Getting Rid Of All The Space Junk In Earth’s Backyard

Space, as the name suggests, is mostly empty. However, since the first satellite launch in 1957, mankind began to populate the Earth orbit with all kinds of spacecraft. On the downside, space also became more and more cluttered with trash from defunct or broken up rocket stages and satellites. Moving at speeds of nearly 30,000 km/h, even the tiniest object can pierce a hole through your spacecraft. Therefore, space junk poses a real threat for both manned and unmanned spacecraft and that is why space agencies are increasing their efforts into tracking, avoiding, and getting rid of it.
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Sensing The Earth’s Wobble In Time

In the 1850s British railway companies started introducing a single standard time to make their timetables consistent. Before that, every city would set its own clock based on the observation of the position of the sun. Nowadays, precise time standards are not only needed so people don’t miss their trains but also make modern communication technologies and satellite navigation work.

Generally, there are two methods of defining time, one is based on the local passage of time as measured by atomic clocks, while the other relies on the exact measurement of Earth’s rotation. The latter is not an easy exercise that involves extragalactic radio sources or huge laser-based gyroscopes. The constant survey of the Earth’s spin tells us that days are constantly getting longer, but surprisingly, severe earthquakes and weather phenomena can also take little discrete bites out of the planet’s supply of rotational kinetic energy.

How do we keep our ultra precisely measured time, the rotation of the Earth, and our position in the heavens in line?

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A Backlit Calendar For All Eternity

The advantage of the irregularities in the Gregorian calendar combined with the seven-day week is that they provide a constant source of yearly revenue for the paper calendar industry. Long before sustainability became a trending topic, people invented reusable, perpetual calendars, but the non-digital versions of these are sometimes complicated tables that are hard to interpret. [andrei.erdei] created an automated perpetual calendar that is mostly hardware but uses some digital tricks to overcome these problems.

The calendar consists of sandwiched panels of smoked acrylic which are backlit by some strips of WS2812Bs. Although the panels could have been processed with a laser cutter, [andrei.erdei] used a CNC which gave him the possibility to mill some grooves in the back panel to hold the LED strips. The stencil for the numbers was simply printed out on paper and the background made opaque by printing several times over the same piece of paper. The electronics consist of an ESP8266 which takes the date from an NTP server and lights up the corresponding LEDs in different colors for weekdays and weekends.

The classic version of this type of perpetual calendar uses a sliding frame but we have also seen completely different versions based on moving gears.

Video after the break.

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A Tetraquark For Muster Mark!

The holy grail of every particle physics experiment is the discovery of a new particle. Finding a new constituent of matter may earn you eternal glory within the history of physics. Unfortunately, since the last missing piece of the Standard Model, the Higgs boson, was discovered in 2012, and with still no clue about the nature of dark matter and dark energy, there is not much hope to stumble upon a new fundamental building block of matter any time soon.

Luckily, this is not true for composite particles, especially the strange world of quark matter still yields some potential for new discoveries. The latest of such was the observation of a new tetraquark by the LHCb experiment. But what the hell is a quark anyway and why is it named after a German dairy product? Continue reading “A Tetraquark For Muster Mark!”

Smashing The Atom: A Brief History Of Particle Accelerators

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”

Bringing The Pi Camera Into Focus With LEGO

Ever since the high-quality camera for the Raspberry Pi was released a few months back it has been the center of attention for many hacks. In this quick build [Martin Mander] shows us how to make a servo-powered focusing mechanism entirely from LEGO.

The inspiration for this project came to him while he was working on his 1979 Merlin Pi Camera and found that setting the focus just right is vital in order to get good quality pictures. So he set himself the goal to build a mechanism that allows him to focus the camera precisely and remotely.

It is the plethora of LEGO-compatible parts that are available off-the-shelf that make such a project possible without the use of any 3D printed components. He not only found a LEGO-compatible continuous rotating servo but also a LEGO-compatible case for the Pi, and a LEGO cogwheel which almost fits exactly onto the camera lens. He also added a tripod mount to the case that allows him to set up the camera anywhere. The camera and focussing mechanism are controlled with a custom GUI based on guizero Python 3 library and the camera can be accessed remotely via VNCViewer.

If you prefer 3D printing over LEGO there are also other stylish Raspi HQ camera builds.

Video after the break.

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7-Segment Display Is No Small Feat

The 7-segment display certainly is a popular build, and surprisingly people still come up with new takes on this over a hundred-year-old way to represent numbers. This time [jegatheesan.soundarapandian] is making it big by building a giant 7 feet tall 7-segment display.

Apparently, the plan is to build a giant clock so he started off by making the first digit. To keep it cheap and simple the segments are made from corrugated cardboard which was carefully cut, folded, and then glued together. The light-diffusing lid is simply made from white paper. He used the ubiquitous WS2812B strips to light up the segments, but things turned out to be more complicated as he was not able to get enough strips to fill up all the segments. This forced him to cut up the strip into individual pieces and space them out by reconnecting the LEDs with wires. Cutting, stripping, and soldering 186 wires took him almost 10 hours. An Arduino Uno serves as the brains of the device and there is a nice Android app to control it via Bluetooth.

We are excited to see the complete clock once it is finished. In the meantime let us remember other epic displays like that made from 144 individual 7-segment displays or the giant LED video wall using 1200 ping pong balls.

Video after the break.

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