According to these scientists, who used 25 separate "parameters" or "variables" to describe every aspect of a bicycle's motion, there's no single reason for a bicycle's balance and stability. As they say:
"A simple explanation does not seem possible because the lean and steer are coupled by a combination of several effects including gyroscopic precession, lateral ground-reaction forces at the front wheel ground contact point trailing behind the steering axis, gravity and inertial reactions from the front assembly having center-of-mass off of the steer axis, and from effects associated with the moment of inertia matrix of the front assembly"
Or, in simple terms, it's partly to do with gyroscopic effects, partly to do with how the mass is distributed on the front wheel, and partly to do with how forces act on the front wheel as it spins. At least, I think that's what they said!'
Will Covid-19 survivors face a lifetime of illness?
Kirstin Coutney, pictured with her daughter Tilly, contracted Covid-19. The 49-year-old mother of two from Bath is still suffering crippling fatigue, six weeks after developing the virus.
Read in Daily Mail: https://apple.news/AH0nEqG1_SJ-Ho1B9VonXeQ
Sunspots go through a cycle roughly every 11 years where they alternate between no sunspots and intense sunspots. This affects temperatures on earth and can interfere with communications. There have been some really bad sunspot eruptions, like around 1860, where the electromagnetic interference damaged telegraph wires. If this were to happen again then we could see disruptions to the electrical grid and communications.
We did not know why this happens every 11 years but now we think that we do. The planets, Earth, Jupiter, and Venus align roughly every 11 years, and the combined effect creates gravitational tidal forces that interfere with the magnetic/electrical currents on the surface of the sun. The video gives more details.