resemble caimans, and they share similar aquatic habitats. Caiman lizards feed on snails, fish, amphibians and other creatures that they find underwater.  Northern Caiman Lizard (Dracaena guianensis) - Muyuna Lodge, Loreto, Peru Northern Caiman Lizard (Dracaena guianensis) - Muyuna Lodge, Loreto, Peru As the sun set, we found ourselves slowly paddling in a different wetland after another unsuccessful Purple-throated Cotinga search. We enjoyed watching a pair of Yellow-chinned Spinetails. This species is widespread in South America but is fairly localized in Peru.  Yellow-chinned Spinetail - Muyuna Lodge, Loreto, Peru You would be hard-pressed to find an activity that Laura likes more than a night-hike in the tropics, and tonight's walk was a good one. We only stayed out for a short while but came away with some nice sightings, including several snakes! Smoky Jungle Frog (Leptodactylus pentadactylus) - Muyuna Lodge, Loreto, Peru Ancylometes sp. - Muyuna Lodge, Loreto, Peru Unidentified net-casting spider (family Deinopidae) - Muyuna Lodge, Loreto, Peru Crowned False Boa (Pseudoboa coronata) - Muyuna Lodge, Loreto, Peru Pierella hortona - Muyuna Lodge, Loreto, Peru Leptodactylus sp. - Muyuna Lodge, Loreto, Peru Sais rosalia - Muyuna Lodge, Loreto, Peru Garden Tree Boa (Corallus hortulana) - Muyuna Lodge, Loreto, Peru I think my favourite sighting of the walk was this Slender Opossum (Marmosops sp.). It was extremely confiding and didn't mind my close approach for photos.  Slender Opossum (Marmoseps sp.) - Muyuna Lodge, Loreto, Peru Though they may resemble a rodent to some (Moises confidently identified it as an "Amazonian Mouse", whatever that is), these are actually a tiny genus of neotropical opossums, meaning that they are a marsupial. Slender opossums typically live in the viny, dense understory where they search for insects, arachnids, flowers and fruit.  Slender Opossum (Marmoseps sp.) - Muyuna Lodge, Loreto, Peru My final post from Peru will include our last couple of days at Muyuna Lodge.

17 hours ago 3 votes
How a Problem About Pigeons Powers Complexity Theory

When pigeons outnumber pigeonholes, some birds must double up. This obvious statement — and its inverse — have deep connections to many areas of math and computer science. The post How a Problem About Pigeons Powers Complexity Theory first appeared on Quanta Magazine

20 hours ago 2 votes
Why Did Korea Split?

The crazy story of a few days that changed Korea forever

22 hours ago 2 votes
Is Planned Obsolescence Real

Yes – it is well-documented that in many industries the design of products incorporates a plan for when the product will need to be replaced. A blatant example was in 1924 when an international meeting of lightbulb manufacturers decided to limit the lifespan of lightbulbs to 1,000 hours, so that consumers would have to constantly […] The post Is Planned Obsolescence Real first appeared on NeuroLogica Blog.

21 hours ago 2 votes
Nutrition Beliefs Are Just-So Stories

But everyone wishes they weren't!

5 hours ago 1 votes