Unraveling Earth's Spin: A Gyroscopic Adventure
Have you ever found yourself in a conversation with someone who holds unconventional scientific beliefs? It's a scenario that can leave you scratching your head. But, in a fascinating twist, a chat with a flat-earth advocate inspired [Bertrand Selva] to create a device that showcases Earth's rotation using a unique gyroscopic approach.
[Bertrand] crafted his invention around a duo of BMI160 MEMS gyroscopes, each with an angular velocity sensitivity of 0.0038 degrees per second. This is a delicate measurement, especially when compared to Earth's rotation rate of 0.00416 degrees per second. To capture this subtle signal amidst the measurement noise, the device employs a clever strategy. It takes readings with the sensors in four distinct positions, effectively canceling out sensor biases and gravitational influences.
Before each test, [Bertrand] carefully oriented the sensors towards true north. A stepper motor then guided the sensors through a cycle of four positions, with a Raspberry Pi Pico recording 128 measurements at each stop. The cycle could repeat up to 200 times, with errors diminishing as the number of cycles increased.
A Kalman filter then processed the raw data, extracting a signal that came remarkably close to Earth's true rotational velocity, within a mere two percent margin. [Bertrand] discovered that the system's accuracy was intricately tied to its alignment with true north. In fact, this alignment effect was so pronounced that it allowed him to use the device as a compass!
While the system didn't sway [Bertrand]'s neighbor, it remains an impressive showcase of ingenuity. It's a testament to how we can uncover the mysteries of our planet's rotation with innovative thinking. For those intrigued, there's even a PlayStation-based method to measure Earth's rotation, and for the precision-seekers, exploring how standards organizations tackle these measurements is a fascinating journey.
So, what do you think? Is this a compelling way to demonstrate Earth's rotation? Or do you have your own unique take on this concept? Feel free to share your thoughts and insights in the comments below!
