GeoLunar_Chrono_Projection

In a corner of your study, a small globe quietly yet precisely marks the passage of cosmic time. This is the "GeoLunar_Chrono_Projection."

This project is a completely new desktop object based on a commercially available STEM educational mini-globe, fusing astronomical accuracy with information display through digital technology. It's designed not just as a model, but as a "living globe" that allows you to experience the changing seasons, the Earth's rotation, world time, and the phases of the moon in real time.

Housed in a matte black case, the Earth appears to float quietly in space. Through the smoke-gray acrylic front, you can see our planet itself, rotating as it is illuminated by the sun.

As a Cross-Disciplinary STEM Educational Tool

This project is more than just a beautiful gadget; it is also a practical STEM educational tool that bridges the elements of geography and science (earth science). It allows for a multidisciplinary learning experience, covering concepts from geography such as the Lambert azimuthal equal-area projection and the longitude/latitude of various cities, to astronomical phenomena like the relationship between the Earth's axial tilt and solar altitude (seasons), its 24-hour rotation, and the phases of the moon—all in a single device.

The Three Core Features

This globe provides multilayered information to the user through the coordination of three different elements.

1. The Physical Globe: Experiencing Seasons and Rotation (Science)

The position of the LEDs changes to simulate the sun's noon altitude according to the season. It illuminates the Earth from a higher position during the summer solstice and a lower one during the winter solstice.

Representation of Solar Altitude: Using a NeoPixel LED strip, LEDs light up at positions that simulate the sun's altitude at noon according to the Earth's current season. This provides an intuitive understanding of why the length of day and temperatures change with the season.

Precise 24-Hour Rotation: A custom-designed 24-hour counter-clockwise clock mechanism is attached to the axis. This ensures the globe completes one rotation in exactly 24 hours, just like the real Earth,

2. The Circular LCD: Earth "Now" from Space (Geography/Science)

A view from the North Pole drawn with the Lambert azimuthal equal-area projection. The tilt of the day-night line (terminator) changes with the summer solstice, winter solstice, and equinoxes.

Lambert Azimuthal Equal-Area Projection: The circular LCD displays a map of the Earth using the Lambert azimuthal equal-area projection, centered on the North Pole. This projection ensures scientific accuracy, visually representing the fact that half of the Earth is always illuminated by the sun by keeping the "areas" of day and night equal.

Real-time Day and Night: The day-night line changes in real time in sync with the Earth's rotation and season. You can see at a glance whether your location is currently in day or night from a cosmic perspective.

3. The OLED Screen: Detailed Data Hub (Geography/Science)

A 3D wireframe Earth rotates, displaying the current time in various cities. On the right, the real-time moon phase is shown.

World Clock: A 3D wireframe Earth rotates in sync with the physical globe. On its front, markers for major cities (e.g., Tokyo, London, New York) and their current times are displayed in real time. The system is extensible, allowing new cities to be easily added by simply inputting their latitude and longitude into the code.

Real-time Moon Phase Display: Information about the Earth's only natural satellite, the Moon, is also essential. The current moon age is calculated and its phase (Full Moon, New Moon, First Quarter, Third Quarter) is displayed graphically for easy understanding.

Build Details and Applications

The heart of this project is M5Stack's AtomS3 Lite. Despite its compact size, it's powerful enough to control two displays and numerous LEDs simultaneously.

The enclosure was unified in matte black, with a design that allows only the information-displaying parts to glow, aiming for a serene aesthetic worthy of admiration. Also, as explained in the latter half of the video, it's possible to separate the transparent OLED and the AtomS3 to create an even smaller gadget.

I hope that this "GeoLunar_Chrono_Projection" becomes a small spark that ignites an interest in the cosmos for many people.